Chemet

Protease Inhibitors

For optimal absorption, administer on an empty stomach with water at least 1 hour before or 2 hours after a meal. Alternatively, take with other fluids such as skim milk, juice, coffee, or tea, or with a light meal such as a meal of dry toast with jelly, juice, or coffee with skim milk and sugar or a meal of corn flakes, skim milk and sugar.
If administered concomitantly with didanosine, administer indinavir on an empty stomach at least 1 hour before didanosine.
To ensure adequate hydration, administer at least 1.5 liters (approximately 48 ounces) of liquids during a 24 hour period.

interstitial nephritis / Delayed / 0-1.0
pancreatitis / Delayed / 0-1.0
hepatic failure / Delayed / 0-1.0
Stevens-Johnson syndrome / Delayed / 0-1.0
erythema multiforme / Delayed / 0-1.0
anaphylactoid reactions / Rapid / 0-1.0
myocardial infarction / Delayed / 0-1.0
hemolytic anemia / Delayed / 0-1.0
intracranial bleeding / Delayed / 0-1.0
GI bleeding / Delayed / 0-1.0
diabetic ketoacidosis / Delayed / 0-1.0
vasculitis / Delayed / 0-1.0
renal tubular obstruction / Delayed / Incidence not known

nephrolithiasis / Delayed / 12.4-29.0
hyperbilirubinemia / Delayed / 14.0-14.0
elevated hepatic enzymes / Delayed / 0-4.9
neutropenia / Delayed / 2.4-2.4
hyperamylasemia / Delayed / 2.1-2.1
dysuria / Early / 1.5-1.5
jaundice / Delayed / 1.5-1.5
crystalluria / Delayed / 0-1.0
hepatitis / Delayed / 0-1.0
depression / Delayed / 0-1.0
angina / Early / 0-1.0
bleeding / Early / 0-1.0
hematoma / Early / 0-1.0
diabetes mellitus / Delayed / 0-1.0
thrombocytopenia / Delayed / 0.9-0.9
hyperglycemia / Delayed / 0.9-0.9
anemia / Delayed / 0.6-0.6
hematuria / Delayed / Incidence not known
flank pain / Delayed / Incidence not known
lipodystrophy / Delayed / Incidence not known
hypertriglyceridemia / Delayed / Incidence not known
hypercholesterolemia / Delayed / Incidence not known
hyperlipidemia / Delayed / Incidence not known

abdominal pain / Early / 16.6-16.6
nausea / Early / 11.7-11.7
vomiting / Early / 8.4-8.4
back pain / Delayed / 8.4-8.4
headache / Early / 5.4-5.4
pruritus / Rapid / 4.2-4.2
diarrhea / Early / 3.3-3.3
dizziness / Early / 3.0-3.0
gastroesophageal reflux / Delayed / 2.7-2.7
dysgeusia / Early / 2.7-2.7
anorexia / Delayed / 2.7-2.7
drowsiness / Early / 2.4-2.4
appetite stimulation / Delayed / 2.1-2.1
asthenia / Delayed / 2.1-2.1
fatigue / Early / 2.1-2.1
malaise / Early / 2.1-2.1
dyspepsia / Early / 1.5-1.5
fever / Early / 1.5-1.5
cough / Delayed / 1.5-1.5
rash / Early / 1.2-1.2
skin hyperpigmentation / Delayed / 0-1.0
alopecia / Delayed / 0-1.0
urticaria / Rapid / 0-1.0
arthralgia / Delayed / 0-1.0
paresthesias / Delayed / 0-1.0
xerosis / Delayed / Incidence not known
gynecomastia / Delayed / Incidence not known
Cushingoid features / Delayed / Incidence not known

Crixivan

Rx

Protease inhibitor (PI)
Indicated to treat HIV infection in combination with other antiretrovirals
Potential for nephrolithiasis

In patients with mild to moderate hepatic impairment due to cirrhosis, reduce the recommended dose to 600 mg PO every 8 hours. Dosing in patients with severe hepatic impairment has not been studied.

No dosage adjustments are recommended. Less than 20% of indinavir is excreted unchanged in the urine.

