CLASSES

Integrase Strand Transfer Inhibitor (INSTI) and Nucleoside and Nucleotide Reverse Transcriptase Inhibitor (NRTI) Combinations

BOXED WARNING

Perform HBV screening in any patient who presents with HIV infection to assure appropriate treatment. Patients who are coinfected with HIV and HBV should be started on a fully suppressive antiretroviral (ARV) regimen with activity against both viruses (regardless of CD4 counts and HBV DNA concentrations). HIV treatment guidelines recommend these patients receive an ARV regimen that contains a dual NRTI backbone of tenofovir alafenamide or tenofovir disoproxil fumarate with either emtricitabine or lamivudine. If tenofovir cannot be used, entecavir should be used in combination with a fully suppressive ARV regimen (note: entecavir should not be considered part of the ARV regimen). Avoid using single-drug therapy to treat HBV (i.e., lamivudine, emtricitabine, tenofovir, or entecavir as the only active agent) as this may result in HIV resistant strains. Further, HBV treatment regimens that include adefovir or telbivudine should also be avoided, as these regimens are associated with a higher incidence of toxicities and increased rates of HBV treatment failure. Most coinfected patients should continue treatment indefinitely with the goal of maximal HIV suppression and prevention of HBV relapse. Patients with hepatitis B and HIV coinfection who discontinue tenofovir or emtricitabine may experience a severe acute hepatitis B exacerbation with some cases resulting in hepatic decompensation and hepatic failure. Therefore, close monitoring of transaminase concentrations every 6 weeks for the first 3 months, and every 3 to 6 months thereafter is recommended in co-infected patients who discontinue NRTI therapy. If appropriate, resumption of anti-hepatitis B treatment may be required. For patients who refuse a fully suppressive ARV regimen, but still require treatment for HBV, consider 48 weeks of peginterferon alfa; do not administer HIV-active medications in the absence of a fully suppressive ARV regimen. Instruct patients to avoid consuming alcohol, and offer vaccinations against hepatitis A and hepatitis B as appropriate.

DEA CLASS

Rx

DESCRIPTION

Fixed-dose combination tablet containing elvitegravir, an HIV integrase strand transfer inhibitor; cobicistat, a pharmacokinetic enhancer; emtricitabine, a nucleoside reverse transcriptase inhibitor or NRTI; and tenofovir alafenamide, an acyclic nucleotide reverse transcriptase inhibitor
Used for the treatment of HIV-1 infection in adults and pediatric patients weighing 25 kg or more
Product contains a different tenofovir prodrug, tenofovir alafenamide, developed to help reduce adverse events

COMMON BRAND NAMES

Genvoya

HOW SUPPLIED

Genvoya Oral Tab

DOSAGE & INDICATIONS

MAXIMUM DOSAGE

1 tablet/day PO (elvitegravir 150 mg/day PO; cobicistat 150 mg/day PO; emtricitabine 200 mg/day PO; tenofovir AF 10 mg/day PO).

1 tablet/day PO (elvitegravir 150 mg/day PO; cobicistat 150 mg/day PO; emtricitabine 200 mg/day PO; tenofovir AF 10 mg/day PO).

1 tablet/day PO (elvitegravir 150 mg/day PO; cobicistat 150 mg/day PO; emtricitabine 200 mg/day PO; tenofovir AF 10 mg/day PO).

weight 25 kg or more: 1 tablet/day PO (elvitegravir 150 mg/day PO; cobicistat 150 mg/day PO; emtricitabine 200 mg/day PO; tenofovir AF 10 mg/day PO).
weight less than 25 kg: Safety and efficacy have not been established.

Safety and efficacy have not been established.

Safety and efficacy have not been established.

DOSING CONSIDERATIONS

Dosage adjustments are not required for mild to moderate hepatic impairment (Child-Pugh Class A and B). Due to lack of data, use is not recommended in patients with severe hepatic impairment (Child-Pugh Class C).

CrCl 30 mL/minute or more: No dosage adjustment needed.
CrCl 15 to 29 mL/minute: Safety and efficacy have not been established.
CrCl less than 15 mL/minute and not on hemodialysis: Safety and efficacy have not been established.
 
Intermittent hemodialysis
For adults who have a CrCl less than 15 mL/minute and are receiving chronic hemodialysis: No dosage adjustment is needed; however, on hemodialysis days administer dose after completion of the hemodialysis session.

ADMINISTRATION

Administer with food.

STORAGE

Genvoya:
- Store and dispense in original container
- Store below 86 degrees F

CONTRAINDICATIONS / PRECAUTIONS

Elvitegravir; cobicistat; emtricitabine; tenofovir alafenamide (AF) is an inhibitor and substrate for CYP3A, and may inhibit the clearance of certain CYP3A substrates. Thus, use is contraindicated with medications that are highly dependent on CYP3A for metabolism and are associated with serious or life-threatening adverse events. This HIV regimen is also contraindicated for use with strong CYP3A inducers (i.e., rifampin, St. John's wort, carbamazepine, phenobarbital, phenytoin); concurrent use of strong CYP3A inducers can lead to a marked decrease in elvitegravir, cobicistat, and tenofovir AF plasma concentrations and loss of antiretroviral efficacy.
 
Elvitegravir; cobicistat; emtricitabine; tenofovir AF constitutes a complete HIV treatment regimen. Use with other antiretroviral medications is not recommended.
 
During baseline evaluation of people with HIV, discuss risk reduction measures and the need for status disclosure to sexual or needle-sharing partners, especially with untreated patients who are still at high risk of HIV transmission. Include the importance of adherence to therapy to achieve and maintain a plasma HIV RNA less than 200 copies/mL. Maintaining a plasma HIV RNA less than 200 copies/mL, including any measurable value below this threshold, with antiretroviral therapy prevents sexual transmission of HIV to their partners. Patients may recognize this concept as Undetectable = Untransmittable or U=U.
 
Unplanned antiretroviral therapy interruption may be necessary for specific situations, such as serious drug toxicity, intercurrent illness or surgery precluding oral intake (e.g., gastroenteritis or pancreatitis), severe hyperemesis gravidarum unresponsive to antiemetics, or drug non-availability. If short-term treatment interruption (i.e., less than 1 to 2 days) is necessary, in general, it is recommended that all antiretroviral agents be discontinued simultaneously, especially if the interruption occurs in a pregnant patient or is because of a serious toxicity. However, if a short-term treatment interruption is anticipated in the case of elective surgery, the pharmacokinetic properties and food requirements of specific drugs should be considered; as stopping all simultaneously in a regimen containing drugs with differing half-lives may result in functional monotherapy of the drug with the longest half-life and may increase the risk for resistant mutations. Health care providers are advised to reinitiate a complete and effective antiretroviral regimen as soon as possible after an interruption of therapy. Planned long-term treatment interruptions are not recommended due to the potential for HIV disease progression (i.e., declining CD4 counts, viral rebound, acute viral syndrome), development of minor HIV-associated manifestations or serious non-AIDS complications, development of drug resistance, increased risk of HIV transmission, and increased risk for opportunistic infections. If therapy must be discontinued, counsel patient on the potential risks and closely monitor for any clinical or laboratory abnormalities. [46638] [42452]

Perform HBV screening in any patient who presents with HIV infection to assure appropriate treatment. Patients who are coinfected with HIV and HBV should be started on a fully suppressive antiretroviral (ARV) regimen with activity against both viruses (regardless of CD4 counts and HBV DNA concentrations). HIV treatment guidelines recommend these patients receive an ARV regimen that contains a dual NRTI backbone of tenofovir alafenamide or tenofovir disoproxil fumarate with either emtricitabine or lamivudine. If tenofovir cannot be used, entecavir should be used in combination with a fully suppressive ARV regimen (note: entecavir should not be considered part of the ARV regimen). Avoid using single-drug therapy to treat HBV (i.e., lamivudine, emtricitabine, tenofovir, or entecavir as the only active agent) as this may result in HIV resistant strains. Further, HBV treatment regimens that include adefovir or telbivudine should also be avoided, as these regimens are associated with a higher incidence of toxicities and increased rates of HBV treatment failure. Most coinfected patients should continue treatment indefinitely with the goal of maximal HIV suppression and prevention of HBV relapse. Patients with hepatitis B and HIV coinfection who discontinue tenofovir or emtricitabine may experience a severe acute hepatitis B exacerbation with some cases resulting in hepatic decompensation and hepatic failure. Therefore, close monitoring of transaminase concentrations every 6 weeks for the first 3 months, and every 3 to 6 months thereafter is recommended in co-infected patients who discontinue NRTI therapy. If appropriate, resumption of anti-hepatitis B treatment may be required. For patients who refuse a fully suppressive ARV regimen, but still require treatment for HBV, consider 48 weeks of peginterferon alfa; do not administer HIV-active medications in the absence of a fully suppressive ARV regimen. Instruct patients to avoid consuming alcohol, and offer vaccinations against hepatitis A and hepatitis B as appropriate.

Lactic acidosis and hepatomegaly with steatosis, including fatal cases, have been reported following use of emtricitabine and tenofovir disoproxil fumarate (another prodrug of tenofovir), both alone and in combination with other antiretroviral medications. Treatment with elvitegravir; cobicistat; emtricitabine; tenofovir alafenamide should be suspended in any patient who develops clinical or laboratory findings suggestive of hepatotoxicity or lactic acidosis, which may include hepatomegaly and steatosis even in the absence of marked elevated hepatic enzymes. Although these adverse events may occur in any drug recipient, some risk factors include impaired hepatic function (e.g., alcoholism), obesity, and prolonged nucleoside exposure. In addition, a majority of these cases have been in females; it is unknown if being pregnant augments the incidence of this syndrome in patients receiving nucleoside analogs. However, because being pregnant itself can mimic some of the early symptoms of the lactic acid and hepatic steatosis syndrome or be associated with other significant disorders of liver metabolism, clinicians need to be alert for early diagnosis of this syndrome. Pregnant women receiving nucleoside analogs should have LFTs and serum electrolytes assessed more frequently during the last trimester and any new symptoms should be evaluated thoroughly.

Studies evaluating the safety and pharmacokinetics of elvitegravir; cobicistat; emtricitabine; tenofovir alafenamide (AF) in patients with severe hepatic disease (Child-Pugh Class C) have not been conducted; use in this population is not recommended. The drug may be used without dose adjustments in patients with mild to moderate hepatic dysfunction (Child-Pugh Class A and B).

Increased body weight has been observed in antiretroviral-naive patients after starting treatment with an integrase inhibitor-containing regimen (including elvitegravir). Weight gain has also been observed after initiation of tenofovir alafenamide and after switching from tenofovir disoproxil fumarate to tenofovir alafenamide. Predictors and mechanisms for the increase in weight are still unclear; however, the weight gain appears to disproportionately affect females, Hispanic patients, and Black patients (particularly Black women). It is unknown whether the increase in weight is associated with significant cardio-metabolic risks or if it is reversible upon treatment discontinuation.

HIV treatment guidelines recommend all patients presenting with HIV infection undergo routine screening for hepatitis C virus (HCV). For HCV seronegative individuals who are at continued high risk of acquiring hepatitis C, specifically men who have sex with men (MSM) or persons who inject drugs, additional HCV screening is recommended annually or as indicated by clinical presentation (e.g., unexplained ALT elevation), risk activities, or exposure. Similarly, the AASLD/IDSA HCV guidelines and the CDC preexposure prophylaxis (PrEP) guidelines recommend HCV serologic testing at baseline and every 12 months for MSM, transgender women, and persons who inject drugs. Use an FDA-approved immunoassay licensed for detection of HCV antibodies (anti-HCV); in settings where acute HCV infection is suspected or in persons with known prior infection that cleared spontaneously or after treatment, use of nucleic acid testing for HCV RNA is recommended. If hepatitis C and HIV coinfection is identified, consider treating both viral infections concurrently. It is recommended to use a fully suppressive antiretroviral therapy and an HCV regimen in all patients with coinfection regardless of CD4 count, as lower CD4 counts do not appear to compromise the efficacy of HCV treatment. In most patients, a simplified pangenotypic HCV regimen (i.e., glecaprevir; pibrentasvir or sofosbuvir; velpatasvir) may be an appropriate choice; however, these regimens are NOT recommended for use in persons with HCV and HIV coinfection who: are treatment-experience with HCV relapse (reinfection after successful therapy is not an exclusion); have decompensated cirrhosis; on a tenofovir disoproxil fumarate containing regimen with eGFR less than 60 mL/minute; on efavirenz, etravirine, nevirapine, or boosted protease inhibitor; have untreated chronic hepatitis B; are pregnant. Patients with HCV and HIV coinfection who meet these exclusion criteria should be treated for HCV following standard approaches as described in the AASLD/IDSA HCV guidelines. Treatment of HCV infection in children younger than 3 years is not usually recommended; however, treatment should be considered for all children 3 years and older with HCV and HIV coinfection who have no contraindications to treatment. Instruct patients with coinfection to avoid consuming alcohol, limit ingestion of potentially hepatotoxic medications, avoid iron supplementation in the absence of documented iron deficiency, and receive vaccinations against hepatitis A and hepatitis B as appropriate.

