Plaquenil

Antimalarials
Other Antiinflammatory and Antirheumatic Agents

Administer with food or milk to minimize gastric indigestion or irritation.

cardiomyopathy / Delayed / 0-1.0
hepatic failure / Delayed / 0-1.0
suicidal ideation / Delayed / 0-1.0
visual impairment / Early / Incidence not known
corneal opacification / Delayed / Incidence not known
retinopathy / Delayed / Incidence not known
macular degeneration / Delayed / Incidence not known
angioedema / Rapid / Incidence not known
exfoliative dermatitis / Delayed / Incidence not known
erythema multiforme / Delayed / Incidence not known
bronchospasm / Rapid / Incidence not known
Stevens-Johnson syndrome / Delayed / Incidence not known
toxic epidermal necrolysis / Delayed / Incidence not known
acute generalized exanthematous pustulosis (AGEP) / Delayed / Incidence not known
Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS) / Delayed / Incidence not known
aplastic anemia / Delayed / Incidence not known
hemolytic anemia / Delayed / Incidence not known
agranulocytosis / Delayed / Incidence not known
hearing loss / Delayed / Incidence not known
ventricular fibrillation / Early / Incidence not known
ventricular tachycardia / Early / Incidence not known
torsade de pointes / Rapid / Incidence not known
heart failure / Delayed / Incidence not known
AV block / Early / Incidence not known
cardiotoxicity / Delayed / Incidence not known
pulmonary hypertension / Delayed / Incidence not known
seizures / Delayed / Incidence not known
nephrotoxicity / Delayed / Incidence not known
hepatotoxicity / Delayed / Incidence not known
porphyria / Delayed / Incidence not known

corneal edema / Early / Incidence not known
ocular toxicity / Delayed / Incidence not known
scotomata / Delayed / Incidence not known
psoriasis / Delayed / Incidence not known
myopathy / Delayed / Incidence not known
peripheral neuropathy / Delayed / Incidence not known
hemolysis / Early / Incidence not known
leukopenia / Delayed / Incidence not known
bone marrow suppression / Delayed / Incidence not known
anemia / Delayed / Incidence not known
thrombocytopenia / Delayed / Incidence not known
bundle-branch block / Early / Incidence not known
QT prolongation / Rapid / Incidence not known
ataxia / Delayed / Incidence not known
nystagmus / Delayed / Incidence not known
psychosis / Early / Incidence not known
dyskinesia / Delayed / Incidence not known
dystonic reaction / Delayed / Incidence not known
depression / Delayed / Incidence not known
confusion / Early / Incidence not known
hallucinations / Early / Incidence not known
mania / Early / Incidence not known
hypoglycemia / Early / Incidence not known
proteinuria / Delayed / Incidence not known
elevated hepatic enzymes / Delayed / Incidence not known

retinal pigment changes / Delayed / Incidence not known
hair discoloration / Delayed / Incidence not known
urticaria / Rapid / Incidence not known
photosensitivity / Delayed / Incidence not known
rash / Early / Incidence not known
skin discoloration / Delayed / Incidence not known
alopecia / Delayed / Incidence not known
pruritus / Rapid / Incidence not known
weakness / Early / Incidence not known
tinnitus / Delayed / Incidence not known
anorexia / Delayed / Incidence not known
diarrhea / Early / Incidence not known
abdominal pain / Early / Incidence not known
vomiting / Early / Incidence not known
nausea / Early / Incidence not known
dizziness / Early / Incidence not known
headache / Early / Incidence not known
irritability / Delayed / Incidence not known
nightmares / Early / Incidence not known
vertigo / Early / Incidence not known
emotional lability / Early / Incidence not known
tremor / Early / Incidence not known
agitation / Early / Incidence not known
anxiety / Delayed / Incidence not known
insomnia / Early / Incidence not known
paranoia / Early / Incidence not known
weight loss / Delayed / Incidence not known
fatigue / Early / Incidence not known

Plaquenil, Quineprox

Rx

Oral disease-modifying antirheumatic drug (DMARD) with antimalarial properties
Used for rheumatoid arthritis, systemic lupus erythematosus, and malaria
Associated with ocular toxicity and cardiomyopathy

†Indicates off-label use

A dosage reduction may be necessary in patients with hepatic disease or those taking concomitant medications known to affect the liver. However, no specific dosage adjustment guidelines are available for patients with hepatic impairment.

A dosage adjustment is not required in patients with renal impairment. However, a dosage reduction may be necessary in patients with renal disease or those taking concomitant medications known to affect the kidney. No specific dosage adjustment guidelines are available for patients with renal impairment.

Acarbose: (Moderate) Careful monitoring of blood glucose is recommended when hydroxychloroquine and antidiabetic agents, including the alpha-glucosidase inhibitors, are coadministered. A decreased dose of the antidiabetic agent may be necessary as severe hypoglycemia has been reported in patients treated concomitantly with hydroxychloroquine and an antidiabetic agent.
Acetazolamide: (Moderate) Caution is warranted with the coadministration of hydroxychloroquine and antiepileptic drugs, such as acetazolamide. Hydroxychloroquine can lower the seizure threshold; therefore, the activity of antiepileptic drugs may be impaired with concomitant use.
Adagrasib: (Major) Concomitant use of adagrasib and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Alfuzosin: (Major) Concomitant use of hydroxychloroquine and alfuzosin increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Alogliptin: (Moderate) Monitor blood glucose during concomitant dipeptidyl peptidase-4 inhibitor (DPP-4) and hydroxychloroquine use; a DPP-4 dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
Alogliptin; Metformin: (Moderate) Monitor blood glucose during concomitant dipeptidyl peptidase-4 inhibitor (DPP-4) and hydroxychloroquine use; a DPP-4 dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant metformin and hydroxychloroquine use; a metformin dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
Alogliptin; Pioglitazone: (Moderate) Monitor blood glucose during concomitant dipeptidyl peptidase-4 inhibitor (DPP-4) and hydroxychloroquine use; a DPP-4 dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant thiazolidinedione and hydroxychloroquine use; a thiazolidinedione dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
Alpha-glucosidase Inhibitors: (Moderate) Careful monitoring of blood glucose is recommended when hydroxychloroquine and antidiabetic agents, including the alpha-glucosidase inhibitors, are coadministered. A decreased dose of the antidiabetic agent may be necessary as severe hypoglycemia has been reported in patients treated concomitantly with hydroxychloroquine and an antidiabetic agent.
Amiodarone: (Major) Concomitant use of hydroxychloroquine and amiodarone increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary. Due to the extremely long half-life of amiodarone, a drug interaction is possible for days to weeks after drug discontinuation.
Amisulpride: (Major) Avoid coadministration of amisulpride and hydroxychloroquine due to the risk of increased QT prolongation. If use together is necessary, obtain an ECG at baseline to assess initial QT interval and determine frequency of subsequent ECG monitoring, avoid any non-essential QT prolonging drugs, and correct electrolyte imbalances. Hydroxychloroquine prolongs the QT interval. Amisulpride causes dose- and concentration-dependent QT prolongation.
Amobarbital: (Moderate) Caution is warranted with the coadministration of hydroxychloroquine and antiepileptic drugs, such as amobarbital. Hydroxychloroquine can lower the seizure threshold; therefore, the activity of antiepileptic drugs may be impaired with concomitant use.