Abacavir; Lamivudine, 3TC; Zidovudine, ZDV: (Moderate) When indinavir and zidovudine, ZDV were administered concurrently, the AUC of indinavir and zidovudine was increased by 13% +/- 48% and 17% +/- 23%, respectively. Dosage adjustments are not recommended when zidovudine is administered with indinavir.
Abemaciclib: (Major) If coadministration with indinavir is necessary, reduce the dose of abemaciclib to 100 mg PO twice daily in patients on either of the recommended starting doses of either 200 mg or 150 mg twice daily. In patients who have had already had a dose reduction to 100 mg twice daily due to adverse reactions, further reduce the dose of abemaciclib to 50 mg PO twice daily. Discontinue abemaciclib for patients unable to tolerate 50 mg twice daily. If indinavir is discontinued, increase the dose of abemaciclib to the original dose after 3 to 5 half-lives of indinavir. Abemaciclib is a CYP3A4 substrate and indinavir is a strong CYP3A4 inhibitor. Coadministration with another strong CYP3A4 inhibitor increased the relative potency adjusted unbound AUC of abemaciclib plus its active metabolites (M2, M18, and M20) by 2.5-fold in cancer patients.
Acalabrutinib: (Major) Avoid the concomitant use of acalabrutinib and indinavir; significantly increased acalabrutinib exposure may occur. Acalabrutinib is a CYP3A4 substrate; indinavir is a strong CYP3A4 inhibitor. In healthy subjects, the Cmax and AUC values of acalabrutinib were increased by 3.9-fold and 5.1-fold, respectively, when acalabrutinib was coadministered with another strong inhibitor for 5 days.
Acarbose: (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors.
Acetaminophen; Caffeine; Dihydrocodeine: (Moderate) Concomitant use of dihydrocodeine with indinavir may increase dihydrocodeine plasma concentrations, resulting in greater metabolism by CYP2D6, increased dihydromorphine concentrations, and prolonged opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of dihydrocodeine until stable drug effects are achieved. Discontinuation of indinavir could decrease dihydrocodeine plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to dihydrocodeine. If indinavir is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Indinavir is a strong inhibitor of CYP3A4, an isoenzyme partially responsible for the metabolism of dihydrocodeine.
Acetaminophen; Codeine: (Moderate) Concomitant use of codeine with indinavir may increase codeine plasma concentrations, resulting in greater metabolism by CYP2D6, increased morphine concentrations, and prolonged opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when codeine is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of codeine until stable drug effects are achieved. Discontinuation of indinavir could decrease codeine plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to codeine. If indinavir is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. Indinavir is a strong inhibitor of CYP3A4.
Acetaminophen; Hydrocodone: (Moderate) Consider a reduced dose of hydrocodone with frequent monitoring for respiratory depression and sedation if concurrent use of indinavir is necessary. It is recommended to avoid this combination when hydrocodone is being used for cough. Hydrocodone is a CYP2D6 and CYP3A4 substrate, and coadministration with CYP2D6 and CYP3A4 inhibitors like indinavir can increase hydrocodone exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of hydrocodone. These effects could be more pronounced with a combined CYP2D6 and CYP3A4 inhibitor. If indinavir is discontinued, hydrocodone plasma concentrations will decrease resulting in reduced efficacy of the opioid and potential withdrawal syndrome in a patient who has developed physical dependence to hydrocodone.
Acetaminophen; Oxycodone: (Moderate) Consider a reduced dose of oxycodone with frequent monitoring for respiratory depression and sedation if concurrent use of indinavir is necessary. If indinavir is discontinued, consider increasing the oxycodone dose until stable drug effects are achieved and monitor for evidence of opioid withdrawal. Oxycodone is a CYP3A4 substrate, and coadministration with a strong CYP3A4 inhibitor like indinavir can increase oxycodone exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of oxycodone. If indinavir is discontinued, oxycodone plasma concentrations will decrease resulting in reduced efficacy of the opioid and potential withdrawal syndrome in a patient who has developed physical dependence to oxycodone.
Adagrasib: (Moderate) Monitor for an increase in adverse effects from both drugs during concomitant use of adagrasib and indinavir. Avoid concomitant use during adagrasib therapy initiation (approximately 8 days); concomitant use before steady state is achieved may increase adagrasib exposure and the risk for adagrasib-related adverse reactions. Although specific recommendations are unavailable for use with adagrasib, a reduced indinavir dose of 600 mg PO every 8 hours is recommended when coadministered with other strong CYP3A inhibitors. Adagrasib and indinavir are both CYP3A substrates and strong CYP3A inhibitors. Concomitant use of a single 200 mg dose of adagrasib with another strong CYP3A inhibitor increased adagrasib exposure by approximately 4-fold, however, no clinically significant differences in pharmacokinetics are predicted at steady state.
Adefovir: (Major) Patients who are concurrently taking adefovir with antiretrovirals like the protease inhibitors, are at risk of developing lactic acidosis and severe hepatomegaly with steatosis. Lactic acidosis and severe hepatomegaly with steatosis, including fatal cases, have been reported with the use of nucleoside analogs alone or in combination with antiretrovirals. A majority of these cases have been in women; obesity and prolonged nucleoside exposure may also be risk factors. Particular caution should be exercised when administering nucleoside analogs to any patient with known risk factors for hepatic disease; however, cases have also been reported in patients with no known risk factors. Suspend adefovir in any patient who develops clinical or laboratory findings suggestive of lactic acidosis or pronounced hepatotoxicity (which may include hepatomegaly and steatosis even in the absence of marked transaminase elevations).
Ado-Trastuzumab emtansine: (Major) Avoid coadministration of indinavir with ado-trastuzumab emtansine if possible due to the risk of elevated exposure to the cytotoxic component of ado-trastuzumab emtansine, DM1. Delay ado-trastuzumab emtansine treatment until indinavir has cleared from the circulation (approximately 3 half-lives of indinavir) when possible. If concomitant use is unavoidable, closely monitor patients for ado-trastuzumab emtansine-related adverse reactions. The cytotoxic component of ado-trastuzumab emtansine, DM1, is metabolized mainly by CYP3A4 and to a lesser extent by CYP3A5; indinavir is a strong CYP3A4 inhibitor. Formal drug interaction studies with ado-trastuzumab emtansine have not been conducted.
Albuterol; Budesonide: (Minor) Use caution when budesonide is coadministered with drugs that inhibit CYP3A enzymes, such as indinavir, and consider dose reduction. Toxicity may occur, particularly excessive HPA-axis suppression.
Aldesleukin, IL-2: (Moderate) In HIV-positive patients treated with aldesleukin, IL-2, and indinavir, the plasma AUC levels of indinavir increased 88% in 8 of 9 patients. The clearance of indinavir was decreased by 56% by day 5 of concurrent therapy. Treatment with IL-2 increased plasma levels of interleukin-6, which is an inhibitor of cytochrome P450 3A4, by 20-fold in these patients. Increased IL-6 levels may have inhibited CYP3A4, resulting in decreased clearance and increased serum levels of indinavir.
Alfentanil: (Moderate) Consider a reduced dose of alfentanil with frequent monitoring for respiratory depression and sedation if concurrent use of protease inhibitors is necessary. If the protease inhibitor is discontinued, consider increasing the alfentanil dose until stable drug effects are achieved and monitor for evidence of opioid withdrawal. Alfentanil is a sensitive CYP3A substrate, and coadministration with CYP3A inhibitors like protease inhibitors can increase alfentanil exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of alfentanil. If the protease inhibitor is discontinued, alfentanil plasma concentrations will decrease resulting in reduced efficacy of the opioid and potential withdrawal syndrome in a patient who has developed physical dependence to alfentanil.
Alfuzosin: (Contraindicated) Concurrent use of alfuzosin and protease inhibitors is contraindicated due to increased alfuzosin exposure. Alfuzosin is a CYP3A substrate and protease inhibitors are moderate to strong CYP3A inhibitors. When coadministered with another strong CYP3A inhibitor, the AUC of alfuzosin was increased by 2.5-fold to 3.2-fold.
Almotriptan: (Moderate) The maximum recommended starting dose of almotriptan is 6.25 mg if coadministration with indinavir is necessary; do not exceed 12.5 mg within a 24-hour period. Concomitant use of almotriptan and indinavir should be avoided in patients with renal or hepatic impairment. Almotriptan is a CYP3A4 substrate and indinavir is a strong CYP3A4 inhibitor. Coadministration with another strong CYP3A4 inhibitor increased almotriptan exposure by approximately 60%.
Alogliptin: (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. A possible mechanism is impairment of beta-cell function. Onset averaged approximately 63 days after initiating protease inhibitor therapy, but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients on antidiabetic therapy should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated.
Alogliptin; Metformin: (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. A possible mechanism is impairment of beta-cell function. Onset averaged approximately 63 days after initiating protease inhibitor therapy, but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients on antidiabetic therapy should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated. (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. Another possible mechanism is impairment of beta-cell function. Onset averaged approximately 63 days after initiating protease inhibitor therapy, but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients taking antidiabetic therapy should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated.
Alogliptin; Pioglitazone: (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. A possible mechanism is impairment of beta-cell function. Onset averaged approximately 63 days after initiating protease inhibitor therapy, but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients on antidiabetic therapy should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated.
Alosetron: (Moderate) Concomitant use of alosetron with indinavir may result in increased serum concentrations of alosetron and increase the risk for adverse reactions. Caution and close monitoring are advised if these drugs are used together. Alosetron is a substrate of hepatic isoenzyme CYP3A4; indinavir is a strong inhibitor of this enzyme. In a study of healthy female subjects, another strong CYP3A4 inhibitor increased mean alosetron AUC by 29%.
Alpha-glucosidase Inhibitors: (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors.
Alprazolam: (Contraindicated) Coadministration of indinavir and alprazolam is contraindicated due to the potential for elevated alprazolam concentrations, which may cause prolonged sedation and respiratory depression. Lorazepam, oxazepam, or temazepam may be safer alternatives if a benzodiazepine must be administered in combination with indinavir, as these benzodiazepines are not oxidatively metabolized. Alprazolam is a CYP3A4 substrate and indinavir is a strong CYP3A4 inhibitor. Coadministration with other strong CYP3A4 inhibitors increased alprazolam exposure by 2.7- to 3.98-fold.
Amiodarone: (Contraindicated) Coadministration of indinavir and amiodarone is contraindicated due to the potential for serious or life-threatening reactions, such as cardiac arrhythmias. Indinavir is an inhibitor of CYP3A4 and increased plasma concentrations of drugs extensively metabolized by this enzyme, such as amiodarone, should be expected with concurrent use.
Amlodipine: (Moderate) Monitor for symptoms of hypotension and edema if coadministration of amlodipine with protease inhibitors is necessary; adjust the dose of amlodipine as clinically appropriate. Amlodipine is a CYP3A substrate and protease inhibitors are moderate to strong CYP3A inhibitors. Coadministration with a moderate CYP3A inhibitor in elderly hypertensive patients increased systemic exposure to amlodipine by 60%. However, coadministration with another moderate CYP3A inhibitor in healthy volunteers did not significantly change amlodipine exposure.
Amlodipine; Atorvastatin: (Major) Use caution and the lowest atorvastatin dose necessary if atorvastatin must be coadministered with indinavir. The risk of developing myopathy/rhabdomyolysis increases when atorvastatin is used concomitantly with CYP3A4 inhibitors such as indinavir. Monitor patients for any signs or symptoms of muscle pain, weakness, or tenderness especially in the initial months of therapy and any time the dosage of either drug is titrated upward. Protease inhibitors inhibit the CYP3A4 metabolism of atorvastatin. The risk of myopathy or rhabdomyolysis should be weighed carefully against the benefits of combined 'statin' and protease inhibitor therapy; there is no assurance that periodic monitoring of CK will prevent the occurrence of severe myopathy and renal damage. (Moderate) Monitor for symptoms of hypotension and edema if coadministration of amlodipine with protease inhibitors is necessary; adjust the dose of amlodipine as clinically appropriate. Amlodipine is a CYP3A substrate and protease inhibitors are moderate to strong CYP3A inhibitors. Coadministration with a moderate CYP3A inhibitor in elderly hypertensive patients increased systemic exposure to amlodipine by 60%. However, coadministration with another moderate CYP3A inhibitor in healthy volunteers did not significantly change amlodipine exposure.
Amlodipine; Benazepril: (Moderate) Monitor for symptoms of hypotension and edema if coadministration of amlodipine with protease inhibitors is necessary; adjust the dose of amlodipine as clinically appropriate. Amlodipine is a CYP3A substrate and protease inhibitors are moderate to strong CYP3A inhibitors. Coadministration with a moderate CYP3A inhibitor in elderly hypertensive patients increased systemic exposure to amlodipine by 60%. However, coadministration with another moderate CYP3A inhibitor in healthy volunteers did not significantly change amlodipine exposure.
Amlodipine; Celecoxib: (Moderate) Monitor for symptoms of hypotension and edema if coadministration of amlodipine with protease inhibitors is necessary; adjust the dose of amlodipine as clinically appropriate. Amlodipine is a CYP3A substrate and protease inhibitors are moderate to strong CYP3A inhibitors. Coadministration with a moderate CYP3A inhibitor in elderly hypertensive patients increased systemic exposure to amlodipine by 60%. However, coadministration with another moderate CYP3A inhibitor in healthy volunteers did not significantly change amlodipine exposure.
Amlodipine; Olmesartan: (Moderate) Monitor for symptoms of hypotension and edema if coadministration of amlodipine with protease inhibitors is necessary; adjust the dose of amlodipine as clinically appropriate. Amlodipine is a CYP3A substrate and protease inhibitors are moderate to strong CYP3A inhibitors. Coadministration with a moderate CYP3A inhibitor in elderly hypertensive patients increased systemic exposure to amlodipine by 60%. However, coadministration with another moderate CYP3A inhibitor in healthy volunteers did not significantly change amlodipine exposure.
Amlodipine; Valsartan: (Moderate) Monitor for symptoms of hypotension and edema if coadministration of amlodipine with protease inhibitors is necessary; adjust the dose of amlodipine as clinically appropriate. Amlodipine is a CYP3A substrate and protease inhibitors are moderate to strong CYP3A inhibitors. Coadministration with a moderate CYP3A inhibitor in elderly hypertensive patients increased systemic exposure to amlodipine by 60%. However, coadministration with another moderate CYP3A inhibitor in healthy volunteers did not significantly change amlodipine exposure.
Amlodipine; Valsartan; Hydrochlorothiazide, HCTZ: (Moderate) Monitor for symptoms of hypotension and edema if coadministration of amlodipine with protease inhibitors is necessary; adjust the dose of amlodipine as clinically appropriate. Amlodipine is a CYP3A substrate and protease inhibitors are moderate to strong CYP3A inhibitors. Coadministration with a moderate CYP3A inhibitor in elderly hypertensive patients increased systemic exposure to amlodipine by 60%. However, coadministration with another moderate CYP3A inhibitor in healthy volunteers did not significantly change amlodipine exposure.
Amobarbital: (Major) Barbiturates may increase the metabolism of indinavir and lead to decreased antiretroviral efficacy. In addition, indinavir may inhibit the CYP metabolism of barbiturates, resulting in increased barbiturate concentrations. Appropriate dose adjustments necessary to ensure optimum levels of both anti-retroviral agent and the barbiturate are unknown. Anticonvulsant serum concentrations should be monitored closely if these agents are added; the patient should be observed for changes in the clinical efficacy of the antiretroviral or anticonvulsant regimen.
Amoxicillin; Clarithromycin; Omeprazole: (Major) Omeprazole has been reported to decrease the oral bioavailability of indinavir. In one study, indinavir plasma levels fell to below 95% of normal in roughly half of the patients receiving omeprazole concurrently. An increase in indinavir dosage resolved the interaction. It is unclear if other gastric acid-pump inhibitors would interact with indinavir in this manner. (Moderate) Clarithromycin is a CYP3A4 inhibitor and may decrease the systemic clearance of indinavir, a CYP3A4 substrate. Patients with impaired renal function may require a reduced dosage of clarithromycin.
Apalutamide: (Major) Coadministration of indinavir with apalutamide is not recommended as there is a potential for decreased indinavir concentrations, which may lead to a reduction of antiretroviral efficacy and the potential development of viral resistance; exposure to apalutamide may also increase. Indinavir is a CYP3A4 substrate and strong inhibitor. Apalutamide is a CYP3A4 substrate and strong inducer.
Aprepitant, Fosaprepitant: (Major) Avoid the concomitant use of indinavir with aprepitant, fosaprepitant due to substantially increased exposure of aprepitant; increased indinavir exposure may also occur. If coadministration cannot be avoided, use caution and monitor for an increase in indinavir- and aprepitant-related adverse effects for several days after administration of a multi-day aprepitant regimen. Coadministration of a single oral dose of aprepitant (125 mg) on day 5 of a 10-day ketoconazole regimen (strong CYP3A4 inhibitor) increased the aprepitant AUC approximately 5-fold, and increased the mean terminal half-life by approximately 3-fold. Indinavir is also a CYP3A4 substrate. Aprepitant, when administered as a 3-day oral regimen (125 mg/80 mg/80 mg), is a moderate CYP3A4 inhibitor and inducer and may additionally increase plasma concentrations of indinavir. For example, a 5-day oral aprepitant regimen increased the AUC of another CYP3A4 substrate, midazolam (single dose), by 2.3-fold on day 1 and by 3.3-fold on day 5. After a 3-day oral aprepitant regimen, the AUC of midazolam (given on days 1, 4, 8, and 15) increased by 25% on day 4, and then decreased by 19% and 4% on days 8 and 15, respectively. As a single 125 mg or 40 mg oral dose, the inhibitory effect of aprepitant on CYP3A4 is weak, with the AUC of midazolam increased by 1.5-fold and 1.2-fold, respectively. After administration, fosaprepitant is rapidly converted to aprepitant and shares many of the same drug interactions. However, as a single 150 mg intravenous dose, fosaprepitant only weakly inhibits CYP3A4 for a duration of 2 days; there is no evidence of CYP3A4 induction. Fosaprepitant 150 mg IV as a single dose increased the AUC of midazolam (given on days 1 and 4) by approximately 1.8-fold on day 1; there was no effect on day 4. Less than a 2-fold increase in the midazolam AUC is not considered clinically important.
Aripiprazole: (Major) Recommendations for managing aripiprazole and indinavir vary by aripiprazole dosage form. For aripiprazole oral dosage forms, administer a quarter of the usual dose. For monthly extended-release aripiprazole injections (Abilify Maintena), reduce the dosage from 400 mg to 200 mg/month or from 300 mg to 160 mg/month. For extended-release aripiprazole injections given once every 2 months (Abilify Asimtufii), reduce the dosage from 960 mg to 720 mg; avoid use in patients known to be poor metabolizers of CYP2D6. Further dosage reductions may be required in patients who are also receiving a strong CYP2D6 inhibitor; see individual product prescribing information for details. Concomitant use may increase aripiprazole exposure and risk for side effects. Aripiprazole is CYP2D6 and CYP3A substrate; indinavir is a weak CYP2D6 and strong CYP3A inhibitor. (Major) Recommendations for managing aripiprazole and indinavir vary by aripiprazole dosage form. For extended-release aripiprazole lauroxil injections (Aristada), reduce the dose to the next lowest strength; no dosage adjustment is required for patients tolerating 441 mg. For extended-release aripiprazole lauroxil injections (Aristada) in patients who are known to be poor metabolizers of CYP2D6, reduce the dose to 441 mg; no dosage adjustment is necessary for patients already tolerating 441 mg. For fixed dose extended-release aripiprazole lauroxil injections (Aristada Initio), avoid concomitant use because the dose cannot be modified. Further dosage reductions may be required in patients who are also receiving a strong CYP2D6 inhibitor; see individual product prescribing information for details. Concomitant use may increase aripiprazole exposure and risk for side effects. Aripiprazole is CYP2D6 and CYP3A substrate; indinavir is a weak CYP2D6 and strong CYP3A inhibitor.
Artemether; Lumefantrine: (Moderate) Indinavir is a substrate/inhibitor and artemether a substrate of the CYP3A4 isoenzyme; therefore, coadministration may lead to increased artemether concentrations. Concomitant use warrants caution due to the potential for increased side effects. (Moderate) Indinavir is a substrate/inhibitor and lumefantrine a substrate of the CYP3A4 isoenzyme; therefore, coadministration may lead to increased lumefantrine concentrations. Concomitant use warrants caution due to the potential for increased side effects, including increased potentiation of QT prolongation.
Asciminib: (Moderate) Closely monitor for asciminib-related adverse reactions if concurrent use of asciminib 200 mg twice daily with indinavir is necessary as asciminib exposure may increase. Asciminib is a CYP3A substrate and indinavir is a strong CYP3A inhibitor.
Aspirin, ASA; Butalbital; Caffeine: (Major) Barbiturates may increase the metabolism of indinavir and lead to decreased antiretroviral efficacy. In addition, indinavir may inhibit the CYP metabolism of barbiturates, resulting in increased barbiturate concentrations. Appropriate dose adjustments necessary to ensure optimum levels of both anti-retroviral agent and the barbiturate are unknown. Anticonvulsant serum concentrations should be monitored closely if these agents are added; the patient should be observed for changes in the clinical efficacy of the antiretroviral or anticonvulsant regimen.
Aspirin, ASA; Carisoprodol; Codeine: (Moderate) Concomitant use of codeine with indinavir may increase codeine plasma concentrations, resulting in greater metabolism by CYP2D6, increased morphine concentrations, and prolonged opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when codeine is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of codeine until stable drug effects are achieved. Discontinuation of indinavir could decrease codeine plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to codeine. If indinavir is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. Indinavir is a strong inhibitor of CYP3A4.
Aspirin, ASA; Omeprazole: (Major) Omeprazole has been reported to decrease the oral bioavailability of indinavir. In one study, indinavir plasma levels fell to below 95% of normal in roughly half of the patients receiving omeprazole concurrently. An increase in indinavir dosage resolved the interaction. It is unclear if other gastric acid-pump inhibitors would interact with indinavir in this manner.
Aspirin, ASA; Oxycodone: (Moderate) Consider a reduced dose of oxycodone with frequent monitoring for respiratory depression and sedation if concurrent use of indinavir is necessary. If indinavir is discontinued, consider increasing the oxycodone dose until stable drug effects are achieved and monitor for evidence of opioid withdrawal. Oxycodone is a CYP3A4 substrate, and coadministration with a strong CYP3A4 inhibitor like indinavir can increase oxycodone exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of oxycodone. If indinavir is discontinued, oxycodone plasma concentrations will decrease resulting in reduced efficacy of the opioid and potential withdrawal syndrome in a patient who has developed physical dependence to oxycodone.
Atazanavir: (Contraindicated) Atazanavir is an inhibitor of CYP3A and is associated with indirect (unconjugated) hyperbilirubinemia. Indinavir is a substrate of CYP3A4 and is also associated with increased unconjugated bilirubin. Due to the potential interactions and the increased risk of hyperbilirubinemia, the concomitant use of atazanavir and indinavir is contraindicated; however, the combination has not been studied.
Atazanavir; Cobicistat: (Contraindicated) Atazanavir is an inhibitor of CYP3A and is associated with indirect (unconjugated) hyperbilirubinemia. Indinavir is a substrate of CYP3A4 and is also associated with increased unconjugated bilirubin. Due to the potential interactions and the increased risk of hyperbilirubinemia, the concomitant use of atazanavir and indinavir is contraindicated; however, the combination has not been studied. (Contraindicated) Concomitant use of indinavir with regimens containing cobicistat and atazanavir is contraindicated. Cobicistat is an inhibitor of CYP3A4, while both atazanavir and indinavir are CYP3A4 substates. In addition, both atazanavir and indinavir are associated with indirect (unconjugated) hyperbilirubinemia. Taking these drugs together may increase the risk for hepatic adverse events, such as hyperbilirubinemia.
Atogepant: (Major) Avoid use of atogepant and indinavir when atogepant is used for chronic migraine. Limit the dose of atogepant to 10 mg PO once daily for episodic migraine if coadministered with indinavir. Concurrent use may increase atogepant exposure and the risk of adverse effects. Atogepant is a substrate of CYP3A and indinavir is a strong CYP3A inhibitor. Coadministration with a strong CYP3A inhibitor resulted in a 5.5-fold increase in atogepant overall exposure and a 2.15-fold increase in atogepant peak concentration.
Atorvastatin: (Major) Use caution and the lowest atorvastatin dose necessary if atorvastatin must be coadministered with indinavir. The risk of developing myopathy/rhabdomyolysis increases when atorvastatin is used concomitantly with CYP3A4 inhibitors such as indinavir. Monitor patients for any signs or symptoms of muscle pain, weakness, or tenderness especially in the initial months of therapy and any time the dosage of either drug is titrated upward. Protease inhibitors inhibit the CYP3A4 metabolism of atorvastatin. The risk of myopathy or rhabdomyolysis should be weighed carefully against the benefits of combined 'statin' and protease inhibitor therapy; there is no assurance that periodic monitoring of CK will prevent the occurrence of severe myopathy and renal damage.
Atorvastatin; Ezetimibe: (Major) Use caution and the lowest atorvastatin dose necessary if atorvastatin must be coadministered with indinavir. The risk of developing myopathy/rhabdomyolysis increases when atorvastatin is used concomitantly with CYP3A4 inhibitors such as indinavir. Monitor patients for any signs or symptoms of muscle pain, weakness, or tenderness especially in the initial months of therapy and any time the dosage of either drug is titrated upward. Protease inhibitors inhibit the CYP3A4 metabolism of atorvastatin. The risk of myopathy or rhabdomyolysis should be weighed carefully against the benefits of combined 'statin' and protease inhibitor therapy; there is no assurance that periodic monitoring of CK will prevent the occurrence of severe myopathy and renal damage.
Atovaquone: (Major) The use of atovaquone with food plus indinavir without food led to a decrease in the trough concentration of indinavir; changes in the AUC or maximum concentration of indinavir did not occur. Caution is advised if these drugs are coadministered.
Atovaquone; Proguanil: (Major) The use of atovaquone with food plus indinavir without food led to a decrease in the trough concentration of indinavir; changes in the AUC or maximum concentration of indinavir did not occur. Caution is advised if these drugs are coadministered.
Avacopan: (Major) Reduce the dose of avacopan to 30 mg once daily if concomitant use of indinavir is necessary. Concomitant use may increase avacopan exposure and risk for avacopan-related adverse effects. Avacopan is a CYP3A substrate and indinavir is a strong CYP3A inhibitor. Concomitant use of another strong CYP3A inhibitor increased avacopan overall exposure 2.19-fold.
Avanafil: (Major) Concomitant use of avanafil and indinavir is not recommended due to the risk for increased avanafil serum concentrations and serious adverse reactions. Avanafil is a substrate of and primarily metabolized by CYP3A4; indinavir is a strong inhibitor of CYP3A4. Coadministration of avanafil with other strong inhibitors of CYP3A4 has resulted in significantly increased exposure to avanafil; indinavir would be expected to have similar effects.
Avapritinib: (Major) Avoid coadministration of avapritinib with indinavir due to the risk of increased avapritinib-related adverse reactions. Avapritinib is a CYP3A4 substrate and indinavir is a strong CYP3A4 inhibitor. Coadministration with another strong CYP3A4 inhibitor is predicted to increase the AUC of avapritinib by 600% at steady-state.
Axitinib: (Major) Avoid coadministration of axitinib with indinavir due to the risk of increased axitinib-related adverse reactions. If coadministration is unavoidable, decrease the dose of axitinib by approximately half; subsequent doses can be increased or decreased based on individual safety and tolerability. Resume the original dose of axitinib approximately 3 to 5 half-lives after indinavir is discontinued. Axitinib is a CYP3A4/5 substrate and indinavir is a strong CYP3A4 inhibitor. Coadministration with another strong CYP3A4/5 inhibitor significantly increased the plasma exposure of axitinib in healthy volunteers.
Azelastine; Fluticasone: (Major) Coadministration of inhaled fluticasone propionate and indinavir is not recommended; use caution with inhaled fluticasone furoate. Increased systemic corticosteroid effects, including Cushing's syndrome and adrenal suppression, may occur. Fluticasone is a CYP3A4 substrate; indinavir is a strong CYP3A4 inhibitor. In drug interaction studies, coadministration with strong inhibitors increased plasma fluticasone exposure resulting in 45% to 86% decreases in serum cortisol AUC. A strong inhibitor increased fluticasone furoate exposure by 1.33-fold with a 27% reduction in weighted mean serum cortisol; this change does not necessitate dose adjustment of fluticasone furoate.
Barbiturates: (Major) Barbiturates may increase the metabolism of indinavir and lead to decreased antiretroviral efficacy. In addition, indinavir may inhibit the CYP metabolism of barbiturates, resulting in increased barbiturate concentrations. Appropriate dose adjustments necessary to ensure optimum levels of both anti-retroviral agent and the barbiturate are unknown. Anticonvulsant serum concentrations should be monitored closely if these agents are added; the patient should be observed for changes in the clinical efficacy of the antiretroviral or anticonvulsant regimen.
Bedaquiline: (Major) Concurrent use of bedaquiline and a strong CYP3A4 inhibitor, such as indinavir, for more than 14 days should be avoided unless the benefits justify the risks. When administered together, indinavir may inhibit the metabolism of bedaquiline resulting in increased systemic exposure (AUC) and potentially more adverse reactions, such as QT prolongation and hepatotoxicity.
Benzhydrocodone; Acetaminophen: (Moderate) Concurrent use of benzhydrocodone with indinavir may increase the risk of increased opioid-related adverse reactions, such as fatal respiratory depression. Consider a dose reduction of benzhydrocodone until stable drug effects are achieved. Monitor patients for respiratory depression and sedation at frequent intervals. Discontinuation of indinavir in a patient taking benzhydrocodone may decrease hydrocodone plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to opioid agonists. If indinavir is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Benzhydrocodone is a prodrug for hydrocodone. Hydrocodone is a substrate for CYP3A4 and CYP2D6. Indinavir is a strong inhibitor of CYP3A4 and a weak in vitro inhibitor of CYP2D6.
Betamethasone: (Moderate) Monitor for corticosteroid-related adverse effects if coadministration is necessary. Consider using an alternative treatment to betametasone, such as a corticosteroid less affected by CYP3A4 (i.e., beclomethasone or prednisolone), particularly if long term use is indicated. Indinavir is a strong CYP3A4 inhibitor and betamethasone is a CYP3A4 substrate. Another strong CYP3A4 inhibitor has been reported to decrease the metabolism of certain corticosteroids by up to 60%, leading to increased risk of corticosteroid side effects.
Bortezomib: (Moderate) In vitro studies with human liver microsomes indicate that bortezomib is a significant substrate for CYP3A4. Agents that inhibit CYP3A4, such indinavir, may increase the exposure to bortezomib and increase the risk for toxicity. The manufacturer warns that patients who are receiving bortezomib concurrently with potent CYP3A4 inhibitors should be closely monitored for potential toxicity.
Bosentan: (Major) Do not administer bosentan with anti-retroviral protease inhibitors that are not boosted with ritonavir as decreased protease inhibitor concentrations are expected. In addition, administration of anti-retroviral protease inhibitors with bosentan may increase bosentan serum concentrations due to the inhibition of the CYP3A4 isoenzyme. In patients who have been receiving protease inhibitor therapy for at least 10 days, initiate bosentan at the recommended initial dose once daily or every other day based on tolerability. For patients on bosentan who need protease inhibitor therapy, discontinue use of bosentan at least 36 hours prior to starting protease inhibitor therapy. After 10 days of the protease inhibitor therapy, bosentan may be restarted at the recommended initial dose once daily or every other day based on tolerability. Bosentan is a substrate for organic anion transport protein (OATP), CYP3A, and CYP2C9. In healthy subjects, initial and steady state trough plasma concentrations of bosentan were approximately 48-fold and 5-fold higher, respectively, after coadministration of bosentan 125 mg twice daily PO and lopinavir; ritonavir 400/100 mg twice daily PO compared to those measured after bosentan alone. This is most likely explained by inhibition by lopinavir of OATP-mediated uptake into hepatocytes; toxicity of bosentan is possible. Monitor for potential adverse effects of bosentan during coadministration with CYP2C9 or CYP3A4 inhibitors; excessive bosentan dosage may result in hypotension or elevated hepatic enzyme. Additionally, bosentan is a significant inducer of CYP3A4 and CYP2C9 hepatic enzymes. Theoretically, bosentan may increase the clearance of the protease inhibitors and potentially lead to a reduction of anti-retroviral efficacy. However, this interaction has not been studied.
Bosutinib: (Major) Avoid concomitant use of bosutinib and indinavir; bosutinib plasma exposure may be significantly increased resulting in an increased risk of bosutinib adverse events (e.g., myelosuppression, GI toxicity). Bosutinib is a CYP3A4 substrate and indinavir is a strong CYP3A4 inhibitor. In a cross-over trial in 24 healthy volunteers, the Cmax and AUC values of bosutinib were increased 5.2-fold and 8.6-fold, respectively, when a single oral dose of bosutinib 100 mg PO was administered after 5 days of a strong CYP3A4 inhibitor.
Brentuximab vedotin: (Minor) Concomitant administration of brentuximab vedotin and indinavir may increase the exposure of monomethyl auristatin E (MMAE), one of the 3 components released from brentuximab vedotin. The manufacturer suggests that potent CYP3A4 inhibitors, such as indinavir, may alter MMAE exposure as MMAE is a CYP3A4 substrate. Monitor patients for adverse reactions.
Brexpiprazole: (Major) Because brexpiprazole is partially metabolized by CYP3A4, the manufacturer recommends that the brexpiprazole dose be reduced to one-half of the usual dose in patients receiving strong inhibitors of CYP3A4 such as indinavir. If these agents are used in combination, the patient should be carefully monitored for brexpiprazole-related adverse reactions. Because brexpiprazole is also metabolized by CYP2D6, patients classified as CYP2D6 poor metabolizers (PMs) who are receiving a strong CYP3A4 inhibitor or patients receiving a combination of a moderate to strong CYP3A4 inhibitor and moderate to strong CYP2D6 inhibitor should have their brexpiprazole dose reduced to one-quarter (25%) of the usual dose. If the co-administered CYP inhibitor is discontinued, adjust the brexpiprazole dose to its original level.
Brigatinib: (Major) Avoid coadministration of brigatinib with indinavir if possible due to increased plasma exposure of brigatinib; an increase in brigatinib-related adverse reactions may occur. If concomitant use is unavoidable, reduce the dose of brigatinib by approximately 50% without breaking tablets (i.e., from 180 mg to 90 mg; from 90 mg to 60 mg); after discontinuation of indinavir, resume the brigatinib dose that was tolerated prior to initiation of indinavir. Brigatinib is a CYP3A4 substrate; indinavir is a strong CYP3A4 inhibitor. Coadministration with another strong CYP3A4 inhibitor increased the AUC and Cmax of brigatinib by 101% and 21%, respectively.
Bromocriptine: (Major) When bromocriptine is used for diabetes, avoid coadministration with indinavir ensuring adequate washout before initiating bromocriptine. Use this combination with caution in patients receiving bromocriptine for other indications. Concurrent use may significantly increase bromocriptine concentrations. Bromocriptine is extensively metabolized in the liver via CYP3A4; indinavir is a strong inhibitor of CYP3A4.
Budesonide: (Minor) Use caution when budesonide is coadministered with drugs that inhibit CYP3A enzymes, such as indinavir, and consider dose reduction. Toxicity may occur, particularly excessive HPA-axis suppression.
Budesonide; Formoterol: (Minor) Use caution when budesonide is coadministered with drugs that inhibit CYP3A enzymes, such as indinavir, and consider dose reduction. Toxicity may occur, particularly excessive HPA-axis suppression.
Budesonide; Glycopyrrolate; Formoterol: (Minor) Use caution when budesonide is coadministered with drugs that inhibit CYP3A enzymes, such as indinavir, and consider dose reduction. Toxicity may occur, particularly excessive HPA-axis suppression.
Bupivacaine Liposomal: (Minor) Bupivacaine is metabolized by cytochrome P450 (CYP) 3A4 isoenzymes. Known inhibitors of CYP 3A4, such as anti-retroviral protease inhibitors, may result in increased systemic levels of bupivacaine when given concurrently, with potential for toxicity. Although not studied, dosage adjustments of bupivacaine may be needed.
Bupivacaine: (Minor) Bupivacaine is metabolized by cytochrome P450 (CYP) 3A4 isoenzymes. Known inhibitors of CYP 3A4, such as anti-retroviral protease inhibitors, may result in increased systemic levels of bupivacaine when given concurrently, with potential for toxicity. Although not studied, dosage adjustments of bupivacaine may be needed.
Bupivacaine; Epinephrine: (Minor) Bupivacaine is metabolized by cytochrome P450 (CYP) 3A4 isoenzymes. Known inhibitors of CYP 3A4, such as anti-retroviral protease inhibitors, may result in increased systemic levels of bupivacaine when given concurrently, with potential for toxicity. Although not studied, dosage adjustments of bupivacaine may be needed.
Bupivacaine; Lidocaine: (Moderate) Anti-retroviral protease inhibitors can inhibit hepatic cytochrome P450 3A4, an isoenzyme that is partially responsible for the metabolism of lidocaine. The concurrent use of systemic lidocaine and anti-retroviral protease inhibitors should be carefully monitored due to the potential for serious toxicity. (Minor) Bupivacaine is metabolized by cytochrome P450 (CYP) 3A4 isoenzymes. Known inhibitors of CYP 3A4, such as anti-retroviral protease inhibitors, may result in increased systemic levels of bupivacaine when given concurrently, with potential for toxicity. Although not studied, dosage adjustments of bupivacaine may be needed.
Bupivacaine; Meloxicam: (Minor) Bupivacaine is metabolized by cytochrome P450 (CYP) 3A4 isoenzymes. Known inhibitors of CYP 3A4, such as anti-retroviral protease inhibitors, may result in increased systemic levels of bupivacaine when given concurrently, with potential for toxicity. Although not studied, dosage adjustments of bupivacaine may be needed.
Buprenorphine: (Major) Since the metabolism of buprenorphine is mediated by CYP3A4, co-administration of strong CYP3A4 inhibitors such as anti-retroviral protease inhibitors (e.g., amprenavir, fosamprenavir, indinavir, nelfinavir) may result in increased systemic exposure to buprenorphine, with the potential for excessive buprenorphine-related side effects; however, studies have shown that nelfinavir has little effect on buprenorphine pharmacokinetics and no significant pharmacodynamic effects. In general, if a protease inhibitor and buprenorphine are used concurrently, monitor accordingly for sedation and respiratory depression and adjust the buprenorphine dosage if needed. Consider conservative buprenorphine therapy in patients already on a CYP3A4 inhibitor. The effect of CYP3A4 inhibitors on buprenorphine implants has not been studied, and the effect may be dependent on the route of administration.
Buprenorphine; Naloxone: (Major) Since the metabolism of buprenorphine is mediated by CYP3A4, co-administration of strong CYP3A4 inhibitors such as anti-retroviral protease inhibitors (e.g., amprenavir, fosamprenavir, indinavir, nelfinavir) may result in increased systemic exposure to buprenorphine, with the potential for excessive buprenorphine-related side effects; however, studies have shown that nelfinavir has little effect on buprenorphine pharmacokinetics and no significant pharmacodynamic effects. In general, if a protease inhibitor and buprenorphine are used concurrently, monitor accordingly for sedation and respiratory depression and adjust the buprenorphine dosage if needed. Consider conservative buprenorphine therapy in patients already on a CYP3A4 inhibitor. The effect of CYP3A4 inhibitors on buprenorphine implants has not been studied, and the effect may be dependent on the route of administration.
Buspirone: (Moderate) When buspirone is administered with an inhibitor of CYP3A4 like indinavir, a lower dose of buspirone is recommended. Dose adjustment of either drug should be based on clinical assessment.
Butabarbital: (Major) Barbiturates may increase the metabolism of indinavir and lead to decreased antiretroviral efficacy. In addition, indinavir may inhibit the CYP metabolism of barbiturates, resulting in increased barbiturate concentrations. Appropriate dose adjustments necessary to ensure optimum levels of both anti-retroviral agent and the barbiturate are unknown. Anticonvulsant serum concentrations should be monitored closely if these agents are added; the patient should be observed for changes in the clinical efficacy of the antiretroviral or anticonvulsant regimen.
Butalbital; Acetaminophen: (Major) Barbiturates may increase the metabolism of indinavir and lead to decreased antiretroviral efficacy. In addition, indinavir may inhibit the CYP metabolism of barbiturates, resulting in increased barbiturate concentrations. Appropriate dose adjustments necessary to ensure optimum levels of both anti-retroviral agent and the barbiturate are unknown. Anticonvulsant serum concentrations should be monitored closely if these agents are added; the patient should be observed for changes in the clinical efficacy of the antiretroviral or anticonvulsant regimen.
Butalbital; Acetaminophen; Caffeine: (Major) Barbiturates may increase the metabolism of indinavir and lead to decreased antiretroviral efficacy. In addition, indinavir may inhibit the CYP metabolism of barbiturates, resulting in increased barbiturate concentrations. Appropriate dose adjustments necessary to ensure optimum levels of both anti-retroviral agent and the barbiturate are unknown. Anticonvulsant serum concentrations should be monitored closely if these agents are added; the patient should be observed for changes in the clinical efficacy of the antiretroviral or anticonvulsant regimen.
Butalbital; Acetaminophen; Caffeine; Codeine: (Major) Barbiturates may increase the metabolism of indinavir and lead to decreased antiretroviral efficacy. In addition, indinavir may inhibit the CYP metabolism of barbiturates, resulting in increased barbiturate concentrations. Appropriate dose adjustments necessary to ensure optimum levels of both anti-retroviral agent and the barbiturate are unknown. Anticonvulsant serum concentrations should be monitored closely if these agents are added; the patient should be observed for changes in the clinical efficacy of the antiretroviral or anticonvulsant regimen. (Moderate) Concomitant use of codeine with indinavir may increase codeine plasma concentrations, resulting in greater metabolism by CYP2D6, increased morphine concentrations, and prolonged opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when codeine is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of codeine until stable drug effects are achieved. Discontinuation of indinavir could decrease codeine plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to codeine. If indinavir is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. Indinavir is a strong inhibitor of CYP3A4.
Butalbital; Aspirin; Caffeine; Codeine: (Major) Barbiturates may increase the metabolism of indinavir and lead to decreased antiretroviral efficacy. In addition, indinavir may inhibit the CYP metabolism of barbiturates, resulting in increased barbiturate concentrations. Appropriate dose adjustments necessary to ensure optimum levels of both anti-retroviral agent and the barbiturate are unknown. Anticonvulsant serum concentrations should be monitored closely if these agents are added; the patient should be observed for changes in the clinical efficacy of the antiretroviral or anticonvulsant regimen. (Moderate) Concomitant use of codeine with indinavir may increase codeine plasma concentrations, resulting in greater metabolism by CYP2D6, increased morphine concentrations, and prolonged opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when codeine is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of codeine until stable drug effects are achieved. Discontinuation of indinavir could decrease codeine plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to codeine. If indinavir is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. Indinavir is a strong inhibitor of CYP3A4.
Cabazitaxel: (Major) Avoid coadministration of cabazitaxel with indinavir if possible due to increased cabazitaxel exposure. If concomitant use is unavoidable, consider reducing the dose of cabazitaxel by 25%. Cabazitaxel is primarily metabolized by CYP3A4 and indinavir is a strong CYP3A4 inhibitor. In a drug interaction study, coadministration with another strong CYP3A4 inhibitor increased cabazitaxel exposure by 25%.
Cabotegravir; Rilpivirine: (Moderate) Close clinical monitoring is advised when administering indinavir with rilpivirine due to an increased potential for rilpivirine-related adverse events. Predictions about the interaction can be made based on metabolic pathways. Indinavir is an inhibitor of the hepatic isoenzyme CYP3A4; rilpivirine is metabolized by this isoenzyme. Coadministration may result in increased rilpivirine plasma concentrations.
Cabozantinib: (Major) Avoid concomitant use of cabozantinib and indinavir due to the risk of increased cabozantinib exposure which may increase the incidence and severity of adverse reactions. If concomitant use is unavoidable, reduce the dose of cabozantinib. For patients taking cabozantinib tablets, reduce the dose of cabozantinib by 20 mg; for patients taking cabozantinib capsules, reduce the dose of cabozantinib by 40 mg. Resume the cabozantinib dose that was used prior to initiating treatment with indinavir 2 to 3 days after discontinuation of indinavir. Cabozantinib is a CYP3A substrate and indinavir is a strong CYP3A inhibitor. Coadministration with another strong CYP3A inhibitor increased cabozantinib exposure by 38%.
Canagliflozin: (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. A possible mechanism is impairment of beta-cell function. Onset averaged approximately 63 days after initiating protease inhibitor therapy, but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients on antidiabetic therapy should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated.