Significant declines in bone mineral density (BMD) were observed in elvitegravir; cobicistat; emtricitabine; tenofovir alafenamide (Genvoya) recipients during clinical trials.[60269] Therefore, BMD monitoring should be considered for patients who have a history of pathologic bone fracture or are at substantial risk for osteopenia or osteoporosis. Although not observed in patients receiving Genvoya, osteomalacia has been associated with the use of tenofovir disoproxil fumarate, and may occur with tenofovir alafenamide. Supplementation with calcium and vitamin D may be beneficial for all drug recipients. Obtain appropriate consultation if bone abnormalities are suspected.[28193]

Avoid administering elvitegravir; cobicistat; emtricitabine; tenofovir alafenamide to patients with severe renal impairment (CrCl 15 to 29 mL/minute) or patients with end-stage renal disease (CrCl less than 15 mL/minute) who are not receiving chronic hemodialysis. Obtain a serum creatinine, estimated CrCl, urine glucose, and urine protein in all patients prior to or when initiating therapy, and during treatment, as clinically appropriate. Assess serum phosphorus in patients with chronic kidney disease. Cobicistat inhibits tubular secretion of creatinine, resulting in elevated creatinine serum concentration; patients who develop a confirmed serum creatinine increase of more than 0.4 mg/dL from baseline should be closely monitored for renal safety. Across all clinical trials, less than 1% of patients treated with elvitegravir; cobicistat; emtricitabine; tenofovir alafenamide experienced serious renal adverse events or discontinued treatment due to a renal adverse event; however, cases of acute renal failure, acute tubular necrosis, proximal renal tubulopathy, and Fanconi syndrome have been reported during postmarketing use of tenofovir alafenamide-containing regimen. In most cases, potential confounders were identified that may have contributed to the reported renal events; however, it is also possible these factors could have predisposed patients to tenofovir-related adverse events. Discontinue treatment in patients who develop clinically significant decreases in renal function or evidence of Fanconi syndrome. In addition, avoid concurrent use with or recently after a nephrotoxic agent, including high-dose or multiple nonsteroidal anti-inflammatory drugs (NSAIDS), as use of these medications together increases the risk for developing renal-related adverse reactions.[60269] [51664]

Immune reconstitution syndrome has been reported in patients treated with combination antiretroviral therapy. During the initial phase of HIV treatment, patients whose immune system responds to elvitegravir; cobicistat; emtricitabine; tenofovir alafenamide (AF) therapy may develop an inflammatory response to indolent or residual opportunistic infections (such as progressive multifocal leukoencephalopathy (PML), Mycobacterium avium infection, cytomegalovirus (CMV), Pneumocystis pneumonia (PCP), or tuberculosis (TB)), which may necessitate further evaluation and treatment.[34362] In addition, autoimmune disease (including Graves' disease, Guillain-Barre syndrome, polymyositis, and autoimmune hepatitis) may also develop; the time to onset is variable and may occur months after treatment initiation.[60269]

Testing for human immunodeficiency virus (HIV) infection resistance is recommended in all antiretroviral treatment-naive patients at the time of HIV diagnosis, regardless of whether treatment will be initiated. Additionally, perform resistance testing prior to initiating or changing any HIV treatment regimen. Transmission of drug-resistant HIV strains has been both well documented and associated with suboptimal virologic response to initial antiretroviral therapy. The prevalence of transmitted drug resistance (TDR) in high-income countries ranges from 9% to 14% and varies by country. In most TDR surveys, non-nucleoside reverse transcriptase inhibitor (NNRTI) resistance and nucleoside reverse transcriptase inhibitor (NRTI) resistance are the most common mutation class types detected, followed by protease inhibitor (PI) and integrase strand transfer inhibitor (INSTI) resistance mutations, respectively. Resistance testing at baseline can help optimize treatment and, thus, virologic response. In the absence of therapy, resistant viruses may decline over time to less than the detection limit of standard resistance tests, but may still increase the risk of treatment failure when therapy is eventually initiated. Thus, if therapy is deferred, resistance testing should still be performed during acute HIV infection with the genotypic resistance test result kept in the patient's medical record until it becomes clinically useful. Additionally, because of the possibility of acquisition of another drug-resistant virus before treatment initiation, repeat resistance testing at the time therapy is initiated would be prudent. Emtricitabine will not likely be effective in individuals who display antimicrobial resistance to lamivudine, due to the similarities between the two drugs. Clinicians should not expect patients with the M184 mutation associated with lamivudine to benefit from an emtricitabine containing regimen. The M184 mutation confers high-level resistance, and emtricitabine, like lamivudine, selects for the M184 mutation. It is important that persons with detectable viral load who plan to switch therapy from lamivudine to emtricitabine have genotypic testing performed to determine whether the M184V mutation is present. A patient's treatment history is also extremely important; if lamivudine has failed in the past, the 184 is archived, thus rendering emtricitabine ineffective in this patient population.

Antiretroviral therapy should be provided to all patients 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. Begin HAART as soon as pregnancy is recognized, or HIV is diagnosed. Elvitegravir; cobicistat; emtricitabine; tenofovir alafenamide (AF) is not recommended for use as an initial regimen in pregnant patients or those who are trying to conceive, as inadequate concentrations of elvitegravir and cobicistat, as well as viral breakthroughs, have been reported during the second and third trimesters. Consider use of more effective antiretroviral regimens. For people who conceive while suppressed on elvitegravir; cobicistat; emtricitabine; tenofovir AF, guidelines recommend the provider and patient engage in shared decision-making regarding continued use. If the decision is made with the patient to continue use during pregnancy, viral loads should be monitored more frequently (i.e., every 1 to 2 months). Available data from the Antiretroviral Pregnancy Registry (APR), which includes first trimester exposures to elvitegravir (more than 370 exposures), cobicistat (more than 505 exposures), emtricitabine (more than 4,225 exposures), and tenofovir AF (more than 680 exposures), 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 exposure occurred in the first trimester, the prevalence of defects was 3% (95% CI: 1.5 to 5.2) for elvitegravir, 3.6% (95% CI: 2.11 to 5.5) for cobicistat, 2.7% (95% CI: 2.2 to 3.2) for emtricitabine, and 3.5% (95% CI: 2.3 to 5.2) for tenofovir AF. Supplemental data from the APR regarding central nervous system birth defects are available. Among the reported exposures to elvitegravir (343 periconception, 27 late first trimester, 70 second/third trimester), 1 central nervous system birth defect was identified during periconception; however, this was not a neural tube or encephalocele defect. Nucleoside reverse transcriptase inhibitors (NRTIs) are known to induce mitochondrial dysfunction. An association of mitochondrial dysfunction in infants and in utero antiretroviral exposure has been suggested, but not established. While the development of severe or fatal mitochondrial disease in exposed infants appears to be extremely rare, more intensive monitoring of hematologic and electrolyte parameters during the first few weeks of life is advised. Nucleoside analogs have been associated with the development of lactic acidosis, especially during pregnancy. It is unclear if pregnancy augments the incidence of lactic acidosis/hepatic steatosis in patients receiving nucleoside analogs. However, because pregnancy itself can mimic some early symptoms of the lactic acid/hepatic steatosis syndrome or be associated with other significant disorders of liver metabolism, clinicians need to be alert for early diagnosis of this syndrome. Pregnant patients receiving nucleoside analogs should have LFTs and serum electrolytes assessed more frequently during the last trimester of pregnancy and any new symptoms should be evaluated thoroughly. Regular laboratory monitoring is recommended to determine antiretroviral efficacy. Monitor CD4 counts at the initial visit. Patients 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 patients on HAART less than 2 years, patients with CD4 count less than 300 cells/mm3, or patients with inconsistent adherence or detectable viral loads. Monitor plasma HIV RNA at the initial visit (with review of prior levels), 2 to 4 weeks after initiating or changing therapy, monthly until undetectable, and then at least every 3 months during pregnancy. Viral load should also be assessed at approximately 36 weeks gestation, or within 4 weeks of delivery, to inform decisions regarding mode of delivery and optimal treatment for newborns. Patients whose HIV RNA levels are above the threshold for resistance testing (usually greater than 500 copies/mL but may be possible for levels greater than 200 copies/mL in some laboratories) should undergo antiretroviral resistance testing (genotypic testing, and if indicated, phenotypic testing). Resistance testing should be conducted before starting therapy in treatment-naive patients who have not been previously tested, starting therapy in treatment-experienced patients (including those who have received pre-exposure prophylaxis), modifying therapy in patients who become pregnant while receiving treatment, or modifying therapy in patients who have suboptimal virologic response to treatment that was started during pregnancy. DO NOT delay initiation of antiretroviral therapy while waiting on the results of resistance testing; treatment regimens can be modified, if necessary, once the testing results are known. First trimester ultrasound is recommended to confirm gestational age and provide accurate estimation of gestational age at delivery. 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 patients 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 patients 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 patients 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 patient 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 elvitegravir; cobicistat; emtricitabine; tenofovir AF; information about the registry can be obtained at www.apregistry.com or by calling 1-800-258-4263.

Although rare, cases of suicidal ideation, behavior, and suicide attempts have been associated with elvitegravir; cobicistat; emtricitabine; tenofovir alafenamide therapy. All of the reported events occurred in patients with a preexisting history of depression or psychiatric illness.

HIV treatment guidelines recommend clinicians provide mothers with evidence-based, patient-centered counseling to support shared decision-making regarding infant feeding. Inform patients that use of replacement feeding (i.e., formula or banked pasteurized donor human milk) eliminates the risk of HIV transmission; thus, replacement feeding is recommended for use when mothers with HIV are not on antiretroviral therapy (ART) or do not have suppressed viral load during pregnancy, as well as at delivery. For patients on ART who have achieved and maintained viral suppression during pregnancy (at minimum throughout the third trimester) and postpartum, the transmission risk from breast-feeding is less than 1%, but not zero. Virologically suppressed mothers who choose to breast-feed should be supported in this decision. If breast-feeding is chosen, counsel the patient about the importance of adherence to therapy and recommend that the infant be exclusively breast-fed for up to 6 months of age, as exclusive breast-feeding has been associated with a lower rate of HIV transmission as compared to mixed feeding (i.e., breast milk and formula). Promptly identify and treat mastitis, thrush, and cracked or bleeding nipples, as these conditions may increase the risk of HIV transmission through breast-feeding. Breast-fed infants 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, healthcare workers may contact the Perinatal HIV Hotline (888-448-8765). It is unknown if tenofovir AF, elvitegravir, or cobicistat are present in human milk; however, limited data suggest small amounts of emtricitabine and tenofovir disoproxil fumarate (DF) are excreted into breast milk. One study estimated exposures to emtricitabine in exclusively breast-fed infants at approximately 2% of the recommended infant dose. In this same study, tenofovir DF exposures in exclusively breast-fed infants were found to be equivalent to 4.2 mcg per day. As a result, breast-fed infants whose mothers are receiving treatment may be at risk of developing viral resistance or other associated adverse events. Other antiretroviral medications whose passage into human breast milk have been evaluated include nevirapine, zidovudine, lamivudine, and nelfinavir.  