Amoxicillin; Clarithromycin; Omeprazole: (Major) Concomitant use of hydroxychloroquine and clarithromycin increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Ampicillin: (Moderate) Administer oral ampicillin 2 hours before or 2 hours after hydroxychloroquine. Ampicillin bioavailability may be decreased with coadministration of hydroxychloroquine as a significant reduction in ampicillin bioavailability was observed with the structurally similar chloroquine in a study of healthy volunteers. The reduction of ampicillin bioavailability could be attributed to slower gastric emptying and enhancement of gut motility produced by chloroquine.
Anagrelide: (Major) Avoid coadministration of anagrelide and hydroxychloroquine due to the risk of increased QT prolongation. If use together is necessary, obtain an ECG at baseline to assess initial QT interval and determine frequency of subsequent ECG monitoring, avoid any non-essential QT prolonging drugs, and correct electrolyte imbalances. Hydroxychloroquine prolongs the QT interval. Torsade de pointes (TdP) and ventricular tachycardia have been reported with anagrelide. In addition, dose-related increases in mean QTc and heart rate were observed in healthy subjects.
Antacids: (Moderate) Hydroxychloroquine absorption may be reduced by antacids as has been observed with the structurally similar chloroquine. Administer hydroxychloroquine and antacids at least 4 hours apart. Of note, a study demonstrated no significant difference in hydroxychloroquine serum concentration in patients taking concomitant antacids (n = 14) compared to those not taking antacids (n = 495).
Apomorphine: (Major) Avoid coadministration of apomorphine and hydroxychloroquine due to the risk of increased QT prolongation. If use together is necessary, obtain an ECG at baseline to assess initial QT interval and determine frequency of subsequent ECG monitoring, avoid any non-essential QT prolonging drugs, and correct electrolyte imbalances. Hydroxychloroquine prolongs the QT interval. Dose-related QTc prolongation is associated with therapeutic apomorphine exposure.
Aripiprazole: (Major) Concomitant use of hydroxychloroquine and aripiprazole increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Arsenic Trioxide: (Major) Avoid coadministration of arsenic trioxide and hydroxychloroquine due to the risk of increased QT prolongation. If use together is necessary, obtain an ECG at baseline to assess initial QT interval and determine frequency of subsequent ECG monitoring, avoid any non-essential QT prolonging drugs, and correct electrolyte imbalances. Hydroxychloroquine prolongs the QT interval. Torsade de pointes (TdP), QT interval prolongation, and complete atrioventricular block have been reported with arsenic trioxide use.
Artemether; Lumefantrine: (Major) Avoid coadministration of artemether; lumefantrine and hydroxychloroquine due to the risk of increased QT prolongation. If use together is necessary, obtain an ECG at baseline to assess initial QT interval and determine frequency of subsequent ECG monitoring, avoid any non-essential QT prolonging drugs, and correct electrolyte imbalances. Hydroxychloroquine prolongs the QT interval. Artemether; lumefantrine is associated with prolongation of the QT interval. (Major) Avoid coadministration of artemether; lumefantrine and hydroxychloroquine due to the risk of increased QT prolongation. If use together is necessary, obtain an ECG at baseline to assess initial QT interval and determine frequency of subsequent ECG monitoring, avoid any non-essential QT prolonging drugs, and correct electrolyte imbalances. Hydroxychloroquine prolongs the QT interval. Artemether; lumefantrine is associated with prolongation of the QT interval.
Asenapine: (Major) Concomitant use of hydroxychloroquine and asenapine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Aspirin, ASA; Citric Acid; Sodium Bicarbonate: (Major) Hydroxychloroquine absorption may be reduced by antacids as has been observed with the structurally similar chloroquine. Administer hydroxychloroquine and antacids at least 4 hours apart. Of note, a study demonstrated no significant difference in hydroxychloroquine serum concentration in patients taking concomitant antacids (n = 14) compared to those not taking antacids (n = 495).
Atomoxetine: (Major) Concomitant use of hydroxychloroquine and atomoxetine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Azithromycin: (Major) Concomitant use of hydroxychloroquine and azithromycin increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Bedaquiline: (Major) Avoid coadministration of bedaquline and hydroxychloroquine due to the risk of increased QT prolongation. If use together is necessary, obtain an ECG at baseline to assess initial QT interval and determine frequency of subsequent ECG monitoring, avoid any non-essential QT prolonging drugs, and correct electrolyte imbalances. Hydroxychloroquine and bedaquiline prolong the QT interval. Discontinue bedaquiline if evidence of serious ventricular arrhythmia or QTcF interval greater than 500 msec.
Betrixaban: (Moderate) Use caution if hydroxychloroquine is coadministered with bextrixaban due to the potential for increased bextrixaban exposure which may increase the risk of bleeding. Bextrixaban is a P-gp substrate; limited data suggests that hydroxychloroquine is a P-gp inhibitor.
Bismuth Subcitrate Potassium; Metronidazole; Tetracycline: (Major) Concomitant use of metronidazole and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Bismuth Subsalicylate; Metronidazole; Tetracycline: (Major) Concomitant use of metronidazole and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Brivaracetam: (Moderate) Caution is warranted with the coadministration of hydroxychloroquine and antiepileptic drugs, such as brivaracetam. Hydroxychloroquine can lower the seizure threshold; therefore, the activity of antiepileptic drugs may be impaired with concomitant use.
Buprenorphine: (Major) Concomitant use of hydroxychloroquine and buprenorphine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Buprenorphine; Naloxone: (Major) Concomitant use of hydroxychloroquine and buprenorphine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Cabotegravir; Rilpivirine: (Major) Concomitant use of rilpivirine and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary. The degree of QT prolongation associated with rilpivirine is not clinically significant when administered within the recommended dosage range; QT prolongation has been described at 3 times the maximum recommended dose.
Calcium Carbonate: (Moderate) Hydroxychloroquine absorption may be reduced by antacids as has been observed with the structurally similar chloroquine. Administer hydroxychloroquine and antacids at least 4 hours apart. Of note, a study demonstrated no significant difference in hydroxychloroquine serum concentration in patients taking concomitant antacids (n = 14) compared to those not taking antacids (n = 495).
Calcium Carbonate; Famotidine; Magnesium Hydroxide: (Moderate) Hydroxychloroquine absorption may be reduced by antacids as has been observed with the structurally similar chloroquine. Administer hydroxychloroquine and antacids at least 4 hours apart. Of note, a study demonstrated no significant difference in hydroxychloroquine serum concentration in patients taking concomitant antacids (n = 14) compared to those not taking antacids (n = 495).
Calcium Carbonate; Magnesium Hydroxide: (Moderate) Hydroxychloroquine absorption may be reduced by antacids as has been observed with the structurally similar chloroquine. Administer hydroxychloroquine and antacids at least 4 hours apart. Of note, a study demonstrated no significant difference in hydroxychloroquine serum concentration in patients taking concomitant antacids (n = 14) compared to those not taking antacids (n = 495).
Calcium Carbonate; Magnesium Hydroxide; Simethicone: (Moderate) Hydroxychloroquine absorption may be reduced by antacids as has been observed with the structurally similar chloroquine. Administer hydroxychloroquine and antacids at least 4 hours apart. Of note, a study demonstrated no significant difference in hydroxychloroquine serum concentration in patients taking concomitant antacids (n = 14) compared to those not taking antacids (n = 495).