Canagliflozin; Metformin: (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. A possible mechanism is impairment of beta-cell function. Onset averaged approximately 63 days after initiating protease inhibitor therapy, but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients on antidiabetic therapy should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated. (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. Another possible mechanism is impairment of beta-cell function. Onset averaged approximately 63 days after initiating protease inhibitor therapy, but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients taking antidiabetic therapy should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated.
Capmatinib: (Moderate) Monitor for an increase in treatment-related adverse reactions if coadministration of capmatinib with indinavir is necessary. Capmatinib is a CYP3A substrate and a P-glycoprotein inhibitor. Indinavir is a strong CYP3A4 inhibitor and a P-gp substrate. Coadministration with another strong CYP3A4 inhibitor increased capmatinib exposure by 42%. Coadministration with P-gp inhibitors may increase indinavir exposure.
Carbamazepine: (Major) Anticonvulsants, such as carbamazepine, may increase the metabolism of indinavir and lead to decreased efficacy. Treatment failures have been reported with protease inhibitors when carbamazepine was used concomitantly. In addition, indinavir is a potent CYP3A inibitor and coadministration may result in increased serum concentrations of carbamazepine. The appropriate drug-dose adjustments necessary to ensure optimum levels of both antiretroviral and anticonvulsant drugs are unknown. If indinavir and carbamazepine are coadministered, the patient should be observed for changes in the clinical efficacy of the antiretroviral regimen or carbamazepine toxicity.
Cariprazine: (Major) Cariprazine and its active metabolites are extensively metabolized by CYP3A4. When a strong CYP3A4 inhibitor, such as indinavir, is initiated in a patient who is on a stable dose of cariprazine, reduce the cariprazine dosage by half. For adult patients taking cariprazine 4.5 mg daily, the dosage should be reduced to 1.5 mg or 3 mg daily. For adult patients taking cariprazine 1.5 mg daily, the dosing frequency should be adjusted to every other day. When the CYP3A4 inhibitor is withdrawn, the cariprazine dosage may need to be increased. When initiating cariprazine in a patient who is stable on a strong CYP3A4 inhibitor, the patient should be administered 1.5 mg of cariprazine on Day 1 and on Day 3 with no dose administered on Day 2. From Day 4 onward, the dose should be administered at 1.5 mg daily, then increased to a maximum dose of 3 mg daily. When the CYP3A4 inhibitor is withdrawn, the cariprazine dosage may need to be increased.
Carvedilol: (Moderate) Increased concentrations of indinavir may occur if it is coadministered with carvedilol; exercise caution. Carvedilol is a P-glycoprotein (P-gp) inhibitor and indinavir is a P-gp substrate.
Cenobamate: (Moderate) Coadministration of indinavir with cenobamate may result in decreased plasma concentrations of indinavir, leading to a reduction of antiretroviral efficacy and the potential development of viral resistance. Although specific recommendations are unavailable for use with cenobamate, an increased indinavir dose is recommended (i.e., 1,000 mg PO every 8 hours) when coadministered with other moderate CYP3A4 inducers. Indinavir is a CYP3A4 substrate and cenobamate is a moderate CYP3A4 inducer. Coadministration with another moderate CYP3A4 inducer decreased indinavir exposure by up to 46%.
Ceritinib: (Major) Avoid concomitant use of ceritinib with indinavir due to increased ceritinib exposure which may increase the incidence and severity of adverse reactions; indinavir exposure may also increase. If concomitant use is necessary, decrease the dose of ceritinib by approximately one-third, rounded to the nearest multiple of 150 mg and monitor for treatment-related adverse reactions. Although specific recommendations are unavailable for use with ceritinib, a reduced indinavir dose of 600 mg PO every 8 hours is recommended when coadministered with other strong CYP3A4 inhibitors. Both drugs are CYP3A substrates and strong CYP3A4 inhibitor. Coadministration with a strong CYP3A inhibitor increased ceritinib exposure by 2.9-fold.
Chlordiazepoxide: (Major) CYP3A4 inhibitors, such as protease inhibitors, may reduce the metabolism of chlordiazepoxide and increase the potential for benzodiazepine toxicity. A decrease in the chlordiazepoxide dose may be needed.
Chlordiazepoxide; Amitriptyline: (Major) CYP3A4 inhibitors, such as protease inhibitors, may reduce the metabolism of chlordiazepoxide and increase the potential for benzodiazepine toxicity. A decrease in the chlordiazepoxide dose may be needed.
Chlordiazepoxide; Clidinium: (Major) CYP3A4 inhibitors, such as protease inhibitors, may reduce the metabolism of chlordiazepoxide and increase the potential for benzodiazepine toxicity. A decrease in the chlordiazepoxide dose may be needed.
Chlorpheniramine; Codeine: (Moderate) Concomitant use of codeine with indinavir may increase codeine plasma concentrations, resulting in greater metabolism by CYP2D6, increased morphine concentrations, and prolonged opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when codeine is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of codeine until stable drug effects are achieved. Discontinuation of indinavir could decrease codeine plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to codeine. If indinavir is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. Indinavir is a strong inhibitor of CYP3A4.
Chlorpheniramine; Dihydrocodeine; Phenylephrine: (Moderate) Concomitant use of dihydrocodeine with indinavir may increase dihydrocodeine plasma concentrations, resulting in greater metabolism by CYP2D6, increased dihydromorphine concentrations, and prolonged opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of dihydrocodeine until stable drug effects are achieved. Discontinuation of indinavir could decrease dih ydrocodeine plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to dihydrocodeine. If indinavir is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Indinavir is a strong inhibitor of CYP3A4, an isoenzyme partially responsible for the metabolism of dihydrocodeine.
Chlorpheniramine; Hydrocodone: (Moderate) Consider a reduced dose of hydrocodone with frequent monitoring for respiratory depression and sedation if concurrent use of indinavir is necessary. It is recommended to avoid this combination when hydrocodone is being used for cough. Hydrocodone is a CYP2D6 and CYP3A4 substrate, and coadministration with CYP2D6 and CYP3A4 inhibitors like indinavir can increase hydrocodone exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of hydrocodone. These effects could be more pronounced with a combined CYP2D6 and CYP3A4 inhibitor. If indinavir is discontinued, hydrocodone plasma concentrations will decrease resulting in reduced efficacy of the opioid and potential withdrawal syndrome in a patient who has developed physical dependence to hydrocodone.
Cidofovir: (Moderate) Additive adverse effects may be seen when cidofovir is given with other agents that cause neutropenia. Patients receiving anti-retroviral protease inhibitors in combination with cidofovir may have an increased risk of iritis or uveitis.
Cilostazol: (Major) Reduce the dose of cilostazol to 50 mg twice daily when coadministered with protease inhibitors and monitor for an increase in cilostazol-related adverse reactions. Concurrent use may increase cilostazol exposure. Cilostazol is a CYP3A substrate; protease inhibitors are moderate to strong CYP3A inhibitors. Coadministration with a strong CYP3A inhibitor increased the cilostazol AUC by 117%. Coadministration with a moderate CYP3A inhibitor increased the AUC of cilostazol (single dose) by 73%; the AUC of 4-trans-hydroxycilostazol increased by 141%.
Cinacalcet: (Moderate) Monitor for cinacalcet-related adverse effects during concomitant use of indinavir and adjust dosage as appropriate based on response. Concomitant use may increase cinacalcet exposure. Cinacalcet is a CYP3A substrate and indinavir is a strong CYP3A inhibitor. Concomitant use with another strong CYP3A inhibitor increased cinacalcet overall exposure by 127%.
Ciprofloxacin: (Moderate) Use caution with the coadministration of ciprofloxacin and indinavir. The plasma concentrations of indinavir may be elevated when administered concurrently with ciprofloxacin. Ciprofloxacin is a CYP3A4 inhibitor and may decrease the systemic clearance of indinavir, a CYP3A4 substrate.
Cisapride: (Contraindicated) Concomitant use of protease inhibitors and cisapride is contraindicated; use increases cisapride exposure and the risk for cisapride-related adverse effects such as QT/QTc prolongation and torsade de pointes (TdP). Cisapride is a CYP3A substrate and protease inhibitors are moderate to strong CYP3A inhibitors. Concomitant use of cisapride with CYP3A inhibitors also is disallowed under the Propulsid Limited Access Program.
Clarithromycin: (Moderate) Clarithromycin is a CYP3A4 inhibitor and may decrease the systemic clearance of indinavir, a CYP3A4 substrate. Patients with impaired renal function may require a reduced dosage of clarithromycin.
Clindamycin: (Moderate) Monitor for an increase in clindamycin-related adverse reactions with coadministration of indinavir as concurrent use may increase clindamycin exposure. Clindamycin is a CYP3A4 substrate; indinavir is a strong inhibitor of CYP3A4.
Clonazepam: (Moderate) Monitor for increased sedation and respiratory depression if clonazepam is coadministered with protease inhibitors; adjust the dose of clonazepam if necessary. The systemic exposure of clonazepam may be increased resulting in an increase in treatment-related adverse reactions. Clonazepam is a CYP3A substrate and protease inhibitors are moderate to strong CYP3A inhibitors.
Clorazepate: (Major) CYP3A4 inhibitors, such as protease inhibitors, may reduce the metabolism of N-desmethyldiazepam, the active metabolite of clorazepate, and increase the potential for benzodiazepine toxicity. Monitor patients closely who receive concurrent therapy.
Clozapine: (Moderate) Caution is advisable during concurrent use of indinavir and clozapine. Indinavir is an inhibitor of CYP3A4, one of the isoenzymes responsible for the metabolism of clozapine. Treatment with clozapine has been associated with QT prolongation, torsade de pointes (TdP), cardiac arrest, and sudden death. Elevated plasma concentrations of clozapine occurring through CYP inhibition may potentially increase the risk of life-threatening arrhythmias, sedation, anticholinergic effects, seizures, orthostasis, or other adverse effects. According to the manufacturer, patients receiving clozapine in combination with an inhibitor of CYP3A4 should be monitored for adverse reactions. Consideration should be given to reducing the clozapine dose if necessary. If the inhibitor is discontinued after dose adjustments are made, monitor for lack of clozapine effectiveness and consider increasing the clozapine dose if necessary.
Cobicistat: (Contraindicated) Concomitant use of indinavir with regimens containing cobicistat and atazanavir is contraindicated. Cobicistat is an inhibitor of CYP3A4, while both atazanavir and indinavir are CYP3A4 substates. In addition, both atazanavir and indinavir are associated with indirect (unconjugated) hyperbilirubinemia. Taking these drugs together may increase the risk for hepatic adverse events, such as hyperbilirubinemia.
Cobimetinib: (Major) Avoid the concurrent use of cobimetinib with indinavir due to the risk of cobimetinib toxicity. Cobimetinib is a CYP3A substrate in vitro, and indinavir is a strong inhibitor of CYP3A. In healthy subjects (n = 15), coadministration of a single 10 mg dose of cobimetinib with itraconazole (200 mg once daily for 14 days), another strong CYP3A4 inhibitor, increased the mean cobimetinib AUC by 6.7-fold (90% CI, 5.6 to 8) and the mean Cmax by 3.2-fold (90% CI, 2.7 to 3.7).
Codeine: (Moderate) Concomitant use of codeine with indinavir may increase codeine plasma concentrations, resulting in greater metabolism by CYP2D6, increased morphine concentrations, and prolonged opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when codeine is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of codeine until stable drug effects are achieved. Discontinuation of indinavir could decrease codeine plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to codeine. If indinavir is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. Indinavir is a strong inhibitor of CYP3A4.
Codeine; Guaifenesin: (Moderate) Concomitant use of codeine with indinavir may increase codeine plasma concentrations, resulting in greater metabolism by CYP2D6, increased morphine concentrations, and prolonged opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when codeine is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of codeine until stable drug effects are achieved. Discontinuation of indinavir could decrease codeine plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to codeine. If indinavir is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. Indinavir is a strong inhibitor of CYP3A4.
Codeine; Guaifenesin; Pseudoephedrine: (Moderate) Concomitant use of codeine with indinavir may increase codeine plasma concentrations, resulting in greater metabolism by CYP2D6, increased morphine concentrations, and prolonged opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when codeine is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of codeine until stable drug effects are achieved. Discontinuation of indinavir could decrease codeine plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to codeine. If indinavir is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. Indinavir is a strong inhibitor of CYP3A4.
Codeine; Phenylephrine; Promethazine: (Moderate) Concomitant use of codeine with indinavir may increase codeine plasma concentrations, resulting in greater metabolism by CYP2D6, increased morphine concentrations, and prolonged opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when codeine is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of codeine until stable drug effects are achieved. Discontinuation of indinavir could decrease codeine plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to codeine. If indinavir is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. Indinavir is a strong inhibitor of CYP3A4.
Codeine; Promethazine: (Moderate) Concomitant use of codeine with indinavir may increase codeine plasma concentrations, resulting in greater metabolism by CYP2D6, increased morphine concentrations, and prolonged opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when codeine is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of codeine until stable drug effects are achieved. Discontinuation of indinavir could decrease codeine plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to codeine. If indinavir is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. Indinavir is a strong inhibitor of CYP3A4.
Colchicine: (Major) Due to the risk for serious colchicine toxicity including multi-organ failure and death, avoid coadministration of colchicine and indinavir in patients with normal renal and hepatic function unless the use of both agents is imperative. Coadministration is contraindicated in patients with renal or hepatic impairment because colchicine accumulation may be greater in these populations. Indinavir can inhibit colchicine's metabolism via CYP3A4, resulting in increased colchicine exposure. If coadministration in patients with normal renal and hepatic function cannot be avoided, adjust the dose of colchicine by either reducing the daily dose or the dosage frequency, and carefully monitor for colchicine toxicity. Specific dosage adjustment recommendations are available for the Colcrys product for patients who have taken indinavir in the past 14 days or require concurrent use: for prophylaxis of gout flares, if the original dose is 0.6 mg twice daily, decrease to 0.3 mg once daily or if the original dose is 0.6 mg once daily, decrease to 0.3 mg once every other day; for treatment of gout flares, give 0.6 mg as a single dose, then 0.3 mg 1 hour later, and do not repeat for at least 3 days; for familial Mediterranean fever, do not exceed a 0.6 mg/day.
Conivaptan: (Contraindicated) Coadministration of conivaptan and indinavir is contraindicated due to the potential for increased conivaptan exposure. Conivaptan is a CYP3A substrate; indinavir is a strong CYP3A inhibitor. In a drug interaction study, coadministration of a strong CYP3A inhibitor increased the exposure of oral conivaptan by 11-fold.
Conjugated Estrogens: (Moderate) Indinavir has been shown to decrease the metabolism of ethinyl estradiol; a similar interaction may occur with other estrogens used for hormone replacement therapy. Patients should be instructed to report any estrogen- related adverse events.
Conjugated Estrogens; Bazedoxifene: (Moderate) Indinavir has been shown to decrease the metabolism of ethinyl estradiol; a similar interaction may occur with other estrogens used for hormone replacement therapy. Patients should be instructed to report any estrogen- related adverse events.
Conjugated Estrogens; Medroxyprogesterone: (Major) Coadministration of medroxyprogesterone, a CYP3A substrate with indinavir, a strong CYP3A inhibitor should be avoided since it is expected to increase concentrations of medroxyprogesterone acetate. Formal drug interaction studies have not been conducted; however, medroxyprogesterone is metabolized primarily by hydroxylation via the CYP3A4 in vitro. Indinavir also decreases the metabolism of oral contraceptives and non-oral combination contraceptives; the AUC for ethinyl estradiol and norethindrone increased by 24+/-17% and 26+/-14%, respectively, when coadministered with indinavir. Women receiving hormonal contraceptives and anti-retroviral protease inhibitors (PIs), such as indinavir, should be instructed to report any breakthrough bleeding or other adverse effects to their prescribers. Because hormonal contraceptives do not protect against the transmission of HIV/AIDS and other sexually transmitted diseases, women who receive hormonal contraceptives with PIs should use an additional barrier method of contraception such as condoms. (Moderate) Indinavir has been shown to decrease the metabolism of ethinyl estradiol; a similar interaction may occur with other estrogens used for hormone replacement therapy. Patients should be instructed to report any estrogen- related adverse events.
Copanlisib: (Major) Avoid the concomitant use of copanlisib and indinavir if possible; increased copanlisib exposure may occur. If coadministration cannot be avoided, reduce the copanlisib dose to 45 mg and monitor patients for copanlisib-related adverse events (e.g., hypertension, infection, and skin rash). Copanlisib is a CYP3A substrate; indinavir is a strong CYP3A inhibitor.
Crizotinib: (Major) Avoid concomitant use of indinavir and crizotinib due to increased plasma concentrations of crizotinib, which may increase the incidence and severity of adverse reactions. If concomitant use is necessary for adults with non-small cell lung cancer (NSCLC) or inflammatory myofibroblastic tumor (IMT), reduce the dose of crizotinib to 250 mg PO once daily. If concomitant use is necessary for young adult or pediatric patients with anaplastic large cell lymphoma or pediatric patients with IMT, reduce the dose of crizotinib to 250 mg PO twice daily for BSA of 1.7 m2 or more; 200 mg PO twice daily for BSA of 1.17 to 1.69 m2; and 250 mg PO once daily for BSA of 0.81 to 1.16 m2; do not use this combination in patients with a BSA of 0.6 to 0.8 m2. Resume the original crizotinib dose after discontinuation of indinavir. Crizotinib is a CYP3A substrate and indinavir is a strong CYP3A inhibitor. Coadministration with one strong CYP3A inhibitor increased the AUC of single-dose crizotinib by 216%. Concomitant use with another strong CYP3A inhibitor increased the steady-state AUC of crizotinib by 57% compared to crizotinib alone.
Cyclophosphamide: (Moderate) Monitor for an increase in cyclophosphamide-related adverse reactions if coadministration with protease inhibitors is necessary. Use of protease inhibitor-based regimens was found to be associated with a higher incidence of infections and neutropenia in patients receiving cyclophosphamide, doxorubicin, and etoposide (CDE) than the use of a Non-Nucleoside Reverse Transcriptase Inhibitor-based regimen. Concomitant use of protease inhibitors may increase the concentration of cytotoxic metabolites.
Cyclosporine: (Moderate) An interaction is anticipated to occur with protease inhibitors and cyclosporine, as CYP3A4 is inhibited by protease inhibitors and cyclosporine is a CYP3A4 substrate. Closely monitor cyclosporine concentrations and adjust the dose of cyclosporine as appropriate if coadministration with an anti-retroviral protease inhibitor is necessary. In a study of 18 HIV-infected patients who underwent renal or hepatic transplant and received concomitant therapy with protease inhibitors and cyclosporine, there was a 3-fold increase in cyclosporine AUC resulting in an 85% reduction in cyclosporine dose over a 2-year period. In another study, HIV-infected, liver and kidney transplant patients required 4- to 5-fold reductions in cyclosporine dose and approximate 50% increases in dosing interval when cyclosporine was coadministered with protease inhibitors. Consider a reduction in cyclosporine dose to 25 mg every 1 to 2 days when coadministered with a boosted protease inhibitor. Cyclosporine toxicity, consisting of fatigue, headache, and GI distress, has been reported by a patient receiving cyclosporine and saquinavir. After receiving saquinavir for 3 days, the cyclosporine trough concentration increased from 150 to 200 mcg/mL up to 580 mcg/mL. Dosages of both agents were decreased by 50% leading to resolution of symptoms.
Dabrafenib: (Major) Avoid the concomitant use of dabrafenib and indinavir; altered levels of either drug may occur. Use of an alternative agent is recommended. If concomitant use of these agents together is unavoidable, monitor patients closely for dabrafenib adverse reactions (e.g., skin toxicity, ocular toxicity, and cardiotoxicity) and for loss of indinavir efficacy. Dabrafenib is a CYP3A4 substrate and moderate CYP3A4 inducer; indinavir is a strong CYP3A4 inhibitor and a sensitive CYP3A4 substrate.
Daclatasvir: (Major) The dose of daclatasvir, a CYP3A4 substrate, must be reduced to 30 mg PO once daily when administered in combination with strong CYP3A4 inhibitors, such as indinavir. Taking these drugs together may increase daclatasvir serum concentrations, and potentially increase the risk for adverse effects. In addition, the therapeutic effects of indinavir, a P-glycoprotein (P-gp) substrate, may be increased by daclatasvir, a P-gp inhibitor.
Dapagliflozin: (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. A possible mechanism is impairment of beta-cell function. Onset averaged approximately 63 days after initiating protease inhibitor therapy, but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients on antidiabetic therapy should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated.
Dapagliflozin; Metformin: (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. A possible mechanism is impairment of beta-cell function. Onset averaged approximately 63 days after initiating protease inhibitor therapy, but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients on antidiabetic therapy should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated. (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. Another possible mechanism is impairment of beta-cell function. Onset averaged approximately 63 days after initiating protease inhibitor therapy, but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients taking antidiabetic therapy should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated.
Dapagliflozin; Saxagliptin: (Major) The metabolism of saxagliptin is primarily mediated by CYP3A4/5. Limit the saxagliptin dose to 2.5 mg once daily when coadministered with a strong CYP3A4/5 inhibitor such as indinavir. New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have also been reported with use of anti-retroviral protease inhibitors. Patients on antidiabetic therapy should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated. (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. A possible mechanism is impairment of beta-cell function. Onset averaged approximately 63 days after initiating protease inhibitor therapy, but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients on antidiabetic therapy should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated.
Daridorexant: (Major) Avoid concomitant use of daridorexant and indinavir. Concomitant use may increase daridorexant exposure and the risk for daridorexant-related adverse effects. Daridorexant is a CYP3A substrate and indinavir is a strong CYP3A inhibitor. Concomitant use of another strong CYP3A inhibitor increased daridorexant overall exposure by over 400%.
Darifenacin: (Moderate) The daily dose of darifenacin should not exceed 7.5 mg PO when administered with indinavir due to increased darifenacin exposure. Darifenacin is a CYP3A4 substrate; indinavir is a strong CYP3A4 inhibitor.
Darunavir: (Moderate) Concurrent administration of darunavir and indinavir results in increased darunavir and indinavir concentrations. The clinical significance of this interaction has not been established, and dosage adjustment recommendations have not been established. Use this combination with caution.
Darunavir; Cobicistat: (Contraindicated) Concomitant use of indinavir with regimens containing cobicistat and atazanavir is contraindicated. Cobicistat is an inhibitor of CYP3A4, while both atazanavir and indinavir are CYP3A4 substates. In addition, both atazanavir and indinavir are associated with indirect (unconjugated) hyperbilirubinemia. Taking these drugs together may increase the risk for hepatic adverse events, such as hyperbilirubinemia. (Moderate) Concurrent administration of darunavir and indinavir results in increased darunavir and indinavir concentrations. The clinical significance of this interaction has not been established, and dosage adjustment recommendations have not been established. Use this combination with caution.
Darunavir; Cobicistat; Emtricitabine; Tenofovir alafenamide: (Contraindicated) Concomitant use of indinavir with regimens containing cobicistat and atazanavir is contraindicated. Cobicistat is an inhibitor of CYP3A4, while both atazanavir and indinavir are CYP3A4 substates. In addition, both atazanavir and indinavir are associated with indirect (unconjugated) hyperbilirubinemia. Taking these drugs together may increase the risk for hepatic adverse events, such as hyperbilirubinemia. (Moderate) Concurrent administration of darunavir and indinavir results in increased darunavir and indinavir concentrations. The clinical significance of this interaction has not been established, and dosage adjustment recommendations have not been established. Use this combination with caution.
Dasatinib: (Major) Avoid coadministration of dasatinib and indinavir due to the potential for increased dasatinib exposure and subsequent toxicity. An alternative to indinavir with no or minimal enzyme inhibition potential is recommended if possible. If coadministration cannot be avoided, consider a dasatinib dose reduction to 40 mg PO daily if original dose was 140 mg daily, 20 mg PO daily if original dose was 100 mg daily, or 20 mg PO daily if original dose was 70 mg daily. Concomitant use of indinavir is not recommended in patients receiving dasatinib 60 mg or 40 mg daily. If dasatinib is not tolerated after dose reduction, consider alternative therapies. If indinavir is stopped, allow a washout of approximately 1 week before increasing the dasatinib dose. Dasatinib is a CYP3A4 substrate; indinavir is a strong CYP3A4 inhibitor. Coadministration of another strong CYP3A4 inhibitor increased the mean Cmax and AUC of dasatinib by 4-fold and 5-fold, respectively.
Deflazacort: (Major) Decrease deflazacort dose to one third of the recommended dosage when coadministered with indinavir. Concurrent use may significantly increase concentrations of 21-desDFZ, the active metabolite of deflazacort, resulting in an increased risk of toxicity. Deflazacort is a CYP3A4 substrate; indinavir is a strong inhibitor of CYP3A4. Administration of deflazacort with clarithromycin, a strong CYP3A4 inhibitor, increased total exposure to 21-desDFZ by about 3-fold.
Delavirdine: (Major) Reduce the adult indinavir dose to 600 mg three times daily when coadministered with delavirdine. At this dose, concurrent use results in increased indinavir AUC (53%) and Cmin (298%). Indinavir has no effects on delavirdine pharmacokinetics.
Desogestrel; Ethinyl Estradiol: (Major) Indinavir decreases the metabolism of oral contraceptives and non-oral combination contraceptives; the AUC for ethinyl estradiol and norethindrone increased by 24+/-17% and 26+/-14%, respectively, when coadministered with indinavir. Women receiving hormonal contraceptives and anti-retroviral protease inhibitors (PIs), such as indinavir, should be instructed to report any breakthrough bleeding or other adverse effects to their prescribers. Because hormonal contraceptives do not protect against the transmission of HIV/AIDS and other sexually transmitted diseases, women who receive hormonal contraceptives with PIs should use an additional barrier method of contraception such as condoms.
Dexamethasone: (Moderate) Monitor for steroid-related adverse reactions and a decrease in indinavir efficacy if concomitant use of dexamethasone and indinavir is necessary. If long term coadministration is required, consider using an alternative corticosteroid, such as beclomethasone or prednisolone. Concomitant use may increase dexamethasone concentrations and decrease indinavir exposure. Dexamethasone is a CYP3A substrate and CYP3A inducer; indinavir is a CYP3A substrate and strong CYP3A inhibitor. Another strong CYP3A inhibitor has been reported to decrease the metabolism of certain corticosteroids by up to 60%, leading to increased risk of corticosteroid side effects.
Dextromethorphan; Quinidine: (Moderate) Concurrent administration of indinavir and quinidine caused indinavir AUC to increase by about 10%. There were no effects on quinidine pharmacokinetics.
Diazepam: (Moderate) Monitor for an increase in diazepam-related adverse reactions, including sedation and respiratory depression, if coadministration with protease inhibitors is necessary. Concurrent use may increase diazepam exposure. Diazepam is a CYP3A4 substrate and protease inhibitors are moderate to strong CYP3A4 inhibitors.
Didanosine, ddI: (Major) Concomitant use of indinavir and didanosine chewable tablets or powder for oral solution may decrease the serum concentratons of indinavir resulting in decreased efficacy. To avoid this interaction, administer indinavir 1 hour prior to didanosine chewable tablets or powder. No clinically significant pharmacokinetic interaction between didanosine capsules and indinavir have been reported.
Dienogest; Estradiol valerate: (Moderate) Indinavir has been shown to decrease the metabolism of ethinyl estradiol; a similar interaction may occur with other estrogens used for hormone replacement therapy. Patients should be instructed to report any estrogen- related adverse events.
Dihydroergotamine: (Contraindicated) Coadministration of ergot alkaloids with potent inhibitors of CYP3A4, like anti-retroviral protease inhibitors is considered contraindicated due to the risk of acute ergot toxicity (e.g., vasospasm leading to cerebral ischemia, peripheral ischemia and/or other serious effects). Several case reports have established the clinical significance of this interaction in the medical literature. In some cases, fatal interactions have occurred.
Diltiazem: (Moderate) Indinavir may inhibit the metabolism of other medications that are metabolized via cytochrome P450 3A4. Although drug interaction studies have not been conducted, the serum concentration of diltiazem may be increased with concomitant administration of indinavir.
Disopyramide: (Major) Indinavir inhibits CYP3A4. Although specific interactions have not been studied, indinavir may interfere with the metabolism of CYP3A4 substrates such as disopyramide, and caution is warranted with coadministration.
Docetaxel: (Major) Avoid coadministration of docetaxel with indinavir if possible due to increased plasma concentrations of docetaxel. If concomitant use is unavoidable, closely monitor for docetaxel-related adverse reactions and consider a 50% dose reduction of docetaxel. Docetaxel is a CYP3A4 substrate and indinavir is a strong CYP3A4 inhibitor. Concomitant use with another strong CYP3A4 inhibitor increased docetaxel exposure by 2.2-fold.
Dofetilide: (Major) Coadministration of CYP3A4 inhibitors, such as indinavir, with dofetilide may decrease the metabolism of dofetilide, thereby increasing the potential for QT prolongation. Dofetilide is a Class III antiarrhythmic agent that has a well-established risk of QT prolongation and torsade de pointes (TdP). Plasma dofetilide concentrations are correlated with the risk of drug-induced proarrhythmias.
Dolutegravir; Rilpivirine: (Moderate) Close clinical monitoring is advised when administering indinavir with rilpivirine due to an increased potential for rilpivirine-related adverse events. Predictions about the interaction can be made based on metabolic pathways. Indinavir is an inhibitor of the hepatic isoenzyme CYP3A4; rilpivirine is metabolized by this isoenzyme. Coadministration may result in increased rilpivirine plasma concentrations.
Donepezil: (Moderate) Indinavir inhibits cytochrome P450 3A4 and may interfere with the metabolism of CYP3A4 substrates, such as donepezil. Caution is warranted with coadministration.
Donepezil; Memantine: (Moderate) Indinavir inhibits cytochrome P450 3A4 and may interfere with the metabolism of CYP3A4 substrates, such as donepezil. Caution is warranted with coadministration.
Doravirine: (Minor) Coadministration of doravirine and indinavir may result in increased doravirine plasma concentrations. Doravirine is a CYP3A4 substrate; indinavir is a strong inhibitor. In drug interaction studies, concurrent use of strong CYP3A4 inhibitors increased doravirine exposure by more than 3-fold; however, this increase was not considered clinically significant.
Doravirine; Lamivudine; Tenofovir disoproxil fumarate: (Minor) Coadministration of doravirine and indinavir may result in increased doravirine plasma concentrations. Doravirine is a CYP3A4 substrate; indinavir is a strong inhibitor. In drug interaction studies, concurrent use of strong CYP3A4 inhibitors increased doravirine exposure by more than 3-fold; however, this increase was not considered clinically significant.
Doxazosin: (Moderate) Monitor blood pressure and for signs of hypotension during coadministration. The plasma concentrations of doxazosin may be elevated when administered concurrently with indinavir. Indinavir is a strong CYP3A4 inhibitor; doxazosin is a CYP3A4 substrate. Coadministration of doxazosin with a moderate CYP3A4 inhibitor resulted in a 10% increase in mean AUC and an insignificant increase in mean Cmax and mean half-life of doxazosin. Although not studied in combination with doxazosin, strong CYP3A4 inhibitors may have a larger impact on doxazosin concentrations and therefore should be used with caution.
Doxercalciferol: (Moderate) Protease inhibitors may decrease efficacy of doxercalciferol. Doxercalciferol is converted in the liver to 1,25-dihydroxyergocalciferol, the major active metabolite, and 1-alpha, 24-dihydroxyvitamin D2, a minor metabolite. Although not specifically studied, cytochrome P450 enzyme inhibitors, including protease inhibitors, may inhibit the 25-hydroxylation of doxercalciferol, thereby decreasing the formation of the active metabolite and thus, decreasing efficacy. Patients should be monitored for a decrease in efficacy if these drugs are administered together.
Doxorubicin Liposomal: (Major) Indinavir is a potent inhibitor of CYP3A4 and in vitro, a mild CYP2D6 inhibitor; doxorubicin is a major CYP2D6 and CYP3A4 substrate. Clinically significant interactions have been reported when doxorubicin was coadministered with inhibitors of CYP2D6 and/or CYP3A4, resulting in increased concentration and clinical effect of doxorubicin. Avoid coadministration of indinavir and doxorubicin if possible. If not possible, closely monitor for increased side effects of doxorubicin including myelosuppression and cardiotoxicity.
Doxorubicin: (Major) Indinavir is a potent inhibitor of CYP3A4 and in vitro, a mild CYP2D6 inhibitor; doxorubicin is a major CYP2D6 and CYP3A4 substrate. Clinically significant interactions have been reported when doxorubicin was coadministered with inhibitors of CYP2D6 and/or CYP3A4, resulting in increased concentration and clinical effect of doxorubicin. Avoid coadministration of indinavir and doxorubicin if possible. If not possible, closely monitor for increased side effects of doxorubicin including myelosuppression and cardiotoxicity.
Dronabinol: (Major) Use caution if coadministration of dronabinol with indinavir is necessary, and closely monitor for an increase in dronabinol-related adverse reactions (e.g., cognitive impairment, psychosis, seizures, and hemodynamic instability, as well as feeling high, dizziness, confusion, somnolence). Indinavir is a strong inhibitor of CYP3A4, and is contraindicated with sensitive drugs that are highly dependent on CYP3A4/5 for clearance. Dronabinol is a CYP2C9 and 3A4 substrate; concomitant use may result in elevated plasma concentrations of dronabinol. The effect of marijuana and dronabinol, THC on the pharmacokinetics of indinavir has also been evaluated in a randomized trial. Although a statistically significant decrease in the Cmax of indinavir was noted in the marijuana arm, the magnitude of changes in indinavir pharmacokinetics were not thought to be clinically significant. In the authors' opinion, the use of marijuana or dronabinol is unlikely to affect the antiretroviral efficacy of indinavir.
Dronedarone: (Contraindicated) The concomitant use of dronedarone and indinavir is contraindicated. Dronedarone is metabolized by CYP3A, is a moderate inhibitor of CYP3A, and is an inhibitor of P-gp. Indinavir is a strong inhibitor of CYP3A4 and is a substrate of CYP3A and P-gp. Repeated doses of ketoconazole, also a strong CYP3A4 inhibitor, increased dronedarone exposure 17-fold and increased dronedarone Cmax 9-fold. No data exist regarding the safe administration of dronedarone with strong CYP3A4 inhibitors; therefore, concomitant use is contraindicated. Also, the effects of dronedarone on the pharmacokinetics of indinavir have not been described, although an increase in indinavir serum concentrations is possible.
Drospirenone: (Major) Indinavir may decrease the metabolism of oral contraceptives and non-oral combination contraceptives. Women receiving hormonal contraceptives and anti-retroviral protease inhibitors (PIs), such as indinavir, should be instructed to report any breakthrough bleeding or other adverse effects to their prescribers. It may be prudent for women who receive hormonal contraceptives with PIs that include ritonavir as a booster to use an additional method of contraception to protect against unwanted pregnancy. Furthermore, because hormonal contraceptives do not protect against the transmission of HIV/AIDS and other sexually transmitted diseases, women who receive hormonal contraceptives with PIs should use an additional barrier method of contraception such as condoms. In women receiving oral contraceptives containing drospirenone, consider monitoring serum potassium concentrations during the first month of dosing in high-risk patients who take strong CYP3A4 inhibitors, such as indinavir, long-term and concomitantly. Drospirenone has antimineralocorticoid effects; the progestin may increase serum potassium.
Drospirenone; Estetrol: (Major) Indinavir may decrease the metabolism of oral contraceptives and non-oral combination contraceptives. Women receiving hormonal contraceptives and anti-retroviral protease inhibitors (PIs), such as indinavir, should be instructed to report any breakthrough bleeding or other adverse effects to their prescribers. It may be prudent for women who receive hormonal contraceptives with PIs that include ritonavir as a booster to use an additional method of contraception to protect against unwanted pregnancy. Furthermore, because hormonal contraceptives do not protect against the transmission of HIV/AIDS and other sexually transmitted diseases, women who receive hormonal contraceptives with PIs should use an additional barrier method of contraception such as condoms. In women receiving oral contraceptives containing drospirenone, consider monitoring serum potassium concentrations during the first month of dosing in high-risk patients who take strong CYP3A4 inhibitors, such as indinavir, long-term and concomitantly. Drospirenone has antimineralocorticoid effects; the progestin may increase serum potassium.
Drospirenone; Estradiol: (Major) Indinavir may decrease the metabolism of oral contraceptives and non-oral combination contraceptives. Women receiving hormonal contraceptives and anti-retroviral protease inhibitors (PIs), such as indinavir, should be instructed to report any breakthrough bleeding or other adverse effects to their prescribers. It may be prudent for women who receive hormonal contraceptives with PIs that include ritonavir as a booster to use an additional method of contraception to protect against unwanted pregnancy. Furthermore, because hormonal contraceptives do not protect against the transmission of HIV/AIDS and other sexually transmitted diseases, women who receive hormonal contraceptives with PIs should use an additional barrier method of contraception such as condoms. In women receiving oral contraceptives containing drospirenone, consider monitoring serum potassium concentrations during the first month of dosing in high-risk patients who take strong CYP3A4 inhibitors, such as indinavir, long-term and concomitantly. Drospirenone has antimineralocorticoid effects; the progestin may increase serum potassium. (Moderate) Indinavir has been shown to decrease the metabolism of ethinyl estradiol; a similar interaction may occur with other estrogens used for hormone replacement therapy. Patients should be instructed to report any estrogen- related adverse events.
Drospirenone; Ethinyl Estradiol: (Major) Indinavir decreases the metabolism of oral contraceptives and non-oral combination contraceptives; the AUC for ethinyl estradiol and norethindrone increased by 24+/-17% and 26+/-14%, respectively, when coadministered with indinavir. Women receiving hormonal contraceptives and anti-retroviral protease inhibitors (PIs), such as indinavir, should be instructed to report any breakthrough bleeding or other adverse effects to their prescribers. Because hormonal contraceptives do not protect against the transmission of HIV/AIDS and other sexually transmitted diseases, women who receive hormonal contraceptives with PIs should use an additional barrier method of contraception such as condoms. (Major) Indinavir may decrease the metabolism of oral contraceptives and non-oral combination contraceptives. Women receiving hormonal contraceptives and anti-retroviral protease inhibitors (PIs), such as indinavir, should be instructed to report any breakthrough bleeding or other adverse effects to their prescribers. It may be prudent for women who receive hormonal contraceptives with PIs that include ritonavir as a booster to use an additional method of contraception to protect against unwanted pregnancy. Furthermore, because hormonal contraceptives do not protect against the transmission of HIV/AIDS and other sexually transmitted diseases, women who receive hormonal contraceptives with PIs should use an additional barrier method of contraception such as condoms. In women receiving oral contraceptives containing drospirenone, consider monitoring serum potassium concentrations during the first month of dosing in high-risk patients who take strong CYP3A4 inhibitors, such as indinavir, long-term and concomitantly. Drospirenone has antimineralocorticoid effects; the progestin may increase serum potassium.
Drospirenone; Ethinyl Estradiol; Levomefolate: (Major) Indinavir decreases the metabolism of oral contraceptives and non-oral combination contraceptives; the AUC for ethinyl estradiol and norethindrone increased by 24+/-17% and 26+/-14%, respectively, when coadministered with indinavir. Women receiving hormonal contraceptives and anti-retroviral protease inhibitors (PIs), such as indinavir, should be instructed to report any breakthrough bleeding or other adverse effects to their prescribers. Because hormonal contraceptives do not protect against the transmission of HIV/AIDS and other sexually transmitted diseases, women who receive hormonal contraceptives with PIs should use an additional barrier method of contraception such as condoms. (Major) Indinavir may decrease the metabolism of oral contraceptives and non-oral combination contraceptives. Women receiving hormonal contraceptives and anti-retroviral protease inhibitors (PIs), such as indinavir, should be instructed to report any breakthrough bleeding or other adverse effects to their prescribers. It may be prudent for women who receive hormonal contraceptives with PIs that include ritonavir as a booster to use an additional method of contraception to protect against unwanted pregnancy. Furthermore, because hormonal contraceptives do not protect against the transmission of HIV/AIDS and other sexually transmitted diseases, women who receive hormonal contraceptives with PIs should use an additional barrier method of contraception such as condoms. In women receiving oral contraceptives containing drospirenone, consider monitoring serum potassium concentrations during the first month of dosing in high-risk patients who take strong CYP3A4 inhibitors, such as indinavir, long-term and concomitantly. Drospirenone has antimineralocorticoid effects; the progestin may increase serum potassium.
Dutasteride: (Moderate) Concurrent administration of dutasteride with protease inhibitors may result in elevated dutasteride plasma concentrations. Dutasteride is metabolized by the hepatic isoenzyme CYP3A4; protease inhibitors are potent inhibitors of this enzyme. Caution and close monitoring are advised if these drugs are administered together.
Dutasteride; Tamsulosin: (Major) Plasma concentrations of tamsulosin may be increased with concomitant use of anti-retroviral protease inhibitors. Tamsulosin is extensively metabolized by CYP3A4 and CYP2D6 hepatic enzymes. In clinical evaluation, concomitant treatment with a strong CYP3A4 inhibitor resulted in significant increases in tamsulosin exposure. Such increases in tamsulosin concentrations may be expected to produce clinically significant and potentially serious side effects, such as hypotension. Therefore, concomitant use of tamsulosin with a strong CYP3A4 inhibitor, or an agent with both CYP3A4 and CYP2D6 inhibitor activity, should be avoided. (Moderate) Concurrent administration of dutasteride with protease inhibitors may result in elevated dutasteride plasma concentrations. Dutasteride is metabolized by the hepatic isoenzyme CYP3A4; protease inhibitors are potent inhibitors of this enzyme. Caution and close monitoring are advised if these drugs are administered together.
Duvelisib: (Major) Reduce duvelisib dose to 15 mg PO twice daily and monitor for increased toxicity of both drugs when coadministered with indinavir. Coadministration may increase the exposure of both drugs. Duvelisib is a substrate and moderate inhibitor of CYP3A; indinavir is a sensitive substrate and strong inhibitor of CYP3A. The increase in exposure to duvelisib is estimated to be approximately 2-fold when used concomitantly with strong CYP3A inhibitors such as indinavir.
Echinacea: (Moderate) Use Echinacea sp. with caution in patients taking medications for human immunodeficiency virus (HIV) infection. Some experts have suggested that Echinacea's effects on the immune system might cause problems for patients with HIV infection, particularly with long-term use. There may be less risk with short-term use (less than 2 weeks). A few pharmacokinetic studies have shown reductions in blood levels of some antiretroviral medications when Echinacea was given, presumably due to CYP induction. However, more study is needed for various HIV treatment regimens. Of the agents studied, the interactions do not appear to be significant or to require dose adjustments at the time of use. Although no dose adjustments are required, monitoring drug concentrations may give reassurance during co-administration. Monitor viral load and other parameters carefully during therapy.
Efavirenz: (Major) Efavirenz increases the CYP3A4 metabolism of indinavir resulting in lower indinavir concentrations. When administered together, the optimal indinavir dose is not known. Increasing the indinavir dose to 1000 mg every 8 hours does not compensate for the increased metabolism. An increased dose of indinavir (1000 mg every 8 hours) given with efavirenz (600 mg once daily) results in decreased indinavir AUC and Cmin, approximately 40% and 50%, respectively, compared to when indinavir (800 mg every 8 hours) is given alone.