ADVERSE REACTIONS

hyperkalemia / Delayed / 7.0-7.0
suicidal ideation / Delayed / 0-1.0
lactic acidosis / Delayed / Incidence not known
nephrotoxicity / Delayed / Incidence not known
renal tubular necrosis / Delayed / Incidence not known
renal failure / Delayed / Incidence not known
Fanconi syndrome / Delayed / Incidence not known
hepatic decompensation / Delayed / Incidence not known
hepatitis B exacerbation / Delayed / Incidence not known
hepatic failure / Delayed / Incidence not known
uveitis / Delayed / Incidence not known
angioedema / Rapid / Incidence not known

hyperlipidemia / Delayed / 11.0-11.0
osteomyelitis / Delayed / 7.0-7.0
fluid retention / Delayed / 7.0-7.0
hypercholesterolemia / Delayed / 4.0-4.0
hematuria / Delayed / 3.0-3.0
hyperamylasemia / Delayed / 3.0-3.0
elevated hepatic enzymes / Delayed / 3.0-3.0
steatosis / Delayed / Incidence not known
hepatomegaly / Delayed / Incidence not known
osteopenia / Delayed / Incidence not known
osteoporosis / Delayed / Incidence not known
hypertriglyceridemia / Delayed / Incidence not known

nausea / Early / 7.0-11.0
diarrhea / Early / 7.0-7.0
headache / Early / 6.0-6.0
fatigue / Early / 5.0-5.0
weight gain / Delayed / Incidence not known
urticaria / Rapid / Incidence not known
rash / Early / Incidence not known