Calcium Carbonate; Simethicone: (Moderate) Hydroxychloroquine absorption may be reduced by antacids as has been observed with the structurally similar chloroquine. Administer hydroxychloroquine and antacids at least 4 hours apart. Of note, a study demonstrated no significant difference in hydroxychloroquine serum concentration in patients taking concomitant antacids (n = 14) compared to those not taking antacids (n = 495).
Calcium; Vitamin D: (Moderate) Hydroxychloroquine absorption may be reduced by antacids as has been observed with the structurally similar chloroquine. Administer hydroxychloroquine and antacids at least 4 hours apart. Of note, a study demonstrated no significant difference in hydroxychloroquine serum concentration in patients taking concomitant antacids (n = 14) compared to those not taking antacids (n = 495).
Canagliflozin: (Moderate) Monitor blood glucose during concomitant SGLT2 inhibitor and hydroxychloroquine use; a SGLT2 inhibitor dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
Canagliflozin; Metformin: (Moderate) Monitor blood glucose during concomitant metformin and hydroxychloroquine use; a metformin dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant SGLT2 inhibitor and hydroxychloroquine use; a SGLT2 inhibitor dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
Carbamazepine: (Moderate) Monitor for a decrease in hydroxychloroquine and carbamazepine efficacy if coadministration is necessary. Antiepileptic drug activity may be impaired if coadministered with hydroxychloroquine and concomitant use may decrease exposure of hydroxychloroquine. Hydroxychloroquine is a CYP3A substrate and carbamazepine is a strong CYP3A inducer.
Ceritinib: (Major) Avoid coadministration of ceritinib and hydroxychloroquine due to the risk of increased QT prolongation. If use together is necessary, obtain an ECG at baseline to assess initial QT interval and determine frequency of subsequent ECG monitoring, avoid any non-essential QT prolonging drugs, and correct electrolyte imbalances. An interruption of ceritinib therapy, dose reduction, or discontinuation of therapy may be necessary if QT prolongation occurs. Ceritinib causes concentration-dependent QT prolongation. Hydroxychloroquine also prolongs the QT interval.
Chlorpromazine: (Major) Concomitant use of hydroxychloroquine and chlorpromazine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Chlorpropamide: (Moderate) Monitor blood glucose during concomitant sulfonylurea and hydroxychloroquine use; a sulfonylurea dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
Cimetidine: (Major) Avoid concomitant use of hydroxychloroquine and cimetidine as cimetidine may inhibit the metabolism of hydroxychloroquine, increasing its plasma concentration. This interaction has been observed on treatment with the structurally similar chloroquine and cannot be ruled out for hydroxychloroquine.
Ciprofloxacin: (Major) Concomitant use of hydroxychloroquine and ciprofloxacin increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Cisapride: (Contraindicated) Avoid concomitant use of hydroxychloroquine and cisapride due to an increased risk for torsade de pointes (TdP) and QT/QTc prolongation.
Citalopram: (Major) Concomitant use of hydroxychloroquine and citalopram increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Clarithromycin: (Major) Concomitant use of hydroxychloroquine and clarithromycin increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Clobazam: (Moderate) Caution is warranted with the coadministration of hydroxychloroquine and antiepileptic drugs, such as clobazam. Hydroxychloroquine can lower the seizure threshold; therefore, the activity of antiepileptic drugs may be impaired with concomitant use.
Clofazimine: (Major) Concomitant use of clofazimine and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Clonazepam: (Moderate) Monitor persons with epilepsy for seizure activity during concomitant clonazepam and hydroxychloroquine use. Hydroxychloroquine can lower the seizure threshold; therefore, the activity of antiepileptic drugs may be impaired with concomitant use.
Clorazepate: (Moderate) Caution is warranted with the coadministration of hydroxychloroquine and antiepileptic drugs, such as clorazepate. Hydroxychloroquine can lower the seizure threshold; therefore, the activity of antiepileptic drugs may be impaired with concomitant use.
Clozapine: (Major) Avoid coadministration of clozapine and hydroxychloroquine due to the risk of increased QT prolongation. If use together is necessary, obtain an ECG at baseline to assess initial QT interval and determine frequency of subsequent ECG monitoring, avoid any non-essential QT prolonging drugs, and correct electrolyte imbalances. Hydroxychloroquine prolongs the QT interval. Treatment with clozapine has been associated with QT prolongation, torsade de pointes (TdP), cardiac arrest, and sudden death.
Codeine; Phenylephrine; Promethazine: (Major) Concomitant use of hydroxychloroquine and promethazine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Codeine; Promethazine: (Major) Concomitant use of hydroxychloroquine and promethazine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Crizotinib: (Major) Avoid coadministration of crizotinib and hydroxychloroquine due to the risk of increased QT prolongation. If use together is necessary, obtain an ECG at baseline to assess initial QT interval and determine frequency of subsequent ECG monitoring, avoid any non-essential QT prolonging drugs, and correct electrolyte imbalances. An interruption of therapy, dose reduction, or discontinuation of therapy may be necessary for crizotinib if QT prolongation occurs. Crizotinib can cause concentration-dependent QT prolongation. Hydroxychloroquine also prolongs the QT interval.
Cyclosporine: (Major) Closely monitor serum cyclosporine concentrations and adjust the dose of cyclosporine as appropriate after starting or stopping hydroxychloroquine therapy. Increased serum concentrations of cyclosporine have been noted when coadministered with hydroxychloroquine. Monitor patients for cyclosporine-related adverse events such as nephrotoxicity or hepatic toxicity.
Dabigatran: (Moderate) Use caution if hydroxychloroquine is coadministered with dabigatran due to the potential for increased dabigatran exposure which may increase the risk of bleeding. Dabigatran is a P-gp substrate; limited data suggests that hydroxychloroquine is a P-gp inhibitor.
Dapagliflozin: (Moderate) Monitor blood glucose during concomitant SGLT2 inhibitor and hydroxychloroquine use; a SGLT2 inhibitor dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
Dapagliflozin; Metformin: (Moderate) Monitor blood glucose during concomitant metformin and hydroxychloroquine use; a metformin dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant SGLT2 inhibitor and hydroxychloroquine use; a SGLT2 inhibitor dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
Dapagliflozin; Saxagliptin: (Moderate) Monitor blood glucose during concomitant dipeptidyl peptidase-4 inhibitor (DPP-4) and hydroxychloroquine use; a DPP-4 dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant SGLT2 inhibitor and hydroxychloroquine use; a SGLT2 inhibitor dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
Dasatinib: (Major) Concomitant use of hydroxychloroquine and dasatinib increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Degarelix: (Major) Concomitant use of hydroxychloroquine and degarelix increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Desflurane: (Major) Concomitant use of hydroxychloroquine and halogenated anesthetics increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Deutetrabenazine: (Major) Avoid coadministration of deutetrabenazine and hydroxychloroquine due to the risk of increased QT prolongation. If use together is necessary, obtain an ECG at baseline to assess initial QT interval and determine frequency of subsequent ECG monitoring, avoid any non-essential QT prolonging drugs, and correct electrolyte imbalances. Hydroxychloroquine prolongs the QT interval. Deutetrabenazine may prolong the QT interval, but the degree of QT prolongation is not clinically significant when deutetrabenazine is administered within the recommended dosage range.