Efavirenz; Emtricitabine; Tenofovir Disoproxil Fumarate: (Major) Efavirenz increases the CYP3A4 metabolism of indinavir resulting in lower indinavir concentrations. When administered together, the optimal indinavir dose is not known. Increasing the indinavir dose to 1000 mg every 8 hours does not compensate for the increased metabolism. An increased dose of indinavir (1000 mg every 8 hours) given with efavirenz (600 mg once daily) results in decreased indinavir AUC and Cmin, approximately 40% and 50%, respectively, compared to when indinavir (800 mg every 8 hours) is given alone.
Efavirenz; Lamivudine; Tenofovir Disoproxil Fumarate: (Major) Efavirenz increases the CYP3A4 metabolism of indinavir resulting in lower indinavir concentrations. When administered together, the optimal indinavir dose is not known. Increasing the indinavir dose to 1000 mg every 8 hours does not compensate for the increased metabolism. An increased dose of indinavir (1000 mg every 8 hours) given with efavirenz (600 mg once daily) results in decreased indinavir AUC and Cmin, approximately 40% and 50%, respectively, compared to when indinavir (800 mg every 8 hours) is given alone.
Elacestrant: (Major) Avoid concomitant use of elacestrant and indinavir due to the risk of increased elacestrant exposure which may increase the risk for adverse effects. Elacestrant is a CYP3A substrate and indinavir is a strong CYP3A inhibitor. Concomitant use with another strong CYP3A inhibitor increased elacestrant overall exposure by 5.3-fold.
Elagolix: (Major) Concomitant use of elagolix 200 mg twice daily and indinavir for more than 1 month is not recommended. Limit concomitant use of elagolix 150 mg once daily and indinavir to 6 months. Monitor for elagolix-related side effects and reduced response to indinavir. Elagolix is a CYP3A substrate and a weak to moderate CYP3A4 inducer; indinavir is a strong inhibitor of CYP3A and a CYP3A4 substrate. Coadministration may increase elagolix plasma concentrations and decrease indinavir concentrations. In drug interaction studies, coadministration of elagolix with another strong CYP3A inhibitor increased the Cmax and AUC of elagolix by 77% and 120%, respectively.
Elagolix; Estradiol; Norethindrone acetate: (Major) Concomitant use of elagolix 200 mg twice daily and indinavir for more than 1 month is not recommended. Limit concomitant use of elagolix 150 mg once daily and indinavir to 6 months. Monitor for elagolix-related side effects and reduced response to indinavir. Elagolix is a CYP3A substrate and a weak to moderate CYP3A4 inducer; indinavir is a strong inhibitor of CYP3A and a CYP3A4 substrate. Coadministration may increase elagolix plasma concentrations and decrease indinavir concentrations. In drug interaction studies, coadministration of elagolix with another strong CYP3A inhibitor increased the Cmax and AUC of elagolix by 77% and 120%, respectively. (Moderate) Indinavir has been shown to decrease the metabolism of ethinyl estradiol; a similar interaction may occur with other estrogens used for hormone replacement therapy. Patients should be instructed to report any estrogen- related adverse events. (Moderate) Many anti-retroviral protease inhibitors may interact with hormonal agents like norethindrone, due to their actions on CYP metabolism, particularly CYP3A4. Data on the effects that protease inhibitors have on the serum concentrations of norethindrone are complex and are based mostly off of data with norethindrone-containing contraceptives. The AUC for norethindrone increased by 26+/-14%, respectively, when a combined oral contraceptive was coadministered with indinavir. Women receiving hormonal contraceptives and anti-retroviral protease inhibitors (PIs), such as indinavir, should be instructed to report any breakthrough bleeding or other adverse effects to their prescribers. Because hormonal contraceptives do not protect against the transmission of HIV/AIDS and other sexually transmitted diseases, women who receive hormonal contraceptives with indinavir should use an additional barrier method of contraception such as condoms.
Elbasvir; Grazoprevir: (Major) Concurrent administration of elbasvir with indinavir should be avoided if possible. Use of these drugs together is expected to significantly increase the plasma concentrations of elbasvir, and may result in adverse effects (i.e., elevated ALT concentrations and hepatotoxicity). Indinavir is a strong inhibitor of the hepatic enzyme CYP3A, while elbasvir is metabolized by CYP3A. (Major) Concurrent administration of grazoprevir with indinavir should be avoided if possible. Use of these drugs together is expected to significantly increase the plasma concentration of grazoprevir, and may result in adverse effects (i.e., elevated ALT concentrations and hepatotoxicity). Indinavir is a strong inhibitor of the hepatic enzyme CYP3A, while grazoprevir is metabolized by CYP3A. In addition, plasma concentrations of indinavir (also a CYP3A substrate) may be increased when given with grazoprevir (a weak CYP3A inhibitor).
Eletriptan: (Contraindicated) Eletriptan is contraindicated for use within 72 hours of using any drug that is a potent CYP3A4 inhibitor as described in the prescribing information of the interacting drug including protease inhibitors. Eletriptan is metabolized via CYP3A4, and coadministration with protease inhibitors may cause increased eletriptan concentrations and thus toxicity.
Elexacaftor; tezacaftor; ivacaftor: (Major) If indinavir and ivacaftor are taken together, administer ivacaftor at the usual recommended dose but reduce the frequency to twice weekly. Coadministration is not recommended in patients younger than 6 months. Ivacaftor is a CYP3A substrate and indinavir is a strong CYP3A inhibitor. Coadministration with another strong CYP3A inhibitor increased ivacaftor exposure by 8.5-fold. (Major) Reduce the dosing frequency of elexacaftor; tezacaftor; ivacaftor to twice a week in the morning, approximately 3 to 4 days apart (i.e., Day 1 and Day 4) when coadministered with indinavir; omit the evening dose of ivacaftor. Coadministration may increase elexacaftor; tezacaftor; ivacaftor exposure and adverse reactions. Elexacaftor, tezacaftor, and ivacaftor are CYP3A substrates; indinavir is a strong CYP3A inhibitor. Coadministration of a strong CYP3A inhibitor increased elexacaftor exposure by 2.8- fold, tezacaftor exposure by 4.5-fold, and ivacaftor exposure by 15.6-fold. (Major) Reduce the dosing frequency of tezacaftor; ivacaftor when coadministered with indinavir; coadministration may increase tezacaftor; ivacaftor exposure and adverse reactions. When combined, dose 1 tezacaftor; ivacaftor combination tablet twice a week, approximately 3 to 4 days apart (i.e., Day 1 and Day 4). The evening dose of ivacaftor should not be taken. Both tezacaftor and ivacaftor are CYP3A substrates (ivacaftor is a sensitive substrate); indinavir is a strong CYP3A inhibitor. Coadministration of a strong CYP3A inhibitor increased tezacaftor and ivacaftor exposure 4- and 15.6-fold, respectively.
Eliglustat: (Major) Coadministration of indinavir and eliglustat is contraindicated in intermediate or poor CYP2D6 metabolizers (IMs or PMs). In extensive CYP2D6 metabolizers (EMs), coadministration of these agents requires dosage reduction of eliglustat to 84 mg PO once daily. The coadministration of eliglustat with both indinavir and a moderate or strong CYP2D6 inhibitor, such as ritonavir, is contraindicated in all patients. Indinavir is a strong CYP3A inhibitor; eliglustat is a CYP3A and CYP2D6 substrate. Coadministration of eliglustat with CYP3A inhibitors increases eliglustat exposure and the risk of serious adverse events (e.g., QT prolongation and cardiac arrhythmias); this risk is the highest in CYP2D6 IMs and PMs because a larger portion of the eliglustat dose is metabolized via CYP3A. Although indinavir's product labeling states that coadministration of certain CYP3A substrates that have the potential for serious adverse events with elevated concentrations are contraindicated, the interaction between ketoconazole (a potent CYP3A inhibitor) and eliglustat was studied during clinical trials. The resultant data supports eliglustat dosage reduction in EMs instead of contraindication. In addition, because indinavir is a P-gp substrate and eliglustat is a P-gp inhibitor, exposure to indinavir may be increased; monitor patients closely for indinavir-related adverse events, including gastrointestinal and renal symptoms.
Elvitegravir; Cobicistat; Emtricitabine; Tenofovir Alafenamide: (Contraindicated) Concomitant use of indinavir with regimens containing cobicistat and atazanavir is contraindicated. Cobicistat is an inhibitor of CYP3A4, while both atazanavir and indinavir are CYP3A4 substates. In addition, both atazanavir and indinavir are associated with indirect (unconjugated) hyperbilirubinemia. Taking these drugs together may increase the risk for hepatic adverse events, such as hyperbilirubinemia. (Major) Avoid coadministration of indinavir with elvitegravir. No data are available regarding use of these drugs concurrently.
Elvitegravir; Cobicistat; Emtricitabine; Tenofovir Disoproxil Fumarate: (Contraindicated) Concomitant use of indinavir with regimens containing cobicistat and atazanavir is contraindicated. Cobicistat is an inhibitor of CYP3A4, while both atazanavir and indinavir are CYP3A4 substates. In addition, both atazanavir and indinavir are associated with indirect (unconjugated) hyperbilirubinemia. Taking these drugs together may increase the risk for hepatic adverse events, such as hyperbilirubinemia. (Major) Avoid coadministration of indinavir with elvitegravir. No data are available regarding use of these drugs concurrently.
Empagliflozin: (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. A possible mechanism is impairment of beta-cell function. Onset averaged approximately 63 days after initiating protease inhibitor therapy, but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients on antidiabetic therapy should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated.
Empagliflozin; Linagliptin: (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. A possible mechanism is impairment of beta-cell function. Onset averaged approximately 63 days after initiating protease inhibitor therapy, but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients on antidiabetic therapy should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated. (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. A possible mechanism is impairment of beta-cell function. Onset averaged approximately 63 days after initiating protease inhibitor therapy, but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients on antidiabetic therapy, such as linagliptin, should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated.
Empagliflozin; Linagliptin; Metformin: (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. A possible mechanism is impairment of beta-cell function. Onset averaged approximately 63 days after initiating protease inhibitor therapy, but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients on antidiabetic therapy should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated. (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. A possible mechanism is impairment of beta-cell function. Onset averaged approximately 63 days after initiating protease inhibitor therapy, but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients on antidiabetic therapy, such as linagliptin, should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated. (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. Another possible mechanism is impairment of beta-cell function. Onset averaged approximately 63 days after initiating protease inhibitor therapy, but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients taking antidiabetic therapy should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated.
Empagliflozin; Metformin: (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. A possible mechanism is impairment of beta-cell function. Onset averaged approximately 63 days after initiating protease inhibitor therapy, but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients on antidiabetic therapy should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated. (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease in hibitors. Another possible mechanism is impairment of beta-cell function. Onset averaged approximately 63 days after initiating protease inhibitor therapy, but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients taking antidiabetic therapy should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated.
Emtricitabine; Rilpivirine; Tenofovir alafenamide: (Moderate) Close clinical monitoring is advised when administering indinavir with rilpivirine due to an increased potential for rilpivirine-related adverse events. Predictions about the interaction can be made based on metabolic pathways. Indinavir is an inhibitor of the hepatic isoenzyme CYP3A4; rilpivirine is metabolized by this isoenzyme. Coadministration may result in increased rilpivirine plasma concentrations.
Emtricitabine; Rilpivirine; Tenofovir Disoproxil Fumarate: (Moderate) Close clinical monitoring is advised when administering indinavir with rilpivirine due to an increased potential for rilpivirine-related adverse events. Predictions about the interaction can be made based on metabolic pathways. Indinavir is an inhibitor of the hepatic isoenzyme CYP3A4; rilpivirine is metabolized by this isoenzyme. Coadministration may result in increased rilpivirine plasma concentrations.
Encorafenib: (Major) Avoid coadministration of encorafenib and indinavir due to increased encorafenib exposure. Increased or decreased indinavir exposure is also possible. If concurrent use cannot be avoided, reduce the encorafenib dose to one-third of the dose used prior to the addition of indinavir. If indinavir is discontinued, the original encorafenib dose may be resumed after 3 to 5 elimination half-lives of indinavir. Encorafenib is a CYP3A4 substrate; in vitro studies with encorafenib showed time-dependent inhibition of CYP3A4 and induction of CYP3A4. Indinavir is a strong CYP3A4 inhibitor and sensitive CYP3A4 substrate. Coadministration of a strong CYP3A4 inhibitor with a single 50 mg dose of encorafenib (0.1 times the recommended dose) increased the encorafenib AUC and Cmax by 3-fold and 68%, respectively.
Entrectinib: (Major) Avoid coadministration of entrectinib with indinavir due to increased entrectinib exposure resulting in increased treatment-related adverse effects. If coadministration cannot be avoided in adults and pediatric patients 12 years and older with BSA greater than 1.5 m2, reduce the entrectinib dose to 100 mg PO once daily. If indinavir is discontinued, resume the original entrectinib dose after 3 to 5 elimination half-lives of indinavir. Entrectinib is a CYP3A4 substrate; indinavir is a strong CYP3A4 inhibitor. Coadministration of a strong CYP3A4 inhibitor increased the AUC of entrectinib by 6-fold in a drug interaction study.
Enzalutamide: (Major) Coadministration of indinavir with enzalutamide is not recommended as there is a potential for decreased indinavir concentrations. Decreased antiretroviral concentrations may lead to a reduction of antiretroviral efficacy and the potential development of viral resistance. Indinavir is metabolized by CYP3A4 and enzalutamide is a strong CYP3A4 inducer.
Eplerenone: (Contraindicated) Coadministration of indinavir and eplerenone is contraindicated. Indinavir potently inhibits the hepatic CYP3A4 isoenzyme and can increase the serum concentrations of eplerenone. Increased eplerenone concentrations may lead to a risk of developing hyperkalemia and hypotension.
Erdafitinib: (Major) Avoid coadministration of erdafitinib and indinavir due to the risk of increased plasma concentrations of erdafitinib. If concomitant use is unavoidable, closely monitor for erdafitinib-related adverse reactions and consider dose modifications as clinically appropriate. If indinavir is discontinued, the dose of erdafitinib may be increased in the absence of drug-related toxicity. Erdafitinib is a CYP3A4 substrate and indinavir is a strong CYP3A4 inhibitor. The mean ratios for the Cmax and AUC of erdafitinib were 105% and 134%, respectively, when coadministered with another strong CYP3A4 inhibitor.
Ergoloid Mesylates: (Contraindicated) Coadministration of ergot alkaloids with potent inhibitors of CYP3A4, like anti-retroviral protease inhibitors is considered contraindicated due to the risk of acute ergot toxicity (e.g., vasospasm leading to cerebral ischemia, peripheral ischemia and/or other serious effects). Several case reports have established the clinical significance of this interaction in the medical literature. In some cases, fatal interactions have occurred.
Ergot alkaloids: (Contraindicated) Coadministration of ergot alkaloids with potent inhibitors of CYP3A4, like anti-retroviral protease inhibitors is considered contraindicated due to the risk of acute ergot toxicity (e.g., vasospasm leading to cerebral ischemia, peripheral ischemia and/or other serious effects). Several case reports have established the clinical significance of this interaction in the medical literature. In some cases, fatal interactions have occurred.
Ergotamine: (Contraindicated) Coadministration of ergot alkaloids with potent inhibitors of CYP3A4, like anti-retroviral protease inhibitors is considered contraindicated due to the risk of acute ergot toxicity (e.g., vasospasm leading to cerebral ischemia, peripheral ischemia and/or other serious effects). Several case reports have established the clinical significance of this interaction in the medical literature. In some cases, fatal interactions have occurred.
Ergotamine; Caffeine: (Contraindicated) Coadministration of ergot alkaloids with potent inhibitors of CYP3A4, like anti-retroviral protease inhibitors is considered contraindicated due to the risk of acute ergot toxicity (e.g., vasospasm leading to cerebral ischemia, peripheral ischemia and/or other serious effects). Several case reports have established the clinical significance of this interaction in the medical literature. In some cases, fatal interactions have occurred.
Erlotinib: (Major) Avoid coadministration of erlotinib with indinavir if possible due to the increased risk of erlotinib-related adverse reactions. If concomitant use is unavoidable and severe reactions occur, reduce the dose of erlotinib by 50 mg decrements. Erlotinib is a CYP3A4 substrate and indinavir is a strong CYP3A4 inhibitor. Coadministration with another strong CYP3A4 inhibitor increased erlotinib exposure by 67%.
Ertugliflozin; Metformin: (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. Another possible mechanism is impairment of beta-cell function. Onset averaged approximately 63 days after initiating protease inhibitor therapy, but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients taking antidiabetic therapy should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated.
Ertugliflozin; Sitagliptin: (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. Another possible mechanism is impairment of beta-cell function. Onset averaged approximately 63 days after initiating protease inhibitor therapy but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients taking antidiabetic agents should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated.
Estazolam: (Moderate) In vitro studies with human liver microsomes indicate that the biotransformation of estazolam to the major circulating metabolite 4-hydroxy-estazolam is mediated by CYP3A. In theory, CYP3A4 inhibitors, such as protease inhibitors, may reduce the metabolism of estazolam and increase the potential for benzodiazepine toxicity (i.e., prolonged sedation and respiratory depression).
Esterified Estrogens: (Moderate) Indinavir has been shown to decrease the metabolism of ethinyl estradiol; a similar interaction may occur with other estrogens used for hormone replacement therapy. Patients should be instructed to report any estrogen- related adverse events.
Esterified Estrogens; Methyltestosterone: (Moderate) Indinavir has been shown to decrease the metabolism of ethinyl estradiol; a similar interaction may occur with other estrogens used for hormone replacement therapy. Patients should be instructed to report any estrogen- related adverse events.
Estradiol: (Moderate) Indinavir has been shown to decrease the metabolism of ethinyl estradiol; a similar interaction may occur with other estrogens used for hormone replacement therapy. Patients should be instructed to report any estrogen- related adverse events.
Estradiol; Levonorgestrel: (Moderate) Indinavir decreases the metabolism of oral contraceptives and non-oral combination contraceptives; the AUC for ethinyl estradiol and norethindrone increased by 24+/-17% and 26+/-14%, respectively, when coadministered with indinavir. Women receiving hormonal contraceptives and anti-retroviral protease inhibitors (PIs), such as indinavir, should be instructed to report any breakthrough bleeding or other adverse effects to their prescribers. Because hormonal contraceptives do not protect against the transmission of HIV/AIDS and other sexually transmitted diseases, women who receive hormonal contraceptives with PIs should use an additional barrier method of contraception such as condoms. (Moderate) Indinavir has been shown to decrease the metabolism of ethinyl estradiol; a similar interaction may occur with other estrogens used for hormone replacement therapy. Patients should be instructed to report any estrogen- related adverse events.
Estradiol; Norethindrone: (Moderate) Indinavir has been shown to decrease the metabolism of ethinyl estradiol; a similar interaction may occur with other estrogens used for hormone replacement therapy. Patients should be instructed to report any estrogen- related adverse events. (Moderate) Many anti-retroviral protease inhibitors may interact with hormonal agents like norethindrone, due to their actions on CYP metabolism, particularly CYP3A4. Data on the effects that protease inhibitors have on the serum concentrations of norethindrone are complex and are based mostly off of data with norethindrone-containing contraceptives. The AUC for norethindrone increased by 26+/-14%, respectively, when a combined oral contraceptive was coadministered with indinavir. Women receiving hormonal contraceptives and anti-retroviral protease inhibitors (PIs), such as indinavir, should be instructed to report any breakthrough bleeding or other adverse effects to their prescribers. Because hormonal contraceptives do not protect against the transmission of HIV/AIDS and other sexually transmitted diseases, women who receive hormonal contraceptives with indinavir should use an additional barrier method of contraception such as condoms.
Estradiol; Norgestimate: (Moderate) Indinavir has been shown to decrease the metabolism of ethinyl estradiol; a similar interaction may occur with other estrogens used for hormone replacement therapy. Patients should be instructed to report any estrogen- related adverse events.
Estradiol; Progesterone: (Moderate) Indinavir decreases the metabolism of oral contraceptives and non-oral combination contraceptives; the AUC for ethinyl estradiol and norethindrone increased by 24+/-17% and 26+/-14%, respectively, when coadministered with indinavir. Women receiving hormonal contraceptives and anti-retroviral protease inhibitors (PIs), such as indinavir, should be instructed to report any breakthrough bleeding or other adverse effects to their prescribers. Because hormonal contraceptives do not protect against the transmission of HIV/AIDS and other sexually transmitted diseases, women who receive hormonal contraceptives with PIs should use an additional barrier method of contraception such as condoms. This interaction does not apply to vaginal preparations of progesterone (e.g., Crinone, Endometrin). (Moderate) Indinavir has been shown to decrease the metabolism of ethinyl estradiol; a similar interaction may occur with other estrogens used for hormone replacement therapy. Patients should be instructed to report any estrogen- related adverse events.
Estropipate: (Moderate) Indinavir has been shown to decrease the metabolism of ethinyl estradiol; a similar interaction may occur with other estrogens used for hormone replacement therapy. Patients should be instructed to report any estrogen- related adverse events.
Eszopiclone: (Major) The adult dose of eszopiclone should not exceed 2 mg/day during co-administration of potent CYP3A4 inhibitors, such as anti-retroviral protease inhibitors. CYP3A4 is a primary metabolic pathway for eszopiclone, and increased systemic exposure to eszopiclone increases the risk of next-day psychomotor or memory impairment, which may decrease the ability to perform tasks requiring full mental alertness such as driving.
Ethinyl Estradiol; Norelgestromin: (Major) Indinavir decreases the metabolism of oral contraceptives and non-oral combination contraceptives; the AUC for ethinyl estradiol and norethindrone increased by 24+/-17% and 26+/-14%, respectively, when coadministered with indinavir. Women receiving hormonal contraceptives and anti-retroviral protease inhibitors (PIs), such as indinavir, should be instructed to report any breakthrough bleeding or other adverse effects to their prescribers. Because hormonal contraceptives do not protect against the transmission of HIV/AIDS and other sexually transmitted diseases, women who receive hormonal contraceptives with PIs should use an additional barrier method of contraception such as condoms.
Ethinyl Estradiol; Norethindrone Acetate: (Major) Indinavir decreases the metabolism of oral contraceptives and non-oral combination contraceptives; the AUC for ethinyl estradiol and norethindrone increased by 24+/-17% and 26+/-14%, respectively, when coadministered with indinavir. Women receiving hormonal contraceptives and anti-retroviral protease inhibitors (PIs), such as indinavir, should be instructed to report any breakthrough bleeding or other adverse effects to their prescribers. Because hormonal contraceptives do not protect against the transmission of HIV/AIDS and other sexually transmitted diseases, women who receive hormonal contraceptives with PIs should use an additional barrier method of contraception such as condoms. (Moderate) Many anti-retroviral protease inhibitors may interact with hormonal agents like norethindrone, due to their actions on CYP metabolism, particularly CYP3A4. Data on the effects that protease inhibitors have on the serum concentrations of norethindrone are complex and are based mostly off of data with norethindrone-containing contraceptives. The AUC for norethindrone increased by 26+/-14%, respectively, when a combined oral contraceptive was coadministered with indinavir. Women receiving hormonal contraceptives and anti-retroviral protease inhibitors (PIs), such as indinavir, should be instructed to report any breakthrough bleeding or other adverse effects to their prescribers. Because hormonal contraceptives do not protect against the transmission of HIV/AIDS and other sexually transmitted diseases, women who receive hormonal contraceptives with indinavir should use an additional barrier method of contraception such as condoms.
Ethinyl Estradiol; Norgestrel: (Major) Indinavir decreases the metabolism of oral contraceptives and non-oral combination contraceptives; the AUC for ethinyl estradiol and norethindrone increased by 24+/-17% and 26+/-14%, respectively, when coadministered with indinavir. Women receiving hormonal contraceptives and anti-retroviral protease inhibitors (PIs), such as indinavir, should be instructed to report any breakthrough bleeding or other adverse effects to their prescribers. Because hormonal contraceptives do not protect against the transmission of HIV/AIDS and other sexually transmitted diseases, women who receive hormonal contraceptives with PIs should use an additional barrier method of contraception such as condoms. (Moderate) Indinavir decreases the metabolism of oral contraceptives and non-oral combination contraceptives; the AUC for ethinyl estradiol and norethindrone increased by 24+/-17% and 26+/-14%, respectively, when coadministered with indinavir. Women receiving hormonal contraceptives and anti-retroviral protease inhibitors (PIs), such as indinavir, should be instructed to report any breakthrough bleeding or other adverse effects to their prescribers. Because hormonal contraceptives do not protect against the transmission of HIV/AIDS and other sexually transmitted diseases, women who receive hormonal contraceptives with PIs should use an additional barrier method of contraception such as condoms.
Ethosuximide: (Moderate) Indinavir may inhibit the metabolism of ethosuximide and may necessitate up to a 50% dose reduction of ethosuximide.
Ethotoin: (Major) Hydantoins like phenytoin, ethotoin, fosphenytoin may increase the metabolism of indinavir and lead to decreased efficacy. In addition, indinavir may inhibit the CYP metabolism of hydantoins, resulting in increased hydantoin concentrations.
Ethynodiol Diacetate; Ethinyl Estradiol: (Major) Indinavir decreases the metabolism of oral contraceptives and non-oral combination contraceptives; the AUC for ethinyl estradiol and norethindrone increased by 24+/-17% and 26+/-14%, respectively, when coadministered with indinavir. Women receiving hormonal contraceptives and anti-retroviral protease inhibitors (PIs), such as indinavir, should be instructed to report any breakthrough bleeding or other adverse effects to their prescribers. Because hormonal contraceptives do not protect against the transmission of HIV/AIDS and other sexually transmitted diseases, women who receive hormonal contraceptives with PIs should use an additional barrier method of contraception such as condoms.
Etonogestrel: (Moderate) Indinavir decreases the metabolism of oral contraceptives and non-oral combination contraceptives; the AUC for ethinyl estradiol and norethindrone increased by 24+/-17% and 26+/-14%, respectively, when coadministered with indinavir. It is unknown whether this applies to etonogestrel. Women receiving hormonal contraceptives and anti-retroviral protease inhibitors (PIs), such as indinavir, should be instructed to report any breakthrough bleeding or other adverse effects to their prescribers. Because hormonal contraceptives do not protect against the transmission of HIV/AIDS and other sexually transmitted diseases, women who receive hormonal contraceptives with PIs should use an additional barrier method of contraception such as condoms.
Etonogestrel; Ethinyl Estradiol: (Major) Indinavir decreases the metabolism of oral contraceptives and non-oral combination contraceptives; the AUC for ethinyl estradiol and norethindrone increased by 24+/-17% and 26+/-14%, respectively, when coadministered with indinavir. Women receiving hormonal contraceptives and anti-retroviral protease inhibitors (PIs), such as indinavir, should be instructed to report any breakthrough bleeding or other adverse effects to their prescribers. Because hormonal contraceptives do not protect against the transmission of HIV/AIDS and other sexually transmitted diseases, women who receive hormonal contraceptives with PIs should use an additional barrier method of contraception such as condoms. (Moderate) Indinavir decreases the metabolism of oral contraceptives and non-oral combination contraceptives; the AUC for ethinyl estradiol and norethindrone increased by 24+/-17% and 26+/-14%, respectively, when coadministered with indinavir. It is unknown whether this applies to etonogestrel. Women receiving hormonal contraceptives and anti-retroviral protease inhibitors (PIs), such as indinavir, should be instructed to report any breakthrough bleeding or other adverse effects to their prescribers. Because hormonal contraceptives do not protect against the transmission of HIV/AIDS and other sexually transmitted diseases, women who receive hormonal contraceptives with PIs should use an additional barrier method of contraception such as condoms.
Etravirine: (Moderate) Etravirine is a CYP3A4 inducer/substrate and a P-glycoprotein (PGP) inhibitor and indinavir is a CYP3A4 inhibitor/substrate and a PGP substrate. Caution is warranted if these drugs are coadministered.
Everolimus: (Major) Avoid coadministration of everolimus with indinavir due to the risk of increased everolimus-related adverse reactions. If concomitant use is unavoidable in patients receiving everolimus for either kidney or liver transplant, closely monitor everolimus whole blood trough concentrations. Everolimus is a sensitive CYP3A4 substrate and P-glycoprotein (P-gp) substrate. Indinavir is a strong CYP3A4 inhibitor. Coadministration with a strong CYP3A4/P-gp inhibitor increased the AUC of everolimus by 15-fold.
Ezetimibe; Simvastatin: (Contraindicated) The coadministration of anti-retroviral protease inhibitors with simvastatin is contraindicated. Taking these drugs together may significantly increase the serum concentration of simvastatin; thereby increasing the risk of myopathy and rhabdomyolysis. One report has demonstrated that ritonavir plus saquinavir therapy markedly increases the AUC for simvastatin by 3059%. Simvastatin is a substrate for CYP3A4 and the drug transporter organic anion transporting polypeptide (OATP1B1); protease inhibitors are CYP3A4 and OATP inhibitors.
Fedratinib: (Major) Avoid coadministration of fedratinib with indinavir as concurrent use may increase fedratinib exposure. If concurrent use cannot be avoided, reduce the dose of fedratinib to 200 mg PO once daily. If indinavir is discontinued, increase the fedratinib dose as follows: 300 mg PO once daily for 2 weeks and then 400 mg PO once daily thereafter as tolerated. Fedratinib is a CYP3A4 substrate; indinavir is a strong CYP3A4 inhibitor. Coadministration of another strong CYP3A4 inhibitor increased fedratinib exposure by 3-fold.
Felodipine: (Moderate) Concurrent use of felodipine and protease inhibitors should be approached with caution and conservative dosing of felodipine due to the potential for significant increases in felodipine exposure. Monitor for evidence of increased felodipine effects including decreased blood pressure and increased heart rate. Felodipine is a sensitive CYP3A substrate and protease inhibitors are moderate to strong CYP3A inhibitors. Concurrent use of a strong CYP3A inhibitor increased felodipine AUC and half-life by approximately 8-fold and 2-fold, respectively. Concurrent use of a moderate CYP3A inhibitor increased felodipine AUC and half-life by approximately 2.5-fold and 2-fold, respectively.
Fentanyl: (Moderate) Consider a reduced dose of fentanyl with frequent monitoring for respiratory depression and sedation if concurrent use of indinavir is necessary. If indinavir is discontinued, consider increasing the fentanyl dose until stable drug effects are achieved and monitor for evidence of opioid withdrawal. Fentanyl is a CYP3A4 substrate, and coadministration with CYP3A4 inhibitors like indinavir can increase fentanyl exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of fentanyl. If indinavir is discontinued, fentanyl plasma concentrations will decrease resulting in reduced efficacy of the opioid and potential withdrawal syndrome in a patient who has developed physical dependence to fentanyl.
Fesoterodine: (Major) Limit the dose of fesoterodine to 4 mg once daily in adults and pediatric patients weighing more than 35 kg if coadministered with anti-retroviral protease inhibitors. Avoid use of fesoterodine and protease inhibitors in pediatric patients weighing 25 to 35 kg. Concurrent use may increase fesoterodine exposure. Fesoterodine is a CYP3A4 substrate and protease inhibitors are strong CYP3A4 inhibitors. Coadministration with another strong CYP3A4 inhibitor led to approximately a doubling of the overall exposure of 5-hydroxymethyl tolterodine (5-HMT), the active metabolite of fesoterodine.
Finasteride; Tadalafil: (Major) For the treatment of erectile dysfunction, do not exceed 10 mg of tadalafil within 72 hours of indinavir for the 'as needed' dose or 2.5 mg daily for the 'once-daily' dose. Avoid the use of tadalafil for pulmonary hypertension during the initiation of indinavir therapy. Stop tadalafil at least 24 hours prior to starting indinavir. After at least 1 week of indinavir therapy, resume tadalafil at 20 mg once daily. Increase to 40 mg once daily based on tolerability. Tadalafil is metabolized by CYP3A4, and indinavir is a potent inhibitor of CYP3A4. Substantially increased tadalafil plasma concentrations may result in increased adverse events including hypotension, syncope, visual changes, and prolonged erection. Although the manufacturer of tadalafil provides recommended dosing for coadministration with ritonavir only, the FDA recommends the same dosage adjustment for the coadministration of tadalafil with all protease inhibitors.
Finerenone: (Contraindicated) Concomitant use of finerenone and indinavir is contraindicated. Concomitant use may increase finerenone exposure and the risk for finerenone-related adverse reactions. Finerenone is a CYP3A substrate and indinavir is a strong CYP3A inhibitor. Coadministration with another strong CYP3A inhibitor increased overall exposure to finerenone by more than 400%.
Flibanserin: (Contraindicated) The concomitant use of flibanserin and strong CYP3A4 inhibitors, such as indinavir, is contraindicated. Strong CYP3A4 inhibitors can increase flibanserin concentrations, which can cause severe hypotension and syncope. If initiating flibanserin following use of a strong CYP3A4 inhibitor, start flibanserin at least 2 weeks after the last dose of the CYP3A4 inhibitor. If initiating a strong CYP3A4 inhibitor following flibanserin use, start the strong CYP3A4 inhibitor at least 2 days after the last dose of flibanserin.
Fluconazole: (Moderate) Due to effects on cytochrome P450 3A4, the combination of indinavir and fluconazole may result in changes in concentrations of one or both of the agents.
Flurazepam: (Moderate) Monitor for an increase in flurazepam-related adverse reactions, including sedation and respiratory depression, if coadministration with protease inhibitors is necessary. Concurrent use may increase flurazepam exposure. Flurazepam is a CYP3A substrate and protease inhibitors are moderate to strong CYP3A inhibitors.
Fluticasone: (Major) Coadministration of inhaled fluticasone propionate and indinavir is not recommended; use caution with inhaled fluticasone furoate. Increased systemic corticosteroid effects, including Cushing's syndrome and adrenal suppression, may occur. Fluticasone is a CYP3A4 substrate; indinavir is a strong CYP3A4 inhibitor. In drug interaction studies, coadministration with strong inhibitors increased plasma fluticasone exposure resulting in 45% to 86% decreases in serum cortisol AUC. A strong inhibitor increased fluticasone furoate exposure by 1.33-fold with a 27% reduction in weighted mean serum cortisol; this change does not necessitate dose adjustment of fluticasone furoate.
Fluticasone; Salmeterol: (Major) Avoid concomitant use of salmeterol with indinavir. Concomitant use increases salmeterol exposure and may increase the incidence and severity of salmeterol-related adverse effects. Signs and symptoms of excessive beta-adrenergic stimulation commonly include tachyarrhythmias, hypertension, and tremor. Salmeterol is a CYP3A substrate and indinavir is a strong CYP3A inhibitor. Coadministration with another strong CYP3A inhibitor increased salmeterol overall exposure 16-fold mainly due to increased bioavailability of the swallowed portion of the dose. (Major) Coadministration of inhaled fluticasone propionate and indinavir is not recommended; use caution with inhaled fluticasone furoate. Increased systemic corticosteroid effects, including Cushing's syndrome and adrenal suppression, may occur. Fluticasone is a CYP3A4 substrate; indinavir is a strong CYP3A4 inhibitor. In drug interaction studies, coadministration with strong inhibitors increased plasma fluticasone exposure resulting in 45% to 86% decreases in serum cortisol AUC. A strong inhibitor increased fluticasone furoate exposure by 1.33-fold with a 27% reduction in weighted mean serum cortisol; this change does not necessitate dose adjustment of fluticasone furoate.
Fluticasone; Umeclidinium; Vilanterol: (Major) Coadministration of inhaled fluticasone propionate and indinavir is not recommended; use caution with inhaled fluticasone furoate. Increased systemic corticosteroid effects, including Cushing's syndrome and adrenal suppression, may occur. Fluticasone is a CYP3A4 substrate; indinavir is a strong CYP3A4 inhibitor. In drug interaction studies, coadministration with strong inhibitors increased plasma fluticasone exposure resulting in 45% to 86% decreases in serum cortisol AUC. A strong inhibitor increased fluticasone furoate exposure by 1.33-fold with a 27% reduction in weighted mean serum cortisol; this change does not necessitate dose adjustment of fluticasone furoate.
Fluticasone; Vilanterol: (Major) Coadministration of inhaled fluticasone propionate and indinavir is not recommended; use caution with inhaled fluticasone furoate. Increased systemic corticosteroid effects, including Cushing's syndrome and adrenal suppression, may occur. Fluticasone is a CYP3A4 substrate; indinavir is a strong CYP3A4 inhibitor. In drug interaction studies, coadministration with strong inhibitors increased plasma fluticasone exposure resulting in 45% to 86% decreases in serum cortisol AUC. A strong inhibitor increased fluticasone furoate exposure by 1.33-fold with a 27% reduction in weighted mean serum cortisol; this change does not necessitate dose adjustment of fluticasone furoate.
Fluvastatin: (Moderate) Concurrent use of indinavir with fluvastatin should be done cautiously. Concomitant use may increase the risk of myopathy and rhabdomyolysis. Indinavir inhibits CYP3A4 metabolism. Because fluvastatin does not rely exclusively on CYP3A4 for its metabolism, indinavir may not interact to the same extent as expected with other HMG-CoAA reductase inhibitors.
Food: (Major) Administration with food high in calories, fat, and protein results in a decrease in the AUC and Cmax of indinavir. (Major) Advise patients to avoid cannabis use during protease inhibitor treatment. Concomitant use may alter the exposure of some cannabinoids and increase the risk for adverse reactions. The cannabinoids delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD) are CYP3A substrates and protease inhibitors are strong CYP3A inhibitors. Concomitant use of a cannabinoid product containing THC and CBD at an approximate 1:1 ratio with another strong CYP3A inhibitor increased THC, 11-OH-THC, and CBD peak exposures by 1.3-, 3-, and 1.9-fold respectively.
Formoterol; Mometasone: (Major) As mometasone is a CYP3A4 substrate, concomitant use with indinavir, a potent inhibitor of CYP3A4, may increase plasma levels and related adverse effects of mometasone; caution is advised.
Fosphenytoin: (Major) Hydantoins like phenytoin, ethotoin, fosphenytoin may increase the metabolism of indinavir and lead to decreased efficacy. In addition, indinavir may inhibit the CYP metabolism of hydantoins, resulting in increased hydantoin concentrations.
Fostamatinib: (Moderate) Monitor for fostamatinib toxicities that may require fostamatinib dose reduction (i.e., elevated hepatic enzymes, neutropenia, high blood pressure, severe diarrhea) if given concurrently with a strong CYP3A4 inhibitor. Concomitant use of fostamatinib with a strong CYP3A4 inhibitor increases exposure to the major active metabolite, R406, which may increase the risk of adverse reactions. R406 is extensively metabolized by CYP3A4; indinavir is a strong CYP3A4 inhibitor. Coadministration of fostamatinib with another strong CYP3A4 inhibitor increased R406 AUC by 102% and Cmax by 37%.
Gefitinib: (Moderate) Monitor for an increase in gefitinib-related adverse reactions if coadministration with indinavir is necessary. Gefitinib is a CYP3A4 substrate and indinavir is a strong CYP3A4 inhibitor. Coadministration with another strong CYP3A4 inhibitor increased gefitinib exposure by 80%.
Gilteritinib: (Major) Consider an alternative to indinavir during treatment with gilteritinib. Concurrent use may increase gilteritinib exposure resulting in treatment-related adverse events. If coadministration is required, frequently monitor for gilteritinib adverse reactions. Interrupt therapy and reduce the gilteritinib dose if serious or life-threatening toxicity occurs. Gilteritinib is a CYP3A4 substrate; indinavir is a strong CYP3A4 inhibitor. Coadministration of a strong CYP3A4 inhibitor increased the gilteritinib AUC by 120% in a drug interaction study.
Glasdegib: (Major) Consider an alternative to indinavir during treatment with glasdegib. Concurrent use may increase glasdegib exposure resulting in treatment-related adverse events including QT prolongation. If coadministration cannot be avoided, monitor for increased adverse events; more frequent ECG monitoring is recommended. Glasdegib is a CYP3A4 substrate; indinavir is a strong CYP3A4 inhibitor. Coadministration of a strong CYP3A4 inhibitor increased the glasdegib AUC by 2.4-fold in a drug interaction study.
Glecaprevir; Pibrentasvir: (Moderate) Caution is advised with the coadministration of glecaprevir and indinavir as coadministration may increase serum concentrations of indinavir and increase the risk of adverse effects. Indinavir is a substrate of P-glycoprotein (P-gp); glecaprevir is a P-gp inhibitor. (Moderate) Caution is advised with the coadministration of pibrentasvir and indinavir as coadministration may increase serum concentrations of indinavir and increase the risk of adverse effects. Indinavir is a substrate of P-glycoprotein (P-gp); pibrentasvir is an inhibitor of P-gp.
Glipizide; Metformin: (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. Another possible mechanism is impairment of beta-cell function. Onset averaged approximately 63 days after initiating protease inhibitor therapy, but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients taking antidiabetic therapy should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated.
Glyburide; Metformin: (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. Another possible mechanism is impairment of beta-cell function. Onset averaged approximately 63 days after initiating protease inhibitor therapy, but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients taking antidiabetic therapy should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated.
Grapefruit juice: (Moderate) Concurrent grapefruit juice may decrease indinavir levels by 26 percent. Individuals should not drastically alter their intake of grapefruit juice or should avoid concurrent use unless advised differently by their healthcare professional.
Guaifenesin; Hydrocodone: (Moderate) Consider a reduced dose of hydrocodone with frequent monitoring for respiratory depression and sedation if concurrent use of indinavir is necessary. It is recommended to avoid this combination when hydrocodone is being used for cough. Hydrocodone is a CYP2D6 and CYP3A4 substrate, and coadministration with CYP2D6 and CYP3A4 inhibitors like indinavir can increase hydrocodone exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of hydrocodone. These effects could be more pronounced with a combined CYP2D6 and CYP3A4 inhibitor. If indinavir is discontinued, hydrocodone plasma concentrations will decrease resulting in reduced efficacy of the opioid and potential withdrawal syndrome in a patient who has developed physical dependence to hydrocodone.
Guanfacine: (Major) Indinavir may significantly increase guanfacine plasma concentrations. FDA-approved labeling for extended-release (ER) guanfacine recommends that, if these agents are taken together, the guanfacine dosage should be decreased to half of the recommended dose. Specific recommendations for immediate-release (IR) guanfacine are not available. Monitor patients closely for alpha-adrenergic effects including hypotension, drowsiness, lethargy, and bradycardia. If indinavir is discontinued, the guanfacine ER dosage should be increased back to the recommended dose. Guanfacine is primarily metabolized by CYP3A4, and indinavir is a strong CYP3A4 inhibitor.
Haloperidol: (Moderate) Indinavir is a substrate and inhibitor of CYP3A4, one of the isoenzymes responsible for the metabolism of haloperidol. Mild to moderate increases in haloperidol plasma concentrations have been reported during concurrent use of haloperidol and substrates or inhibitors of CYP3A4. Until more data are available, it is advisable to closely monitor for adverse events when these medications are co-administered.
Homatropine; Hydrocodone: (Moderate) Consider a reduced dose of hydrocodone with frequent monitoring for respiratory depression and sedation if concurrent use of indinavir is necessary. It is recommended to avoid this combination when hydrocodone is being used for cough. Hydrocodone is a CYP2D6 and CYP3A4 substrate, and coadministration with CYP2D6 and CYP3A4 inhibitors like indinavir can increase hydrocodone exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of hydrocodone. These effects could be more pronounced with a combined CYP2D6 and CYP3A4 inhibitor. If indinavir is discontinued, hydrocodone plasma concentrations will decrease resulting in reduced efficacy of the opioid and potential withdrawal syndrome in a patient who has developed physical dependence to hydrocodone.
Hydantoins: (Major) Hydantoins like phenytoin, ethotoin, fosphenytoin may increase the metabolism of indinavir and lead to decreased efficacy. In addition, indinavir may inhibit the CYP metabolism of hydantoins, resulting in increased hydantoin concentrations.
Hydrocodone: (Moderate) Consider a reduced dose of hydrocodone with frequent monitoring for respiratory depression and sedation if concurrent use of indinavir is necessary. It is recommended to avoid this combination when hydrocodone is being used for cough. Hydrocodone is a CYP2D6 and CYP3A4 substrate, and coadministration with CYP2D6 and CYP3A4 inhibitors like indinavir can increase hydrocodone exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of hydrocodone. These effects could be more pronounced with a combined CYP2D6 and CYP3A4 inhibitor. If indinavir is discontinued, hydrocodone plasma concentrations will decrease resulting in reduced efficacy of the opioid and potential withdrawal syndrome in a patient who has developed physical dependence to hydrocodone.