DRUG INTERACTIONS

Abacavir; Dolutegravir; Lamivudine: (Major) Do not coadminister lamivudine, 3TC-containing products and emtricitabine-containing products due to similarities between emtricitabine and lamivudine. (Moderate) Caution is warranted when cobicistat is administered with dolutegravir as there is a potential for elevated dolutegravir concentrations. Dolutegravir is a substrate of CYP3A4 and P-glycoprotein (P-gp). Cobicistat is a strong inhibitor of CYP3A4 and an inhibitor of P-gp.
Abacavir; Lamivudine, 3TC: (Major) Do not coadminister lamivudine, 3TC-containing products and emtricitabine-containing products due to similarities between emtricitabine and lamivudine.
Abacavir; Lamivudine, 3TC; Zidovudine, ZDV: (Major) Do not coadminister lamivudine, 3TC-containing products and emtricitabine-containing products due to similarities between emtricitabine and lamivudine.
Abemaciclib: (Major) If coadministration with cobicistat 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 cobicistat is discontinued, increase the dose of abemaciclib to the original dose after 3 to 5 half-lives of cobicistat. Abemaciclib is a CYP3A4 substrate and cobicistat 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.
Abrocitinib: (Moderate) Coadministration of tenofovir alafenamide with abrocitinib may result in increased plasma concentrations of tenofovir leading to an increase in tenofovir-related adverse effects. Tenofovir alafenamide is a P-gp substrate and abrocitinib is a P-gp inhibitor.
Acalabrutinib: (Major) Avoid the concomitant use of acalabrutinib and cobicistat; significantly increased acalabrutinib exposure may occur. Acalabrutinib is a CYP3A4 substrate; cobicistat 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. (Moderate) Coadministration of acalabrutinib and tenofovir alafenamide may increase the absorption and plasma concentration of tenofovir alafenamide. Acalabrutinib is an inhibitor of the breast cancer resistance protein (BCRP) transporter in vitro; it may inhibit intestinal BCRP. Tenofovir alafenamide is a BCRP substrate.
Acetaminophen; Aspirin, ASA; Caffeine: (Moderate) Monitor for changes in renal function if tenofovir alafenamide is administered in combination with nephrotoxic agents, such as salicylates. Tenofovir is primarily excreted via the kidneys by a combination of glomerular filtration and active tubular secretion. Coadministration of tenofovir alafenamide with a drug that reduces renal function or competes for active tubular secretion may increase concentrations of tenofovir and other renally eliminated drugs, thus, increasing the risk of adverse reactions.
Acetaminophen; Aspirin: (Moderate) Monitor for changes in renal function if tenofovir alafenamide is administered in combination with nephrotoxic agents, such as salicylates. Tenofovir is primarily excreted via the kidneys by a combination of glomerular filtration and active tubular secretion. Coadministration of tenofovir alafenamide with a drug that reduces renal function or competes for active tubular secretion may increase concentrations of tenofovir and other renally eliminated drugs, thus, increasing the risk of adverse reactions.
Acetaminophen; Aspirin; Diphenhydramine: (Moderate) Caution is warranted when cobicistat is administered with diphenhydramine as there is a potential for elevated diphenhydramine and cobicistat concentrations. Diphenhydramine is a substrate/inhibitor of CYP2D6 and a substrate of CYP2C9. Cobicistat is an substrate/inhibitor of CYP2D6. (Moderate) Caution is warranted when elvitegravir is administered with diphenhydramine as there is a potential for decreased diphenhydramine concentrations. Diphenhydramine is a substrate of CYP2C9, while elvitegravir is a CYP2C9 inducer. (Moderate) Monitor for changes in renal function if tenofovir alafenamide is administered in combination with nephrotoxic agents, such as salicylates. Tenofovir is primarily excreted via the kidneys by a combination of glomerular filtration and active tubular secretion. Coadministration of tenofovir alafenamide with a drug that reduces renal function or competes for active tubular secretion may increase concentrations of tenofovir and other renally eliminated drugs, thus, increasing the risk of adverse reactions.
Acetaminophen; Caffeine; Dihydrocodeine: (Moderate) Concomitant use of dihydrocodeine with cobicistat 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 cobicistat could decrease dihydrocodeine plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to dihydrocodeine. If cobicistat is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Cobicistat is a strong inhibitor of CYP3A4, an isoenzyme partially responsible for the metabolism of dihydrocodeine.
Acetaminophen; Chlorpheniramine: (Moderate) Caution is warranted when cobicistat is administered with chlorpheniramine as there is a potential for elevated chlorpheniramine and cobicistat concentrations. Chlorpheniramine is a CYP2D6 substrate/inhibitor. Cobicistat is a substrate/inhibitor of CYP2D6.
Acetaminophen; Chlorpheniramine; Dextromethorphan: (Moderate) Caution is warranted when cobicistat is administered with chlorpheniramine as there is a potential for elevated chlorpheniramine and cobicistat concentrations. Chlorpheniramine is a CYP2D6 substrate/inhibitor. Cobicistat is a substrate/inhibitor of CYP2D6. (Moderate) Use of dextromethorphan with cobicistat may result in increased dextromethorphan exposure. Cobicistat inhibits CYP2D6 and dextromethorphan is a CYP2D6 substrate. Monitor for dextromethorphan-related side effects, such as drowsiness, nausea or vomiting, sweating, restlessness, or tremor.
Acetaminophen; Chlorpheniramine; Dextromethorphan; Phenylephrine: (Moderate) Caution is warranted when cobicistat is administered with chlorpheniramine as there is a potential for elevated chlorpheniramine and cobicistat concentrations. Chlorpheniramine is a CYP2D6 substrate/inhibitor. Cobicistat is a substrate/inhibitor of CYP2D6. (Moderate) Use of dextromethorphan with cobicistat may result in increased dextromethorphan exposure. Cobicistat inhibits CYP2D6 and dextromethorphan is a CYP2D6 substrate. Monitor for dextromethorphan-related side effects, such as drowsiness, nausea or vomiting, sweating, restlessness, or tremor.
Acetaminophen; Chlorpheniramine; Dextromethorphan; Pseudoephedrine: (Moderate) Caution is warranted when cobicistat is administered with chlorpheniramine as there is a potential for elevated chlorpheniramine and cobicistat concentrations. Chlorpheniramine is a CYP2D6 substrate/inhibitor. Cobicistat is a substrate/inhibitor of CYP2D6. (Moderate) Use of dextromethorphan with cobicistat may result in increased dextromethorphan exposure. Cobicistat inhibits CYP2D6 and dextromethorphan is a CYP2D6 substrate. Monitor for dextromethorphan-related side effects, such as drowsiness, nausea or vomiting, sweating, restlessness, or tremor.
Acetaminophen; Chlorpheniramine; Phenylephrine : (Moderate) Caution is warranted when cobicistat is administered with chlorpheniramine as there is a potential for elevated chlorpheniramine and cobicistat concentrations. Chlorpheniramine is a CYP2D6 substrate/inhibitor. Cobicistat is a substrate/inhibitor of CYP2D6.
Acetaminophen; Codeine: (Moderate) Concomitant use of codeine with cobicistat 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 cobicistat could decrease codeine plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to codeine. If cobicistat 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. Cobicistat is a strong inhibitor of CYP3A4.
Acetaminophen; Dextromethorphan: (Moderate) Use of dextromethorphan with cobicistat may result in increased dextromethorphan exposure. Cobicistat inhibits CYP2D6 and dextromethorphan is a CYP2D6 substrate. Monitor for dextromethorphan-related side effects, such as drowsiness, nausea or vomiting, sweating, restlessness, or tremor.
Acetaminophen; Dextromethorphan; Doxylamine: (Moderate) Use of dextromethorphan with cobicistat may result in increased dextromethorphan exposure. Cobicistat inhibits CYP2D6 and dextromethorphan is a CYP2D6 substrate. Monitor for dextromethorphan-related side effects, such as drowsiness, nausea or vomiting, sweating, restlessness, or tremor.
Acetaminophen; Dextromethorphan; Guaifenesin; Phenylephrine: (Moderate) Use of dextromethorphan with cobicistat may result in increased dextromethorphan exposure. Cobicistat inhibits CYP2D6 and dextromethorphan is a CYP2D6 substrate. Monitor for dextromethorphan-related side effects, such as drowsiness, nausea or vomiting, sweating, restlessness, or tremor.
Acetaminophen; Dextromethorphan; Guaifenesin; Pseudoephedrine: (Moderate) Use of dextromethorphan with cobicistat may result in increased dextromethorphan exposure. Cobicistat inhibits CYP2D6 and dextromethorphan is a CYP2D6 substrate. Monitor for dextromethorphan-related side effects, such as drowsiness, nausea or vomiting, sweating, restlessness, or tremor.
Acetaminophen; Dextromethorphan; Phenylephrine: (Moderate) Use of dextromethorphan with cobicistat may result in increased dextromethorphan exposure. Cobicistat inhibits CYP2D6 and dextromethorphan is a CYP2D6 substrate. Monitor for dextromethorphan-related side effects, such as drowsiness, nausea or vomiting, sweating, restlessness, or tremor.
Acetaminophen; Dextromethorphan; Pseudoephedrine: (Moderate) Use of dextromethorphan with cobicistat may result in increased dextromethorphan exposure. Cobicistat inhibits CYP2D6 and dextromethorphan is a CYP2D6 substrate. Monitor for dextromethorphan-related side effects, such as drowsiness, nausea or vomiting, sweating, restlessness, or tremor.
Acetaminophen; Diphenhydramine: (Moderate) Caution is warranted when cobicistat is administered with diphenhydramine as there is a potential for elevated diphenhydramine and cobicistat concentrations. Diphenhydramine is a substrate/inhibitor of CYP2D6 and a substrate of CYP2C9. Cobicistat is an substrate/inhibitor of CYP2D6. (Moderate) Caution is warranted when elvitegravir is administered with diphenhydramine as there is a potential for decreased diphenhydramine concentrations. Diphenhydramine is a substrate of CYP2C9, while elvitegravir is a CYP2C9 inducer.
Acetaminophen; Hydrocodone: (Moderate) Consider a reduced dose of hydrocodone with frequent monitoring for respiratory depression and sedation if concurrent use of cobicistat 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 cobicistat 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 cobicistat 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; Ibuprofen: (Moderate) Monitor for changes in renal function if tenofovir alafenamide is administered in combination with nephrotoxic agents, such as nonsteroidal antiinflammatory drugs (NSAIDs). Tenofovir is primarily excreted via the kidneys by a combination of glomerular filtration and active tubular secretion. Coadministration of tenofovir alafenamide with a drug that reduces renal function or competes for active tubular secretion may increase concentrations of tenofovir and other renally eliminated drugs, thus, increasing the risk of adverse reactions. (Moderate) Monitor for nonsteroidal antiinflammatory drug (NSAID) or emtricitabine-related adverse events during concomitant use. Concomitant use may increase NSAID or emtricitabine concentrations. Coadministration of drugs that reduce renal function or compete for active tubular secretion, such as NSAIDs and emtricitabine, may increase the risk of adverse reactions. (Moderate) The plasma concentrations of ibuprofen may be decreased when administered concurrently with elvitegravir. Patients may experience decreased analgesic or anti-inflammatory effects when these drugs are coadministered. Elvitegravir is a CYP2C9 inducer, while ibuprofen is a CYP2C9 substrate.
Acetaminophen; Oxycodone: (Moderate) Consider a reduced dose of oxycodone with frequent monitoring for respiratory depression and sedation if concurrent use of cobicistat is necessary. If cobicistat 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 cobicistat 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 cobicistat 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.
Acyclovir: (Moderate) Monitor for acyclovir or emtricitabine-related adverse events during concomitant use. Concomitant use may increase acyclovir or emtricitabine concentrations. Coadministration of drugs that reduce renal function or compete for active tubular secretion, such as acyclovir and emtricitabine, may increase the risk of adverse reactions. (Moderate) Monitor for changes in renal function if tenofovir alafenamide is administered in combination with a nephrotoxic agent, such as acyclovir. Tenofovir is primarily excreted via the kidneys by a combination of glomerular filtration and active tubular secretion. Coadministration of tenofovir alafenamide with a drug that reduces renal function or competes for active tubular secretion may increase concentrations of tenofovir and other renally eliminated drugs, thus, increasing the risk of adverse reactions.
Adagrasib: (Moderate) Coadministration of tenofovir alafenamide with adagrasib may result in increased plasma concentrations of tenofovir leading to an increase in tenofovir-related adverse effects. Tenofovir alafenamide is a P-gp substrate and adagrasib is a P-gp inhibitor. (Moderate) Monitor for an increase in adverse effects from both drugs during concomitant use of adagrasib and cobicistat. 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. Adagrasib and cobicistat 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: (Moderate) Monitor for changes in renal function if tenofovir alafenamide is administered in combination with a nephrotoxic agent, such as adefovir. Tenofovir is primarily excreted via the kidneys by a combination of glomerular filtration and active tubular secretion. Coadministration of tenofovir alafenamide with a drug that reduces renal function or competes for active tubular secretion may increase concentrations of tenofovir and other renally eliminated drugs; thus, increasing the risk of developing renal-related adverse reactions. (Moderate) Patients who are concurrently taking adefovir with emtricitabine 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 cobicistat 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 cobicistat has cleared from the circulation (approximately 3 half-lives of cobicistat) 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; cobicistat is a strong CYP3A4 inhibitor. Formal drug interaction studies with ado-trastuzumab emtansine have not been conducted.
Afatinib: (Moderate) If the concomitant use of cobicistat and afatinib is necessary, monitor for afatinib-related adverse reactions. If the original dose of afatinib is not tolerated, consider reducing the daily dose of afatinib by 10 mg; resume the previous dose of afatinib as tolerated after discontinuation of cobicistat. The manufacturer of afatinib recommends permanent discontinuation of therapy for severe or intolerant adverse drug reactions at a dose of 20 mg per day, but does not address a minimum dose otherwise. Afatinib is a P-glycoprotein (P-gp) substrate and cobicistat is a P-gp inhibitor; coadministration may increase plasma concentrations of afatinib. Administration with another P-gp inhibitor, given 1 hour before a single dose of afatinib, increased afatinib exposure by 48%; there was no change in afatinib exposure when the P-gp inhibitor was administered at the same time as afatinib or 6 hours later. In healthy subjects, the relative bioavailability for AUC and Cmax of afatinib was 119% and 104%, respectively, when coadministered with the same P-gp inhibitor, and 111% and 105% when the inhibitor was administered 6 hours after afatinib.