Dexmedetomidine: (Major) Concomitant use of dexmedetomidine and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Dextromethorphan; Quinidine: (Major) Concomitant use of quinidine and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Diazepam: (Moderate) Monitor persons with epilepsy for seizure activity during concomitant diazepam and hydroxychloroquine use. Hydroxychloroquine can lower the seizure threshold; therefore, the activity of antiepileptic drugs may be impaired with concomitant use.
Digoxin: (Moderate) Monitor serum digoxin concentrations in patients receiving digoxin and hydroxychloroquine as coadministration may result in increased serum digoxin concentrations.
Dipeptidyl Peptidase-4 Inhibitors: (Moderate) Monitor blood glucose during concomitant dipeptidyl peptidase-4 inhibitor (DPP-4) and hydroxychloroquine use; a DPP-4 dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
Disopyramide: (Major) Concomitant use of hydroxychloroquine and disopyramide increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Dofetilide: (Major) Concomitant use of hydroxychloroquine and dofetilide increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Dolasetron: (Major) Avoid coadministration of dolasetron and hydroxychloroquine due to the risk of increased QT prolongation. If use together is necessary, obtain an ECG at baseline to assess initial QT interval and determine frequency of subsequent ECG monitoring, avoid any non-essential QT prolonging drugs, and correct electrolyte imbalances. Hydroxychloroquine prolongs the QT interval. Dolasetron has been associated with a dose-dependent prolongation in the QT, PR, and QRS intervals on an electrocardiogram.
Dolutegravir; Rilpivirine: (Major) Concomitant use of rilpivirine and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary. The degree of QT prolongation associated with rilpivirine is not clinically significant when administered within the recommended dosage range; QT prolongation has been described at 3 times the maximum recommended dose.
Donepezil: (Major) Concomitant use of hydroxychloroquine and donepezil increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Donepezil; Memantine: (Major) Concomitant use of hydroxychloroquine and donepezil increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Dronedarone: (Contraindicated) Avoid concomitant use of hydroxychloroquine and dronedarone due to an increased risk for torsade de pointes (TdP) and QT/QTc prolongation.
Droperidol: (Major) Avoid coadministration of droperidol and hydroxychloroquine due to the risk of increased QT prolongation. If use together is necessary, obtain an ECG at baseline to assess initial QT interval and determine frequency of subsequent ECG monitoring, avoid any non-essential QT prolonging drugs, and correct electrolyte imbalances. Initiate droperidol at a low dose and increase the dose as needed to achieve the desired effect. Hydroxychloroquine prolongs the QT interval. Droperidol administration is associated with an established risk for QT prolongation and torsade de pointes (TdP).
Dulaglutide: (Moderate) Monitor blood glucose during concomitant incretin mimetic and hydroxychloroquine use; an incretin mimetic dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
Edoxaban: (Moderate) Use caution if hydroxychloroquine is coadministered with edoxaban due to the potential for increased edoxaban exposure which may increase the risk of bleeding. Edoxaban is a P-gp substrate; limited data suggests that hydroxychloroquine is a P-gp inhibitor.
Efavirenz: (Major) Concomitant use of hydroxychloroquine and efavirenz increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Efavirenz; Emtricitabine; Tenofovir Disoproxil Fumarate: (Major) Concomitant use of hydroxychloroquine and efavirenz increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Efavirenz; Lamivudine; Tenofovir Disoproxil Fumarate: (Major) Concomitant use of hydroxychloroquine and efavirenz increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Eliglustat: (Major) Avoid coadministration of eliglustat and hydroxychloroquine due to the risk of increased QT prolongation. If use together is necessary, obtain an ECG at baseline to assess initial QT interval and determine frequency of subsequent ECG monitoring, avoid any non-essential QT prolonging drugs, and correct electrolyte imbalances. Hydroxychloroquine prolongs the QT interval. Eliglustat is predicted to cause PR, QRS, and/or QT prolongation at significantly elevated plasma concentrations.
Empagliflozin: (Moderate) Monitor blood glucose during concomitant SGLT2 inhibitor and hydroxychloroquine use; a SGLT2 inhibitor dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
Empagliflozin; Linagliptin: (Moderate) Monitor blood glucose during concomitant dipeptidyl peptidase-4 inhibitor (DPP-4) and hydroxychloroquine use; a DPP-4 dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant SGLT2 inhibitor and hydroxychloroquine use; a SGLT2 inhibitor dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
Empagliflozin; Linagliptin; Metformin: (Moderate) Monitor blood glucose during concomitant dipeptidyl peptidase-4 inhibitor (DPP-4) and hydroxychloroquine use; a DPP-4 dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant metformin and hydroxychloroquine use; a metformin dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant SGLT2 inhibitor and hydroxychloroquine use; a SGLT2 inhibitor dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
Empagliflozin; Metformin: (Moderate) Monitor blood glucose during concomitant metformin and hydroxychloroquine use; a metformin dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant SGLT2 inhibitor and hydroxychloroquine use; a SGLT2 inhibitor dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
Emtricitabine; Rilpivirine; Tenofovir alafenamide: (Major) Concomitant use of rilpivirine and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary. The degree of QT prolongation associated with rilpivirine is not clinically significant when administered within the recommended dosage range; QT prolongation has been described at 3 times the maximum recommended dose.
Emtricitabine; Rilpivirine; Tenofovir Disoproxil Fumarate: (Major) Concomitant use of rilpivirine and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary. The degree of QT prolongation associated with rilpivirine is not clinically significant when administered within the recommended dosage range; QT prolongation has been described at 3 times the maximum recommended dose.
Encorafenib: (Major) Concomitant use of hydroxychloroquine and encorafenib increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Entrectinib: (Major) Concomitant use of hydroxychloroquine and entrectinib increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Eribulin: (Major) Concomitant use of hydroxychloroquine and eribulin increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Ertugliflozin: (Moderate) Monitor blood glucose during concomitant SGLT2 inhibitor and hydroxychloroquine use; a SGLT2 inhibitor dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
Ertugliflozin; Metformin: (Moderate) Monitor blood glucose during concomitant metformin and hydroxychloroquine use; a metformin dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant SGLT2 inhibitor and hydroxychloroquine use; a SGLT2 inhibitor dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
Ertugliflozin; Sitagliptin: (Moderate) Monitor blood glucose during concomitant dipeptidyl peptidase-4 inhibitor (DPP-4) and hydroxychloroquine use; a DPP-4 dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant SGLT2 inhibitor and hydroxychloroquine use; a SGLT2 inhibitor dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
Erythromycin: (Major) Concomitant use of hydroxychloroquine and erythromycin increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Escitalopram: (Major) Concomitant use of hydroxychloroquine and escitalopram increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Eslicarbazepine: (Moderate) Caution is warranted with the coadministration of hydroxychloroquine and antiepileptic drugs, such as eslicarbazepine. Hydroxychloroquine can lower the seizure threshold; therefore, the activity of antiepileptic drugs may be impaired with concomitant use.