Hydrocodone; Ibuprofen: (Moderate) Consider a reduced dose of hydrocodone with frequent monitoring for respiratory depression and sedation if concurrent use of indinavir is necessary. It is recommended to avoid this combination when hydrocodone is being used for cough. Hydrocodone is a CYP2D6 and CYP3A4 substrate, and coadministration with CYP2D6 and CYP3A4 inhibitors like indinavir can increase hydrocodone exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of hydrocodone. These effects could be more pronounced with a combined CYP2D6 and CYP3A4 inhibitor. If indinavir is discontinued, hydrocodone plasma concentrations will decrease resulting in reduced efficacy of the opioid and potential withdrawal syndrome in a patient who has developed physical dependence to hydrocodone.
Hydrocodone; Pseudoephedrine: (Moderate) Consider a reduced dose of hydrocodone with frequent monitoring for respiratory depression and sedation if concurrent use of indinavir is necessary. It is recommended to avoid this combination when hydrocodone is being used for cough. Hydrocodone is a CYP2D6 and CYP3A4 substrate, and coadministration with CYP2D6 and CYP3A4 inhibitors like indinavir can increase hydrocodone exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of hydrocodone. These effects could be more pronounced with a combined CYP2D6 and CYP3A4 inhibitor. If indinavir is discontinued, hydrocodone plasma concentrations will decrease resulting in reduced efficacy of the opioid and potential withdrawal syndrome in a patient who has developed physical dependence to hydrocodone.
Ibrexafungerp: (Major) Decrease the ibrexafungerp dose to 150 mg PO every 12 hours for 1 day if administered concurrently with indinavir. Coadministration may result in increased ibrexafungerp exposure and toxicity. Ibrexafungerp is a CYP3A substrate and indinavir is a strong CYP3A inhibitor. Coadministration with another strong CYP3A inhibitor increased the AUC and Cmax of ibrexafungerp by 5.8-fold and 2.5-fold, respectively.
Ibrutinib: (Major) Avoid concomitant use of ibrutinib and indinavir; ibrutinib plasma concentrations may increase resulting in severe ibrutinib toxicity (e.g., hematologic toxicity, bleeding, infection). Ibrutinib is a CYP3A4 substrate and indinavir is a strong CYP3A4 inhibitor. Coadministration with other strong CYP3A4 inhibitors increased ibrutinib exposure by 5.7-fold to 24-fold.
Ibuprofen; Oxycodone: (Moderate) Consider a reduced dose of oxycodone with frequent monitoring for respiratory depression and sedation if concurrent use of indinavir is necessary. If indinavir is discontinued, consider increasing the oxycodone dose until stable drug effects are achieved and monitor for evidence of opioid withdrawal. Oxycodone is a CYP3A4 substrate, and coadministration with a strong CYP3A4 inhibitor like indinavir can increase oxycodone exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of oxycodone. If indinavir is discontinued, oxycodone plasma concentrations will decrease resulting in reduced efficacy of the opioid and potential withdrawal syndrome in a patient who has developed physical dependence to oxycodone.
Idelalisib: (Major) Coadministration of idelalisib with indinavir may increase the exposure of both drugs; use alternative agents if possible. Although specific recommendations are unavailable for use with idelalisib, a reduced dose of indinavir 600 mg PO every 8 hours is recommended when coadministered with other strong CYP3A inhibitors. If concomitant use of these drugs is required, monitor patients frequently for signs and symptoms of idelalisib- and indinavir-related adverse reactions. Idelalisib and atazanavir are both CYP3A4 substrates and strong CYP3A4 inhibitors. Exposure of another sensitive CYP3A substrate was increased 5.4-fold when coadministered with idelalisib. Additionally, coadministration with another strong CYP3A inhibitor increased idelalisib exposure by 1.8-fold.
Ifosfamide: (Moderate) Monitor for a decrease in the efficacy of ifosfamide if coadministration with indinavir is necessary. Ifosfamide is metabolized by CYP3A4 to its active alkylating metabolites. Indinavir is a strong CYP3A4 inhibitor. Coadministration may decrease plasma concentrations of these active metabolites, decreasing the effectiveness of ifosfamide treatment.
Iloperidone: (Major) Reduce the iloperidone dose by one-half if coadministered with indinavir. If indinavir is discontinued, increase the iloperidone dose to the previous level. Increased iloperidone exposure may occur with concurrent use. Iloperidone is a CYP3A4 substrate. Indinavir is a strong CYP3A4 inhibitor. Coadministration of another strong CYP3A4 inhibitor increased the AUC of iloperidone and its metabolites P88 and P95 by 57%, 55% and 35%, respectively.
Imatinib: (Major) Protease Inhibitors inhibit cytochrome P450 CYP3A4 and may decrease the metabolism of imatinib and increase imatinib concentrations leading to an increased incidence of adverse reactions. In addition, because imatinib inhibits CYP2C9, CYP2D6, and CYP3A4/5, the metabolism of protease inhibitors may be decreased by imatinib. Close monitoring of the antiviral and antineoplastic responses is recommended.
Incretin Mimetics: (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of protease inhibitors. Patients taking antidiabetic agents should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated.
Infigratinib: (Major) Avoid concomitant use of infigratinib and indinavir. Coadministration may increase infigratinib exposure, increasing the risk for adverse effects. Infigratinib is a CYP3A4 substrate and indinavir is a strong CYP3A4 inhibitor. Coadministration with another strong CYP3A4 inhibitor increased the AUC of infigratinib by 622%.
Insulins: (Moderate) Monitor patients receiving insulin closely for changes in diabetic control, specifically hyperglycemia, when anti-retroviral protease inhibitors are instituted. New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. Another possible mechanism is impairment of beta-cell function. Onset averaged approximately 63 days after initiating protease inhibitor therapy, but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment.
Interferons: (Moderate) The concomitant use of interferons and anti-retroviral protease inhibitors should be done with caution as both can cause hepatotoxicity. Closely monitor patients for treatment-associated toxicities, especially hepatic decompensation. Most protease inhibitors have been associated with episodes of liver toxicity. Cirrhotic chronic HCV infected patients co-infected with HIV receiving HAART and alpha interferons appear to be at increased risk for hepatic decompensation (e.g., Childs-Pugh score 6 or more) compared to patients not receiving HAART. The HCV-HIV International Panel recommends the management of hepatotoxicity should be based on the knowledge of the mechanisms involved for each drug. Furthermore, they state that there are lower rates of liver-related mortality in coinfected patients taking HAART, even in those with end-stage liver disease, compared with patients not receiving HAART.
Irinotecan Liposomal: (Major) Avoid administration of indinavir during treatment with irinotecan and for at least 1 week prior to starting therapy unless there are no therapeutic alternatives. Irinotecan is a CYP3A4 substrate and its active metabolite, SN-38, is a UGT1A1 substrate. Indinavir is a UGT1A1 inhibitor and a strong CYP3A4 inhibitor. Coadministration with another strong CYP3A4 and UGT1A1 inhibitor increased exposure to both irinotecan and SN-38.
Irinotecan: (Major) Avoid administration of indinavir during treatment with irinotecan and for at least 1 week prior to starting therapy unless there are no therapeutic alternatives. Irinotecan is a CYP3A4 substrate and its active metabolite, SN-38, is a UGT1A1 substrate. Indinavir is a UGT1A1 inhibitor and a strong CYP3A4 inhibitor. Coadministration with another strong CYP3A4 and UGT1A1 inhibitor increased exposure to both irinotecan and SN-38.
Isavuconazonium: (Contraindicated) Concomitant use of isavuconazonium with indinavir is contraindicated due to the risk for increased isavuconazole serum concentrations and serious adverse reactions, such as hepatic toxicity. Isavuconazole, the active moiety of isavuconazonium, is a sensitive substrate of hepatic isoenzyme CYP3A4; indinavir is a strong inhibitor of this enzyme. According to the manufacturer, coadministration of isavuconazole with strong CYP3A4 inhibitors is contraindicated. Isavuconazole serum concentrations were increased 5-fold when coadministered with ketoconazole, another strong CYP3A4 inhibitor. Elevated indinavir concentrations would also be expected with coadministration, as indinavir is a substrate and isavuconazole is an inhibitor of CYP3A4 and the drug transporter P-glycoprotein (P-gp).
Isoniazid, INH: (Minor) Indinavir and isoniazid, INH, administered concurrently for 1 week resulted in a 13% increase in isoniazid AUC. No effects on indinavir pharmacokinetics were reported. No dosage adjustments for either agent are recommended.
Isoniazid, INH; Pyrazinamide, PZA; Rifampin: (Contraindicated) Indinavir and rifampin should not be coadministered. Administration of indinavir and rifampin for one week resulted in a 89% decrease in the indinavir AUC. The administration of rifampin with indinavir, alone or in combination with ritonavir, could lead to subtherapeutic concentrations of indinavir. (Minor) Indinavir and isoniazid, INH, administered concurrently for 1 week resulted in a 13% increase in isoniazid AUC. No effects on indinavir pharmacokinetics were reported. No dosage adjustments for either agent are recommended.
Isoniazid, INH; Rifampin: (Contraindicated) Indinavir and rifampin should not be coadministered. Administration of indinavir and rifampin for one week resulted in a 89% decrease in the indinavir AUC. The administration of rifampin with indinavir, alone or in combination with ritonavir, could lead to subtherapeutic concentrations of indinavir. (Minor) Indinavir and isoniazid, INH, administered concurrently for 1 week resulted in a 13% increase in isoniazid AUC. No effects on indinavir pharmacokinetics were reported. No dosage adjustments for either agent are recommended.
Isradipine: (Moderate) Monitor for an increase in isradipine-related adverse reactions including hypotension if coadministration with protease inhibitors is necessary. Concomitant use may increase isradipine exposure. Isradipine is a CYP3A substrate and protease inhibitors are moderate to strong CYP3A inhibitors.
Istradefylline: (Major) Do not exceed 20 mg once daily of istradefylline if administered with indinavir as istradefylline exposure and adverse effects may increase. Indinavir is a strong CYP3A4 inhibitor. Istradefylline exposure was increased by 2.5-fold when administered with a strong inhibitor in a drug interaction study.
Itraconazole: (Major) Monitor for increased indinavir and itraconazole adverse reactions if coadministration is necessary. Dose reduction of indinavir to 600 mg every 8 hours is recommended when administering itraconazole 200 mg twice daily concurrently. An itraconazole dose reduction may also be necessary. Both itraconazole and indinavir are strong CYP3A4 inhibitors and substrates.
Ivabradine: (Contraindicated) Coadministration of ivabradine and indinavir is contraindicated. Ivabradine is primarily metabolized by CYP3A4; indinavir is a strong CYP3A4 inhibitor. Coadministration will increase the plasma concentrations of ivabradine. Increased ivabradine concentrations may result in bradycardia exacerbation and conduction disturbances.
Ivacaftor: (Major) If indinavir and ivacaftor are taken together, administer ivacaftor at the usual recommended dose but reduce the frequency to twice weekly. Coadministration is not recommended in patients younger than 6 months. Ivacaftor is a CYP3A substrate and indinavir is a strong CYP3A inhibitor. Coadministration with another strong CYP3A inhibitor increased ivacaftor exposure by 8.5-fold.
Ivosidenib: (Major) Avoid coadministration of ivosidenib with indinavir due to increased plasma concentrations of ivosidenib, which increases the risk of QT prolongation; indinavir exposure may also decrease. If concomitant use is unavoidable, reduce the dose of ivosidenib to 250 mg PO once daily. Monitor ECGs for QTc prolongation and monitor electrolytes, correcting any electrolyte abnormalities as clinically appropriate. Monitor for loss of efficacy of indinavir. If indinavir is discontinued, wait at least 5 half-lives of indinavir before increasing the dose of ivosidenib to the recommended dose of 500 mg PO once daily. Ivosidenib is a CYP3A4 substrate and inducer; indinavir is a strong CYP3A4 inhibitor and sensitive substrate. Coadministration with another strong CYP3A4 inhibitor increased ivosidenib single-dose AUC to 269% of control, with no change in Cmax.
Ixabepilone: (Major) Avoid concurrent use of ixabepilone and indinavir due to increased ixabepilone exposure, which may increase the risk of adverse reactions. If concomitant use is unavoidable, reduce the dose of ixabepilone to 20 mg/m2. Ixabepilone is a CYP3A substrate and indinavir is a strong CYP3A inhibitor. Coadministration with another strong CYP3A inhibitor increased ixabepilone exposure by 79%.
Ketoconazole: (Major) Avoid indinavir for 2 weeks prior to and during treatment with ketoconazole. Concomitant use may increase exposure of both drugs and increase the risk of adverse effects. If concomitant use is necessary, monitor closely for adverse reactions; a ketoconazole dose reduction may be necessary. Although specific recommendations are unavailable for use with ketoconazole, a reduced indinavir dose of 600 mg PO every 8 hours is recommended when coadministered with other strong CYP3A4 inhibitors. Both ketoconazole and indinavir are CYP3A substrates and strong CYP3A inhibitors.
Lacosamide: (Moderate) Use caution during concurrent use of lacosamide and indinavir, particularly in patients with renal or hepatic impairment. Lacosamide is a CYP3A4 substrate; indinavir is a potent inhibitor of CYP3A4. Patients with renal or hepatic impairment may have significantly increased exposure to lacosamide if coadminsitered with a strong CYP3A4 inhibitor. Dosage reduction of lacosamide may be necessary in this population.
Lamivudine, 3TC; Zidovudine, ZDV: (Moderate) When indinavir and zidovudine, ZDV were administered concurrently, the AUC of indinavir and zidovudine was increased by 13% +/- 48% and 17% +/- 23%, respectively. Dosage adjustments are not recommended when zidovudine is administered with indinavir.
Lansoprazole; Amoxicillin; Clarithromycin: (Moderate) Clarithromycin is a CYP3A4 inhibitor and may decrease the systemic clearance of indinavir, a CYP3A4 substrate. Patients with impaired renal function may require a reduced dosage of clarithromycin.
Lapatinib: (Major) Avoid coadministration of lapatinib with indinavir due to increased plasma concentrations of lapatinib; exposure to indinavir may also increase. If concomitant use is unavoidable, decrease the dose of lapatinib to 500 mg PO once daily. If indinavir is discontinued, increase lapatinib to the indicated dose after a washout period of approximately 1 week. Lapatinib is a CYP3A4 substrate, weak CYP3A4 inhibitor, and P-glycoprotein (P-gp) inhibitor. Indinavir is a strong CYP3A4 inhibitor, a sensitive CYP3A4 substrate, and a P-gp substrate. Concomitant use with another strong CYP3A4 inhibitor increased lapatinib exposure by 3.6-fold and increased the half-life of lapatinib by 1.7-fold.
Larotrectinib: (Major) Avoid coadministration of larotrectinib with indinavir due to increased larotrectinib exposure resulting in increased treatment-related adverse effects. If coadministration cannot be avoided, reduce the larotrectinib dose by 50%. If indinavir is discontinued, resume the original larotrectinib dose after 3 to 5 elimination half-lives of indinavir. Larotrectinib is a CYP3A4 substrate; indinavir is a strong CYP3A4 inhibitor. Coadministration of a strong CYP3A4 inhibitor increased the AUC of larotrectinib by 4.3-fold in a drug interaction study.
Lefamulin: (Major) Avoid coadministration of indinavir with oral lefamulin due to increased lefamulin exposure; indinavir may be administered with intravenous lefamulin. Lefamulin is a CYP3A4 substrate and indinavir is a strong CYP3A4 inhibitor. Coadministration of a strong CYP3A4 inhibitor increased the exposure of oral and intravenous lefamulin by 165% and 31%, respectively.
Lemborexant: (Major) Avoid coadministration of lemborexant and indinavir as concurrent use is expected to significantly increase lemborexant exposure and the risk of adverse effects. Lemborexant is a CYP3A4 substrate; indinavir is a strong CYP3A4 inhibitor. Coadministration of lemborexant with another strong CYP3A4 inhibitor increased the lemborexant AUC by up to 4.5-fold.
Leniolisib: (Major) Avoid concomitant use of leniolisib and indinavir due to the risk for increased leniolisib exposure which may increase the risk for adverse effects. Leniolisib is a CYP3A substrate and indinavir is a strong CYP3A inhibitor. Concomitant use with another strong CYP3A inhibitor increased leniolisib overall exposure by 2-fold.
Lesinurad: (Moderate) Lesinurad may decrease the systemic exposure and therapeutic efficacy of indinavir; monitor for potential reduction in efficacy. Indinavir is a CYP3A substrate, and lesinurad is a weak CYP3A inducer.
Lesinurad; Allopurinol: (Moderate) Lesinurad may decrease the systemic exposure and therapeutic efficacy of indinavir; monitor for potential reduction in efficacy. Indinavir is a CYP3A substrate, and lesinurad is a weak CYP3A inducer.
Letermovir: (Moderate) Concurrent use of indinavir and letermovir may result in elevated indinavir plasma concentrations. In patients who are also receiving treatment with cyclosporine, the magnitude of this interaction may be amplified. Indinavir is primarily metabolized by CYP3A4. Letermovir is a moderate CYP3A4 inhibitor; however, when given with cyclosporine, the combined effect on CYP3A4 substrates may be similar to a strong CYP3A4 inhibitor.
Leuprolide; Norethindrone: (Moderate) Many anti-retroviral protease inhibitors may interact with hormonal agents like norethindrone, due to their actions on CYP metabolism, particularly CYP3A4. Data on the effects that protease inhibitors have on the serum concentrations of norethindrone are complex and are based mostly off of data with norethindrone-containing contraceptives. The AUC for norethindrone increased by 26+/-14%, respectively, when a combined oral contraceptive was coadministered with indinavir. Women receiving hormonal contraceptives and anti-retroviral protease inhibitors (PIs), such as indinavir, should be instructed to report any breakthrough bleeding or other adverse effects to their prescribers. Because hormonal contraceptives do not protect against the transmission of HIV/AIDS and other sexually transmitted diseases, women who receive hormonal contraceptives with indinavir should use an additional barrier method of contraception such as condoms.
Levamlodipine: (Moderate) Monitor for symptoms of hypotension and edema if coadministration of amlodipine with protease inhibitors is necessary; adjust the dose of amlodipine as clinically appropriate. Amlodipine is a CYP3A substrate and protease inhibitors are moderate to strong CYP3A inhibitors. Coadministration with a moderate CYP3A inhibitor in elderly hypertensive patients increased systemic exposure to amlodipine by 60%. However, coadministration with another moderate CYP3A inhibitor in healthy volunteers did not significantly change amlodipine exposure.
Levoketoconazole: (Major) Avoid indinavir for 2 weeks prior to and during treatment with ketoconazole. Concomitant use may increase exposure of both drugs and increase the risk of adverse effects. If concomitant use is necessary, monitor closely for adverse reactions; a ketoconazole dose reduction may be necessary. Although specific recommendations are unavailable for use with ketoconazole, a reduced indinavir dose of 600 mg PO every 8 hours is recommended when coadministered with other strong CYP3A4 inhibitors. Both ketoconazole and indinavir are CYP3A substrates and strong CYP3A inhibitors.
Levomilnacipran: (Major) The adult dose of levomilnacipran should not exceed 80 mg/day during concurrent use of strong CYP3A4 inhibitors. Indinavir is considered a strong inhibitor of CYP3A4. Levomilnacipran is partially metabolized by CYP3A4, and decreased metabolism of the drug can lead to an increased risk of adverse effects such as urinary retention.
Levonorgestrel: (Moderate) Indinavir decreases the metabolism of oral contraceptives and non-oral combination contraceptives; the AUC for ethinyl estradiol and norethindrone increased by 24+/-17% and 26+/-14%, respectively, when coadministered with indinavir. Women receiving hormonal contraceptiv es and anti-retroviral protease inhibitors (PIs), such as indinavir, should be instructed to report any breakthrough bleeding or other adverse effects to their prescribers. Because hormonal contraceptives do not protect against the transmission of HIV/AIDS and other sexually transmitted diseases, women who receive hormonal contraceptives with PIs should use an additional barrier method of contraception such as condoms.
Levonorgestrel; Ethinyl Estradiol: (Major) Indinavir decreases the metabolism of oral contraceptives and non-oral combination contraceptives; the AUC for ethinyl estradiol and norethindrone increased by 24+/-17% and 26+/-14%, respectively, when coadministered with indinavir. Women receiving hormonal contraceptives and anti-retroviral protease inhibitors (PIs), such as indinavir, should be instructed to report any breakthrough bleeding or other adverse effects to their prescribers. Because hormonal contraceptives do not protect against the transmission of HIV/AIDS and other sexually transmitted diseases, women who receive hormonal contraceptives with PIs should use an additional barrier method of contraception such as condoms. (Moderate) Indinavir decreases the metabolism of oral contraceptives and non-oral combination contraceptives; the AUC for ethinyl estradiol and norethindrone increased by 24+/-17% and 26+/-14%, respectively, when coadministered with indinavir. Women receiving hormonal contraceptives and anti-retroviral protease inhibitors (PIs), such as indinavir, should be instructed to report any breakthrough bleeding or other adverse effects to their prescribers. Because hormonal contraceptives do not protect against the transmission of HIV/AIDS and other sexually transmitted diseases, women who receive hormonal contraceptives with PIs should use an additional barrier method of contraception such as condoms.
Levonorgestrel; Ethinyl Estradiol; Ferrous Bisglycinate: (Major) Indinavir decreases the metabolism of oral contraceptives and non-oral combination contraceptives; the AUC for ethinyl estradiol and norethindrone increased by 24+/-17% and 26+/-14%, respectively, when coadministered with indinavir. Women receiving hormonal contraceptives and anti-retroviral protease inhibitors (PIs), such as indinavir, should be instructed to report any breakthrough bleeding or other adverse effects to their prescribers. Because hormonal contraceptives do not protect against the transmission of HIV/AIDS and other sexually transmitted diseases, women who receive hormonal contraceptives with PIs should use an additional barrier method of contraception such as condoms. (Moderate) Indinavir decreases the metabolism of oral contraceptives and non-oral combination contraceptives; the AUC for ethinyl estradiol and norethindrone increased by 24+/-17% and 26+/-14%, respectively, when coadministered with indinavir. Women receiving hormonal contraceptives and anti-retroviral protease inhibitors (PIs), such as indinavir, should be instructed to report any breakthrough bleeding or other adverse effects to their prescribers. Because hormonal contraceptives do not protect against the transmission of HIV/AIDS and other sexually transmitted diseases, women who receive hormonal contraceptives with PIs should use an additional barrier method of contraception such as condoms.
Levonorgestrel; Ethinyl Estradiol; Ferrous Fumarate: (Major) Indinavir decreases the metabolism of oral contraceptives and non-oral combination contraceptives; the AUC for ethinyl estradiol and norethindrone increased by 24+/-17% and 26+/-14%, respectively, when coadministered with indinavir. Women receiving hormonal contraceptives and anti-retroviral protease inhibitors (PIs), such as indinavir, should be instructed to report any breakthrough bleeding or other adverse effects to their prescribers. Because hormonal contraceptives do not protect against the transmission of HIV/AIDS and other sexually transmitted diseases, women who receive hormonal contraceptives with PIs should use an additional barrier method of contraception such as condoms. (Moderate) Indinavir decreases the metabolism of oral contraceptives and non-oral combination contraceptives; the AUC for ethinyl estradiol and norethindrone increased by 24+/-17% and 26+/-14%, respectively, when coadministered with indinavir. Women receiving hormonal contraceptives and anti-retroviral protease inhibitors (PIs), such as indinavir, should be instructed to report any breakthrough bleeding or other adverse effects to their prescribers. Because hormonal contraceptives do not protect against the transmission of HIV/AIDS and other sexually transmitted diseases, women who receive hormonal contraceptives with PIs should use an additional barrier method of contraception such as condoms.
Levothyroxine: (Moderate) Closely monitor the thyroid status of any patient taking thyroid hormones concurrently with indinavir. Hyperthyroidism was reported in a patient when indinavir was added to a stable levothyroxine dosing regimen. Indinavir inhibits UDP-glucuronosyl transferase, which may have decreased the metabolism of the thyroid hormone and may explain the increased thyroxine levels observed. Patients receiving levothyroxine should be carefully monitored when indinavir is started; if hyperthyroidism is detected, reducing the levothyroxine dose should reestablish a euthyroid state. Theoretically, similar interactions may occur between indinavir and other thyroid hormones, given that both T4 and T3 are metabolized to some degree via hepatic UDP-glucuronosyl transferase.
Levothyroxine; Liothyronine (Porcine): (Moderate) Closely monitor the thyroid status of any patient taking thyroid hormones concurrently with indinavir. Hyperthyroidism was reported in a patient when indinavir was added to a stable levothyroxine dosing regimen. Indinavir inhibits UDP-glucuronosyl transferase, which may have decreased the metabolism of the thyroid hormone and may explain the increased thyroxine levels observed. Patients receiving levothyroxine should be carefully monitored when indinavir is started; if hyperthyroidism is detected, reducing the levothyroxine dose should reestablish a euthyroid state. Theoretically, similar interactions may occur between indinavir and other thyroid hormones, given that both T4 and T3 are metabolized to some degree via hepatic UDP-glucuronosyl transferase.
Levothyroxine; Liothyronine (Synthetic): (Moderate) Closely monitor the thyroid status of any patient taking thyroid hormones concurrently with indinavir. Hyperthyroidism was reported in a patient when indinavir was added to a stable levothyroxine dosing regimen. Indinavir inhibits UDP-glucuronosyl transferase, which may have decreased the metabolism of the thyroid hormone and may explain the increased thyroxine levels observed. Patients receiving levothyroxine should be carefully monitored when indinavir is started; if hyperthyroidism is detected, reducing the levothyroxine dose should reestablish a euthyroid state. Theoretically, similar interactions may occur between indinavir and other thyroid hormones, given that both T4 and T3 are metabolized to some degree via hepatic UDP-glucuronosyl transferase.
Lidocaine: (Moderate) Anti-retroviral protease inhibitors can inhibit hepatic cytochrome P450 3A4, an isoenzyme that is partially responsible for the metabolism of lidocaine. The concurrent use of systemic lidocaine and anti-retroviral protease inhibitors should be carefully monitored due to the potential for serious toxicity.
Lidocaine; Epinephrine: (Moderate) Anti-retroviral protease inhibitors can inhibit hepatic cytochrome P450 3A4, an isoenzyme that is partially responsible for the metabolism of lidocaine. The concurrent use of systemic lidocaine and anti-retroviral protease inhibitors should be carefully monitored due to the potential for serious toxicity.
Lidocaine; Prilocaine: (Moderate) Anti-retroviral protease inhibitors can inhibit hepatic cytochrome P450 3A4, an isoenzyme that is partially responsible for the metabolism of lidocaine. The concurrent use of systemic lidocaine and anti-retroviral protease inhibitors should be carefully monitored due to the potential for serious toxicity.
Linagliptin: (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. A possible mechanism is impairment of beta-cell function. Onset averaged approximately 63 days after initiating protease inhibitor therapy, but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients on antidiabetic therapy, such as linagliptin, should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated.
Linagliptin; Metformin: (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. A possible mechanism is impairment of beta-cell function. Onset averaged approximately 63 days after initiating protease inhibitor therapy, but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients on antidiabetic therapy, such as linagliptin, should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated. (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. Another possible mechanism is impairment of beta-cell function. Onset averaged approximately 63 days after initiating protease inhibitor therapy, but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients taking antidiabetic therapy should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated.
Liothyronine: (Moderate) Closely monitor the thyroid status of any patient taking thyroid hormones concurrently with indinavir. Hyperthyroidism was reported in a patient when indinavir was added to a stable levothyroxine dosing regimen. Indinavir inhibits UDP-glucuronosyl transferase, which may have decreased the metabolism of the thyroid hormone and may explain the increased thyroxine levels observed. Patients receiving levothyroxine should be carefully monitored when indinavir is started; if hyperthyroidism is detected, reducing the levothyroxine dose should reestablish a euthyroid state. Theoretically, similar interactions may occur between indinavir and other thyroid hormones, given that both T4 and T3 are metabolized to some degree via hepatic UDP-glucuronosyl transferase.
Lofexidine: (Moderate) Monitor for orthostatic hypotension and bradycardia during concurrent use of lofexidine and indinavir. Coadministration may increase lofexidine exposure. Lofexidine is a CYP2D6 substrate; indinavir is a CYP2D6 inhibitor. Coadministration with a strong CYP2D6 inhibitor increased the lofexidine AUC by 28%.
Lomitapide: (Contraindicated) Concomitant use of indinavir and lomitapide is contraindicated. If treatment with indinavir is unavoidable, lomitapide should be stopped during the course of treatment. Indinavir is a strong CYP3A4 inhibitor. The exposure to lomitapide was increased 27-fold in the presence of ketoconazole, a strong CYP3A4 inhibitor.
Lonafarnib: (Contraindicated) Concomitant use of lonafarnib and indinavir is contraindicated and may increase the exposure and risk of adverse effects from both drugs. If concomitant use is necessary, consider reducing the dose of indinavir to 600 mg PO every 8 hours. Lonafarnib is a sensitive CYP3A4 substrate and strong CYP3A4 inhibitor; indinavir is a CYP3A4 substrate and strong CYP3A4 inhibitor. Coadministration with another strong CYP3A4 inhibitor increased the exposure of lonafarnib by 425%.
Loperamide: (Moderate) Monitor for loperamide-associated adverse reactions, such as CNS effects and cardiac toxicities (i.e., syncope, ventricular tachycardia, QT prolongation, torsade de pointes, cardiac arrest), if coadministered with indinavir. Concurrent use may increase loperamide exposure. Loperamide is a CYP3A4 substrate and indinavir is a strong CYP3A4 inhibitor. Coadministration with another strong CYP3A4 and P-gp inhibitor increased loperamide exposure by 3.8-fold.
Loperamide; Simethicone: (Moderate) Monitor for loperamide-associated adverse reactions, such as CNS effects and cardiac toxicities (i.e., syncope, ventricular tachycardia, QT prolongation, torsade de pointes, cardiac arrest), if coadministered with indinavir. Concurrent use may increase loperamide exposure. Loperamide is a CYP3A4 substrate and indinavir is a strong CYP3A4 inhibitor. Coadministration with another strong CYP3A4 and P-gp inhibitor increased loperamide exposure by 3.8-fold.
Lopinavir; Ritonavir: (Moderate) Decrease the indinavir dose to 600 mg twice daily when administered in combination with lopinavir; ritonavir. The once-daily dose of lopinavir; ritonavir in combination with indinavir has not been studied. Use of these drugs together increases plasma concentrations of indinavir. (Minor) Ritonavir inhibits the clearance of indinavir, and increased indinavir serum concentrations are seen with concurrent administration. In a pharmacokinetic study in healthy volunteers, the AUC of single indinavir dose increased 185 to 475% during concurrent ritonavir dosing; the mean indinavir half-life increased from 1.2 to 2.7 hours. In an observational study of HIV-infected patients, the combination of indinavir 1200 mg and ritonavir 100 mg, both twice daily, led to high systemic exposure to indinavir and was not well tolerated. The combination of indinavir 800 mg and ritonavir 100 mg twice daily resulted in therapeutic indinavir serum concentrations with improved tolerability and similar maximum serum concentrations as the approved indinavir dosage of 800 mg three times a day. Patients should be closely monitored for possible indinavir toxicity during concurrent administration; indinavir dosage reductions may be necessary. The recommended dosing regimen for this combination is indinavir 800 mg twice daily plus ritonavir 100 or 200 mg twice daily.
Lorazepam: (Moderate) Monitor for an increase in lorazepam-related adverse reactions and consider reducing the dose of lorazepam if concomitant use of lorazepam and indinavir is necessary. Avoid lorazepam extended-release capsules and utilize lorazepam immediate-release dosage forms that can be easily titrated. Lorazepam is an UGT substrate and indinavir is an UGT inhibitor.
Lorlatinib: (Major) Avoid coadministration of lorlatinib with indinavir due to increased plasma concentrations of lorlatinib, which may increase the incidence and severity of adverse reactions. Plasma concentrations of indinavir may also decrease, leading to a reduction of antiretroviral efficacy and the potential development of viral resistance. If concomitant use is unavoidable, reduce the starting dose of lorlatinib from 100 mg to 75 mg once daily, or from 75 mg to 50 mg once daily. Although specific indinavir recommendations are unavailable for use with lorlatinib, an increased dose is recommended (i.e., 1,000 mg PO every 8 hours) when coadministered with other moderate CYP3A4 inducers. If indinavir is discontinued, resume the original dose of lorlatinib after 3 half-lives of indinavir. Lorlatinib is a CYP3A substrate and moderate inducer. Indinavir is a CYP3A substrate and strong inhibitor. Coadministration with another strong CYP3A4 inhibitor increased lorlatinib exposure by 42%. Coadministration with another moderate CYP3A4 inducer decreased indinavir exposure by up to 46%.
Lovastatin: (Contraindicated) Concurrent use of lovastatin and anti-retroviral protease inhibitors is contraindicated. The risk of developing myopathy, rhabdomyolysis, and acute renal failure is substantially increased if lovastatin is administered concomitantly with anti-retroviral protease inhibitors. Lovastatin is a substrate of CYP3A4 and anti-retroviral protease inhibitors are strong inhibitors of CYP3A4; therefore, coadministration may result in substantial increases in plasma concentrations of lovastatin.
Lumacaftor; Ivacaftor: (Major) If indinavir and ivacaftor are taken together, administer ivacaftor at the usual recommended dose but reduce the frequency to twice weekly. Coadministration is not recommended in patients younger than 6 months. Ivacaftor is a CYP3A substrate and indinavir is a strong CYP3A inhibitor. Coadministration with another strong CYP3A inhibitor increased ivacaftor exposure by 8.5-fold. (Major) Lumacaftor; ivacaftor may decrease the therapeutic efficacy of indinavir; avoid concurrent use if possible. If concomitant use of indinavir is necessary, monitor antiretroviral efficacy, consider therapeutic drug monitoring, and adjust therapy as necessary. Lumacaftor; ivacaftor dosage adjustment is not required when indinavir is started in a patient already taking lumacaftor; ivacaftor. However, if lumacaftor; ivacaftor is initiated in a patient already taking indinavir, reduce the dose of lumacaftor; ivacaftor to 1 tablet PO daily or 1 packet of oral granules every other day for the first week of treatment, and then increase to the usual recommended daily dose. This dosage adjustment is also necessary if lumacaftor; ivacaftor therapy has been interrupted for more than 1 week and re-initiated while the patient is taking indinavir. The 1-week lead-in period at the lower lumacaftor; ivacaftor dosage allows for lumacaftor's induction of CYP3A to reach steady state. Indinavir is a substrate and strong inhibitor of CYP3A. Ivacaftor is a CYP3A substrate, and lumacaftor is a strong CYP3A inducer. Lumacaftor's induction of CYP3A may decrease the systemic exposure of indinavir and decrease its therapeutic efficacy. Although indinavir is a strong CYP3A4 inhibitor, net ivacaftor exposure at steady state is not expected to exceed that achieved with ivacaftor monotherapy (i.e., 150 mg PO every 12 hours) because of lumacaftor's CYP3A induction. In pharmacokinetic studies, coadministration of lumacaftor; ivacaftor with another strong CYP3A4 inhibitor increased ivacaftor exposure by 4.3-fold. Lastly, indinavir is also a substrate of the drug transporter P-glycoprotein (P-gp), and lumacaftor; ivacaftor has the potential to both induce and inhibit P-gp. The net effect on P-gp substrates is not clear, but their exposure may be affected.
Lumacaftor; Ivacaftor: (Major) Lumacaftor; ivacaftor may decrease the therapeutic efficacy of indinavir; avoid concurrent use if possible. If concomitant use of indinavir is necessary, monitor antiretroviral efficacy, consider therapeutic drug monitoring, and adjust therapy as necessary. Lumacaftor; ivacaftor dosage adjustment is not required when indinavir is started in a patient already taking lumacaftor; ivacaftor. However, if lumacaftor; ivacaftor is initiated in a patient already taking indinavir, reduce the dose of lumacaftor; ivacaftor to 1 tablet PO daily or 1 packet of oral granules every other day for the first week of treatment, and then increase to the usual recommended daily dose. This dosage adjustment is also necessary if lumacaftor; ivacaftor therapy has been interrupted for more than 1 week and re-initiated while the patient is taking indinavir. The 1-week lead-in period at the lower lumacaftor; ivacaftor dosage allows for lumacaftor's induction of CYP3A to reach steady state. Indinavir is a substrate and strong inhibitor of CYP3A. Ivacaftor is a CYP3A substrate, and lumacaftor is a strong CYP3A inducer. Lumacaftor's induction of CYP3A may decrease the systemic exposure of indinavir and decrease its therapeutic efficacy. Although indinavir is a strong CYP3A4 inhibitor, net ivacaftor exposure at steady state is not expected to exceed that achieved with ivacaftor monotherapy (i.e., 150 mg PO every 12 hours) because of lumacaftor's CYP3A induction. In pharmacokinetic studies, coadministration of lumacaftor; ivacaftor with another strong CYP3A4 inhibitor increased ivacaftor exposure by 4.3-fold. Lastly, indinavir is also a substrate of the drug transporter P-glycoprotein (P-gp), and lumacaftor; ivacaftor has the potential to both induce and inhibit P-gp. The net effect on P-gp substrates is not clear, but their exposure may be affected.
Lumateperone: (Major) Reduce the dose of lumateperone to 10.5 mg once daily if concomitant use of indinavir is necessary. Concurrent use may increase lumateperone exposure and the risk of adverse effects. Lumateperone is a CYP3A4 substrate; indinavir is a strong CYP3A4 inhibitor. Coadministration with a strong CYP3A4 inhibitor increased lumateperone exposure by approximately 4-fold.
Lurasidone: (Contraindicated) Concurrent use of lurasidone with strong CYP3A4 inhibitors, such as indinavir, is contraindicated. Lurasidone is primarily metabolized by CYP3A4. Increased lurasidone plasma concentrations are expected when the drug is co-administered with inhibitors of CYP3A4.
Lurbinectedin: (Major) Avoid concomitant use of lurbinectedin and indinavir due to the risk of increased lurbinectedin exposure which may increase the risk of adverse reactions. If concomitant use is necessary, reduce the dose of lurbinectedin by 50%. Lurbinectedin is a CYP3A substrate and indinavir is a strong CYP3A inhibitor. Coadministration with another strong CYP3A inhibitor increased the overall exposure of lurbinectedin by 2.7-fold.
Macitentan: (Major) Avoid concurrent use of macitentan and indinavir. Indinavir is a strong inhibitor of CYP3A4. Coadminsitration of macitentan with another strong CYP3A4 inhibitor (ketoconazole) approximately doubles macitentan exposure. Consider alternative treatment options for pulmonary hypertension if treatment with indinavir is necessary.
Maraviroc: (Major) Coadministration of maraviroc, a CYP3A substrate, with indinavir, a strong CYP3A4 inhibitor, may result in increased maraviroc concentrations. Reduce the dose of maraviroc when coadministered with strong CYP3A inhibitors; coadministration of maraviroc with strong CYP3A inhibitors is contraindicated in patients with CrCl less than 30 mL/min. Adjust the maraviroc dosage as follows when administered with indinavir (with or without a concomitant CYP3A inducer): adults and children weighing 40 kg or more: 150 mg PO twice daily; children weighing 30 to 39 kg: 100 mg PO twice daily; children weighing 20 to 29 kg: 75 mg PO twice daily (or 80 mg PO twice daily for solution); children weighing 10 to 19 kg: 50 mg PO twice daily; children weighing 2 to 9 kg: use not recommended.
Mavacamten: (Contraindicated) Mavacamten is contraindicated for use with indinavir due to risk of heart failure due to systolic dysfunction. Concomitant use increases mavacamten exposure and may decrease plasma concentrations of indinavir leading to a reduction of antiretroviral efficacy and the potential development of viral resistance. Mavacamten is a substrate and moderate inducer of CYP3A and indinavir is a substrate and strong inhibitor of CYP3A. Concomitant use of mavacamten with a strong CYP3A inhibitor is predicted to increase mavacamten overall exposure up to 130%. Coadministration with another moderate CYP3A inducer decreased indinavir exposure by up to 46%.
Medroxyprogesterone: (Major) Coadministration of medroxyprogesterone, a CYP3A substrate with indinavir, a strong CYP3A inhibitor should be avoided since it is expected to increase concentrations of medroxyprogesterone acetate. Formal drug interaction studies have not been conducted; however, medroxyprogesterone is metabolized primarily by hydroxylation via the CYP3A4 in vitro. Indinavir also decreases the metabolism of oral contraceptives and non-oral combination contraceptives; the AUC for ethinyl estradiol and norethindrone increased by 24+/-17% and 26+/-14%, respectively, when coadministered with indinavir. Women receiving hormonal contraceptives and anti-retroviral protease inhibitors (PIs), such as indinavir, should be instructed to report any breakthrough bleeding or other adverse effects to their prescribers. Because hormonal contraceptives do not protect against the transmission of HIV/AIDS and other sexually transmitted diseases, women who receive hormonal contraceptives with PIs should use an additional barrier method of contraception such as condoms.
Mefloquine: (Moderate) Mefloquine is metabolized by CYP3A4. Indinavir is an inhibitor of this enzyme and may decrease the clearance of mefloquine and increase mefloquine systemic exposure.
Megestrol: (Major) Due to the significant decrease in the exposure of indinavir by megestrol acetate, administration of a higher dose of indinavir should be considered when coadministering with megestrol acetate. Specific adjustment recommendations are not available, but should be determined by viral response. In one pharmacokinetic study of healthy male subjects, co-administration of megestrol acetate (675 mg/day for 14 days) and indinavir (a single dose 800 mg) resulted in a 32% decrease in the Cmax of indinavir and a 21% decrease in the AUC of indinavir.
Metformin: (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. Another possible mechanism is impairment of beta-cell function. Onset averaged approximately 63 days after initiating protease inhibitor therapy, but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients taking antidiabetic therapy should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated.
Metformin; Repaglinide: (Moderate) Coadministration of repaglinide and protease inhibitors may increase or decrease glucose concentrations and increase repaglinide AUC; if coadministration is necessary, repaglinide dosage adjustment may be necessary and increased frequency of glucose monitoring is recommended. New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. In addition, repaglinide is a substrate of the hepatic isoenzyme CYP3A4 and the drug transporter organic anion transporting polypeptide (OATP1B1); protease inhibitors are potent CYP3A4 inhibitors and inhibitors of OATP. (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. Another possible mechanism is impairment of beta-cell function. Onset averaged approximately 63 days after initiating protease inhibitor therapy, but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients taking antidiabetic therapy should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated.
Metformin; Rosiglitazone: (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. Another possible mechanism is impairment of beta-cell function. Onset averaged approximately 63 days after initiating protease inhibitor therapy, but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients taking antidiabetic therapy should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated.
Metformin; Saxagliptin: (Major) The metabolism of saxagliptin is primarily mediated by CYP3A4/5. Limit the saxagliptin dose to 2.5 mg once daily when coadministered with a strong CYP3A4/5 inhibitor such as indinavir. New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have also been reported with use of anti-retroviral protease inhibitors. Patients on antidiabetic therapy should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated. (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. Another possible mechanism is impairment of beta-cell function. Onset averaged approximately 63 days after initiating protease inhibitor therapy, but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients taking antidiabetic therapy should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated.
Metformin; Sitagliptin: (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. Another possible mechanism is impairment of beta-cell function. Onset averaged approximately 63 days after initiating protease inhibitor therapy but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients taking antidiabetic agents should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated. (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. Another possible mechanism is impairment of beta-cell function. Onset averaged approximately 63 days after initiating protease inhibitor therapy, but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients taking antidiabetic therapy should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated.
Methadone: (Moderate) Caution is advised with the coadministration of indinavir and methadone as concurrent use may result in incresed serum concentrations of methadone. Indinavir is a CYP3A4 inhibitor and may decrease the metabolism of methadone, a CYP3A4 substrate. However, administration of indinavir (800 mg every 8 hours) with methadone (2060 mg daily) for one week, in subjects on methadone maintenance, resulted in no change in methadone AUC. Based on a comparison to historical data, there was little or no change in indinavir AUC. Patients should be monitored for increased methadone side effects during concurrent use.
Methohexital: (Major) Barbiturates may increase the metabolism of indinavir and lead to decreased antiretroviral efficacy. In addition, indinavir may inhibit the CYP metabolism of barbiturates, resulting in increased barbiturate concentrations. Appropriate dose adjustments necessary to ensure optimum levels of both anti-retroviral agent and the barbiturate are unknown. Anticonvulsant serum concentrations should be monitored closely if these agents are added; the patient should be observed for changes in the clinical efficacy of the antiretroviral or anticonvulsant regimen.
Methylergonovine: (Contraindicated) Coadministration of ergot alkaloids with potent inhibitors of CYP3A4, like anti-retroviral protease inhibitors is considered contraindicated due to the risk of acute ergot toxicity (e.g., vasospasm leading to cerebral ischemia, peripheral ischemia and/or other serious effects). Several case reports have established the clinical significance of this interaction in the medical literature. In some cases, fatal interactions have occurred.