Aldesleukin, IL-2: (Moderate) Caution is warranted when cobicistat is administered with aldesleukin, IL-2 as there is a potential for elevated cobicistat concentrations. Aldesleukin, IL-2 is a CYP3A4 inhibitor and cobicistat is a substrate of CYP3A4. (Moderate) Caution is warranted when elvitegravir is administered with aldesleukin, IL-2 as there is a potential for elevated elvitegravir concentrations. Aldesleukin, IL-2 is a CYP3A4 inhibitor and elvitegravir is a substrate of CYP3A4.
Alfentanil: (Moderate) The plasma concentrations of alfentanil may be elevated when administered concurrently with cobicistat. Clinical monitoring for adverse effects, such as hypotension, nausea, itching, and respiratory depression, is recommended during coadministration. Cobicistat is a CYP3A4 inhibitor and alfentanil is a CYP3A4 substrate.
Alfuzosin: (Contraindicated) Alfuzosin is contraindicated for use with cobicistat due to the potential for serious/life-threatening reactions, including hypotension. Coadministration is expected to reduce the metabolism and increase systemic exposure to alfuzosin. Alfuzosin is primarily metabolized by CYP3A4; cobicistat is a strong inhibitor of this enzyme. Coadministration of another strong CYP3A4 inhibitor increased the alfuzosin AUC by 2.5-fold to 3.2-fold.
Aliskiren: (Moderate) The plasma concentrations of aliskiren may be elevated when administered concurrently with cobicistat. Clinical monitoring for adverse effects, such as decreased blood pressure, is recommended during coadministration. Cobicistat is a CYP3A4 and P-glycoprotein (P-gp) inhibitor and aliskiren is a CYP3A4 and P-gp substrate.
Aliskiren; Hydrochlorothiazide, HCTZ: (Moderate) The plasma concentrations of aliskiren may be elevated when administered concurrently with cobicistat. Clinical monitoring for adverse effects, such as decreased blood pressure, is recommended during coadministration. Cobicistat is a CYP3A4 and P-glycoprotein (P-gp) inhibitor and aliskiren is a CYP3A4 and P-gp substrate.
Almotriptan: (Moderate) The maximum recommended starting dose of almotriptan is 6.25 mg if coadministration with cobicistat is necessary; do not exceed 12.5 mg within a 24-hour period. Concomitant use of almotriptan and cobicistat should be avoided in patients with renal or hepatic impairment. Almotriptan is a CYP3A4; cobicistat is a strong CYP3A4 inhibitor. Coadministration with another strong CYP3A4 inhibitor increased almotriptan exposure by approximately 60%.
Alogliptin; Metformin: (Moderate) Concurrent administration of metformin and cobicistat may increase the risk of lactic acidosis. Cobicistat is a potent inhibitor of the human multidrug and toxic extrusion 1 (MATE1) on proximal renal tubular cells; metformin is a MATE1 substrate. Inhibition of MATE1 by cobicistat may decrease metformin eliminiation by blocking renal tubular secretion. If these drugs are given together, closely monitor for signs of metformin toxicity; metformin dose adjustments may be needed.
Alosetron: (Moderate) Concomitant use of alosetron with cobicistat 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; cobicistat is a strong inhibitor of this enzyme. In a study of healthy female subjects, another strong CYP3A4 inhibitor increased mean alosetron AUC by 29%.
Alpelisib: (Major) Avoid coadministration of alpelisib with cobicistat due to increased exposure to alpelisib and the risk of alpelisib-related toxicity. If concomitant use is unavoidable, closely monitor for alpelisib-related adverse reactions. Alpelisib is a BCRP substrate and cobicistat is a BCRP inhibitor.
Alprazolam: (Contraindicated) Coadministration of cobicistat 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 cobicistat, as these benzodiazepines are not oxidatively metabolized. Alprazolam is a CYP3A4 substrate and cobicistat is a strong CYP3A4 inhibitor. Coadministration with other strong CYP3A4 inhibitors increased alprazolam exposure by 2.7- to 3.98-fold.
Amikacin: (Moderate) Monitor for changes in renal function if tenofovir alafenamide is administered in combination with nephrotoxic agents, such as aminoglycosides. Tenofovir is primarily excreted via the kidneys by a combination of glomerular filtration and active tubular secretion. Coadministration of tenofovir alafenamide with a drug that reduces renal function or competes for active tubular secretion may increase concentrations of tenofovir and other renally eliminated drugs; thus, increasing the risk of developing renal-related adverse reactions. (Moderate) Monitor for changes in serum creatinine and adverse reactions, such as lactic acidosis or hepatotoxicity if emtricitabine is administered in combination with nephrotoxic agents, such as aminoglycosides. Consider the potential for drug interaction prior to and during concurrent use of these medications. Both emtricitabine and aminoglycosides are excreted via the kidneys by a combination of glomerular filtration and active tubular secretion. While no drug interactions due to competition for renal excretion have been observed, coadministration of these medications may increase concentrations of both drugs.
Aminoglycosides: (Moderate) Monitor for changes in renal function if tenofovir alafenamide is administered in combination with nephrotoxic agents, such as aminoglycosides. Tenofovir is primarily excreted via the kidneys by a combination of glomerular filtration and active tubular secretion. Coadministration of tenofovir alafenamide with a drug that reduces renal function or competes for active tubular secretion may increase concentrations of tenofovir and other renally eliminated drugs; thus, increasing the risk of developing renal-related adverse reactions. (Moderate) Monitor for changes in serum creatinine and adverse reactions, such as lactic acidosis or hepatotoxicity if emtricitabine is administered in combination with nephrotoxic agents, such as aminoglycosides. Consider the potential for drug interaction prior to and during concurrent use of these medications. Both emtricitabine and aminoglycosides are excreted via the kidneys by a combination of glomerular filtration and active tubular secretion. While no drug interactions due to competition for renal excretion have been observed, coadministration of these medications may increase concentrations of both drugs.
Aminosalicylate sodium, Aminosalicylic acid: (Moderate) Monitor for changes in renal function if tenofovir alafenamide is administered in combination with nephrotoxic agents, such as salicylates. Tenofovir is primarily excreted via the kidneys by a combination of glomerular filtration and active tubular secretion. Coadministration of tenofovir alafenamide with a drug that reduces renal function or competes for active tubular secretion may increase concentrations of tenofovir and other renally eliminated drugs, thus, increasing the risk of adverse reactions.
Amiodarone: (Moderate) Caution and therapeutic drug concentrations monitoring, if available, is recommended during coadministration of amiodarone with cobicistat. Amiodarone is a substrate and inhibitor of CYP3A4 and an inhibitor CYP2D6, cobicistat is a substrate and strong inhibitor of CYP3A and CYP2D6. Concurrent use may result in elevated concentration of both drugs. (Moderate) Coadministration of tenofovir alafenamide with amiodarone may result in increased plasma concentrations of tenofovir leading to an increase in tenofovir-related adverse effects. Tenofovir alafenamide is a P-gp substrate and amiodarone is a P-gp inhibitor.
Amitriptyline: (Moderate) Close monitoring for antidepressant response and careful dose titrations of the antidepressant therapy is recommended during coadministration of tricyclic antidepressants (TCAs) and cobicistat. Concurrent use may result in elevated TCA plasma concentrations.
Amlodipine: (Moderate) Monitor for symptoms of hypotension and edema if coadministration of amlodipine with cobicistat is necessary; adjust the dose of amlodipine as clinically appropriate. Cobicistat is a strong CYP3A inhibitor and amlodipine is a CYP3A substrate. Coadministration with a moderate CYP3A4 inhibitor in elderly hypertensive patients increased systemic exposure to amlodipine by 60%. Strong CYP3A4 inhibitors may increase the plasma concentrations of amlodipine to a greater extent.
Amlodipine; Atorvastatin: (Major) When administering atorvastatin concurrently with cobicistat, use the lowest starting dose of atorvastatin and carefully titrate while monitoring for adverse events (myopathy); DO NOT exceed a maximum daily atorvastatin dose of 20 mg daily. Cobicistat is a strong CYP3A4 inhibitor and atorvastatin is a CYP3A4 substrate. Coadministration with other strong CYP3A4 inhibitors increased atorvastatin exposure by 3.3- to 4.4-fold. (Moderate) Monitor for symptoms of hypotension and edema if coadministration of amlodipine with cobicistat is necessary; adjust the dose of amlodipine as clinically appropriate. Cobicistat is a strong CYP3A inhibitor and amlodipine is a CYP3A substrate. Coadministration with a moderate CYP3A4 inhibitor in elderly hypertensive patients increased systemic exposure to amlodipine by 60%. Strong CYP3A4 inhibitors may increase the plasma concentrations of amlodipine to a greater extent.
Amlodipine; Benazepril: (Moderate) Monitor for symptoms of hypotension and edema if coadministration of amlodipine with cobicistat is necessary; adjust the dose of amlodipine as clinically appropriate. Cobicistat is a strong CYP3A inhibitor and amlodipine is a CYP3A substrate. Coadministration with a moderate CYP3A4 inhibitor in elderly hypertensive patients increased systemic exposure to amlodipine by 60%. Strong CYP3A4 inhibitors may increase the plasma concentrations of amlodipine to a greater extent.
Amlodipine; Celecoxib: (Moderate) Monitor for changes in renal function if tenofovir alafenamide is administered in combination with nephrotoxic agents, such as nonsteroidal antiinflammatory drugs (NSAIDs). Tenofovir is primarily excreted via the kidneys by a combination of glomerular filtration and active tubular secretion. Coadministration of tenofovir alafenamide with a drug that reduces renal function or competes for active tubular secretion may increase concentrations of tenofovir and other renally eliminated drugs, thus, increasing the risk of adverse reactions. (Moderate) Monitor for nonsteroidal antiinflammatory drug (NSAID) or emtricitabine-related adverse events during concomitant use. Concomitant use may increase NSAID or emtricitabine concentrations. Coadministration of drugs that reduce renal function or compete for active tubular secretion, such as NSAIDs and emtricitabine, may increase the risk of adverse reactions. (Moderate) Monitor for symptoms of hypotension and edema if coadministration of amlodipine with cobicistat is necessary; adjust the dose of amlodipine as clinically appropriate. Cobicistat is a strong CYP3A inhibitor and amlodipine is a CYP3A substrate. Coadministration with a moderate CYP3A4 inhibitor in elderly hypertensive patients increased systemic exposure to amlodipine by 60%. Strong CYP3A4 inhibitors may increase the plasma concentrations of amlodipine to a greater extent. (Moderate) The plasma concentrations of celecoxib may be decreased when administered concurrently with elvitegravir. Patients may experience a decreased analgesic effect when these drugs are coadministered. Elvitegravir is a CYP2C9 inducer, while celecoxib is a CYP2C9 substrate.
Amlodipine; Olmesartan: (Moderate) Monitor for symptoms of hypotension and edema if coadministration of amlodipine with cobicistat is necessary; adjust the dose of amlodipine as clinically appropriate. Cobicistat is a strong CYP3A inhibitor and amlodipine is a CYP3A substrate. Coadministration with a moderate CYP3A4 inhibitor in elderly hypertensive patients increased systemic exposure to amlodipine by 60%. Strong CYP3A4 inhibitors may increase the plasma concentrations of amlodipine to a greater extent.
Amlodipine; Valsartan: (Moderate) Caution is warranted when elvitegravir is administered with valsartan as there is a potential for decreased valsartan concentrations. Valsartan is a substrate of CYP2C9; elvitegravir is a CYP2C9 inducer. (Moderate) Monitor for symptoms of hypotension and edema if coadministration of amlodipine with cobicistat is necessary; adjust the dose of amlodipine as clinically appropriate. Cobicistat is a strong CYP3A inhibitor and amlodipine is a CYP3A substrate. Coadministration with a moderate CYP3A4 inhibitor in elderly hypertensive patients increased systemic exposure to amlodipine by 60%. Strong CYP3A4 inhibitors may increase the plasma concentrations of amlodipine to a greater extent. (Minor) Caution is warranted when cobicistat is administered with valsartan as there is a potential for increased valsartan concentrations. Valsartan is a substrate of organic anion transporting polypeptide (OATP)1B1. Cobicistat is an inhibitor of OATP.
Amlodipine; Valsartan; Hydrochlorothiazide, HCTZ: (Moderate) Caution is warranted when elvitegravir is administered with valsartan as there is a potential for decreased valsartan concentrations. Valsartan is a substrate of CYP2C9; elvitegravir is a CYP2C9 inducer. (Moderate) Monitor for symptoms of hypotension and edema if coadministration of amlodipine with cobicistat is necessary; adjust the dose of amlodipine as clinically appropriate. Cobicistat is a strong CYP3A inhibitor and amlodipine is a CYP3A substrate. Coadministration with a moderate CYP3A4 inhibitor in elderly hypertensive patients increased systemic exposure to amlodipine by 60%. Strong CYP3A4 inhibitors may increase the plasma concentrations of amlodipine to a greater extent. (Minor) Caution is warranted when cobicistat is administered with valsartan as there is a potential for increased valsartan concentrations. Valsartan is a substrate of organic anion transporting polypeptide (OATP)1B1. Cobicistat is an inhibitor of OATP.
Amoxicillin; Clarithromycin; Omeprazole: (Major) Avoid concurrent use of clarithromycin with regimens containing cobicistat and atazanavir or darunavir; use of an alternative antibiotic is recommended. Taking these drugs together may result in elevated concentrations of clarithromycin, cobicistat, atazanavir and darunavir. Both clarithromycin and cobicistat are inhibitors of CYP3A4, an isoenzyme responsible for the metabolism of cobicistat, atazanavir and darunavir. (Moderate) Coadministration of clarithromycin and tenofovir alafenamide may result in elevated tenofovir concentrations. Clarithromycin is an inhibitor of the drug transporter P-glycoprotein (P-gp). Tenofovir alafenamide is a P-gp substrate. However, when tenofovir alafenamide is administered as part of a cobicistat-containing product, its availability is increased by cobicistat and a further increase of tenofovir alafenamide concentrations is not expected upon coadministration of an additional P-gp inhibitor. (Minor) The plasma concentrations of omeprazole may be elevated when administered concurrently with cobicistat. Clinical monitoring for adverse effects, such as GI effects, is recommended during coadministration. Cobicistat is a strong CYP3A4 inhibitor, while omeprazole is a CYP3A4 substrate.
Amphotericin B lipid complex (ABLC): (Moderate) Monitor for changes in renal function if tenofovir alafenamide is administered in combination with a nephrotoxic agent, such as amphotericin B. Tenofovir is primarily excreted via the kidneys by a combination of glomerular filtration and active tubular secretion. Coadministration of tenofovir alafenamide with a drug that reduces renal function or competes for active tubular secretion may increase concentrations of tenofovir and other renally eliminated drugs; thus, increasing the risk of developing renal-related adverse reactions.