Ethosuximide: (Moderate) Caution is warranted with the coadministration of hydroxychloroquine and antiepileptic drugs, such as ethosuximide. Hydroxychloroquine can lower the seizure threshold; therefore, the activity of antiepileptic drugs may be impaired with concomitant use.
Ethotoin: (Moderate) Caution is warranted with the coadministration of hydroxychloroquine and antiepileptic drugs, such as ethotoin. Hydroxychloroquine can lower the seizure threshold; therefore, the activity of antiepileptic drugs may be impaired with concomitant use.
Exenatide: (Moderate) Monitor blood glucose during concomitant incretin mimetic and hydroxychloroquine use; an incretin mimetic dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
Felbamate: (Moderate) Caution is warranted with the coadministration of hydroxychloroquine and antiepileptic drugs, such as felbamate. Hydroxychloroquine can lower the seizure threshold; therefore, the activity of antiepileptic drugs may be impaired with concomitant use.
Fingolimod: (Major) Avoid coadministration of fingolimod and hydroxychloroquine due to the risk of increased QT prolongation. If coadministration cannot be avoided, overnight monitoring with continuous ECG in a medical facility is advised after the first fingolimod dose for patients taking QT prolonging drugs with a known risk of torsade de pointes (TdP). Also, avoid any non-essential QT prolonging drugs and correct electrolyte imbalances. Monitor ECG throughout therapy. Hydroxychloroquine prolongs the QT interval. Fingolimod initiation results in decreased heart rate and may prolong the QT interval. Fingolimod has not been studied in patients treated with drugs that prolong the QT interval, but drugs that prolong the QT interval have been associated with cases of TdP in patients with bradycardia.
Flecainide: (Major) Concomitant use of hydroxychloroquine and flecainide increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Fluconazole: (Major) Concomitant use of hydroxychloroquine and fluconazole increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Fluoxetine: (Major) Concomitant use of hydroxychloroquine and fluoxetine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Fluphenazine: (Major) Concomitant use of hydroxychloroquine and fluphenazine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Fluvoxamine: (Major) Concomitant use of hydroxychloroquine and fluvoxamine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Foscarnet: (Major) Concomitant use of hydroxychloroquine and foscarnet increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Fosphenytoin: (Moderate) Monitor for a decrease in hydroxychloroquine and fosphenytoin efficacy if coadministration is necessary. Antiepileptic drug activity may be impaired if coadministered with hydroxychloroquine and concomitant use may decrease exposure of hydroxychloroquine. Hydroxychloroquine is a CYP3A substrate and fosphenytoin is a strong CYP3A inducer.
Fostemsavir: (Major) Avoid coadministration of hydroxychloroquine and fostemsavir due to the risk of increased QT prolongation. If use together is necessary, obtain an ECG at baseline to assess initial QT interval and determine frequency of subsequent ECG monitoring, avoid any non-essential QT prolonging drugs, and correct electrolyte imbalances. Hydroxychloroquine prolongs the QT interval. Supratherapeutic doses of fostemsavir (2,400 mg twice daily, four times the recommended daily dose) have been shown to cause QT prolongation. Fostemsavir causes dose-dependent QT prolongation.
Gabapentin: (Moderate) Monitor persons with epilepsy for seizure activity during concomitant gabapentin and hydroxychloroquine use. Hydroxychloroquine can lower the seizure threshold; therefore, the activity of antiepileptic drugs may be impaired with concomitant use.
Gemifloxacin: (Major) Avoid coadministration of gemifloxacin and hydroxychloroquine due to the risk of increased QT prolongation. If use together is necessary, obtain an ECG at baseline to assess initial QT interval and determine frequency of subsequent ECG monitoring, avoid any non-essential QT prolonging drugs, and correct electrolyte imbalances. Gemifloxacin may prolong the QT interval in some patients. The maximal change in the QTc interval occurs approximately 5 to 10 hours following oral administration of gemifloxacin. The likelihood of QTc prolongation may increase with increasing dose of the drug; therefore, the recommended dose should not be exceeded especially in patients with renal or hepatic impairment where the Cmax and AUC are slightly higher.
Gemtuzumab Ozogamicin: (Major) Avoid coadministration of gemtuzumab and hydroxychloroquine due to the risk of increased QT prolongation. If use together is necessary, obtain an ECG at baseline to assess initial QT interval and determine frequency of subsequent ECG monitoring, avoid any non-essential QT prolonging drugs, and correct electrolyte imbalances. Hydroxychloroquine prolongs the QT interval. Although QT interval prolongation has not been reported with gemtuzumab ozogamicin, it has been reported with other drugs that contain calicheamicin.
Gilteritinib: (Major) Concomitant use of hydroxychloroquine and gilteritinib increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Glasdegib: (Major) Avoid coadministration of glasdegib and hydroxychloroquine due to the risk of increased QT prolongation. If use together is necessary, obtain an ECG at baseline to assess initial QT interval and determine frequency of subsequent ECG monitoring, avoid any non-essential QT prolonging drugs, and correct electrolyte imbalances. Hydroxychloroquine prolongs the QT interval. Glasdegib therapy may result in QT prolongation and ventricular arrhythmias including ventricular fibrillation and ventricular tachycardia.
Glimepiride: (Moderate) Monitor blood glucose during concomitant sulfonylurea and hydroxychloroquine use; a sulfonylurea dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
Glipizide: (Moderate) Monitor blood glucose during concomitant sulfonylurea and hydroxychloroquine use; a sulfonylurea dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
Glipizide; Metformin: (Moderate) Monitor blood glucose during concomitant metformin and hydroxychloroquine use; a metformin dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant sulfonylurea and hydroxychloroquine use; a sulfonylurea dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
Glyburide: (Moderate) Monitor blood glucose during concomitant sulfonylurea and hydroxychloroquine use; a sulfonylurea dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
Glyburide; Metformin: (Moderate) Monitor blood glucose during concomitant metformin and hydroxychloroquine use; a metformin dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant sulfonylurea and hydroxychloroquine use; a sulfonylurea dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
Goserelin: (Major) Concomitant use of hydroxychloroquine and goserelin acetate increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Granisetron: (Major) Concomitant use of hydroxychloroquine and granisetron increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Halogenated Anesthetics: (Major) Concomitant use of hydroxychloroquine and halogenated anesthetics increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Haloperidol: (Major) Avoid coadministration of haloperidol and hydroxychloroquine due to the risk of increased QT prolongation. If use together is necessary, obtain an ECG at baseline to assess initial QT interval and determine frequency of subsequent ECG monitoring, avoid any non-essential QT prolonging drugs, and correct electrolyte imbalances. Hydroxychloroquine prolongs the QT interval. QT prolongation and torsade de pointes (TdP) have been observed during haloperidol treatment. Excessive doses (particularly in the overdose setting) or IV administration of haloperidol may be associated with a higher risk of QT prolongation.