Midazolam: (Major) Protease inhibitors may increase midazolam concentrations; the risk for midazolam-related adverse effects varies by midazolam dosage form and route of administration. Oral midazolam use is contraindicated. Intranasal midazolam should be avoided when possible. Additional monitoring and a dosage reduction may be necessary with parenteral midazolam. Midazolam is a CYP3A substrate and protease inhibitors are CYP3A inhibitors. Protease inhibitors have been shown to increase oral midazolam AUCs by up to 3-fold, resulting in clinically significant potentiation of sedation.
Midostaurin: (Major) Avoid the concomitant use of midostaurin and indinavir due to the risk of increased midostaurin exposure which may increase the incidence and severity of adverse reactions. If concomitant use cannot be avoided, monitor patients for signs and symptoms of midostaurin toxicity, particularly during the first week of midostaurin therapy for those with systemic mastocytosis/mast cell leukemia and during the first week of each cycle for those with acute myeloid leukemia. Midostaurin is a CYP3A4 substrate and indinavir is a strong CYP3A4 inhibitor. Coadministration of one strong CYP3A4 inhibitor with a single dose of midostaurin increased the exposure of midostaurin and its active metabolites CGP62221 and CGP52421 by 10.4-fold, 3.5-fold, and 1.2-fold, respectively. Coadministration of another strong CYP3A4 inhibitor with twice daily doses of midostaurin increased Day 28 trough concentrations of midostaurin, CGP62221, and CGP52421 by 2.1-fold, 1.2-fold, and 1.3-fold respectively compared with day 21 trough levels with midostaurin alone.
Mifepristone: (Major) Caution is advised when administering indinavir with mifepristone because increased serum concentrations of either drug may occur. When mifepristone is used in the treatment of Cushing's syndrome, coadministration with indinavir should be done only when necessary, and in such cases the dose of mifepristone should be limited to a maximum dose of 900 mg per day. In a patient already receiving indinavir, initiate mifepristone at a dose of 300 mg and titrate to a maximum of 900 mg if clinically indicated. If therapy with indinavir is initiated in a patient already receiving mifepristone 300 mg, dosage adjustments are not required. If therapy with indinavir is initiated in a patient already receiving mifepristone 600 mg, reduce dose of mifepristone to 300 mg and titrate to a maximum of 600 mg if clinically indicated. If therapy with indinavir is initiated in a patient already receiving 900 mg, reduce dose of mifepristone to 600 mg and titrate to a maximum of 900 mg if clinically indicated. If therapy with indinavir is initiated in a patient already receiving 1,200 mg, reduce the mifepristone dose to 900 mg. Both mifepristone and indinavir are substrates and strong inhibitors of CYP3A4.
Miglitol: (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors.
Mirtazapine: (Moderate) Concurrent administration of mirtazapine and indinavir may result in elevated mirtazapine plasma concentrations. If these drugs are coadministered, monitor patients for adverse effects associated with mirtazapine, such as constipation, drowsiness, dizziness, and QT prolongation, and decrease the dose if necessary. Mirtazapine is a substrate of CYP3A4 and protease inhibitors are potent inhibitors of CYP3A4.
Mirvetuximab Soravtansine: (Moderate) Closely monitor for mirvetuximab soravtansine-related adverse reactions if concomitant use of indinavir is necessary. DM4, the cytotoxic component of mirvetuximab soravtansine, is a CYP3A substrate and indinavir is a strong CYP3A inhibitor. Concomitant use may increase unconjugated DM4 exposure.
Mitapivat: (Major) Avoid coadministration of mitapivat with indinavir due to increased risk of adverse reactions from mitapivat. Coadministration increases mitapivat concentrations. Mitapivat is a CYP3A substrate and indinavir is a strong CYP3A inhibitor. Concomitant use with other strong CYP3A inhibitors increased mitapivat overall exposure by 3.6 to 4.9-fold.
Mitotane: (Major) Concomitant use of mitotane with indinavir should be undertaken with caution due to potential decreased indinavir concentrations, leading to a reduction of antiretroviral efficacy and the potential development of viral resistance. Mitotane is a strong CYP3A4 inducer and indinavir is a CYP3A4 substrate; coadministration may result in decreased plasma concentrations of indinavir. Administration of indinavir and another strong CYP3A inducer, rifampin, for one week resulted in a 89% decrease in the indinavir AUC. Concomitant administration of yet another strong CYP3A inducer, St. John's wort, with indinavir to healthy volunteers decreased mean indinavir plasma concentrations by 57% and trough concentrations by 81%.
Mobocertinib: (Major) Avoid concomitant use of mobocertinib and indinavir. Concomitant use may increase mobocertinib exposure and the risk for adverse reactions such as QT prolongation. Mobocertinib is a CYP3A substrate and indinavir is a strong CYP3A inhibitor. Use of a strong CYP3A inhibitor is predicted to increase the overall exposure of mobocertinib and its active metabolites by 374% to 419%.
Mometasone: (Major) As mometasone is a CYP3A4 substrate, concomitant use with indinavir, a potent inhibitor of CYP3A4, may increase plasma levels and related adverse effects of mometasone; caution is advised.
Naldemedine: (Major) Monitor for potential naldemedine-related adverse reactions if coadministered with indinavir. The plasma concentrations of naldemedine may be increased during concurrent use. Naldemedine is a CYP3A4 substrate; indinavir is a strong CYP3A4 inhibitor.
Naloxegol: (Contraindicated) Concomitant use of naloxegol with indinavir is contraindicated. Naloxegol is metabolized primarily by CYP3A. Strong CYP3A4 inhibitors, such as indinavir, can significantly increase exposure to naloxegol which may precipitate opioid withdrawal symptoms such as hyperhidrosis, chills, diarrhea, abdominal pain, anxiety, irritability, and yawning.
Nanoparticle Albumin-Bound Paclitaxel: (Moderate) Monitor for an increase in paclitaxel-related adverse reactions if coadministration of nab-paclitaxel with indinavir is necessary due to the risk of increased plasma concentrations of paclitaxel. Nab-paclitaxel is a CYP3A4 substrate and indinavir is a strong CYP3A4 inhibitor. In vitro, coadministration with both strong and moderate CYP3A4 inhibitors increased paclitaxel exposure; however, the concentrations used exceeded those found in vivo following normal therapeutic doses. The pharmacokinetics of paclitaxel may also be altered in vivo as a result of interactions with CYP3A4 inhibitors.
Nanoparticle Albumin-Bound Sirolimus: (Major) Avoid concomitant use of sirolimus and protease inhibitors; a sirolimus dosage reduction may be considered if concomitant use is necessary. Coadministration may increase sirolimus concentrations and increase the risk for sirolimus-related adverse effects.
Nateglinide: (Moderate) Concurrent administration of nateglinide with some protease inhibitors may result in elevated nateglinide plasma concentrations via inhibition of CYP2C9. Ritonavir may induce CYP2C9 leading to a reduction of nateglinide concentrations. Monitor blood glucose concentrations during coadministration as hypoglycemia or hyperglycemia could occur. New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. Monitor blood glucose concentrations during coadministration. Caution and close monitoring are advised if these drugs are administered together.
Nebivolol: (Moderate) Monitor for increased toxicity as well as increased therapeutic effect of nebivolol if coadministered with indinavir. Nebivolol is metabolized by CYP2D6. Although data are lacking, CYP2D6 inhibitors, such as indinavir, could potentially increase nebivolol plasma concentrations via CYP2D6 inhibition; the clinical significance of this potential interaction is unknown, but an increase in adverse effects is possible.
Nebivolol; Valsartan: (Moderate) Monitor for increased toxicity as well as increased therapeutic effect of nebivolol if coadministered with indinavir. Nebivolol is metabolized by CYP2D6. Although data are lacking, CYP2D6 inhibitors, such as indinavir, could potentially increase nebivolol plasma concentrations via CYP2D6 inhibition; the clinical significance of this potential interaction is unknown, but an increase in adverse effects is possible.
Nefazodone: (Major) Nefazodone inhibits the metabolism of anti-retroviral protease inhibitors. Nefazodone has been used to treat depression in patients on these medications concurrently. However, the potential drug interactions with anti-retroviral agents indicate that it is essential to evaluate for appropriate dosing of both agents to avoid adverse effects of either the anti-retroviral or nefazodone treatment.
Nelfinavir: (Major) Limited data support the combination of indinavir 1200 mg and nelfinavir 1250 mg both twice daily; however, coadministration results in increased plasma concentrations of both drugs. When given concurrently, nelfinavir plasma AUC increased by 83% and the indinavir plasma AUC increased 51%.
Neratinib: (Major) Avoid concomitant use of indinavir with neratinib due to an increased risk of neratinib-related toxicity. Neratinib is a CYP3A4 substrate and indinavir is a strong CYP3A4 inhibitor. Coadministration with another strong CYP3A4 inhibitor increased neratinib exposure by 381%; concomitant use with other strong inhibitors of CYP3A4 may also increase neratinib concentrations.
Netupitant, Fosnetupitant; Palonosetron: (Moderate) Netupitant is a moderate inhibitor of CYP3A4 and should be used with caution in patients receiving concomitant medications that are primarily metabolized through CYP3A4 since the plasma concentrations of the primary substrate can increase; the inhibitory effect on CYP3A4 can last for multiple days. Indinavir is partially metabolized by CYP3A4. In addition, netupitant is mainly metabolized by CYP3A4. Coadministration of netupitant; palonosetron with a strong CYP3A4 inhibitor can significantly increase the systemic exposure to netupitant. Indinavir is a strong CYP3A4 inhibitor. No dosage adjustment is necessary for single dose administration of netupitant; palonosetron.
Nevirapine: (Major) Coadministration of nevirapine and indinavir may result in decreased indinavir exposure; however, an appropriate dose of indinavir when coadministered with nevirapine has not been established. Additionally, concomitant use may increase the exposure of nevirapine. Monitor for an increase in nevirapine-related adverse reactions if coadministration with indinavir is necessary. Nevirapine is a CYP3A4 substrate and weak CYP3A inducer; indinavir is a CYP3A substrate and strong CYP3A4 inhibitor. Coadministration with a moderate CYP3A4 inhibitor increased nevirapine exposure by 100%; concomitant use with a strong CYP3A4 inhibitor may also increase nevirapine exposure.
Niacin; Simvastatin: (Contraindicated) The coadministration of anti-retroviral protease inhibitors with simvastatin is contraindicated. Taking these drugs together may significantly increase the serum concentration of simvastatin; thereby increasing the risk of myopathy and rhabdomyolysis. One report has demonstrated that ritonavir plus saquinavir therapy markedly increases the AUC for simvastatin by 3059%. Simvastatin is a substrate for CYP3A4 and the drug transporter organic anion transporting polypeptide (OATP1B1); protease inhibitors are CYP3A4 and OATP inhibitors.
Nicardipine: (Moderate) Anti-retroviral protease inhibitors may decrease the hepatic CYP metabolism of calcium-channel blockers (mainly through CYP3A4 inhibition) resulting in increased calcium-channel blocker concentrations. Ritonavir also prolongs the PR interval in some patients; however, the impact on the PR interval of coadministration of ritonavir with other drugs that prolong the PR interval (including calcium channel blockers) has not been evaluated. If coadministration of these drugs is warranted, do so with caution and careful monitoring. Decreased calcium-channel blocker doses may be warranted.
Nifedipine: (Moderate) According to the manufacturer of nifedipine, coadministration with indinavir may result in increased exposure to nifedipine, and initiation of nifedipine should begin with the lowest available dose. Anti-retroviral protease inhibitors may decrease the hepatic CYP metabolism of calcium-channel blockers (mainly through CYP3A4 inhibition) resulting in increased calcium-channel blocker concentrations. If coadministration of these drugs is warranted, do so with caution and careful monitoring. Decreased calcium-channel blocker doses may be warranted.
Nilotinib: (Major) Avoid the concomitant use of nilotinib and indinavir; increased plasma concentrations of either drug may occur. If coadministration is required, reduce the nilotinib dose to 300 mg once daily in patients with resistant or intolerant Ph+ CML or to 200 mg once daily in patients with newly diagnosed Ph+ CML. Additionally, monitor patients closely for prolongation of the QT interval and for adverse reactions associated with nilotinib or indinavir. If indinavir is discontinued, a washout period should be allowed before adjusting the nilotinib dosage upward to the indicated dose. Nilotinib is a substrate and moderate inhibitor of CYP3A4 and indinavir is a sensitive substrate and strong inhibitor of CYP3A4.
Nimodipine: (Moderate) Anti-retroviral protease inhibitors are CYP3A4 inhibitors and may decrease the hepatic metabolism of nimodipine, leading to increased plasma concentrations of nimodipine. In addition, ritonavir and calcium channel blockers both prolong the PR interval and the manufacturer for ritonavir recommends caution during coadministration. Monitor therapeutic response and for adverse effects, such as hypotension. Decreased calcium-channel blocker doses may be warranted.
Nirmatrelvir; Ritonavir: (Minor) Ritonavir inhibits the clearance of indinavir, and increased indinavir serum concentrations are seen with concurrent administration. In a pharmacokinetic study in healthy volunteers, the AUC of single indinavir dose increased 185 to 475% during concurrent ritonavir dosing; the mean indinavir half-life increased from 1.2 to 2.7 hours. In an observational study of HIV-infected patients, the combination of indinavir 1200 mg and ritonavir 100 mg, both twice daily, led to high systemic exposure to indinavir and was not well tolerated. The combination of indinavir 800 mg and ritonavir 100 mg twice daily resulted in therapeutic indinavir serum concentrations with improved tolerability and similar maximum serum concentrations as the approved indinavir dosage of 800 mg three times a day. Patients should be closely monitored for possible indinavir toxicity during concurrent administration; indinavir dosage reductions may be necessary. The recommended dosing regimen for this combination is indinavir 800 mg twice daily plus ritonavir 100 or 200 mg twice daily.
Nisoldipine: (Major) Avoid coadministration of nisoldipine with protease inhibitors due to increased plasma concentrations of nisoldipine. If coadministration is unavoidable, monitor blood pressure closely during concurrent use of these medications. Nisoldipine is a CYP3A substrate and protease inhibitors are moderate to strong CYP3A inhibitors. Coadministration with another CYP3A inhibitor increased the AUC of nisoldipine by 30% to 45%.
Norethindrone Acetate; Ethinyl Estradiol; Ferrous fumarate: (Major) Indinavir decreases the metabolism of oral contraceptives and non-oral combination contraceptives; the AUC for ethinyl estradiol and norethindrone increased by 24+/-17% and 26+/-14%, respectively, when coadministered with indinavir. Women receiving hormonal contraceptives and anti-retroviral protease inhibitors (PIs), such as indinavir, should be instructed to report any breakthrough bleeding or other adverse effects to their prescribers. Because hormonal contraceptives do not protect against the transmission of HIV/AIDS and other sexually transmitted diseases, women who receive hormonal contraceptives with PIs should use an additional barrier method of contraception such as condoms. (Moderate) Many anti-retroviral protease inhibitors may interact with hormonal agents like norethindrone, due to their actions on CYP metabolism, particularly CYP3A4. Data on the effects that protease inhibitors have on the serum concentrations of norethindrone are complex and are based mostly off of data with norethindrone-containing contraceptives. The AUC for norethindrone increased by 26+/-14%, respectively, when a combined oral contraceptive was coadministered with indinavir. Women receiving hormonal contraceptives and anti-retroviral protease inhibitors (PIs), such as indinavir, should be instructed to report any breakthrough bleeding or other adverse effects to their prescribers. Because hormonal contraceptives do not protect against the transmission of HIV/AIDS and other sexually transmitted diseases, women who receive hormonal contraceptives with indinavir should use an additional barrier method of contraception such as condoms.
Norethindrone: (Moderate) Many anti-retroviral protease inhibitors may interact with hormonal agents like norethindrone, due to their actions on CYP metabolism, particularly CYP3A4. Data on the effects that protease inhibitors have on the serum concentrations of norethindrone are complex and are based mostly off of data with norethindrone-containing contraceptives. The AUC for norethindrone increased by 26+/-14%, respectively, when a combined oral contraceptive was coadministered with indinavir. Women receiving hormonal contraceptives and anti-retroviral protease inhibitors (PIs), such as indinavir, should be instructed to report any breakthrough bleeding or other adverse effects to their prescribers. Because hormonal contraceptives do not protect against the transmission of HIV/AIDS and other sexually transmitted diseases, women who receive hormonal contraceptives with indinavir should use an additional barrier method of contraception such as condoms.
Norethindrone; Ethinyl Estradiol: (Major) Indinavir decreases the metabolism of oral contraceptives and non-oral combination contraceptives; the AUC for ethinyl estradiol and norethindrone increased by 24+/-17% and 26+/-14%, respectively, when coadministered with indinavir. Women receiving hormonal contraceptives and anti-retroviral protease inhibitors (PIs), such as indinavir, should be instructed to report any breakthrough bleeding or other adverse effects to their prescribers. Because hormonal contraceptives do not protect against the transmission of HIV/AIDS and other sexually transmitted diseases, women who receive hormonal contraceptives with PIs should use an additional barrier method of contraception such as condoms. (Moderate) Many anti-retroviral protease inhibitors may interact with hormonal agents like norethindrone, due to their actions on CYP metabolism, particularly CYP3A4. Data on the effects that protease inhibitors have on the serum concentrations of norethindrone are complex and are based mostly off of data with norethindrone-containing contraceptives. The AUC for norethindrone increased by 26+/-14%, respectively, when a combined oral contraceptive was coadministered with indinavir. Women receiving hormonal contraceptives and anti-retroviral protease inhibitors (PIs), such as indinavir, should be instructed to report any breakthrough bleeding or other adverse effects to their prescribers. Because hormonal contraceptives do not protect against the transmission of HIV/AIDS and other sexually transmitted diseases, women who receive hormonal contraceptives with indinavir should use an additional barrier method of contraception such as condoms.
Norethindrone; Ethinyl Estradiol; Ferrous fumarate: (Major) Indinavir decreases the metabolism of oral contraceptives and non-oral combination contraceptives; the AUC for ethinyl estradiol and norethindrone increased by 24+/-17% and 26+/-14%, respectively, when coadministered with indinavir. Women receiving hormonal contraceptives and anti-retroviral protease inhibitors (PIs), such as indinavir, should be instructed to report any breakthrough bleeding or other adverse effects to their prescribers. Because hormonal contraceptives do not protect against the transmission of HIV/AIDS and other sexually transmitted diseases, women who receive hormonal contraceptives with PIs should use an additional barrier method of contraception such as condoms. (Moderate) Many anti-retroviral protease inhibitors may interact with hormonal agents like norethindrone, due to their actions on CYP metabolism, particularly CYP3A4. Data on the effects that protease inhibitors have on the serum concentrations of norethindrone are complex and are based mostly off of data with norethindrone-containing contraceptives. The AUC for norethindrone increased by 26+/-14%, respectively, when a combined oral contraceptive was coadministered with indinavir. Women receiving hormonal contraceptives and anti-retroviral protease inhibitors (PIs), such as indinavir, should be instructed to report any breakthrough bleeding or other adverse effects to their prescribers. Because hormonal contraceptives do not protect against the transmission of HIV/AIDS and other sexually transmitted diseases, women who receive hormonal contraceptives with indinavir should use an additional barrier method of contraception such as condoms.
Norgestimate; Ethinyl Estradiol: (Major) Indinavir decreases the metabolism of oral contraceptives and non-oral combination contraceptives; the AUC for ethinyl estradiol and norethindrone increased by 24+/-17% and 26+/-14%, respectively, when coadministered with indinavir. Women receiving hormonal contraceptives and anti-retroviral protease inhibitors (PIs), such as indinavir, should be instructed to report any breakthrough bleeding or other adverse effects to their prescribers. Because hormonal contraceptives do not protect against the transmission of HIV/AIDS and other sexually transmitted diseases, women who receive hormonal contraceptives with PIs should use an additional barrier method of contraception such as condoms.
Norgestrel: (Moderate) Indinavir decreases the metabolism of oral contraceptives and non-oral combination contraceptives; the AUC for ethinyl estradiol and norethindrone increased by 24+/-17% and 26+/-14%, respectively, when coadministered with indinavir. Women receiving hormonal contraceptives and anti-retroviral protease inhibitors (PIs), such as indinavir, should be instructed to report any breakthrough bleeding or other adverse effects to their prescribers. Because hormonal contraceptives do not protect against the transmission of HIV/AIDS and other sexually transmitted diseases, women who receive hormonal contraceptives with PIs should use an additional barrier method of contraception such as condoms.
Olaparib: (Major) Avoid coadministration of olaparib with indinavir due to the risk of increased olaparib-related adverse reactions. If concomitant use is unavoidable, reduce the dose of olaparib to 100 mg twice daily; the original dose may be resumed 3 to 5 elimination half-lives after indinavir is discontinued. Olaparib is a CYP3A substrate and indinavir is a strong CYP3A4 inhibitor; concomitant use may increase olaparib exposure. Coadministration with another strong CYP3A inhibitor increased the olaparib Cmax by 42% and the AUC by 170%.
Oliceridine: (Moderate) Monitor patients closely for respiratory depression and sedation at frequent intervals and base subsequent doses on the patient's severity of pain and response to treatment if concomitant administration of oliceridine and indinavir is necessary; less frequent dosing of oliceridine may be required. Concomitant use of oliceridine and indinavir may increase the plasma concentration of oliceridine, resulting in increased or prolonged opioid effects. If indinavir is discontinued, consider increasing the oliceridine dose until stable drug effects are achieved and monitor for evidence of opioid withdrawal. Oliceridine is a CYP3A4 substrate and indinavir is a strong CYP3A4 inhibitor.
Olmesartan; Amlodipine; Hydrochlorothiazide, HCTZ: (Moderate) Monitor for symptoms of hypotension and edema if coadministration of amlodipine with protease inhibitors is necessary; adjust the dose of amlodipine as clinically appropriate. Amlodipine is a CYP3A substrate and protease inhibitors are moderate to strong CYP3A inhibitors. Coadministration with a moderate CYP3A inhibitor in elderly hypertensive patients increased systemic exposure to amlodipine by 60%. However, coadministration with another moderate CYP3A inhibitor in healthy volunteers did not significantly change amlodipine exposure.
Olopatadine; Mometasone: (Major) As mometasone is a CYP3A4 substrate, concomitant use with indinavir, a potent inhibitor of CYP3A4, may increase plasma levels and related adverse effects of mometasone; caution is advised.
Omaveloxolone: (Major) Avoid concomitant use of omaveloxolone and indinavir. If concomitant use is necessary, decrease omaveloxolone dose to 50 mg once daily. Concomitant use may increase omaveloxolone exposure and the risk for omaveloxolone-related adverse effects. Omaveloxolone is a CYP3A substrate and indinavir is a strong CYP3A inhibitor. Concomitant use with another strong CYP3A inhibitor increased omaveloxolone overall exposure by 4-fold.
Omeprazole: (Major) Omeprazole has been reported to decrease the oral bioavailability of indinavir. In one study, indinavir plasma levels fell to below 95% of normal in roughly half of the patients receiving omeprazole concurrently. An increase in indinavir dosage resolved the interaction. It is unclear if other gastric acid-pump inhibitors would interact with indinavir in this manner.
Omeprazole; Amoxicillin; Rifabutin: (Major) Omeprazole has been reported to decrease the oral bioavailability of indinavir. In one study, indinavir plasma levels fell to below 95% of normal in roughly half of the patients receiving omeprazole concurrently. An increase in indinavir dosage resolved the interaction. It is unclear if other gastric acid-pump inhibitors would interact with indinavir in this manner. (Major) Reduce rifabutin dose to 150 mg PO once daily and increase indinavir dose from 800 mg to 1,000 mg 3 times daily if concomitant use is necessary. Monitor for decrease in indinavir efficacy and for rifabutin-related adverse effects, such as uveitis and neutropenia. Concomitant use may increase rifabutin exposure and decrease indinavir exposure. Rifabutin is a CYP3A substrate and moderate CYP3A inducer; indinavir is a CYP3A substrate and strong CYP3A inhibitor. Coadministration increased rifabutin exposure by 173% and decreased indinavir exposure by 34%.
Omeprazole; Sodium Bicarbonate: (Major) Omeprazole has been reported to decrease the oral bioavailability of indinavir. In one study, indinavir plasma levels fell to below 95% of normal in roughly half of the patients receiving omeprazole concurrently. An increase in indinavir dosage resolved the interaction. It is unclear if other gastric acid-pump inhibitors would interact with indinavir in this manner.
Oritavancin: (Major) Concomitant use of oritavancin with indinavir may decrease the effectiveness of indinavir; therefore, use caution, and monitor therapeutic effects of indinavir when coadministered. Oritavancin is a weak inducer of CYP3A4 and indinavir is a CYP3A4 substrate.
Orlistat: (Major) According to the manufacturer of orlistat, HIV RNA levels should be frequently monitored in patients receiving orlistat while being treated for HIV infection with anti-retroviral protease inhibitors. Loss of virological control has been reported in HIV-infected patients taking orlistat with atazanavir, ritonavir, tenofovir disoproxil fumarate, emtricitabine, lopinavir; ritonavir, and emtricitabine; efavirenz; tenofovir disoproxil fumarate. The exact mechanism for this interaction is not known, but may involve inhibition of systemic absorption of the anti-retroviral agent. If an increased HIV viral load is confirmed, orlistat should be discontinued.
Osilodrostat: (Major) Reduce the dose of osilodrostat by one-half during coadministration of indinavir; concurrent use may increase osilodrostat exposure and the risk of osilodrostat-related adverse reactions. Osilodrostat is a CYP3A4 substrate and indinavir is a strong CYP3A4 inhibitor.
Osimertinib: (Moderate) Monitor for an increase in indinavir-related adverse reactions if coadministration with osimertinib is necessary. Indinavir is a P-glycoprotein (P-gp) substrate and osimertinib is a P-gp inhibitor. Concomitant use may increase indinavir exposure.
Ospemifene: (Moderate) Coadministration of indinavir and ospemifene may increase ospemifene systemic concentrations and increase the risk of ospemifene-related adverse reactions. Indinavir is a strong CYP3A4 inhibitor, and ospemifene is a CYP3A4 substrate. Strong CYP3A4 inhibitors increase the systemic exposure of ospemifene by approximately1.4-fold.
Oxybutynin: (Moderate) Monitor for an increase in oxybutynin-related adverse reactions if coadministration with protease inhibitors is necessary. Oxybutynin is a CYP3A substrate and protease inhibitors are moderate to strong CYP3A inhibitors. Coadministration with another strong CYP3A inhibitor increased mean oxybutynin plasma concentrations by approximately 2-fold. Concomitant use with moderate CYP3A inhibitors may alter the mean pharmacokinetic parameters of oxybutynin, although the clinical relevance of these potential interactions is unknown.
Oxycodone: (Moderate) Consider a reduced dose of oxycodone with frequent monitoring for respiratory depression and sedation if concurrent use of indinavir is necessary. If indinavir is discontinued, consider increasing the oxycodone dose until stable drug effects are achieved and monitor for evidence of opioid withdrawal. Oxycodone is a CYP3A4 substrate, and coadministration with a strong CYP3A4 inhibitor like indinavir can increase oxycodone exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of oxycodone. If indinavir is discontinued, oxycodone plasma concentrations will decrease resulting in reduced efficacy of the opioid and potential withdrawal syndrome in a patient who has developed physical dependence to oxycodone.
Paclitaxel: (Minor) Indinavir inhibits cytochrome P450 3A4. Although specific interactions have not been studied, Indinavir may reduce the metabolism of CYP3A4 substrates, such as paclitaxel, and caution is warranted with coadministration.
Pacritinib: (Contraindicated) Concurrent use of pacritinib with indinavir is contraindicated due to increased pacritinib exposure which increases the risk of adverse reactions. Pacritinib is a CYP3A substrate and indinavir is a strong CYP3A inhibitor.
Palbociclib: (Major) Avoid coadministration of indinavir with palbociclib; significantly increased palbociclib exposure may occur. Concentrations of indinavir may also increase. If concomitant use cannot be avoided, reduce the dose of palbociclib to 75 mg PO once daily and monitor for increased adverse reactions. If indinavir is discontinued, increase the palbociclib dose (after 3 to 5 half-lives of indinavir) to the dose used before initiation of indinavir. Palbociclib is primarily metabolized by CYP3A4 and indinavir is a strong CYP3A4 inhibitor. In a drug interaction trial, coadministration with another strong CYP3A4 inhibitor increased the AUC and Cmax of palbociclib by 87% and 34%, respectively. Palbociclib is also a weak time-dependent inhibitor of CYP3A and indinavir is a sensitive CYP3A4 substrate.
Palovarotene: (Major) Avoid concomitant use of palovarotene and indinavir due to the risk for increased palovarotene exposure which may increase the risk for adverse effects. Palovarotene is a CYP3A substrate and indinavir is a strong CYP3A inhibitor. Concomitant use with another strong CYP3A inhibitor increased palovarotene overall exposure by 3-fold.
Panobinostat: (Major) Use caution when administering panobinostat and indinavir together; reduce the initial panobinostat dose from 20 mg PO to 10 mg PO. Indinavir is a strong CYP3A4 inhibitor and panobinostat is a CYP3A4 substrate. The panobinostat Cmax and AUC (0-48hr) values were increased by 62% and 73%, respectively, in patients with advanced cancer who received a single 20 mg-dose of panobinostat after taking 14 days of a strong CYP3A4 inhibitor.
Paricalcitol: (Moderate) Paricalcitol is partially metabolized by CYP3A4. Care should be taken when dosing paricalcitol with strong CYP3A4 inhibitors, such as protease inhibitors. Dose adjustments of paricalcitol may be required. Monitor plasma PTH and serum calcium and phosphorous concentrations if a patient initiates or discontinues therapy with this combination.
Paroxetine: (Moderate) Monitor for an increase in paroxetine-related adverse reactions, including serotonin syndrome, if concomitant use with indinavir is necessary. Concomitant use may increase paroxetine exposure. Paroxetine is a CYP2D6 substrate and indinavir is a weak CYP2D6 inhibitor. Coadministration with a weak CYP2D6 inhibitor increased paroxetine overall exposure by 50%.
Pazopanib: (Major) Avoid administering pazopanib with strong CYP3A4 inhibitors, such as indinavir. If co-administration with a strong CYP3A4 inhibitor is unavoidable, reduce the pazopanib dose to 400 mg PO once daily; further dose adjustments may be necessary if adverse effects occur. The concomitant use of pazopanib, a weak CYP3A4 inhibitor and a CYP3A4 substrate, and indinavir, a strong CYP3A4 inhibitor and CYP3A4 substrate, may result in altered pazopanib and/or indinavir concentrations.
Pemigatinib: (Major) Avoid coadministration of pemigatinib and indinavir due to the risk of increased pemigatinib exposure which may increase the risk of adverse reactions. If coadministration is unavoidable, reduce the dose of pemigatinib to 9 mg PO once daily if original dose was 13.5 mg per day and to 4.5 mg PO once daily if original dose was 9 mg per day. If indinavir is discontinued, resume the original pemigatinib dose after 3 elimination half-lives of indinavir. Pemigatinib is a CYP3A4 substrate and indinavir is a strong CYP3A4 inhibitor. Coadministration with another strong CYP3A4 inhibitor increased pemigatinib exposure by 88%.
Pentobarbital: (Major) Barbiturates may increase the metabolism of indinavir and lead to decreased antiretroviral efficacy. In addition, indinavir may inhibit the CYP metabolism of barbiturates, resulting in increased barbiturate concentrations. Appropriate dose adjustments necessary to ensure optimum levels of both anti-retroviral agent and the barbiturate are unknown. Anticonvulsant serum concentrations should be monitored closely if these agents are added; the patient should be observed for changes in the clinical efficacy of the antiretroviral or anticonvulsant regimen.
Perampanel: (Moderate) Concurrent use of perampanel with indinavir, may increase exposure to perampanel and lead to elevated plasma concentrations. Indinavir is a potent inhibitor of CYP3A4, an enzyme responsible for perampanel metabolism. Monitor patients for increases in adverse effects such as anger, anxiety, irritability, somnolence, dizziness, or nausea. Dose adjustment may be required.
Perindopril; Amlodipine: (Moderate) Monitor for symptoms of hypotension and edema if coadministration of amlodipine with protease inhibitors is necessary; adjust the dose of amlodipine as clinically appropriate. Amlodipine is a CYP3A substrate and protease inhibitors are moderate to strong CYP3A inhibitors. Coadministration with a moderate CYP3A inhibitor in elderly hypertensive patients increased systemic exposure to amlodipine by 60%. However, coadministration with another moderate CYP3A inhibitor in healthy volunteers did not significantly change amlodipine exposure.
Pexidartinib: (Major) Avoid concomitant use of pexidartinib and indinavir due to the risk of increased pexidartinib exposure which may increase the risk for adverse effects; concomitant use may also decrease indinavir plasma concentrations and reduce its efficacy. If concomitant use is necessary, reduce the pexidartinib dosage as follows: 500 mg/day or 375 mg/day of pexidartinib, reduce to 125 mg twice daily; 250 mg/day of pexidartinib, reduce to 125 mg once daily. If indinavir is discontinued, increase the pexidartinib dose to the original dose after 3 plasma half-lives of indinavir. Although specific recommendations are unavailable for use with pexidartinib, an increased indinavir dose is recommended (i.e., 1,000 mg PO every 8 hours) when coadministered with other moderate CYP3A inducers. Pexidartinib is a CYP3A and UGT substrate and moderate CYP3A inducer; indinavir is a CYP3A substrate, strong CYP3A inhibitor, and UGT inhibitor. Coadministration of another strong CYP3A inhibitor increased pexidartinib exposure by 70%. Coadministration with another moderate CYP3A inducer decreased indinavir exposure by up to 46%.
Phenobarbital: (Major) Barbiturates may increase the metabolism of indinavir and lead to decreased antiretroviral efficacy. In addition, indinavir may inhibit the CYP metabolism of barbiturates, resulting in increased barbiturate concentrations. Appropriate dose adjustments necessary to ensure optimum levels of both anti-retroviral agent and the barbiturate are unknown. Anticonvulsant serum concentrations should be monitored closely if these agents are added; the patient should be observed for changes in the clinical efficacy of the antiretroviral or anticonvulsant regimen.
Phenobarbital; Hyoscyamine; Atropine; Scopolamine: (Major) Barbiturates may increase the metabolism of indinavir and lead to decreased antiretroviral efficacy. In addition, indinavir may inhibit the CYP metabolism of barbiturates, resulting in increased barbiturate concentrations. Appropriate dose adjustments necessary to ensure optimum levels of both anti-retroviral agent and the barbiturate are unknown. Anticonvulsant serum concentrations should be monitored closely if these agents are added; the patient should be observed for changes in the clinical efficacy of the antiretroviral or anticonvulsant regimen.
Phenytoin: (Major) Hydantoins like phenytoin, ethotoin, fosphenytoin may increase the metabolism of indinavir and lead to decreased efficacy. In addition, indinavir may inhibit the CYP metabolism of hydantoins, resulting in increased hydantoin concentrations.
Pimavanserin: (Major) Because pimavanserin is primarily metabolized by CYP3A4 and CYP3A5, the manufacturer recommends that the pimavanserin dose be reduced to 10 mg/day PO in patients receiving strong inhibitors of CYP3A4 such as indinavir. If these agents are used in combination, the patient should be carefully monitored for pimavanserin-related adverse reactions, including nausea, vomiting, confusion, loss of balance or coordination, and QT prolongation.
Pimozide: (Contraindicated) Coadministration of pimozide with protease inhibitors is contraindicated due to the risk of life threatening arrhythmias such as torsade de pointes (TdP). Pimozide is thought to be metabolized through CYP3A4, and to a lesser extent CYP1A2 and CYP2D6. Elevated pimozide plasma levels are probable when coadministered with CYP450 inhibitors, such as the protease inhibitors. Increased plasma concentrations of pimozide have been associated with QT prolongation and serious cardiovascular adverse events including death due to TdP.
Pioglitazone; Metformin: (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. Another possible mechanism is impairment of beta-cell function. Onset averaged approximately 63 days after initiating protease inhibitor therapy, but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients taking antidiabetic therapy should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated.
Pirtobrutinib: (Major) Avoid concomitant use of pirtobrutinib and indinavir due to the risk of increased pirtobrutinib exposure which may increase the risk for adverse effects. If concomitant use is necessary, reduce the pirtobrutinib dose by 50 mg. If the current pirtobrutinib dosage is 50 mg once daily, interrupt pirtobrutinib treatment for the duration of indinavir use. Resume the previous dose of pirtobrutinib after indinavir is discontinued for 5 half-lives. Pirtobrutinib is a CYP3A substrate and indinavir is a strong CYP3A inhibitor. Concomitant with another strong CYP3A inhibitor increased pirtobrutinib overall exposure by 49%.
Polatuzumab Vedotin: (Moderate) Monitor for increased polatuzumab vedotin toxicity during coadministration of indinavir due to the risk of elevated exposure to the cytotoxic component of polatuzumab vedotin, MMAE. MMAE is metabolized by CYP3A4; indinavir is a strong CYP3A4 inhibitor. Strong CYP3A4 inhibitors are predicted to increase the exposure of MMAE by 45%.
Ponatinib: (Major) Avoid coadministration of ponatinib and indinavir due to the potential for increased ponatinib exposure. If concurrent use cannot be avoided, reduce the ponatinib dose to the next lower dose level (45 mg to 30 mg; 30 mg to 15 mg; 15 mg to 10 mg). If the patient is taking ponatinib 10 mg once daily prior to concurrent use, avoid the use of indinavir and consider alternative therapy. After indinavir has been discontinued for 3 to 5 half-lives, resume the dose of ponatinib that was tolerated prior to starting indinavir. Ponatinib is a CYP3A4 substrate; indinavir is a strong CYP3A4 inhibitor. Coadministration with another strong CYP3A4 inhibitor increased the ponatinib AUC by 78%.
Posaconazole: (Moderate) No clinically significant interactions were observed when posaconazole (200 mg PO daily) was administered with indinavir; thus, indinavir dosage adjustments are not required. However, use caution when administering posaconazole concurrently with indinavir. Posaconazole is a potent inhibitor of CYP3A4, an isoenzyme responsible for the metabolism of indinavir. Further, both posaconazole and indinavir are substrates for the drug efflux protein, P-glycoprotein, which when administered together may increase the absorption or decrease the clearance of the other drug. This complex interaction could ultimately result in altered plasma concentrations of both posaconazole and indinavir.
Pralsetinib: (Major) Avoid concomitant use of indinavir with pralsetinib due to the risk of increased pralsetinib exposure which may increase the risk of adverse reactions. If concomitant use is necessary, reduce the daily dose of pralsetinib by 100 mg. Pralsetinib is a CYP3A substrate and indinavir is a strong CYP3A inhibitor. Coadministration with a strong CYP3A inhibitor is predicted to increase the overall exposure of pralsetinib by 122%.
Pramlintide: (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors.
Primidone: (Major) Barbiturates may increase the metabolism of indinavir and lead to decreased antiretroviral efficacy. In addition, indinavir may inhibit the CYP metabolism of barbiturates, resulting in increased barbiturate concentrations. Appropriate dose adjustments necessary to ensure optimum levels of both anti-retroviral agent and the barbiturate are unknown. Anticonvulsant serum concentrations should be monitored closely if these agents are added; the patient should be observed for changes in the clinical efficacy of the antiretroviral or anticonvulsant regimen.
Probenecid; Colchicine: (Major) Due to the risk for serious colchicine toxicity including multi-organ failure and death, avoid coadministration of colchicine and indinavir in patients with normal renal and hepatic function unless the use of both agents is imperative. Coadministration is contraindicated in patients with renal or hepatic impairment because colchicine accumulation may be greater in these populations. Indinavir can inhibit colchicine's metabolism via CYP3A4, resulting in increased colchicine exposure. If coadministration in patients with normal renal and hepatic function cannot be avoided, adjust the dose of colchicine by either reducing the daily dose or the dosage frequency, and carefully monitor for colchicine toxicity. Specific dosage adjustment recommendations are available for the Colcrys product for patients who have taken indinavir in the past 14 days or require concurrent use: for prophylaxis of gout flares, if the original dose is 0.6 mg twice daily, decrease to 0.3 mg once daily or if the original dose is 0.6 mg once daily, decrease to 0.3 mg once every other day; for treatment of gout flares, give 0.6 mg as a single dose, then 0.3 mg 1 hour later, and do not repeat for at least 3 days; for familial Mediterranean fever, do not exceed a 0.6 mg/day.
Progesterone: (Moderate) Indinavir decreases the metabolism of oral contraceptives and non-oral combination contraceptives; the AUC for ethinyl estradiol and norethindrone increased by 24+/-17% and 26+/-14%, respectively, when coadministered with indinavir. Women receiving hormonal contraceptives and anti-retroviral protease inhibitors (PIs), such as indinavir, should be instructed to report any breakthrough bleeding or other adverse effects to their prescribers. Because hormonal contraceptives do not protect against the transmission of HIV/AIDS and other sexually transmitted diseases, women who receive hormonal contraceptives with PIs should use an additional barrier method of contraception such as condoms. This interaction does not apply to vaginal preparations of progesterone (e.g., Crinone, Endometrin).
Propafenone: (Major) Propafenone should be used with caution with drugs that inhibit CYP3A4, such as antiretroviral protease inhibitors, which could decrease the hepatic metabolism of propafenone.
Quazepam: (Major) CYP3A4 inhibitors, such as protease inhibitors, may reduce the metabolism of quazepam and increase the potential for benzodiazepine toxicity. A decrease in the quazepam dose may be needed.
Quetiapine: (Major) Avoid concurrent use of quetiapine and anti-retroviral protease inhibitors, such as indinavir. Indinavir may inhibit the CYP3A4 metabolism of quetiapine, resulting in elevated quetiapine plasma concentrations. If administration of indinavir is required in a patient taking quetiapine, reduce the quetiapine dose to one sixth of the current dose and monitor for quetiapine-related adverse events. If indinavir is discontinued, increase the quetiapine dose by 6-fold.
Quinidine: (Moderate) Concurrent administration of indinavir and quinidine caused indinavir AUC to increase by about 10%. There were no effects on quinidine pharmacokinetics.
Quinine: (Major) Anti-retroviral protease inhibitors can inhibit the metabolism of CYP3A4 substrates such as quinine. In theory, this interaction could potentially result in drug accumulation and quinine toxicity. Monitor for potential quinine toxicity and decrease quinine dosage if needed.
Quizartinib: (Major) Avoid concomitant use of indinavir with quizartinib due to the risk of increased quizartinib exposure which may increase the risk of adverse reactions. If concomitant use is necessary, reduce the dose of quizartinib to 26.5 mg for patients taking a daily dose of 53 mg, and to 17.7 mg for patients taking a daily dose of 35.4 mg or 26.5 mg; interrupt quizartinib therapy for the duration of the strong CYP3A inhibitor use for patients already taking a daily dose of 17.7 mg. Quizartinib is a CYP3A substrate and indinavir is a strong CYP3A inhibitor. Coadministration with another strong CYP3A inhibitor increased the overall exposure of quizartinib by 94%.
Ramelteon: (Moderate) The serum concentrations of ramelteon may increase when ramelteon is administered with strong CYP3A4 inhibitors like the anti-retroviral protease inhibitors. Because there is the potential for multiple CYPP450 enzyme inhibition interactions between protease inhibitors and ramelteon, caution should be used if these 2 drugs are coadministered. The patient should be monitored closely for toxicity even though ramelteon has a wide therapeutic index.
Ranolazine: (Contraindicated) Ranolazine is contraindicated in patients receiving drugs known to be strong CYP3A inhibitors including indinavir. Inhibition of ranolazine CYP3A metabolism could lead to increased ranolazine plasma concentrations, QTc prolongation, and possibly torsade de pointes. In addition, ranolazine may increase the absorption of indinavir via inhibition of P-glycoprotein transport.
Red Yeast Rice: (Contraindicated) The risk of myopathy, including rhabdomyolysis, may be increased when anti-retroviral protease inhibitors are given in combination with most HMG-CoA reductase inhibitors. Since compounds in red yeast rice claim to have HMG-CoA reductase inhibitor activity, coadministration of red yeast rice with anti-retroviral protease inhibitors is not recommended.
Regorafenib: (Major) Avoid coadministration of regorafenib with indinavir due to increased plasma concentrations of regorafenib and decreased plasma concentrations of the active metabolites M-2 and M-5, which may lead to increased toxicity. Regorafenib is a CYP3A4 substrate and indinavir is a strong CYP3A4 inhibitor. Coadministration with another strong CYP3A4 inhibitor increased regorafenib exposure by 33% and decreased exposure of M-2 and M-5 by 93% each.
Relugolix; Estradiol; Norethindrone acetate: (Moderate) Indinavir has been shown to decrease the metabolism of ethinyl estradiol; a similar interaction may occur with other estrogens used for hormone replacement therapy. Patients should be instructed to report any estrogen- related adverse events. (Moderate) Many anti-retroviral protease inhibitors may interact with hormonal agents like norethindrone, due to their actions on CYP metabolism, particularly CYP3A4. Data on the effects that protease inhibitors have on the serum concentrations of norethindrone are complex and are based mostly off of data with norethindrone-containing contraceptives. The AUC for norethindrone increased by 26+/-14%, respectively, when a combined oral contraceptive was coadministered with indinavir. Women receiving hormonal contraceptives and anti-retroviral protease inhibitors (PIs), such as indinavir, should be instructed to report any breakthrough bleeding or other adverse effects to their prescribers. Because hormonal contraceptives do not protect against the transmission of HIV/AIDS and other sexually transmitted diseases, women who receive hormonal contraceptives with indinavir should use an additional barrier method of contraception such as condoms.