Amphotericin B liposomal (LAmB): (Moderate) Monitor for changes in renal function if tenofovir alafenamide is administered in combination with a nephrotoxic agent, such as amphotericin B. Tenofovir is primarily excreted via the kidneys by a combination of glomerular filtration and active tubular secretion. Coadministration of tenofovir alafenamide with a drug that reduces renal function or competes for active tubular secretion may increase concentrations of tenofovir and other renally eliminated drugs; thus, increasing the risk of developing renal-related adverse reactions.
Amphotericin B: (Moderate) Monitor for changes in renal function if tenofovir alafenamide is administered in combination with a nephrotoxic agent, such as amphotericin B. Tenofovir is primarily excreted via the kidneys by a combination of glomerular filtration and active tubular secretion. Coadministration of tenofovir alafenamide with a drug that reduces renal function or competes for active tubular secretion may increase concentrations of tenofovir and other renally eliminated drugs; thus, increasing the risk of developing renal-related adverse reactions.
Antacids: (Moderate) Separate administration of elvitegravir and antacids by at least 2 hours. Due to the formation of ionic complexes in the gastrointestinal tract, simultaneous administration results in lower elvitegravir plasma concentrations.
Apalutamide: (Major) Coadministration of cobicistat with apalutamide is not recommended as there is a potential for decreased cobicistat concentrations. Decreased antiretroviral concentrations may lead to a reduction of antiretroviral efficacy and the potential development of viral resistance. In addition, there is a potential for increased apalutamide exposure. If these drugs are used together, monitor for an increase in apalutamide-related adverse reactions. Consider reducing the dose of apalutamide if necessary based on tolerability in patients experiencing grade 3 or higher adverse reactions or intolerable toxicities. Apalutamide is a substrate and strong inducer of CYP3A4. Cobicistat is a substrate and strong inhibitor of CYP3A4. Coadministration with one strong CYP3A4 inhibitor decreased the Cmax of single-dose apalutamide by 22% and the AUC remained similar. Concomitant use with another strong CYP3A4 inhibitor is predicted to increase the single-dose apalutamide AUC by 24% but have no effect on Cmax; the steady-state Cmax and AUC are predicted to increase by 38% and 51%, respectively. The steady-state exposure of the active moieties (unbound apalutamide plus potency-adjusted unbound N-desmethyl apalutamide) is predicted to increase by 28%. (Major) Coadministration of elvitegravir with apalutamide is not recommended as there is a potential for decreased elvitegravir concentrations. Decreased antiretroviral concentrations may lead to a reduction of antiretroviral efficacy and the potential development of viral resistance. Elvitegravir is metabolized by CYP3A4 and apalutamide is a strong CYP3A4 inducer.
Apixaban: (Major) Reduce the apixaban dose by 50% when coadministered with drugs that are both strong inhibitors of CYP3A4 and P-gp, such as cobicistat containing medications. If patients are already receiving 2.5 mg twice daily, avoid concomitant administration. Concomitant administration results in increased exposure to apixaban and an increase in the risk of bleeding.
Aprepitant, Fosaprepitant: (Major) Avoid the concomitant use due to substantially increased exposure of aprepitant; increased cobicistat exposure may also occur. If coadministration cannot be avoided, use caution and monitor for an increase in cobicistat- and aprepitant-related adverse effects for several days after administration of a multi-day aprepitant regimen. After administration, fosaprepitant is rapidly converted to aprepitant and shares the same drug interactions. Cobicistat is a strong CYP3A4 inhibitor and aprepitant is a CYP3A4 substrate. Coadministration with another strong CYP3A4 inhibitor increased the AUC of aprepitant by approximately 5-fold, and the mean terminal half-life by approximately 3-fold. Cobicistat 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. When administered as a single oral or single intravenous dose, the inhibitory effect of aprepitant on CYP3A4 is weak and did not result in a clinically significant increase in the AUC of a sensitive substrate. (Major) Use caution if elvitegravir and aprepitant, fosaprepitant are used concurrently and monitor for an increase in elvitegravir-related adverse effects for several days after administration of a multi-day aprepitant regimen. Elvitegravir is 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 increase plasma concentrations of elvitegravir. 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 cobicistat 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; cobicistat is a weak CYP2D6 and strong CYP3A inhibitor. (Major) Recommendations for managing aripiprazole and cobicistat 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; cobicistat is a weak CYP2D6 and strong CYP3A inhibitor.
Armodafinil: (Major) Coadministration of cobicistat with armodafinil is not recommended as there is a potential for elevated armodafinil concentrations and decreased cobicistat concentrations. Decreased antiretroviral concentrations may lead to a reduction of antiretroviral efficacy and the potential development of viral resistance. Armodafinil is a CYP3A4 substrate/inducer and a P-glycoprotein (P-gp) substrate. Cobicistat is an inhibitor of CYP3A4 and P-gp, and a substrate of CYP3A4. (Major) Coadministration of with armodafinil is not recommended as there is a potential for decreased elvitegravir concentrations. Decreased antiretroviral concentrations may lead to a reduction of antiretroviral efficacy and the potential development of viral resistance. Armodafinil is a CYP3A4 inducer, while elvitegravir is a substrate of CYP3A4.
Artemether; Lumefantrine: (Moderate) Caution is warranted when cobicistat with artemether; lumefantrine as there is a potential for elevated artemether, lumefantrine, and cobicistat concentrations. Both artemether and lumefantrine are CYP3A4 substrate and lumefantrine is CYP2D6 inhibitor. Cobicistat is a strong inhibitor of CYP3A4 and a substrate of CYP2D6. Coadministration with another strong CYP3A4 inhibitor increased lumefantrine exposure by 1.6-fold. (Moderate) Caution is warranted when cobicistat with artemether; lumefantrine as there is a potential for elevated artemether, lumefantrine, and cobicistat concentrations. Both artemether and lumefantrine are CYP3A4 substrates and lumefantrine is CYP2D6 inhibitor. Cobicistat is a strong inhibitor of CYP3A4 and a substrate of CYP2D6. In a drug interaction study, administration of a strong CYP3A4 inhibitor, resulted in a moderate increase in exposure to artemether, DHA, and lumefantrine.
Asciminib: (Moderate) Closely monitor for asciminib-related adverse reactions if concurrent use of asciminib 200 mg twice daily with cobicistat is necessary as asciminib exposure may increase. Asciminib is a CYP3A substrate and cobicistat is a strong CYP3A inhibitor.
Asenapine: (Moderate) Caution is warranted when cobicistat is administered with asenapine as there is a potential for increased aspenapine concentrations. Asenapine is a substrate of CYP3A4 and CYP2D6. Cobicistat is an inhibitor of CYP3A4 and CYP2D6.
Aspirin, ASA: (Moderate) Monitor for changes in renal function if tenofovir alafenamide is administered in combination with nephrotoxic agents, such as salicylates. Tenofovir is primarily excreted via the kidneys by a combination of glomerular filtration and active tubular secretion. Coadministration of tenofovir alafenamide with a drug that reduces renal function or competes for active tubular secretion may increase concentrations of tenofovir and other renally eliminated drugs, thus, increasing the risk of adverse reactions.
Aspirin, ASA; Butalbital; Caffeine: (Moderate) Monitor for changes in renal function if tenofovir alafenamide is administered in combination with nephrotoxic agents, such as salicylates. Tenofovir is primarily excreted via the kidneys by a combination of glomerular filtration and active tubular secretion. Coadministration of tenofovir alafenamide with a drug that reduces renal function or competes for active tubular secretion may increase concentrations of tenofovir and other renally eliminated drugs, thus, increasing the risk of adverse reactions.
Aspirin, ASA; Caffeine: (Moderate) Monitor for changes in renal function if tenofovir alafenamide is administered in combination with nephrotoxic agents, such as salicylates. Tenofovir is primarily excreted via the kidneys by a combination of glomerular filtration and active tubular secretion. Coadministration of tenofovir alafenamide with a drug that reduces renal function or competes for active tubular secretion may increase concentrations of tenofovir and other renally eliminated drugs, thus, increasing the risk of adverse reactions.
Aspirin, ASA; Caffeine; Orphenadrine: (Moderate) Monitor for changes in renal function if tenofovir alafenamide is administered in combination with nephrotoxic agents, such as salicylates. Tenofovir is primarily excreted via the kidneys by a combination of glomerular filtration and active tubular secretion. Coadministration of tenofovir alafenamide with a drug that reduces renal function or competes for active tubular secretion may increase concentrations of tenofovir and other renally eliminated drugs, thus, increasing the risk of adverse reactions.
Aspirin, ASA; Carisoprodol: (Moderate) Monitor for changes in renal function if tenofovir alafenamide is administered in combination with nephrotoxic agents, such as salicylates. Tenofovir is primarily excreted via the kidneys by a combination of glomerular filtration and active tubular secretion. Coadministration of tenofovir alafenamide with a drug that reduces renal function or competes for active tubular secretion may increase concentrations of tenofovir and other renally eliminated drugs, thus, increasing the risk of adverse reactions.
Aspirin, ASA; Carisoprodol; Codeine: (Moderate) Concomitant use of codeine with cobicistat 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 cobicistat could decrease codeine plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to codeine. If cobicistat 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. Cobicistat is a strong inhibitor of CYP3A4. (Moderate) Monitor for changes in renal function if tenofovir alafenamide is administered in combination with nephrotoxic agents, such as salicylates. Tenofovir is primarily excreted via the kidneys by a combination of glomerular filtration and active tubular secretion. Coadministration of tenofovir alafenamide with a drug that reduces renal function or competes for active tubular secretion may increase concentrations of tenofovir and other renally eliminated drugs, thus, increasing the risk of adverse reactions.
Aspirin, ASA; Citric Acid; Sodium Bicarbonate: (Moderate) Monitor for changes in renal function if tenofovir alafenamide is administered in combination with nephrotoxic agents, such as salicylates. Tenofovir is primarily excreted via the kidneys by a combination of glomerular filtration and active tubular secretion. Coadministration of tenofovir alafenamide with a drug that reduces renal function or competes for active tubular secretion may increase concentrations of tenofovir and other renally eliminated drugs, thus, increasing the risk of adverse reactions. (Moderate) Separate administration of elvitegravir and antacids by at least 2 hours. Due to the formation of ionic complexes in the gastrointestinal tract, simultaneous administration results in lower elvitegravir plasma concentrations.
Aspirin, ASA; Dipyridamole: (Moderate) Monitor for changes in renal function if tenofovir alafenamide is administered in combination with nephrotoxic agents, such as salicylates. Tenofovir is primarily excreted via the kidneys by a combination of glomerular filtration and active tubular secretion. Coadministration of tenofovir alafenamide with a drug that reduces renal function or competes for active tubular secretion may increase concentrations of tenofovir and other renally eliminated drugs, thus, increasing the risk of adverse reactions.
Aspirin, ASA; Omeprazole: (Moderate) Monitor for changes in renal function if tenofovir alafenamide is administered in combination with nephrotoxic agents, such as salicylates. Tenofovir is primarily excreted via the kidneys by a combination of glomerular filtration and active tubular secretion. Coadministration of tenofovir alafenamide with a drug that reduces renal function or competes for active tubular secretion may increase concentrations of tenofovir and other renally eliminated drugs, thus, increasing the risk of adverse reactions. (Minor) The plasma concentrations of omeprazole may be elevated when administered concurrently with cobicistat. Clinical monitoring for adverse effects, such as GI effects, is recommended during coadministration. Cobicistat is a strong CYP3A4 inhibitor, while omeprazole is a CYP3A4 substrate.
Aspirin, ASA; Oxycodone: (Moderate) Consider a reduced dose of oxycodone with frequent monitoring for respiratory depression and sedation if concurrent use of cobicistat is necessary. If cobicistat 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 cobicistat 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 cobicistat 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. (Moderate) Monitor for changes in renal function if tenofovir alafenamide is administered in combination with nephrotoxic agents, such as salicylates. Tenofovir is primarily excreted via the kidneys by a combination of glomerular filtration and active tubular secretion. Coadministration of tenofovir alafenamide with a drug that reduces renal function or competes for active tubular secretion may increase concentrations of tenofovir and other renally eliminated drugs, thus, increasing the risk of adverse reactions.
Aspirin, ASA; Pravastatin: (Major) The plasma concentrations of pravastatin may be elevated when administered concurrently with cobicistat. Clinical monitoring for adverse effects, such as rhabdomyolysis or GI effects, is recommended during coadministration. Cobicistat is a organic anion transporting polypeptide (OATP) inhibitor, while pravastatin is a OATP1B1 substrate. (Moderate) Monitor for changes in renal function if tenofovir alafenamide is administered in combination with nephrotoxic agents, such as salicylates. Tenofovir is primarily excreted via the kidneys by a combination of glomerular filtration and active tubular secretion. Coadministration of tenofovir alafenamide with a drug that reduces renal function or competes for active tubular secretion may increase concentrations of tenofovir and other renally eliminated drugs, thus, increasing the risk of adverse reactions.
Atazanavir: (Moderate) Coadministration of atazanavir boosted with ritonavir and elvitagravir results in significantly elevated plasma concentrations of elvitegravir. The recommended dosing regimen for these drugs used in combination is: elvitegravir 85 mg PO once daily with atazanavir/ritonavir 300/100 mg PO once daily. No data are available for use of other dosage. (Moderate) Concurrent use of atazanavir with tenofovir alafenamide may result in elevated tenofovir serum concentrations. Tenofovir alafenamide is a substrate for the drug transporter organic anion transporting polypeptide (OATP1B1/1B3); atazanavir is an OATP1B1 inhibitor. Monitor for increased toxicities if these drugs are given together.