Histrelin: (Major) Concomitant use of hydroxychloroquine and histrelin acetate increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Hydroxyzine: (Major) Concomitant use of hydroxychloroquine and hydroxyzine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Ibutilide: (Major) Concomitant use of ibutilide and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Iloperidone: (Major) Concomitant use of iloperidone and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Incretin Mimetics: (Moderate) Monitor blood glucose during concomitant incretin mimetic and hydroxychloroquine use; an incretin mimetic dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
Inotuzumab Ozogamicin: (Major) Concomitant use of inotuzumab and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Insulin Aspart: (Moderate) Monitor blood glucose during concomitant insulin and hydroxychloroquine use; an insulin dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
Insulin Aspart; Insulin Aspart Protamine: (Moderate) Monitor blood glucose during concomitant insulin and hydroxychloroquine use; an insulin dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
Insulin Degludec: (Moderate) Monitor blood glucose during concomitant insulin and hydroxychloroquine use; an insulin dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
Insulin Degludec; Liraglutide: (Moderate) Monitor blood glucose during concomitant incretin mimetic and hydroxychloroquine use; an incretin mimetic dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant insulin and hydroxychloroquine use; an insulin dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
Insulin Detemir: (Moderate) Monitor blood glucose during concomitant insulin and hydroxychloroquine use; an insulin dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
Insulin Glargine: (Moderate) Monitor blood glucose during concomitant insulin and hydroxychloroquine use; an insulin dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
Insulin Glargine; Lixisenatide: (Moderate) Monitor blood glucose during concomitant incretin mimetic and hydroxychloroquine use; an incretin mimetic dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant insulin and hydroxychloroquine use; an insulin dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
Insulin Glulisine: (Moderate) Monitor blood glucose during concomitant insulin and hydroxychloroquine use; an insulin dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
Insulin Lispro: (Moderate) Monitor blood glucose during concomitant insulin and hydroxychloroquine use; an insulin dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
Insulin Lispro; Insulin Lispro Protamine: (Moderate) Monitor blood glucose during concomitant insulin and hydroxychloroquine use; an insulin dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
Insulin, Inhaled: (Moderate) Monitor blood glucose during concomitant insulin and hydroxychloroquine use; an insulin dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
Insulins: (Moderate) Monitor blood glucose during concomitant insulin and hydroxychloroquine use; an insulin dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
Isoflurane: (Major) Concomitant use of hydroxychloroquine and halogenated anesthetics increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Isoniazid, INH; Pyrazinamide, PZA; Rifampin: (Major) Avoid concomitant use of hydroxychloroquine and rifampin as lack of efficacy of hydroxychloroquine was reported when administered together. Coadministration may decrease the exposure of hydroxychloroquine. Hydroxychloroquine may be a CYP3A4 substrate in vitro, and rifampin is a strong CYP3A4 inducer.
Isoniazid, INH; Rifampin: (Major) Avoid concomitant use of hydroxychloroquine and rifampin as lack of efficacy of hydroxychloroquine was reported when administered together. Coadministration may decrease the exposure of hydroxychloroquine . Hydroxychloroquine may be a CYP3A4 substrate in vitro, and rifampin is a strong CYP3A4 inducer.
Isophane Insulin (NPH): (Moderate) Monitor blood glucose during concomitant insulin and hydroxychloroquine use; an insulin dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
Itraconazole: (Major) Concomitant use of itraconazole and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Ivosidenib: (Major) Avoid coadministration of ivosidenib and hydroxychloroquine due to the risk of increased QT prolongation. If use together is necessary, obtain an ECG at baseline to assess initial QT interval and determine frequency of subsequent ECG monitoring, avoid any non-essential QT prolonging drugs, and correct electrolyte imbalances. Dose reduce or interrupt ivosidenib therapy if QT prolongation occurs. Prolongation of the QTc interval and ventricular arrhythmias have been reported in patients treated with ivosidenib. Hydroxychloroquine also prolongs the QT interval.
Ketoconazole: (Contraindicated) Avoid concomitant use of ketoconazole and hydroxychloroquine due to an increased risk for torsade de pointes (TdP) and QT/QTc prolongation.
Lacosamide: (Moderate) Caution is warranted with the coadministration of hydroxychloroquine and antiepileptic drugs, such as lacosamide. Hydroxychloroquine can lower the seizure threshold; therefore, the activity of antiepileptic drugs may be impaired with concomitant use.
Lamotrigine: (Moderate) Monitor for seizures during concomitant use of hydroxychloroquine and lamotrigine. Hydroxychloroquine can lower the seizure threshold and the activity of antiepileptics may be impaired during concomitant use.
Lansoprazole; Amoxicillin; Clarithromycin: (Major) Concomitant use of hydroxychloroquine and clarithromycin increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Lanthanum Carbonate: (Major) Oral compounds known to interact with antacids, like hydroxychloroquine, may interact with lanthanum carbonate. Hydroxychloroquine absorption may be reduced by antacids as has been observed with the structurally similar chloroquine. Administer hydroxychloroquine and lanthanum carbonate at least 4 hours apart. Of note, a study demonstrated no significant difference in hydroxychloroquine serum concentration in patients taking concomitant antacids (n = 14) compared to those not taking antacids (n = 495).
Lapatinib: (Major) Avoid coadministration of lapatinib and hydroxychloroquine due to the increased risk of QT prolongation. If use together is necessary, obtain an ECG at baseline to assess initial QT interval and determine frequency of subsequent ECG monitoring, avoid any non-essential QT prolonging drugs, and correct electrolyte imbalances. Hydroxychloroquine prolongs the QT interval. Lapatinib has also been associated with concentration-dependent QT prolongation; ventricular arrhythmias and torsade de pointes (TdP) have been reported in postmarketing experience with lapatinib.
Lefamulin: (Major) Avoid coadministration of lefamulin and hydroxychloroquine due to the increased risk of QT prolongation. If use together is necessary, obtain an ECG at baseline to assess initial QT interval and determine frequency of subsequent ECG monitoring, avoid any non-essential QT prolonging drugs, and correct electrolyte imbalances. Hydroxychloroquine prolongs the QT interval. Lefamulin has a concentration dependent QTc prolongation effect. The pharmacodynamic interaction potential to prolong the QT interval of the electrocardiogram between lefamulin and other drugs that effect cardiac conduction is unknown.
Lenvatinib: (Major) Concomitant use of lenvatinib and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Leuprolide: (Major) Concomitant use of leuprolide and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Leuprolide; Norethindrone: (Major) Concomitant use of leuprolide and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Levetiracetam: (Moderate) Monitor persons with epilepsy for seizure activity during concomitant levetiracetam and hydroxychloroquine use. Hydroxychloroquine can lower the seizure threshold; therefore, the activity of antiepileptic drugs may be impaired with concomitant use.
Levofloxacin: (Major) Concomitant use of hydroxychloroquine and levofloxacin increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Levoketoconazole: (Contraindicated) Avoid concomitant use of ketoconazole and hydroxychloroquine due to an increased risk for torsade de pointes (TdP) and QT/QTc prolongation.