Repaglinide: (Moderate) Coadministration of repaglinide and protease inhibitors may increase or decrease glucose concentrations and increase repaglinide AUC; if coadministration is necessary, repaglinide dosage adjustment may be necessary and increased frequency of glucose monitoring is recommended. New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. In addition, repaglinide is a substrate of the hepatic isoenzyme CYP3A4 and the drug transporter organic anion transporting polypeptide (OATP1B1); protease inhibitors are potent CYP3A4 inhibitors and inhibitors of OATP.
Retapamulin: (Moderate) Coadministration of retapamulin with strong CYP3A4 inhibitors, such as indinavir, in patients younger than 24 months is not recommended. Systemic exposure of topically administered retapamulin may be higher in patients younger than 24 months than in patients 2 years and older. Retapamulin is a CYP3A4 substrate.
Ribavirin: (Major) The concomitant use of ribavirin and anti-retroviral protease inhibitors should be done with caution as both can cause hepatic damage. Most protease inhibitors have been associated with episodes of liver toxicity, with lopinavir/low-dose ritonavir, fosamprenavir/low-dose ritonavir, and nelfinavir being less hepatotoxic and tipranavir/low-dose ritonavir being the most hepatotoxic. Hyperbilirubinemia is often associated with atazanavir and/or indinavir therapy but does not reflect liver damage and is related to the inhibition of UDP glucuronosyltransferase. Overall, the HCV-HIV International Panel recommends the management of hepatotoxicity should be based on the knowledge of the mechanisms involved for each drug. Furthermore, they state that there are lower rates of liver-related mortality in coinfected patients taking HAART, even in those with end-stage liver disease, compared with patients not receiving HAART. Closely monitor patients for treatment-associated toxicities, especially hepatic decompensation.
Ribociclib: (Major) Avoid coadministration of indinavir with ribociclib if possible due to increased ribociclib exposure resulting in a risk of QT prolongation; increased indinavir exposure may also occur. If concomitant use is unavoidable, reduce the dose of ribociclib to 400 mg PO once daily; monitor ECGs for QT prolongation and monitor electrolytes. If indinavir is discontinued, the original dose of ribociclib may be resumed after at least 5 half-lives of indinavir. Ribociclib is a CYP3A4 substrate and strong inhibitor that has been shown to prolong the QTc interval in a dose- and concentration-related manner. Indinavir is a sensitive CYP3A4 substrate and strong inhibitor. Coadministration with another strong CYP3A4 inhibitor increased ribociclib exposure in healthy subjects by 3.2-fold.
Ribociclib; Letrozole: (Major) Avoid coadministration of indinavir with ribociclib if possible due to increased ribociclib exposure resulting in a risk of QT prolongation; increased indinavir exposure may also occur. If concomitant use is unavoidable, reduce the dose of ribociclib to 400 mg PO once daily; monitor ECGs for QT prolongation and monitor electrolytes. If indinavir is discontinued, the original dose of ribociclib may be resumed after at least 5 half-lives of indinavir. Ribociclib is a CYP3A4 substrate and strong inhibitor that has been shown to prolong the QTc interval in a dose- and concentration-related manner. Indinavir is a sensitive CYP3A4 substrate and strong inhibitor. Coadministration with another strong CYP3A4 inhibitor increased ribociclib exposure in healthy subjects by 3.2-fold.
Rifabutin: (Major) Reduce rifabutin dose to 150 mg PO once daily and increase indinavir dose from 800 mg to 1,000 mg 3 times daily if concomitant use is necessary. Monitor for decrease in indinavir efficacy and for rifabutin-related adverse effects, such as uveitis and neutropenia. Concomitant use may increase rifabutin exposure and decrease indinavir exposure. Rifabutin is a CYP3A substrate and moderate CYP3A inducer; indinavir is a CYP3A substrate and strong CYP3A inhibitor. Coadministration increased rifabutin exposure by 173% and decreased indinavir exposure by 34%.
Rifampin: (Contraindicated) Indinavir and rifampin should not be coadministered. Administration of indinavir and rifampin for one week resulted in a 89% decrease in the indinavir AUC. The administration of rifampin with indinavir, alone or in combination with ritonavir, could lead to subtherapeutic concentrations of indinavir.
Rifapentine: (Major) Avoid coadministration of protease inhibitors and rifapentine as concurrent use may result in significant decreases in the plasma concentrations of the antiretroviral agents, leading to a reduction of antiretroviral efficacy and the potential development of viral resistance. Protease inhibitors are CYP3A4 substrates and rifapentine is a strong CYP3A4 inducer. Additionally, HIV patients treated with rifapentine have a higher rate of TB relapse than those treated with other rifamycin-based regimens; an alternative agent is recommended.
Rilpivirine: (Moderate) Close clinical monitoring is advised when administering indinavir with rilpivirine due to an increased potential for rilpivirine-related adverse events. Predictions about the interaction can be made based on metabolic pathways. Indinavir is an inhibitor of the hepatic isoenzyme CYP3A4; rilpivirine is metabolized by this isoenzyme. Coadministration may result in increased rilpivirine plasma concentrations.
Rimegepant: (Major) Avoid coadministration of rimegepant with indinavir; concurrent use may significantly increase rimegepant exposure. Rimegepant is a CYP3A4 substrate and indinavir is a strong CYP3A4 inhibitor. Coadministration of rimegepant with another strong CYP3A4 inhibitor increased rimegepant exposure by 4-fold.
Riociguat: (Moderate) Concomitant use of riociguat with strong cytochrome CYP3A inhibitors may result in hypotension. Indinavir is a potent inhibitor of CYP3A4. Monitor for signs and symptoms of hypotension on initiation and on treatment with strong CYP inhibitors. A dose reduction should be considered in patients who may not tolerate the hypotensive effect of riociguat.
Ripretinib: (Moderate) Monitor patients more frequently for ripretinib-related adverse reactions if coadministered with indinavir. Coadministration may increase the exposure of ripretinib and its active metabolite (DP-5439), which may increase the risk of adverse reactions. Ripretinib and DP-5439 are metabolized by CYP3A4 and indinavir is a strong CYP3A4 inhibitor. Coadministration with another strong CYP3A4 inhibitor increased ripretinib and DP-5439 exposure by 99%.
Ritonavir: (Minor) Ritonavir inhibits the clearance of indinavir, and increased indinavir serum concentrations are seen with concurrent administration. In a pharmacokinetic study in healthy volunteers, the AUC of single indinavir dose increased 185 to 475% during concurrent ritonavir dosing; the mean indinavir half-life increased from 1.2 to 2.7 hours. In an observational study of HIV-infected patients, the combination of indinavir 1200 mg and ritonavir 100 mg, both twice daily, led to high systemic exposure to indinavir and was not well tolerated. The combination of indinavir 800 mg and ritonavir 100 mg twice daily resulted in therapeutic indinavir serum concentrations with improved tolerability and similar maximum serum concentrations as the approved indinavir dosage of 800 mg three times a day. Patients should be closely monitored for possible indinavir toxicity during concurrent administration; indinavir dosage reductions may be necessary. The recommended dosing regimen for this combination is indinavir 800 mg twice daily plus ritonavir 100 or 200 mg twice daily.
Rivaroxaban: (Major) Avoid concomitant administration of rivaroxaban and indinavir; significant increases in rivaroxaban exposure may increase bleeding risk. Rivaroxaban is a substrate of CYP3A4/5 and the P-glycoprotein (P-gp) transporter. Indinavir, a strong CYP3A4 inhibitor, is typically given in combination with ritonavir, a combined P-gp and strong CYP3A4 inhibitor. Concurrent use of a single dose of rivaroxaban and ritonavir, a combined P-gp and strong CYP3A4 inhibitor, led to an increase in the steady-state rivaroxaban AUC by 150% and to an increase in Cmax by 60%. Similar increases in pharmacodynamic effects such as factor Xa inhibition and PT prolongation were also observed.
Roflumilast: (Moderate) Coadminister indinavir and roflumilast cautiously as this may lead to increased systemic exposure to roflumilast; roflumilast-induced adverse effects may occur. Indinavir is a strong inhibitor of CYP3A4 and roflumilast is a CYP3A4 substrate. In a pharmacokinetic study, administration of a single dose of roflumilast in patients receiving another CYP3A4 inhibitor resulted in variably increased roflumilast Cmax and AUC, as well as decreased Cmax and increased AUC of the active metabolite roflumilast N-oxide.
Romidepsin: (Moderate) The concomitant use of romidepsin, a CYP3A4 substrate, and indinavir, a strong CYP3A4 inhibitor, may increase romidepsin plasma exposure. If these agents are used together, monitor patients for signs and symptoms of romidepsin toxicity including hematologic toxicity, infection, and electrocardiogram changes; therapy interruption or discontinuation or a dosage reduction may be required if toxicity develops.
Ruxolitinib: (Major) Reduce the ruxolitinib dosage when coadministered with indinavir in patients with myelofibrosis (MF) or polycythemia vera (PV) as increased ruxolitinib exposure and toxicity may occur. No dose adjustments are necessary for patients with graft-versus-host disease; however, monitor blood counts more frequently for toxicity and adjust ruxolitinib dosage for adverse reactions. In MF patients, reduce the initial dose to 10 mg PO twice daily for platelet count of 100,000 cells/mm3 or more and 5 mg PO once daily for platelet count of 50,000 to 99,999 cells/mm3. In PV patients, reduce the initial dose to 5 mg PO twice daily. In MF or PV patients stable on ruxolitinib dose of 10 mg PO twice daily or more, reduce dose by 50%; in patients stable on ruxolitinib dose of 5 mg PO twice daily, reduce ruxolitinib to 5 mg PO once daily. Avoid the use of indinavir in MF or PV patients who are stable on a ruxolitinib dose of 5 mg PO once daily. Ruxolitinib is a CYP3A4 substrate and indinavir is a strong CYP3A4 inhibitor.
Sacituzumab Govitecan: (Major) Avoid coadministration of sacituzumab govitecan and indinavir due to the risk of increased sacituzumab govitecan exposure which may increase the risk of adverse reactions. The cytotoxic component of sacituzumab govitecan, SN-38, is metabolized by UGT1A1 and indinavir is a UGT1A1 inhibitor. Formal drug interaction studies with sacituzumab govitecan have not been conducted but the concomitant use of UGT1A1 inhibitors is expected to increase SN-38 exposure.
Salmeterol: (Major) Avoid concomitant use of salmeterol with indinavir. Concomitant use increases salmeterol exposure and may increase the incidence and severity of salmeterol-related adverse effects. Signs and symptoms of excessive beta-adrenergic stimulation commonly include tachyarrhythmias, hypertension, and tremor. Salmeterol is a CYP3A substrate and indinavir is a strong CYP3A inhibitor. Coadministration with another strong CYP3A inhibitor increased salmeterol overall exposure 16-fold mainly due to increased bioavailability of the swallowed portion of the dose.
Saquinavir: (Major) There are insufficient data to support any dosing recommendations for indinavir and saquinavir boosted with ritonavir. If prescribed together, closely monitor for adverse events. Both indinavir and saquinavir boosted with ritonavir are substrates and inhibitors of CYP3A4. When indinavir and saquinavir are administered concurrently, a greater than 350% increase in saquinavir AUC is noted; the AUC of indinavir may also increase.
Saxagliptin: (Major) The metabolism of saxagliptin is primarily mediated by CYP3A4/5. Limit the saxagliptin dose to 2.5 mg once daily when coadministered with a strong CYP3A4/5 inhibitor such as indinavir. New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have also been reported with use of anti-retroviral protease inhibitors. Patients on antidiabetic therapy should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated.
Secobarbital: (Major) Barbiturates may increase the metabolism of indinavir and lead to decreased antiretroviral efficacy. In addition, indinavir may inhibit the CYP metabolism of barbiturates, resulting in increased barbiturate concentrations. Appropriate dose adjustments necessary to ensure optimum levels of both anti-retroviral agent and the barbiturate are unknown. Anticonvulsant serum concentrations should be monitored closely if these agents are added; the patient should be observed for changes in the clinical efficacy of the antiretroviral or anticonvulsant regimen.
Segesterone Acetate; Ethinyl Estradiol: (Major) Indinavir decreases the metabolism of oral contraceptives and non-oral combination contraceptives; the AUC for ethinyl estradiol and norethindrone increased by 24+/-17% and 26+/-14%, respectively, when coadministered with indinavir. Women receiving hormonal contraceptives and anti-retroviral protease inhibitors (PIs), such as indinavir, should be instructed to report any breakthrough bleeding or other adverse effects to their prescribers. Because hormonal contraceptives do not protect against the transmission of HIV/AIDS and other sexually transmitted diseases, women who receive hormonal contraceptives with PIs should use an additional barrier method of contraception such as condoms. (Moderate) Indinavir may decrease the metabolism of Segesterone. Indinavir decreases the metabolism of oral contraceptives and non-oral combination contraceptives; the AUC for ethinyl estradiol and norethindrone increased by 24+/-17% and 26+/-14%, respectively, when coadministered with indinavir. It is unknown whether this applies to segesterone. Women receiving hormonal contraceptives and anti-retroviral protease inhibitors (PIs), such as indinavir, should be instructed to report any breakthrough bleeding or other adverse effects to their prescribers. Because hormonal contraceptives do not protect against the transmission of HIV/AIDS and other sexually transmitted diseases, women who receive hormonal contraceptives with PIs should use an additional barrier method of contraception such as condoms.
Selpercatinib: (Major) Avoid coadministration of selpercatinib and indinavir due to the risk of increased selpercatinib exposure which may increase the risk of adverse reactions, including QT prolongation. If coadministration is unavoidable, reduce the dose of selpercatinib to 40 mg PO twice daily if original dose was 120 mg twice daily, and to 80 mg PO twice daily if original dose was 160 mg twice daily. Monitor ECGs for QT prolongation more frequently. If indinavir is discontinued, resume the original selpercatinib dose after 3 to 5 elimination half-lives of indinavir. Selpercatinib is a CYP3A4 substrate and indinavir is a strong CYP3A4 inhibitor. Coadministration with another strong CYP3A4 inhibitor increased selpercatinib exposure by 133%.
Selumetinib: (Major) Avoid coadministration of selumetinib and indinavir due to the risk of increased selumetinib exposure which may increase the risk of adverse reactions. If coadministration is unavoidable, reduce the dose of selumetinib to 20 mg/m2 PO twice daily if original dose was 25 mg/m2 twice daily and 15 mg/m2 PO twice daily if original dose was 20 mg/m2 twice daily. If indinavir is discontinued, resume the original selumetinib dose after 3 elimination half-lives of indinavir. Selumetinib is a CYP3A4 substrate and indinavir is a strong CYP3A4 inhibitor. Coadministration with another strong CYP3A4 inhibitor increased selumetinib exposure by 49%.
Sildenafil: (Major) Sildenafil is contraindicated for use with indinavir when used for pulmonary arterial hypertension (PAH). If used for erectile dysfunction, the dose of sildenafil should not exceed 25 mg in 48 hours with increased monitoring for adverse reactions during times of coadministration. Concurrent use is expected to substantially increase the sildenafil plasma concentrations and may result in increased associated adverse events including hypotension, syncope, visual changes, and prolonged erection. Sildenafil is a sensitive CYP3A4 substrate; indinavir is a strong CYP3A4 inhibitor. In a small pharmacokinetic study, the coadministration of a single dose of sildenafil (25 mg) to patients receiving indinavir (800 mg every 8 hours) resulted in markedly increased sildenafil AUC values (340% increase), as compared to historical controls. In two of the six subjects, prolonged clinical effects of sildenafil were noted for 72 hours after a single dose of sildenafil.
Silodosin: (Major) Silodosin is extensively metabolized by hepatic cytochrome P450 3A4. In theory, drugs that inhibit CYP3A4 such as anti-retroviral protease inhibitors may cause significant increases in silodosin plasma concentrations.
Simvastatin: (Contraindicated) The coadministration of anti-retroviral protease inhibitors with simvastatin is contraindicated. Taking these drugs together may significantly increase the serum concentration of simvastatin; thereby increasing the risk of myopathy and rhabdomyolysis. One report has demonstrated that ritonavir plus saquinavir therapy markedly increases the AUC for simvastatin by 3059%. Simvastatin is a substrate for CYP3A4 and the drug transporter organic anion transporting polypeptide (OATP1B1); protease inhibitors are CYP3A4 and OATP inhibitors.
Siponimod: (Moderate) Concomitant use of siponimod and indinavir may increase siponimod exposure. If the patient is also receiving a drug regimen containing a moderate CYP2C9 inhibitor, use of siponimod is not recommended due to a significant increase in siponimod exposure. Siponimod is a CYP2C9 and CYP3A4 substrate; indinavir is a strong CYP3A4 inhibitor. Coadministration with a moderate CYP2C9/CYP3A4 dual inhibitor led to a 2-fold increase in the exposure of siponimod.
Sirolimus: (Major) Avoid concomitant use of sirolimus and protease inhibitors; a sirolimus dosage reduction may be considered if concomitant use is necessary. Coadministration may increase sirolimus concentrations and increase the risk for sirolimus-related adverse effects.
Sitagliptin: (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. Another possible mechanism is impairment of beta-cell function. Onset averaged approximately 63 days after initiating protease inhibitor therapy but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients taking antidiabetic agents should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated.
Sofosbuvir; Velpatasvir: (Moderate) Use caution when administering velpatasvir with indinavir. Taking these medications together may increase the plasma concentrations of velpatasvir and indinavir, potentially resulting in adverse events. Indinavir is a substrate for the drug transporters P-glycoprotein (P-gp). Velpatasvir is an inhibitor of P-gp. Indinavir is also a potent CYP3A4 inhibitor; velpatasvir is a substrate of CYP3A4.
Sofosbuvir; Velpatasvir; Voxilaprevir: (Moderate) Plasma concentrations of indinavir, a P-glycoprotein (P-gp) substrate, may be increased when administered concurrently with voxilaprevir, a P-gp inhibitor. Monitor patients for increased side effects if these drugs are administered concurrently. (Moderate) Use caution when administering velpatasvir with indinavir. Taking these medications together may increase the plasma concentrations of velpatasvir and indinavir, potentially resulting in adverse events. Indinavir is a substrate for the drug transporters P-glycoprotein (P-gp). Velpatasvir is an inhibitor of P-gp. Indinavir is also a potent CYP3A4 inhibitor; velpatasvir is a substrate of CYP3A4.
Solifenacin: (Major) If coadministered with indinavir, do not exceed a 5 mg daily dose of solifenacin in adults; do not exceed the initial starting dose in pediatric patients. The plasma concentrations of solifenacin may be elevated when administered concurrently with indinavir. Solifenacin is a CYP3A4 substrate and indinavir is a strong CYP3A4 inhibitor. Coadministration of another strong CYP3A4 inhibitor increased solifenacin exposure by 2.7-fold.
Sonidegib: (Major) Avoid the concomitant use of sonidegib and indinavir; sonidegib levels may be significantly increased resulting in an increased risk of adverse events, particularly musculoskeletal toxicity. Sonidegib is a CYP3A4 substrate and indinavir is a strong CYP3A4 inhibitor. Coadministration of another strong CYP3A4 inhibitor increased the mean Cmax and AUC of sonidegib by 2.2-fold and 1.5-fold, respectively.
Sorafenib: (Moderate) Monitor for an increase in indinavir-related adverse reactions if coadministration with sorafenib is necessary. Indinavir is a P-glycoprotein (P-gp) substrate. Sorafenib inhibits P-gp in vitro and may increase the concentrations of concomitantly administered drugs that are P-gp substrates.
Sotorasib: (Moderate) Coadministration of indinavir with sotorasib may result in decreased plasma concentrations of indinavir, leading to a reduction of antiretroviral efficacy and the potential development of viral resistance. Although specific recommendations are unavailable for use with sotorasib, an increased indinavir dose is recommended (i.e., 1,000 mg PO every 8 hours) when coadministered with other moderate CYP3A4 inducers. Indinavir is a CYP3A4 substrate and sotorasib is a moderate CYP3A4 inducer. Coadministration with another moderate CYP3A4 inducer decreased indinavir exposure by up to 46%.
Sparsentan: (Major) Avoid concomitant use of sparsentan and indinavir. Concomitant use may increase sparsentan exposure and the risk for sparsentan-related adverse effects. Sparsentan is a CYP3A substrate and indinavir is a strong CYP3A inhibitor. Concomitant use with another strong CYP3A inhibitor increased sparsentan overall exposure by 174%.
St. John's Wort, Hypericum perforatum: (Contraindicated) Coadministration of protease inhibitors and St. John's wort is contraindicated due to the risk of decreased plasma concentrations of the antiviral agents, leading to a reduction of antiretroviral efficacy and the potential development of viral resistance. Protease inhibitors are CYP3A4 substrates and St. John's wort is a strong CYP3A4 inducer.
Stiripentol: (Moderate) Consider a dose adjustment of indinavir when coadministered with stiripentol. Coadministration may alter plasma concentrations of indinavir resulting in an increased risk of adverse reactions and/or decreased efficacy. Indinavir is a sensitive CYP3A4 substrate. In vitro data predicts inhibition or induction of CYP3A4 by stiripentol potentially resulting in clinically significant interactions.
Sufentanil: (Moderate) Because the dose of the sufentanil sublingual tablets cannot be titrated, consider an alternate opiate if protease inhibitors must be administered. Consider a reduced dose of sufentanil injection with frequent monitoring for respiratory depression and sedation if concurrent use of protease inhibitors is necessary. If protease inhibitors is discontinued, consider increasing the sufentanil injection dose until stable drug effects are achieved and monitor for evidence of opioid withdrawal. Sufentanil is a CYP3A substrate, and coadministration with a CYP3A inhibitor like protease inhibitors can increase sufentanil exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of sufentanil. If protease inhibitors is discontinued, sufentanil plasma concentrations will decrease resulting in reduced efficacy of the opioid and potential withdrawal syndrome in a patient who has developed physical dependence to sufentanil.
Sulfamethoxazole; Trimethoprim, SMX-TMP, Cotrimoxazole: (Minor) Concomitant administration of indinavir and trimethoprim should be done with caution. Administration of indinavir and sulfamethoxazole; trimethoprim, SMX-TMP significantly increased the AUC of trimethoprim. There was no effect on the AUC of indinavir or sulfamethoxazole.
Sulfonylureas: (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. A possible mechanism is impairment of beta-cell function. Onset averaged approximately 63 days after initiating protease inhibitor therapy, but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients on antidiabetic agents should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated.
Sunitinib: (Major) Avoid coadministration of indinavir with sunitinib if possible due to increased sunitinib exposure, which may increase the risk of QT prolongation. If concomitant use is unavoidable, monitor the QT interval more frequently and consider reducing the daily dose of sunitinib to a minimum of 37.5 mg for patients with GIST or RCC, and to a minimum of 25 mg for patients with pNET. Sunitinib is a CYP3A4 substrate and indinavir is a strong CYP3A4 inhibitor. Coadministration with another strong CYP3A4 inhibitor increased exposure to sunitinib and its primary active metabolite by 51%.
Suvorexant: (Major) Coadministration of suvorexant and indinavir is not recommended due to the potential for significantly increased suvorexant exposure. Suvorexant is a CYP3A4 substrate. Indinavir is a strong CYP3A4 inhibitor. Coadministration of another strong CYP3A4 inhibitor increased the suvorexant AUC by 2.8-fold.
Tacrolimus: (Major) Decrease tacrolimus dose and closely monitor tacrolimus serum concentrations if coadministration with indinavir is necessary; additional dosage reductions may be required. Concurrent use may increase tacrolimus serum concentrations and increase the risk of toxicity. Consider a tacrolimus dose reduction to 0.5 mg to 1 mg once per week when coadministered with a protease inhibitor. In one study, the tacrolimus half-life increased to 10.6 days in one patient and 20.6 days in another following coadministration of tacrolimus and a protease inhibitor combination. Up to 80% reductions in tacrolimus dosages and 7-fold increase in dosage intervals were needed when tacrolimus was coadministered with protease inhibitors in studies. Tacrolimus is a sensitive CYP3A4 substrate with a narrow therapeutic index; indinavir is a strong CYP3A4 inhibitor.
Tadalafil: (Major) For the treatment of erectile dysfunction, do not exceed 10 mg of tadalafil within 72 hours of indinavir for the 'as needed' dose or 2.5 mg daily for the 'once-daily' dose. Avoid the use of tadalafil for pulmonary hypertension during the initiation of indinavir therapy. Stop tadalafil at least 24 hours prior to starting indinavir. After at least 1 week of indinavir therapy, resume tadalafil at 20 mg once daily. Increase to 40 mg once daily based on tolerability. Tadalafil is metabolized by CYP3A4, and indinavir is a potent inhibitor of CYP3A4. Substantially increased tadalafil plasma concentrations may result in increased adverse events including hypotension, syncope, visual changes, and prolonged erection. Although the manufacturer of tadalafil provides recommended dosing for coadministration with ritonavir only, the FDA recommends the same dosage adjustment for the coadministration of tadalafil with all protease inhibitors.
Tamsulosin: (Major) Plasma concentrations of tamsulosin may be increased with concomitant use of anti-retroviral protease inhibitors. Tamsulosin is extensively metabolized by CYP3A4 and CYP2D6 hepatic enzymes. In clinical evaluation, concomitant treatment with a strong CYP3A4 inhibitor resulted in significant increases in tamsulosin exposure. Such increases in tamsulosin concentrations may be expected to produce clinically significant and potentially serious side effects, such as hypotension. Therefore, concomitant use of tamsulosin with a strong CYP3A4 inhibitor, or an agent with both CYP3A4 and CYP2D6 inhibitor activity, should be avoided.
Tasimelteon: (Major) Concurrent use of tasimelteon and strong inhibitors of CYP3A4, such as indinavir, should be avoided if possible. Because tasimelteon is partially metabolized via CYP3A4, a large increase in exposure of tasimelteon with the potential for adverse reactions is possible if these drugs are coadministered. During administration of tasimelteon and another potent CYP3A4 inhibitor, tasimelteon exposure increased by about 50%.
Tazemetostat: (Major) Avoid coadministration of tazemetostat with indinavir as concurrent use may increase tazemetostat exposure and the frequency and severity of adverse reactions. Tazemetostat is a CYP3A4 substrate and indinavir is a strong CYP3A4 inhibitor. Coadministration of a moderate CYP3A4 inhibitor increased tazemetostat exposure by 3.1-fold.
Telmisartan; Amlodipine: (Moderate) Monitor for symptoms of hypotension and edema if coadministration of amlodipine with protease inhibitors is necessary; adjust the dose of amlodipine as clinically appropriate. Amlodipine is a CYP3A substrate and protease inhibitors are moderate to strong CYP3A inhibitors. Coadministration with a moderate CYP3A inhibitor in elderly hypertensive patients increased systemic exposure to amlodipine by 60%. However, coadministration with another moderate CYP3A inhibitor in healthy volunteers did not significantly change amlodipine exposure.
Temsirolimus: (Major) Avoid coadministration of indinavir with temsirolimus due to increased plasma concentrations of the primary active metabolite of temsirolimus (sirolimus); exposure to indinavir may also increase. If concomitant use is unavoidable, consider reducing the dose of temsirolimus to 12.5 mg per week. Allow a washout period of approximately 1 week after discontinuation of indinavir before increasing temsirolimus to its original dose. Temsirolimus is a CYP3A4 substrate and indinavir is a strong CYP3A4 inhibitor. Coadministration with another strong CYP3A4 inhibitor did not significantly affect temsirolimus exposure, but increased the AUC and Cmax of sirolimus by 3.1-fold and 2.2-fold, respectively. Indinavir is also a P-glycoprotein (P-gp) substrate and temsirolimus is a P-gp inhibitor. Concomitant use may lead to increased concentrations of indinavir.
Terbinafine: (Moderate) Due to the risk for terbinafine related adverse effects, caution is advised when coadministering indinavir. Although this interaction has not been studied by the manufacturer, and published literature suggests the potential for interactions to be low, taking these drugs together may increase the systemic exposure of terbinafine. Predictions about the interaction can be made based on the metabolic pathways of both drugs. Terbinafine is metabolized by at least 7 CYP isoenyzmes, with major contributions coming from CYP3A4; indinavir is an inhibitor of this enzyme. Monitor patients for adverse reactions if these drugs are coadministered.
Tezacaftor; Ivacaftor: (Major) If indinavir and ivacaftor are taken together, administer ivacaftor at the usual recommended dose but reduce the frequency to twice weekly. Coadministration is not recommended in patients younger than 6 months. Ivacaftor is a CYP3A substrate and indinavir is a strong CYP3A inhibitor. Coadministration with another strong CYP3A inhibitor increased ivacaftor exposure by 8.5-fold. (Major) Reduce the dosing frequency of tezacaftor; ivacaftor when coadministered with indinavir; coadministration may increase tezacaftor; ivacaftor exposure and adverse reactions. When combined, dose 1 tezacaftor; ivacaftor combination tablet twice a week, approximately 3 to 4 days apart (i.e., Day 1 and Day 4). The evening dose of ivacaftor should not be taken. Both tezacaftor and ivacaftor are CYP3A substrates (ivacaftor is a sensitive substrate); indinavir is a strong CYP3A inhibitor. Coadministration of a strong CYP3A inhibitor increased tezacaftor and ivacaftor exposure 4- and 15.6-fold, respectively.
Thiazolidinediones: (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. Onset averaged approximately 63 days after initiating protease inhibitor therapy, but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients on antidiabetic agents should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated. In addition, coadministration of atazanavir with rosiglitazone may result in elevated rosiglitazone plasma concentrations. Rosiglitazone is a substrate for CYP2C8; atazanavir is a weak inhibitor of CYP2C8.
Thiotepa: (Major) Avoid the concomitant use of thiotepa and indinavir if possible; reduced metabolism to the active thiotepa metabolite may result in decreased thiotepa efficacy. Consider an alternative agent with no or minimal potential to inhibit CYP3A4. If coadministration is necessary, monitor patients for signs of reduced thiotepa efficacy. In vitro, thiotepa is metabolized via CYP3A4 to the active metabolite, TEPA; indinavir is a strong CYP3A4 inhibitor.
Thyroid hormones: (Moderate) Closely monitor the thyroid status of any patient taking thyroid hormones concurrently with indinavir. Hyperthyroidism was reported in a patient when indinavir was added to a stable levothyroxine dosing regimen. Indinavir inhibits UDP-glucuronosyl transferase, which may have decreased the metabolism of the thyroid hormone and may explain the increased thyroxine levels observed. Patients receiving levothyroxine should be carefully monitored when indinavir is started; if hyperthyroidism is detected, reducing the levothyroxine dose should reestablish a euthyroid state. Theoretically, similar interactions may occur between indinavir and other thyroid hormones, given that both T4 and T3 are metabolized to some degree via hepatic UDP-glucuronosyl transferase.
Ticagrelor: (Major) Avoid the concomitant use of ticagrelor and strong CYP3A4 inhibitors, such as indinavir. Ticagrelor is a substrate of CYP3A4/5 and concomitant use with indinavir substantially increases ticagrelor exposure which may increase the bleeding risk.
Tisotumab Vedotin: (Moderate) Monitor for tisotumab vedotin-related adverse reactions if concomitant use with indinavir is necessary due to increased monomethyl auristatin E (MMAE) exposure which may increase the incidence and severity of adverse reactions. MMAE, the active component of tisotumab vedotin, is a CYP3A substrate and indinavir is a strong CYP3A inhibitor. Clinical drug interaction studies have not been conducted for tisotumab vedotin. However, coadministration of another antibody-drug conjugate that contains MMAE with a strong CYP3A inhibitor increased unconjugated MMAE exposure by 34%.
Tofacitinib: (Major) A dosage reduction of tofacitinib is necessary if coadministered with indinavir. In patients receiving 5 mg or less twice daily, reduce to once daily dosing; in patients receiving 10 mg twice daily, reduce to 5 mg twice daily; in patients receiving 22 mg once daily of the extended-release (XR) formulation, switch to 11 mg XR once daily; in patients receiving 11 mg XR once daily, switch to the immediate-release formulation at a dose of 5 mg once daily. Tofacitinib exposure is increased when coadministered with indinavir. Indinavir is a strong CYP3A4 inhibitor; tofacitinib is a CYP3A4 substrate. Coadministration with another strong CYP3A4 inhibitor increased tofacitinib exposure by 2-fold.
Tolterodine: (Major) Reduce the dose of immediate-release tolterodine to 1 mg twice daily and extended-release tolterodine to 2 mg once daily if coadministered with indinavir. Concurrent use may increase tolterodine exposure. Indinavir is a strong CYP3A4 inhibitor. In CYP2D6 poor metabolizers, the CYP3A4 pathway becomes important in tolterodine elimination. Because it is difficult to assess which patients will be poor CYP2D6 metabolizers, reduced doses of tolterodine are advised when administered with strong CYP3A4 inhibitors. In a drug interaction study, coadministration of a strong CYP3A4 inhibitor increased the tolterodine AUC by 2.5-fold in CYP2D6 poor metabolizers.
Tolvaptan: (Contraindicated) The concomitant use of tolvaptan and indinavir is contraindicated. Concurrent use is expected to increase tolvaptan exposure. Tolvaptan is a sensitive CYP3A4 substrate; indinavir is a strong inhibitor of CYP3A4. Coadministration of another strong CYP3A4 inhibitor increased tolvaptan exposure 5-fold. No data exists regarding the appropriate dose adjustment needed to allow safe administration of tolvaptan with strong CYP3A4 inhibitors.
Toremifene: (Major) Avoid coadministration of indinavir with toremifene if possible due to increased plasma concentrations of toremifene which may result in QT prolongation. If concomitant use is unavoidable, closely monitor ECGs for QT prolongation and monitor electrolytes; correct hypokalemia or hypomagnesemia prior to administration of toremifene. Toremifene is a CYP3A4 substrate that has been shown to prolong the QTc interval in a dose- and concentration-related manner, and indinavir is a strong CYP3A4 inhibitor. Coadministration with another strong CYP3A4 inhibitor increased toremifene exposure by 2.9-fold; exposure to N-demethyltoremifene was reduced by 20%.
Trabectedin: (Major) Avoid the concomitant use of trabectedin with indinavir due to the risk of increased trabectedin exposure. Trabectedin is a CYP3A substrate and indinavir is a strong CYP3A inhibitor. Coadministration with another strong CYP3A inhibitor increased the systemic exposure of a single dose of trabectedin (0.58 mg/m2 IV) by 66% compared to a single dose of trabectedin (1.3 mg/m2) given alone.
Trandolapril; Verapamil: (Moderate) Coadministration of ritonavir with verapamil may increase the serum concentrations of verapamil, potentially resulting in verapamil toxicity. The manufacturer for ritonavir recommends caution when coadministering this combination. A similar effect could be expected with other anti-retroviral protease inhibitors, which are also inhibitors of CYP3A4.
Trazodone: (Major) Avoid coadministration of trazodone with indinavir due to the potential for increased trazodone exposure and associated adverse effects including QT prolongation. If concurrent use cannot be avoided, consider a reduced dose of trazodone based on tolerability. Trazodone is a CYP3A4 substrate; indinavir is a strong CYP3A4 inhibitor. Coadministration of other strong CYP3A4 inhibitors increased the exposure of trazodone compared to the use of trazodone alone.
Triamcinolone: (Moderate) Indinavir may inhibit the CYP3A4 metabolism of triamcinolone, resulting in increased plasma triamcinolone concentrations and reduced serum cortisol concentrations. There have been reports of clinically significant drug interactions in patients receiving another strong CYP3A4 inhibitor with triamcinolone, resulting in systemic corticosteroid effects including, but not limited to, Cushing syndrome and adrenal suppression. Consider the benefit-risk of concomitant use and monitor for systemic corticosteroid side effects. Consider using an alternative treatment to triamcinolone, such as a corticosteroid not metabolized by CYP3A4 (i.e., beclomethasone or prednisolone). In some patients, a corticosteroid dose adjustment may be needed. If corticosteroid therapy is to be discontinued, consider tapering the dose over a period of time to decrease the potential for withdrawal.
Triazolam: (Contraindicated) Coadministration of triazolam, a primary CYP3A4 substrate, with strong CYP3A4 inhibitors, such as protease inhibitors, is contraind icated by the manufacturer of triazolam due to the risk for increased and prolonged sedation and respiratory depression. Concurrent use is expected to produce large increases in systemic exposure to triazolam, with the potential for serious adverse effects.
Trimethoprim: (Minor) Concomitant administration of indinavir and trimethoprim should be done with caution. Administration of indinavir and sulfamethoxazole; trimethoprim, SMX-TMP significantly increased the AUC of trimethoprim. There was no effect on the AUC of indinavir or sulfamethoxazole.
Tucatinib: (Moderate) Coadministration of indinavir with tucatinib may result in increased plasma concentrations of indinavir, leading to an increase in indinavir-related adverse effects. Although specific recommendations are unavailable for use with tucatinib, a reduced indinavir dose of 600 mg PO every 8 hours is recommended when coadministered with other strong CYP3A4 inhibitors. Indinavir is a CYP3A4 substrate and tucatinib is a strong CYP3A4 inhibitor.
Ubrogepant: (Contraindicated) Coadministration of ubrogepant and indinavir is contraindicated as concurrent use may increase ubrogepant exposure and the risk of adverse effects. Ubrogepant is a CYP3A4 substrate; indinavir is a strong CYP3A4 inhibitor. Coadministration with another strong CYP3A4 inhibitor resulted in a 9.7-fold increase in the exposure of ubrogepant.
Ulipristal: (Minor) Ulipristal is a substrate of CYP3A4 and indinavir is a CYP3A4 inhibitor. Concomitant use may increase the plasma concentration of ulipristal resulting in an increased risk for adverse events.
Upadacitinib: (Major) During concomitant use of upadacitinib and indinavir reduce the upadacitinib dosage to 15 mg once daily. During induction for ulcerative colitis and Crohn's disease reduce the upadacitinib dosage to 30 mg once daily. Concomitant use may increase upadacitinib exposure and risk for adverse effects. Concomitant use with another strong CYP3A inhibitor increased upadacitinib overall exposure 1.75-fold.
Valbenazine: (Major) The dose of valbenazine should be reduced to 40 mg once daily during co-administration with a strong CYP3A4 inhibitor, such as indinavir. QT prolongation is not clinically significant at valbenazine concentrations expected with recommended dosing; however, valbenazine concentrations may be higher in patients taking a strong CYP3A4 inhibitor and QT prolongation may become clinically significant.
Vardenafil: (Major) Do not use vardenafil orally disintegrating tablets with indinavir due to increased vardenafil exposure; do not exceed a single dose of 2.5 mg per 24-hour period of vardenafil oral tablets. Vardenafil is primarily metabolized by CYP3A4/5; indinavir is a strong CYP3A4 inhibitor. Coadministration with other strong CYP3A4 inhibitors increased the AUC of vardenafil by 10- to 16-fold.
Vemurafenib: (Major) Avoid the concomitant use of vemurafenib and indinavir; vemurafenib exposure may be increased resulting in an increased risk of adverse events, including QT prolongation. If use with indinavir cannot be avoided, consider a vemurafenib dose reduction; monitor patients closely for the development of adverse events and dose reduce or discontinue therapy based on manufacturer guidance. Vemurafenib is a CYP3A4 substrate; indinavir is a strong CYP3A4 inhibitor. Coadministration with another strong CYP3A4 inhibitor increased the exposure of vemurafenib by 40%.
Venetoclax: (Major) Coadministration of indinavir with venetoclax is contraindicated during the initiation and ramp-up phase in patients with chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL); consider an alternative medication or adjust the venetoclax dose with close monitoring for toxicity (e.g., hematologic toxicity, GI toxicity, and tumor lysis syndrome) in patients receiving a steady daily dose of venetoclax if concurrent use is necessary. In patients with acute myeloid leukemia (AML), reduce the venetoclax dose and monitor for toxicity during concurrent use. Resume the original venetoclax dose 2 to 3 days after discontinuation of indinavir. Specific venetoclax dosage adjustments are as follows: CLL/SLL patients at steady daily dose: 100 mg/day. AML patients: 10 mg on day 1, 20 mg on day 2, 50 mg on day 3, then 100 mg/day starting on day 4. Venetoclax is a CYP3A4 substrate; indinavir is a strong CYP3A4 inhibitor. Coadministration of strong CYP3A4 inhibitors increased the venetoclax AUC by 90% to 690% in drug interaction studies.
Venlafaxine: (Minor) Serum concentrations of indinavir may decrease when coadministered with venlafaxine. In a study of 9 healthy volunteers, coadministration resulted in a 28% decrease in the AUC of indinavir and a 36% decrease in indinavir Cmax. Indinavir did not affect the pharmacokinetics of venlafaxine or its metabolite (i.e., ODV). The clinical significance of this interaction is unknown.
Verapamil: (Moderate) Coadministration of ritonavir with verapamil may increase the serum concentrations of verapamil, potentially resulting in verapamil toxicity. The manufacturer for ritonavir recommends caution when coadministering this combination. A similar effect could be expected with other anti-retroviral protease inhibitors, which are also inhibitors of CYP3A4.
Vilazodone: (Major) Because CYP3A4 is the primary isoenzyme involved in the metabolism of vilazodone, the manufacturer of vilazodone recommends that the daily dose not exceed 20 mg/day during concurrent use of a strong CYP3A4 inhibitor, such as indinavir. The original vilazodone dose can be resumed when the CYP3A4 inhibitor is discontinued.
Vinblastine: (Moderate) Monitor for an earlier onset and/or increased severity of vinblastine-related adverse reactions, including myelosuppression, constipation, and peripheral neuropathy, if coadministration with indinavir is necessary. Vinblastine is a CYP3A4 substrate and indinavir is a strong CYP3A4 inhibitor.
Vincristine Liposomal: (Major) The plasma concentrations of vincristine may be significantly elevated when administered concurrently with protease inhibitors. Consideration should be given to temporarily withholding the regimen in patients who develop significant hematological or gastrointestinal toxicity when protease inhibitors are coadministered with vincristine. Vincristine is a CYP3A4 and P-glycoprotein (P-gp) substrate; protease inhibitors are CYP3A4 inhibitors and some also inhibit P-gp. If the antiretroviral regimen needs to be withheld for a prolonged period, consider use of a revised regimen that does not include a CYP3A4 and P-gp inhibitor.
Vincristine: (Major) The plasma concentrations of vincristine may be significantly elevated when administered concurrently with protease inhibitors. Consideration should be given to temporarily withholding the regimen in patients who develop significant hematological or gastrointestinal toxicity when protease inhibitors are coadministered with vincristine. Vincristine is a CYP3A4 and P-glycoprotein (P-gp) substrate; protease inhibitors are CYP3A4 inhibitors and some also inhibit P-gp. If the antiretroviral regimen needs to be withheld for a prolonged period, consider use of a revised regimen that does not include a CYP3A4 and P-gp inhibitor.
Vinorelbine: (Moderate) Monitor for an earlier onset and/or increased severity of vinorelbine-related adverse reactions, including constipation and peripheral neuropathy, if coadministration with indinavir is necessary. Vinorelbine is a CYP3A4 substrate and indinavir is a strong CYP3A4 inhibitor.
Voclosporin: (Contraindicated) Concomitant use of voclosporin and indinavir is contraindicated; concomitant use may increase the exposure of voclosporin and the risk of voclosporin-related adverse effects such as nephrotoxicity, hypertension, and QT prolongation. Voclosporin is a sensitive CYP3A4 substrate and indinavir is a strong CYP3A4 inhibitor. Coadministration with another strong CYP3A4 inhibitor increased voclosporin exposure by approximately 19-fold.
Vonoprazan; Amoxicillin; Clarithromycin: (Moderate) Clarithromycin is a CYP3A4 inhibitor and may decrease the systemic clearance of indinavir, a CYP3A4 substrate. Patients with impaired renal function may require a reduced dosage of clarithromycin.
Vorapaxar: (Major) Avoid coadministration of vorapaxar and indinavir. Increased serum concentrations of vorapaxar are possible when vorapaxar, a CYP3A4 substrate, is coadministered with indinavir, a strong CYP3A inhibitor. Increased exposure to vorapaxar may increase the risk of bleeding complications.
Warfarin: (Moderate) Monitor the INR and adjust the dose as necessary if warfarin is coadministered with indinavir. Concurrent use may increase the INR and the risk of bleeding. Indinavir is a CYP3A4 inhibitor and the R-enantiomer of warfarin is a 3A4 substrate. The S-enantiomer exhibits 2 to 5 times more anticoagulant activity than the R-enantiomer, but the R-enantiomer generally has a slower clearance.
Zaleplon: (Moderate) Zaleplon is partially metabolized by CYP3A4, and concurrent use of strong CYP3A4 inhibitors, such as indinavir, may decrease the clearance of zaleplon. Routine dosage adjustments of zaleplon are not required. Dosage adjustments should be made on an individual basis according to efficacy and tolerability.
Zanubrutinib: (Major) Decrease the zanubrutinib dose to 80 mg PO once daily if coadministered with indinavir. Coadministration may result in increased zanubrutinib exposure and toxicity (e.g., infection, bleeding, and atrial arrhythmias). Interrupt zanubrutinib therapy as recommended for adverse reactions. After discontinuation of indinavir, resume the previous dose of zanubrutinib. Zanubrutinib is a CYP3A4 substrate; indinavir is a strong CYP3A4 inhibitor. The AUC of zanubrutinib was increased by 278% when coadministered with another strong CYP3A4 inhibitor.
Zidovudine, ZDV: (Moderate) When indinavir and zidovudine, ZDV were administered concurrently, the AUC of indinavir and zidovudine was increased by 13% +/- 48% and 17% +/- 23%, respectively. Dosage adjustments are not recommended when zidovudine is administered with indinavir.
Zolpidem: (Moderate) Consider decreasing the dose of zolpidem if coadministration with protease inhibitors is necessary. Zolpidem is a CYP3A4 substrate and protease inhibitors are strong CYP3A4 inhibitors. Coadministration with strong CYP3A4 inhibitors increased the AUC of zolpidem by 34% to 70%.
Zonisamide: (Minor) Zonisamide is a weak inhibitor of P-glycoprotein (P-gp), and indinavir is a substrate of P-gp. There is theoretical potential for zonisamide to affect the pharmacokinetics of drugs that are P-gp substrates. Use caution when starting or stopping zonisamide or changing the zonisamide dosage in patients also receiving drugs which are P-gp substrates.