Atazanavir; Cobicistat: (Moderate) Coadministration of atazanavir boosted with ritonavir and elvitagravir results in significantly elevated plasma concentrations of elvitegravir. The recommended dosing regimen for these drugs used in combination is: elvitegravir 85 mg PO once daily with atazanavir/ritonavir 300/100 mg PO once daily. No data are available for use of other dosage. (Moderate) Concurrent use of atazanavir with tenofovir alafenamide may result in elevated tenofovir serum concentrations. Tenofovir alafenamide is a substrate for the drug transporter organic anion transporting polypeptide (OATP1B1/1B3); atazanavir is an OATP1B1 inhibitor. Monitor for increased toxicities if these drugs are given together. (Moderate) The plasma concentrations of tenofovir may be elevated when administered concurrently with cobicistat. Clinical monitoring for adverse effects is recommended during coadministration. Cobicistat is an inhibitor of the drug transporters P-glycoprotein (P-gp), breast cancer resistance protein (BCRP), and organic anion transport protein (OATP1B1/1B3). Tenofovir alafenamide is a substrate for all three transporters.
Atogepant: (Major) Avoid use of atogepant and cobicistat when atogepant is used for chronic migraine. Limit the dose of atogepant to 10 mg PO once daily for episodic migraine if coadministered with cobicistat. Concurrent use may increase atogepant exposure and the risk of adverse effects. Atogepant is a substrate of CYP3A and OATP1B1/3; cobicistat is a strong CYP3A inhibitor and an OATP1B1/3 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. Coadministration with an OATP1B1/3 inhibitor resulted in a 2.85-fold increase in atogepant overall exposure and a 2.23-fold increase in atogepant peak concentration.
Atomoxetine: (Moderate) The plasma concentrations of atomoxetine may be elevated when administered concurrently with cobicistat. Clinical monitoring for adverse effects, such as dizziness, drowsiness, hypertension, and other cardiac adverse events, is recommended during coadministration and dosage adjustments for atomoxetine may be warranted. Cobicistat is a CYP2D6 inhibitor and atomoxetine is a CYP2D6 substrate.
Atorvastatin: (Major) When administering atorvastatin concurrently with cobicistat, use the lowest starting dose of atorvastatin and carefully titrate while monitoring for adverse events (myopathy); DO NOT exceed a maximum daily atorvastatin dose of 20 mg daily. Cobicistat is a strong CYP3A4 inhibitor and atorvastatin is a CYP3A4 substrate. Coadministration with other strong CYP3A4 inhibitors increased atorvastatin exposure by 3.3- to 4.4-fold.
Atorvastatin; Ezetimibe: (Major) When administering atorvastatin concurrently with cobicistat, use the lowest starting dose of atorvastatin and carefully titrate while monitoring for adverse events (myopathy); DO NOT exceed a maximum daily atorvastatin dose of 20 mg daily. Cobicistat is a strong CYP3A4 inhibitor and atorvastatin is a CYP3A4 substrate. Coadministration with other strong CYP3A4 inhibitors increased atorvastatin exposure by 3.3- to 4.4-fold.
Atropine; Benzoic Acid; Hyoscyamine; Methenamine; Methylene Blue; Phenyl Salicylate: (Moderate) Monitor for changes in renal function if tenofovir alafenamide is administered in combination with nephrotoxic agents, such as salicylates. Tenofovir is primarily excreted via the kidneys by a combination of glomerular filtration and active tubular secretion. Coadministration of tenofovir alafenamide with a drug that reduces renal function or competes for active tubular secretion may increase concentrations of tenofovir and other renally eliminated drugs, thus, increasing the risk of adverse reactions.
Avacopan: (Major) Reduce the dose of avacopan to 30 mg once daily if concomitant use of cobicistat is necessary. Concomitant use may increase avacopan exposure and risk for avacopan-related adverse effects. Avacopan is a CYP3A substrate and cobicistat is a strong CYP3A inhibitor. Concomitant use of another strong CYP3A inhibitor increased avacopan overall exposure 2.19-fold.
Avanafil: (Major) Do not use avanafil in patients receiving cobicistat due to the risk for increased avanafil serum concentrations and serious adverse reactions. Avanafil is a sensitive CYP3A4 substrate; cobicistat is a strong CYP3A4 inhibitor. Coadministration of other strong CYP3A4 inhibitors increased the avanafil AUC by 13-fold.
Avapritinib: (Major) Avoid coadministration of avapritinib with cobicistat due to the risk of increased avapritinib-related adverse reactions. Avapritinib is a CYP3A4 substrate and cobicistat 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 cobicistat 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 cobicistat is discontinued. Axitinib is a CYP3A4/5 substrate and cobicistat 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 cobicistat 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; cobicistat 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.
Bacitracin: (Moderate) Monitor for changes in renal function if tenofovir alafenamide is administered in combination with a nephrotoxic agent, such as bacitracin. Tenofovir is primarily excreted via the kidneys by a combination of glomerular filtration and active tubular secretion. Coadministration of tenofovir alafenamide with a drug that reduces renal function or competes for active tubular secretion may increase concentrations of tenofovir and other renally eliminated drugs; thus, increasing the risk of developing renal-related adverse reactions.
Barium Sulfate: (Moderate) Tenofovir-containing products should be avoided with concurrent or recent use of a nephrotoxic agent, such as radiopaque contrast agents. Tenofovir is primarily excreted via the kidneys by a combination of glomerular filtration and active tubular secretion. Coadministration of tenofovir alafenamide with drugs that are eliminated by active tubular secretion may increase concentrations of tenofovir and/or the co-administered drug. Drugs that decrease renal function may also increase concentrations of tenofovir. Renal impairment, which may include hypophosphatemia, has been reported with the use of tenofovir with a majority of the cases occurring in patients who have underlying systemic or renal disease or who are concurrently taking nephrotoxic agents. Monitor patients receiving concomitant nephrotoxic agents for changes in serum creatinine and phosphorus, and urine glucose and protein.
Bedaquiline: (Major) Concurrent use of bedaquiline and cobicistat should be avoided due to the potential risk of adverse reactions to bedaquiline because of increased systemic exposure. Bedaquiline is a CYP3A4 substrate; cobicistat is a strong CYP3A4 inhibitor. Concurrent use of another strong CYP3A4 inhibitor increased bedaquiline exposure by 22%.
Benzhydrocodone; Acetaminophen: (Moderate) Concurrent use of benzhydrocodone with cobicistat 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 cobicistat 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 cobicistat 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. Cobicistat is a strong inhibitor of CYP3A4 and a weak inhibitor of CYP2D6.
Benzoic Acid; Hyoscyamine; Methenamine; Methylene Blue; Phenyl Salicylate: (Moderate) Monitor for changes in renal function if tenofovir alafenamide is administered in combination with nephrotoxic agents, such as salicylates. Tenofovir is primarily excreted via the kidneys by a combination of glomerular filtration and active tubular secretion. Coadministration of tenofovir alafenamide with a drug that reduces renal function or competes for active tubular secretion may increase concentrations of tenofovir and other renally eliminated drugs, thus, increasing the risk of adverse reactions.
Berotralstat: (Major) Reduce the berotralstat dose to 110 mg PO once daily in patients chronically taking cobicistat. Concurrent use may increase berotralstat exposure and the risk of adverse effects. Additionally, monitor for cobicistat-related adverse effects as concurrent use may also increase cobicistat exposure. Berotralstat is a P-gp and BCRP substrate and moderate CYP3A4 inhibitor; cobicistat is a CYP3A4 substrate and P-gp and BCRP inhibitor. Coadministration with another P-gp and BCRP inhibitor increased berotralstat exposure by 69%. (Moderate) Coadministration of tenofovir alafenamide with berotralstat may result in increased plasma concentrations of tenofovir leading to an increase in tenofovir-related adverse effects. Tenofovir alafenamide is a P-glycoprotein (P-gp) substrate and berotralstat is a P-gp inhibitor.
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. Cobicistat 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.
Betrixaban: (Major) Avoid betrixaban use in patients with severe renal impairment receiving cobicistat. Reduce betrixaban dosage to 80 mg PO once followed by 40 mg PO once daily in all other patients receiving cobicistat. Bleeding risk may be increased; monitor patients closely for signs and symptoms of bleeding. Betrixaban is a substrate of P-gp; cobicistat inhibits P-gp.
Bexarotene: (Major) Coadministration of cobicistat with bexarotene is not recommended as there is a potential for decreased cobicistat concentrations. Decreased antiretroviral concentrations may lead to a reduction of antiretroviral efficacy and the potential development of viral resistance. Bexarotene is a CYP3A4 inducer. Cobicistat is a substrate of CYP3A4. (Major) Coadministration of elvitegravir with bexarotene is not recommended as there is a potential for decreased elvitegravir concentrations. Decreased antiretroviral concentrations may lead to a reduction of antiretroviral efficacy and the potential development of viral resistance. Bexarotene is a CYP3A4 inducer, while elvitegravir is a substrate of CYP3A4.
Bismuth Subsalicylate: (Moderate) Monitor for changes in renal function if tenofovir alafenamide is administered in combination with nephrotoxic agents, such as salicylates. Tenofovir is primarily excreted via the kidneys by a combination of glomerular filtration and active tubular secretion. Coadministration of tenofovir alafenamide with a drug that reduces renal function or competes for active tubular secretion may increase concentrations of tenofovir and other renally eliminated drugs, thus, increasing the risk of adverse reactions.
Bismuth Subsalicylate; Metronidazole; Tetracycline: (Moderate) Monitor for changes in renal function if tenofovir alafenamide is administered in combination with nephrotoxic agents, such as salicylates. Tenofovir is primarily excreted via the kidneys by a combination of glomerular filtration and active tubular secretion. Coadministration of tenofovir alafenamide with a drug that reduces renal function or competes for active tubular secretion may increase concentrations of tenofovir and other renally eliminated drugs, thus, increasing the risk of adverse reactions.
Bortezomib: (Moderate) Monitor for signs of bortezomib toxicity and consider a bortezomib dose reduction if coadministration of cobicistat is necessary. Bortezomib exposure may be increased. Bortezomib is a CYP3A4 substrate; cobicistat is a strong CYP3A4 inhibitor. Coadministration of another strong CYP3A4 inhibitor increased bortezomib exposure by 35%.
Bosentan: (Major) Coadministation of bosentan with elvitegravir may result in elevated bosentan plasma concentrations and reduced elvitegravir concentrations. In patients receiving the antiretroviral for at least 10 days, start bosentan at 62.5 mg daily or every other day (depending on tolerability). When the antiretroviral is initiated in a patients currently receiving bosentan, discontinue bosentan at least 36 hours prior to starting the antiretroviral. After at least 10 days, restart bosentan at 62.5 mg daily or every other day based on tolerability. (Major) The plasma concentrations of bosentan may increase when administered with regimens containing cobicistat and atazanavir or darunavir. In addition, coadministration may result in decreased concentrations of cobicistat, atazanavir, and darunavir. In patients receiving the antiretrovirals for at least 10 days, start bosentan at 62.5 mg daily or every other day (depending on tolerability). When the antiretrovirals are initiated in a patients currently receiving bosentan, discontinue bosentan at least 36 hours prior to starting the antiretroviral regimen. After at least 10 days, restart bosentan at 62.5 mg daily or every other day based on tolerability. If switching from a ritonavir boosted antiretroviral regimen to a cobicistat boosted regimen, maintain current bosentan dose.
Bosutinib: (Major) Avoid concomitant use of bosutinib and cobicistat; 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 cobicistat is a strong CYP3A4 inhibitor. 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: (Moderate) Closely monitor for an increase in brentuximab-related adverse reactions, including peripheral neuropathy or gastrointestinal side effects, if coadministration with cobicistat is necessary. Monomethyl auristatin E (MMAE), one of the 3 components released from brentuximab vedotin, is a CYP3A4 substrate and cobicistat is a strong CYP3A4 inhibitor. Coadministration with another strong CYP3A4 inhibitor increased MMAE exposure by approximately 34%.
Brexpiprazole: (Major) Because brexpiprazole is primarily metabolized by CYP3A4 and CYP2D6, the manufacturer recommends that the brexpiprazole dose be reduced to one-quarter (25%) of the usual dose in patients receiving a moderate to strong inhibitor of CYP3A4 in combination with a moderate to strong inhibitor of CYP2D6. Cobicistat is a moderate to strong inhibitor of both CYP3A4 and CYP2D6. If these agents are used in combination, the patient should be carefully monitored for brexpiprazole-related adverse reactions. If cobicistat is discontinued, adjust the brexpiprazole dosage to its original level.
Brigatinib: (Major) Avoid coadministration of brigatinib with cobicistat 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 cobicistat, resume the brigatinib dose that was tolerated prior to initiation of cobicistat. Brigatinib is a CYP3A4 substrate; cobicistat is a strong CYP3A4 inhibitor. Coadministration with another strong CYP3A4 inhibitor increased the AUC and Cmax of brigatinib by 101% and 21%, respectively. (Moderate) Monitor for an increase in tenofovir-related adverse reactions if coadministration with brigatinib is necessary. Tenofovir alafenamide is a substrate of P-glycoprotein (P-gp) and BCRP. Brigatinib inhibits both P-gp and BCRP in vitro and may have the potential to increase concentrations of substrates of these transporters.
Brimonidine; Timolol: (Moderate) Coadministration of cobicistat (a CYP2D6 inhibitor) with beta-blockers metabolized by CYP2D6, such as timolol, may result in elevated beta-blocker serum concentrations. If used concurrently, close clinical monitoring with appropriate beta-blocker dose reductions are advised.
Brincidofovir: (Moderate) Postpone the administration of cobicistat for at least three hours after brincidofovir administration and increase monitoring for brincidofovir-related adverse reactions (i.e., elevated hepatic enzymes and bilirubin, diarrhea, other gastrointestinal adverse events) if concomitant use of brincidofovir and cobicistat is necessary. Brincidofovir is an OATP1B1/3 substrate and cobicistat is an OATP1B1/3 inhibitor. In a drug interaction study, the mean AUC and Cmax of brincidofovir increased by 374% and 269%, respectively, when administered with another OATP1B1/3 inhibitor.
Bromocriptine: (Major) When bromocriptine is used for diabetes, avoid coadministration with cobicistat 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; cobicistat is a strong inhibitor of CYP3A4.