Linagliptin: (Moderate) Monitor blood glucose during concomitant dipeptidyl peptidase-4 inhibitor (DPP-4) and hydroxychloroquine use; a DPP-4 dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
Linagliptin; Metformin: (Moderate) Monitor blood glucose during concomitant dipeptidyl peptidase-4 inhibitor (DPP-4) and hydroxychloroquine use; a DPP-4 dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant metformin and hydroxychloroquine use; a metformin dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
Liraglutide: (Moderate) Monitor blood glucose during concomitant incretin mimetic and hydroxychloroquine use; an incretin mimetic dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
Lithium: (Major) Concomitant use of hydroxychloroquine and lithium increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Lixisenatide: (Moderate) Monitor blood glucose during concomitant incretin mimetic and hydroxychloroquine use; an incretin mimetic dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
Lofexidine: (Major) Concomitant use of lofexidine and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Loperamide: (Major) Concomitant use of hydroxychloroquine and loperamide increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Loperamide; Simethicone: (Major) Concomitant use of hydroxychloroquine and loperamide increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Lopinavir; Ritonavir: (Major) Concomitant use of lopinavir and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Lorazepam: (Moderate) Monitor persons with epilepsy for seizure activity during concomitant lorazepam and hydroxychloroquine use. Hydroxychloroquine can lower the seizure threshold; therefore, the activity of antiepileptic drugs may be impaired with concomitant use.
Macimorelin: (Major) Avoid coadministration of macimorelin and hydroxychloroquine due to an increased risk of QT prolongation and torsade de pointes-type ventricular tachycardia. Sufficient washout time of drugs that are known to prolong the QT interval prior to administration of macimorelin is recommended. If use together is necessary, obtain an ECG at baseline to assess initial QT interval and determine frequency of subsequent ECG monitoring, avoid any non-essential QT prolonging drugs, and correct electrolyte imbalances. Treatment with macimorelin has been associated with an increase in the corrected QT (QTc) interval. Hydroxychloroquine prolongs the QT interval.
Maprotiline: (Major) Avoid coadministration of maprotiline and hydroxychloroquine due to an increased risk of QT prolongation. If use together is necessary, obtain an ECG at baseline to assess initial QT interval and determine frequency of subsequent ECG monitoring, avoid any non-essential QT prolonging drugs, and correct electrolyte imbalances. Hydroxychloroquine prolongs the QT interval. Maprotiline has been reported to prolong the QT interval, particularly in overdose or with higher-dose prescription therapy (elevated serum concentrations). Cases of long QT syndrome and torsade de pointes (TdP) tachycardia have been described with maprotiline use, but rarely occur when the drug is used alone in normal prescribed doses and in the absence of other known risk factors for QT prolongation. Limited data are available regarding the safety of maprotiline in combination with other QT-prolonging drugs.
Mefloquine: (Major) Avoid coadministration of hydroxychloroquine with mefloquine due to an increased risk of QT prolongation and seizures. These drugs are both analogs of quinine. If use together is necessary, obtain an ECG at baseline to assess initial QT interval and determine frequency of subsequent ECG monitoring, avoid any non-essential QT prolonging drugs, and correct electrolyte imbalances. Hydroxychloroquine prolongs the QT interval. There is evidence that the use of halofantrine after mefloquine causes a significant lengthening of the QTc interval. Mefloquine alone has not been reported to cause QT prolongation. Also, both drugs may lower the seizure threshold.
Meglitinides: (Moderate) Careful monitoring of blood glucose is recommended when hydroxychloroquine and antidiabetic agents, including the meglitinides, are coadministered. A decreased dose of the antidiabetic agent may be necessary as severe hypoglycemia has been reported in patients treated concomitantly with hydroxychloroquine and an antidiabetic agent.
Metformin: (Moderate) Monitor blood glucose during concomitant metformin and hydroxychloroquine use; a metformin dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
Metformin; Repaglinide: (Moderate) Careful monitoring of blood glucose is recommended when hydroxychloroquine and antidiabetic agents, including the meglitinides, are coadministered. A decreased dose of the antidiabetic agent may be necessary as severe hypoglycemia has been reported in patients treated concomitantly with hydroxychloroquine and an antidiabetic agent. (Moderate) Monitor blood glucose during concomitant metformin and hydroxychloroquine use; a metformin dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
Metformin; Rosiglitazone: (Moderate) Monitor blood glucose during concomitant metformin and hydroxychloroquine use; a metformin dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant thiazolidinedione and hydroxychloroquine use; a thiazolidinedione dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
Metformin; Saxagliptin: (Moderate) Monitor blood glucose during concomitant dipeptidyl peptidase-4 inhibitor (DPP-4) and hydroxychloroquine use; a DPP-4 dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant metformin and hydroxychloroquine use; a metformin dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
Metformin; Sitagliptin: (Moderate) Monitor blood glucose during concomitant dipeptidyl peptidase-4 inhibitor (DPP-4) and hydroxychloroquine use; a DPP-4 dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant metformin and hydroxychloroquine use; a metformin dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
Methadone: (Major) Concomitant use of methadone and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Methotrexate: (Moderate) Monitor for increased methotrexate-related adverse reactions during concomitant hydroxychloroquine use. Concomitant use may increase the risk for methotrexate toxicity.
Methsuximide: (Moderate) Caution is warranted with the coadministration of hydroxychloroquine and antiepileptic drugs, such as methsuximide. Hydroxychloroquine can lower the seizure threshold; therefore, the activity of antiepileptic drugs may be impaired with concomitant use.
Metronidazole: (Major) Concomitant use of metronidazole and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Midostaurin: (Major) Concomitant use of midostaurin and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Mifepristone: (Major) Concomitant use of hydroxychloroquine and mifepristone increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Miglitol: (Moderate) Careful monitoring of blood glucose is recommended when hydroxychloroquine and antidiabetic agents, including the alpha-glucosidase inhibitors, are coadministered. A decreased dose of the antidiabetic agent may be necessary as severe hypoglycemia has been reported in patients treated concomitantly with hydroxychloroquine and an antidiabetic agent.
Mirtazapine: (Major) Concomitant use of hydroxychloroquine and mirtazapine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Mobocertinib: (Major) Concomitant use of mobocertinib and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Moxifloxacin: (Major) Concomitant use of hydroxychloroquine and moxifloxacin increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Nateglinide: (Moderate) Careful monitoring of blood glucose is recommended when hydroxychloroquine and antidiabetic agents, including the meglitinides, are coadministered. A decreased dose of the antidiabetic agent may be necessary as severe hypoglycemia has been reported in patients treated concomitantly with hydroxychloroquine and an antidiabetic agent.
Nilotinib: (Major) Concomitant use of nilotinib and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Ofloxacin: (Major) Concomitant use of hydroxychloroquine and ofloxacin increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Olanzapine: (Major) Concomitant use of olanzapine and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Olanzapine; Fluoxetine: (Major) Concomitant use of hydroxychloroquine and fluoxetine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary. (Major) Concomitant use of olanzapine and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Olanzapine; Samidorphan: (Major) Concomitant use of olanzapine and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Omeprazole; Sodium Bicarbonate: (Major) Hydroxychloroquine absorption may be reduced by antacids as has been observed with the structurally similar chloroquine. Administer hydroxychloroquine and antacids at least 4 hours apart. Of note, a study demonstrated no significant difference in hydroxychloroquine serum concentration in patients taking concomitant antacids (n = 14) compared to those not taking antacids (n = 495).
Ondansetron: (Major) Concomitant use of hydroxychloroquine and ondansetron increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary. Do not exceed 16 mg of IV ondansetron in a single dose; the degree of QT prolongation associated with ondansetron significantly increases above this dose.