Chemet/Crixivan Oral Cap: 200mg, 400mg

NOTE: The following maximum dosage limits apply for typical indinavir use; maximum dosage limits may be altered based on certain individual patient circumstances, such as in the case of specific drug interactions.

Indinavir is a competitive inhibitor of HIV-1 protease, an enzyme involved in the replication of HIV. During the later stages of the HIV growth cycle, the gag and gag-pol gene products are first translated into polyproteins and become immature virus budding particles. HIV protease is responsible for cleaving these precursor molecules to produce the final structural proteins of a mature virion core, and to activate reverse transcriptase for a new round of infection. Thus, protease is necessary for the production of mature virions. Viral protease inhibition renders the virus noninfectious. In test systems, the IC95 (95% inhibitory concentration) of indinavir was 25 to 100 nM. Indinavir has been shown to be synergistic with zidovudine and didanosine in vitro cell cultures.
 
The development of resistance to HIV-protease inhibitors occurs as a result of mutations. Mutations produce amino acid substitutions in the viral protease, thereby altering the targets for protease inhibitors. There have been 11 amino acid residue positions identified that are associated with resistance to protease inhibitors. Greater levels of resistance were associated with the expression of multiple amino acid substitutions. Varying degrees of cross-resistance has been observed between indinavir and other protease inhibitors.[28731]

Indinavir is administered orally. Once absorbed, approximately 60% is bound to plasma proteins. It is metabolized to 7 metabolites, 1 glucuronide conjugate and 6 oxidative metabolites. In vitro studies show that the oxidative metabolites are generated as a result of metabolism by the cytochrome P450 3A4 enzyme. About 83% of a 400 mg dose is excreted in the feces and urine, with less than 20% excreted unchanged in the urine. The elimination half-life is approximately 1.8 hours.
 
Affected cytochrome P450 isoenzymes and drug transporters: CYP3A4, CYP2D6, P-gp, UGT1A1
Indinavir is a substrate of CYP3A4 and P-glycoprotein (P-gp), a significant inhibitor of CYP3A4, and may be a weak inhibitor of CYP2D6.[34557] [28731] Studies have also found indinavir to be an inhibitor of uridine diphosphoglucuronosyltransferase UGT1A1.[34813] [60258]

Antiretroviral therapy should be provided to all women during pregnancy, regardless of HIV RNA concentrations or CD4 cell count. Using highly active antiretroviral combination therapy (HAART) to maximally suppress viral replication is the most effective strategy to prevent the development of resistance and to minimize the risk of perinatal transmission. In treatment-naive women, begin HAART as soon as pregnancy is recognized or HIV is diagnosed, without waiting for the results of resistance testing; subsequent modifications to the treatment regimen should be made once the test results are available. Women who are currently receiving antiretroviral treatment when pregnancy is recognized should continue their treatment regimen if it is currently effective in suppressing viral replication; consider resistance testing if HIV RNA concentrations are more than 500 copies/mL. For women not currently receiving HAART, but who have previously received treatment, obtain a complete and accurate history of all prior antiretroviral regimens used and results of prior resistance testing, and perform resistance testing if HIV RNA concentrations are more than 500 copies/mL; treatment should be initiated prior to receiving resistance test results. Due to substantial alterations in indinavir pharmacokinetics during pregnancy, indinavir is not recommended for used in pregnant patients. According to HIV guidelines, women who become pregnant while taking indinavir should be switched to an alternative treatment regimen. Available data from the Antiretroviral Pregnancy Registry (APR), which includes over 280 first trimester exposures to indinavir, have shown no difference in the risk of overall major birth defects when compared to the 2.7% background rate among pregnant women in the US. When indinavir exposure occurred in the first trimester, prevalence of defects was 2.4% (95% CI: 1.0 to 4.9). Regular laboratory monitoring is recommended to determine antiretroviral efficacy. Monitor CD4 counts at the initial visit. Women who have been on HAART for at least 2 years and have consistent viral suppression and CD4 counts consistently greater than 300 cells/mm3 do not need CD4 counts monitored after the initial visit during the pregnancy. However, CD4 counts should be monitored every 3 months during pregnancy for women on HAART less than 2 years, women with CD4 count less than 300 cells/mm3, or women with inconsistent adherence or detectable viral loads. Monitor plasma HIV RNA at the initial visit, 2 to 4 weeks after initiating or changing therapy, monthly until undetectable, then at least every 3 months during pregnancy, and at 34 to 36 weeks gestation. Perform antiretroviral resistance assay (genotypic testing, and if indicated, phenotypic testing) at baseline in all women with HIV RNA concentrations greater than 500 copies/mL, unless they have already been tested for resistance. First trimester ultrasound is recommended to confirm gestational age and provide an accurate estimation of gestational age at deliver. A second trimester ultrasound can be used for both anatomical survey and determination of gestational age in those patients not seen until later in gestation. Perform standard glucose screening in women receiving antiretroviral therapy at 24 to 28 weeks gestation, although it should be noted that some experts would perform earlier screening with ongoing chronic protease inhibitor-based therapy initiated prior to pregnancy, similar to recommendations for women with high-risk factors for glucose intolerance. Liver function testing is recommended within 2 to 4 weeks after initiating or changing antiretroviral therapy, and approximately every 3 months thereafter during pregnancy (or as needed). All pregnant women should be counseled about the importance of adherence to their antiretroviral regimen to reduce the potential for development of resistance and perinatal transmission. It is strongly recommended that antiretroviral therapy, once initiated, not be discontinued. If a woman decides to discontinue therapy, a consultation with an HIV specialist is recommended. There is a pregnancy exposure registry that monitors outcomes in pregnant patients exposed to indinavir; information about the registry can be obtained at www.apregistry.com or by calling 1-800-258-4263.

To reduce the risk of postnatal transmission, mothers with HIV within the United States are advised by the Centers for Disease Control and Prevention to avoid breast-feeding. This recommendation applies to both untreated women and women who are receiving antiretroviral therapy. If a mother with HIV opts to breast-feed, the infant should undergo immediate diagnostic and virologic HIV testing. Testing should continue throughout breast-feeding and up to 6 months after cessation of breast-feeding. For expert consultation, health care workers may contact the Perinatal HIV Hotline (888-448-8765).[42452] Limited data suggest indinavir is excreted into breast-milk. An analysis of one woman's breast milk, following administration of indinavir 600 mg twice daily, revealed milk concentrations ranging between 90% and 540% of the maternal serum concentration. Other antiretroviral medications whose passage into human breast milk have been evaluated include nevirapine, zidovudine, lamivudine, and nelfinavir.