Brompheniramine; Dextromethorphan; Guaifenesin: (Moderate) Use of dextromethorphan with cobicistat may result in increased dextromethorphan exposure. Cobicistat inhibits CYP2D6 and dextromethorphan is a CYP2D6 substrate. Monitor for dextromethorphan-related side effects, such as drowsiness, nausea or vomiting, sweating, restlessness, or tremor.
Brompheniramine; Dextromethorphan; Phenylephrine: (Moderate) Use of dextromethorphan with cobicistat may result in increased dextromethorphan exposure. Cobicistat inhibits CYP2D6 and dextromethorphan is a CYP2D6 substrate. Monitor for dextromethorphan-related side effects, such as drowsiness, nausea or vomiting, sweating, restlessness, or tremor.
Brompheniramine; Pseudoephedrine; Dextromethorphan: (Moderate) Use of dextromethorphan with cobicistat may result in increased dextromethorphan exposure. Cobicistat inhibits CYP2D6 and dextromethorphan is a CYP2D6 substrate. Monitor for dextromethorphan-related side effects, such as drowsiness, nausea or vomiting, sweating, restlessness, or tremor.
Budesonide: (Moderate) Avoid coadministration of oral budesonide and cobistat due to the potential for increased budesonide exposure. Use caution with inhaled forms of budesonide as systemic exposure to the corticosteroid may also increase. Elevated budesonide serum concentrations may result in Cushing's syndrome and adrenal suppression. Budesonide is a CYP3A4 and P-glycoprotein (P-gp) substrate; cobicistat is a strong inhibitor of CYP3A4 and P-gp. In the presence of another strong CYP3A4 inhibitor, the systemic exposure to oral budesonide was increased by 8-fold. Corticosteroids, such as beclomethasone and prednisolone, whose concentrations are less affected by strong CYP3A4 inhibitors, should be considered, especially for long-term use.
Budesonide; Formoterol: (Moderate) Avoid coadministration of oral budesonide and cobistat due to the potential for increased budesonide exposure. Use caution with inhaled forms of budesonide as systemic exposure to the corticosteroid may also increase. Elevated budesonide serum concentrations may result in Cushing's syndrome and adrenal suppression. Budesonide is a CYP3A4 and P-glycoprotein (P-gp) substrate; cobicistat is a strong inhibitor of CYP3A4 and P-gp. In the presence of another strong CYP3A4 inhibitor, the systemic exposure to oral budesonide was increased by 8-fold. Corticosteroids, such as beclomethasone and prednisolone, whose concentrations are less affected by strong CYP3A4 inhibitors, should be considered, especially for long-term use.
Budesonide; Glycopyrrolate; Formoterol: (Moderate) Avoid coadministration of oral budesonide and cobistat due to the potential for increased budesonide exposure. Use caution with inhaled forms of budesonide as systemic exposure to the corticosteroid may also increase. Elevated budesonide serum concentrations may result in Cushing's syndrome and adrenal suppression. Budesonide is a CYP3A4 and P-glycoprotein (P-gp) substrate; cobicistat is a strong inhibitor of CYP3A4 and P-gp. In the presence of another strong CYP3A4 inhibitor, the systemic exposure to oral budesonide was increased by 8-fold. Corticosteroids, such as beclomethasone and prednisolone, whose concentrations are less affected by strong CYP3A4 inhibitors, should be considered, especially for long-term use.
Bupivacaine Liposomal: (Minor) Plasma concentrations of bupivacaine may be elevated when administered concurrently with cobicistat. Clinical monitoring for adverse effects, such as cardiotoxic effects, hypotension, or CNS toxicity, is recommended during coadministration. Cobicistat is a CYP3A4 inhibitor, while bupivacaine is a CYP3A4 substrate.
Bupivacaine: (Minor) Plasma concentrations of bupivacaine may be elevated when administered concurrently with cobicistat. Clinical monitoring for adverse effects, such as cardiotoxic effects, hypotension, or CNS toxicity, is recommended during coadministration. Cobicistat is a CYP3A4 inhibitor, while bupivacaine is a CYP3A4 substrate.
Bupivacaine; Epinephrine: (Minor) Plasma concentrations of bupivacaine may be elevated when administered concurrently with cobicistat. Clinical monitoring for adverse effects, such as cardiotoxic effects, hypotension, or CNS toxicity, is recommended during coadministration. Cobicistat is a CYP3A4 inhibitor, while bupivacaine is a CYP3A4 substrate.
Bupivacaine; Lidocaine: (Moderate) Monitor for lidocaine-related adverse reactions if coadministration with cobicistat is necessary. Lidocaine is a CYP3A4 substrate and cobicistat is a strong CYP3A4 inhibitor. (Minor) Plasma concentrations of bupivacaine may be elevated when administered concurrently with cobicistat. Clinical monitoring for adverse effects, such as cardiotoxic effects, hypotension, or CNS toxicity, is recommended during coadministration. Cobicistat is a CYP3A4 inhibitor, while bupivacaine is a CYP3A4 substrate.
Bupivacaine; Meloxicam: (Moderate) Caution is warranted when elvitegravir is administered with meloxicam as there is a potential for decreased meloxicam concentrations. Meloxicam is primarily metabolized by CYP2C9, while elvitegravir is a CYP2C9 inducer. (Moderate) Monitor for changes in renal function if tenofovir alafenamide is administered in combination with nephrotoxic agents, such as nonsteroidal antiinflammatory drugs (NSAIDs). Tenofovir is primarily excreted via the kidneys by a combination of glomerular filtration and active tubular secretion. Coadministration of tenofovir alafenamide with a drug that reduces renal function or competes for active tubular secretion may increase concentrations of tenofovir and other renally eliminated drugs, thus, increasing the risk of adverse reactions. (Moderate) Monitor for nonsteroidal antiinflammatory drug (NSAID) or emtricitabine-related adverse events during concomitant use. Concomitant use may increase NSAID or emtricitabine concentrations. Coadministration of drugs that reduce renal function or compete for active tubular secretion, such as NSAIDs and emtricitabine, may increase the risk of adverse reactions. (Minor) Plasma concentrations of bupivacaine may be elevated when administered concurrently with cobicistat. Clinical monitoring for adverse effects, such as cardiotoxic effects, hypotension, or CNS toxicity, is recommended during coadministration. Cobicistat is a CYP3A4 inhibitor, while bupivacaine is a CYP3A4 substrate.
Buprenorphine: (Moderate) Concomitant use of buprenorphine and cobicistat can increase the plasma concentration of buprenorphine, resulting in increased or prolonged opioid effects, particularly when cobicistat is added after a stable buprenorphine dose is achieved. If concurrent use is necessary, consider dosage reduction of buprenorphine until stable drug effects are achieved. Monitor patient for respiratory depression and sedation at frequent intervals. When stopping cobicistat, the buprenorphine concentration may decrease, potentially resulting in decreased opioid efficacy or a withdrawal syndrome in patients who had developed physical dependency. If cobicistat is discontinued, consider increasing buprenorphine dosage until stable drug effects are achieved. Monitor for signs of opioid withdrawal. Buprenorphine is a substrate of CYP3A and cobicistat is a CYP3A inhibitor. (Moderate) The plasma concentrations of buprenorphine and its metabolite, norbuprenorphine, are elevated when administered concurrently with elvitegravir. Dose adjustments are not required; however clinical monitoring for adverse effects, such as CNS side effects or respiratory depression, is recommended during coadministration.
Buprenorphine; Naloxone: (Moderate) Concomitant use of buprenorphine and cobicistat can increase the plasma concentration of buprenorphine, resulting in increased or prolonged opioid effects, particularly when cobicistat is added after a stable buprenorphine dose is achieved. If concurrent use is necessary, consider dosage reduction of buprenorphine until stable drug effects are achieved. Monitor patient for respiratory depression and sedation at frequent intervals. When stopping cobicistat, the buprenorphine concentration may decrease, potentially resulting in decreased opioid efficacy or a withdrawal syndrome in patients who had developed physical dependency. If cobicistat is discontinued, consider increasing buprenorphine dosage until stable drug effects are achieved. Monitor for signs of opioid withdrawal. Buprenorphine is a substrate of CYP3A and cobicistat is a CYP3A inhibitor. (Moderate) The plasma concentrations of buprenorphine and its metabolite, norbuprenorphine, are elevated when administered concurrently with elvitegravir. Dose adjustments are not required; however clinical monitoring for adverse effects, such as CNS side effects or respiratory depression, is recommended during coadministration. (Moderate) The plasma concentrations of buprenorphine and naloxone may be elevated when administered concurrently with cobicistat. When initiating buprenorphine; naloxone in patients currently on a regimen containing cobicistat and atazanavir or darunavir, use the lowest buprenorphine; naloxone starting dose and slowly titrate to desired effect. When initiating antiretroviral regimens containing cobicistat and atazanavir or darunavir to patients on buprenorphine; naloxone, an adjustment of buprenorphine; naloxone dose may be needed. Monitoring for adverse effects, such as CNS side effects or respiratory depression, is recommended during coadministration. Cobicistat is a CYP3A4 inhibitor, while buprenorphine is a CYP3A4 substrate.
Bupropion: (Moderate) Caution is warranted when cobicistat is administered with bupropion as there is a potential for elevated cobicistat concentrations. Bupropion is a CYP2D6 inhibitor in vitro, while cobicistat is a substrate of CYP2D6.
Bupropion; Naltrexone: (Moderate) Caution is warranted when cobicistat is administered with bupropion as there is a potential for elevated cobicistat concentrations. Bupropion is a CYP2D6 inhibitor in vitro, while cobicistat is a substrate of CYP2D6.
Buspirone: (Moderate) A low dose of buspirone used cautiously is recommended when coadministered with cobicistat. If a patient has been titrated to a stable dosage of buspirone, a dose adjustment of buspirone may be necessary to avoid adverse events attributable to buspirone. Administering cobicistat with buspirone may increase buspirone concentration and risk for adverse events. Buspirone is a sensitive substrate of CYP3A4. Cobicistat is a strong CYP3A4 inhibitor. Coadministration with another strong CYP3A4 inhibitor increased the buspirone AUC by 19-fold with an increased incidence of buspirone-related adverse effects.
Butalbital; Acetaminophen; Caffeine; Codeine: (Moderate) Concomitant use of codeine with cobicistat 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 cobicistat could decrease codeine plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to codeine. If cobicistat 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. Cobicistat is a strong inhibitor of CYP3A4.
Butalbital; Aspirin; Caffeine; Codeine: (Moderate) Concomitant use of codeine with cobicistat 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 cobicistat could decrease codeine plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to codeine. If cobicistat 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. Cobicistat is a strong inhibitor of CYP3A4. (Moderate) Monitor for changes in renal function if tenofovir alafenamide is administered in combination with nephrotoxic agents, such as salicylates. Tenofovir is primarily excreted via the kidneys by a combination of glomerular filtration and active tubular secretion. Coadministration of tenofovir alafenamide with a drug that reduces renal function or competes for active tubular secretion may increase concentrations of tenofovir and other renally eliminated drugs, thus, increasing the risk of adverse reactions.
Cabazitaxel: (Major) Avoid coadministration of cabazitaxel with cobicistat 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 cobicistat is a strong CYP3A4 inhibitor. In a drug interaction study, coadministration with another strong CYP3A4 inhibitor increased cabazitaxel exposure by 25%.
Cabotegravir; Rilpivirine: (Moderate) The plasma concentrations of rilpivirine may be elevated when administered concurrently with cobicistat. Clinical monitoring for adverse effects is recommended during coadministration. Rilpivirine is a CYP3A4 substrate and cobicistat is a strong inhibitor of CYP3A4.
Cabozantinib: (Major) Avoid concomitant use of cabozantinib and cobicistat 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 cobicistat 2 to 3 days after discontinuation of cobicistat. Cabozantinib is a CYP3A substrate and cobicistat is a strong CYP3A inhibitor. Coadministration with another strong CYP3A inhibitor increased cabozantinib exposure by 38%. (Minor) Monitor for an increase in both cabozantinib- and tenofovir-related adverse reactions if coadministration is necessary. Cabozantinib is a Multidrug Resistance Protein 2 (MRP2) substrate and tenofovir is an MRP2 inhibitor. MRP2 inhibitors have the potential to increase plasma concentrations of cabozantinib. Cabozantinib is also P-gp inhibitor and has the potential to increase plasma concentrations of P-gp substrates such as tenofovir. The clinical relevance of either of these interactions is unknown.
Calcium (oral): (Moderate) Separate administration of elvitegravir and calcium by at least 2 hours. Due to the formation of ionic complexes in the gastrointestinal tract, simultaneous administration results in lower elvitegravir plasma concentrations.
Calcium Acetate: (Moderate) Separate administration of elvitegravir and calcium by at least 2 hours. Due to the formation of ionic complexes in the gastrointestinal tract, simultaneous administration results in lower elvitegravir plasma concentrations.
Calcium Carbonate: (Moderate) Separate administration of elvitegravir and calcium by at least 2 hours. Due to the formation of ionic complexes in the gastrointestinal tract, simultaneous administration results in lower elvitegravir plasma concentrations.
Calcium Carbonate; Famotidine; Magnesium Hydroxide: (Moderate) Separate administration of elvitegravir and calcium by at least 2 hours. Due to the formation of ionic complexes in the gastrointestinal tract, simultaneous administration results in lower elvitegravir plasma concentrations.
Calcium Carbonate; Magnesium Hydroxide: (Moderate) Separate administration of elvitegravir and calcium by at least 2 hours. Due to the formation of ionic complexes in the gastrointestinal tract, simultaneous administration results in lower elvitegravir plasma concentrations.
Calcium Carbonate; Magnesium Hydroxide; Simethicone: (Moderate) Separate administration of elvitegravir and calcium by at least 2 hours. Due to the formation of ionic complexes in the gastrointestinal tract, simultaneous administration results in lower elvitegravir plasma concentrations.
Calcium Carbonate; Risedronate: (Moderate) Separate administration of elvitegravir and calcium by at least 2 hours. Due to the formation of ionic complexes in the gastrointestinal tract, simultaneous administration results in lower elvitegravir plasma concentrations.
Calcium Carbonate; Simethicone: (Moderate) Separate administration of elvitegravir and calcium by at least 2 hours. Due to the formation of ionic complexes in the gastrointestinal tract, simultaneous administration results in lower elvitegravir plasma concentrations.
Calcium Gluconate: (Moderate) Separate administration of elvitegravir and calcium by at least 2 hours. Due to the formation of ionic complexes in the gastrointestinal tract, simultaneous administration results in lower elvitegravir plasma concentrations.
Calcium;