Osilodrostat: (Major) Concomitant use of osilodrostat and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Osimertinib: (Major) Concomitant use of osimertinib and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Oxaliplatin: (Major) Concomitant use of oxaliplatin and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Ozanimod: (Major) Avoid coadministration of hydroxychloroquine and ozanimod due to the risk of increased QT prolongation. If use together is necessary, obtain an ECG at baseline to assess initial QT interval and determine frequency of subsequent ECG monitoring, avoid any non-essential QT prolonging drugs, and correct electrolyte imbalances. Hydroxychloroquine prolongs the QT interval. Ozanimod initiation may result in a transient decrease in heart rate and atrioventricular conduction delays. Ozanimod has not been studied in patients taking concurrent QT prolonging drugs; however, QT prolonging drugs have been associated with torsade de pointes in patients with bradycardia.
Pacritinib: (Major) Concomitant use of pacritinib and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Paliperidone: (Major) Concomitant use of paliperidone and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Panobinostat: (Major) Concomitant use of panobinostat and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Pasireotide: (Major) Concomitant use of pasireotide and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Pazopanib: (Major) Concomitant use of pazopanib and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Penicillamine: (Major) Do not use penicillamine concurrently with antimalarials due to an increased risk of severe hematologic and renal adverse reactions.
Pentamidine: (Major) Concomitant use of pentamidine and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Pentobarbital: (Moderate) Caution is warranted with the coadministration of hydroxychloroquine and antiepileptic drugs, such as pentobarbital. Hydroxychloroquine can lower the seizure threshold; therefore, the activity of antiepileptic drugs may be impaired with concomitant use.
Perampanel: (Moderate) Caution is warranted with the coadministration of hydroxychloroquine and antiepileptic drugs, such as perampanel. Hydroxychloroquine can lower the seizure threshold; therefore, the activity of antiepileptic drugs may be impaired with concomitant use.
Perphenazine: (Major) Concomitant use of perphenazine and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Perphenazine; Amitriptyline: (Major) Concomitant use of perphenazine and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Phenobarbital: (Moderate) Caution is warranted with the coadministration of hydroxychloroquine and antiepileptic drugs, such as phenobarbital. Hydroxychloroquine can lower the seizure threshold; therefore, the activity of antiepileptic drugs may be impaired with concomitant use. Additionally, coadministration of phenobarbital may decrease exposure of hydroxychloroquine resulting in decreased efficacy.
Phenobarbital; Hyoscyamine; Atropine; Scopolamine: (Moderate) Caution is warranted with the coadministration of hydroxychloroquine and antiepileptic drugs, such as phenobarbital. Hydroxychloroquine can lower the seizure threshold; therefore, the activity of antiepileptic drugs may be impaired with concomitant use. Additionally, coadministration of phenobarbital may decrease exposure of hydroxychloroquine resulting in decreased efficacy.
Phentermine; Topiramate: (Moderate) Monitor persons with epilepsy for seizure activity during concomitant topiramate and hydroxychloroquine use. Hydroxychloroquine can lower the seizure threshold; therefore, the activity of antiepileptic drugs may be impaired with concomitant use.
Phenytoin: (Moderate) Monitor for a decrease in hydroxychloroquine and phenytoin efficacy if coadministration is necessary. Antiepileptic drug activity may be impaired if coadministered with hydroxychloroquine and concomitant use may decrease exposure of hydroxychloroquine. Hydroxychloroquine is a CYP3A substrate and phenytoin is a strong CYP3A inducer.
Pimavanserin: (Major) Concomitant use of pimavanserin and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Pimozide: (Contraindicated) Avoid concomitant use of pimozide and hydroxychloroquine due to an increased risk for torsade de pointes (TdP) and QT/QTc prolongation.
Pioglitazone: (Moderate) Monitor blood glucose during concomitant thiazolidinedione and hydroxychloroquine use; a thiazolidinedione dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
Pioglitazone; Glimepiride: (Moderate) Monitor blood glucose during concomitant sulfonylurea and hydroxychloroquine use; a sulfonylurea dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant thiazolidinedione and hydroxychloroquine use; a thiazolidinedione dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
Pioglitazone; Metformin: (Moderate) Monitor blood glucose during concomitant metformin and hydroxychloroquine use; a metformin dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant thiazolidinedione and hydroxychloroquine use; a thiazolidinedione dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
Pitolisant: (Major) Concomitant use of pitolisant and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Ponesimod: (Major) Avoid coadministration of hydroxychloroquine and ponesimod due to the risk of increased QT prolongation. If use together is necessary, obtain an ECG at baseline to assess initial QT interval and determine frequency of subsequent ECG monitoring, avoid any non-essential QT prolonging drugs, and correct electrolyte imbalances. Hydroxychloroquine prolongs the QT interval. Ponesimod initiation may result in a transient decrease in heart rate and atrioventricular conduction delays. Ponesimod has not been studied in patients taking concurrent QT prolonging drugs; however, QT prolonging drugs have been associated with torsade de pointes in patients with bradycardia.
Posaconazole: (Major) Concomitant use of posaconazole and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Pramlintide: (Moderate) Careful monitoring of blood glucose is recommended when hydroxychloroquine and antidiabetic agents, including pramlintide, are coadministered. A decreased dose of the antidiabetic agent may be necessary as severe hypoglycemia has been reported in patients treated concomitantly with hydroxychloroquine and an antidiabetic agent.
Praziquantel: (Minor) Hydroxychloroquine may reduce praziquantel bioavailability and maximum serum concentrations as was observed with the structurally similar chloroquine. The mechanism of the interaction is not certain. Clinicians should be alert to the possibility of praziquantel failure if hydroxychloroquine is used.
Pregabalin: (Moderate) Monitor persons with epilepsy for seizure activity during concomitant pregabalin and hydroxychloroquine use. Hydroxychloroquine can lower the seizure threshold; therefore, the activity of antiepileptic drugs may be impaired with concomitant use.
Primaquine: (Major) Concomitant use of primaquine and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Primidone: (Moderate) Caution is warranted with the coadministration of hydroxychloroquine and antiepileptic drugs, such as primidone. Hydroxychloroquine can lower the seizure threshold; therefore, the activity of antiepileptic drugs may be impaired with concomitant use.
Procainamide: (Major) Concomitant use of procainamide and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Prochlorperazine: (Major) Concomitant use of prochlorperazine and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Promethazine: (Major) Concomitant use of hydroxychloroquine and promethazine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Promethazine; Dextromethorphan: (Major) Concomitant use of hydroxychloroquine and promethazine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Promethazine; Phenylephrine: (Major) Concomitant use of hydroxychloroquine and promethazine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Propafenone: (Major) Concomitant use of hydroxychloroquine and propafenone increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Quetiapine: (Major) Concomitant use of hydroxychloroquine and quetiapine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Quinidine: (Major) Concomitant use of quinidine and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Quinine: (Major) Concomitant use of quinine and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Quizartinib: (Major) Concomitant use of quizartinib and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Rabies Vaccine: (Major) If administered concurrently, antimalarials can impair the immunologic response to the rabies vaccine, thereby, decreasing its protective effect. If possible, administration of antimalarials should be avoided during use of the rabies vaccine for postexposure prophylaxis. When antimalarials must be administered to persons also receiving the rabies vaccine for postexposure prophylaxis, a serum rabies antibody titer should be obtained on day 14 (day of the 4th vaccination) to ensure an acceptable antibody response has been induced.
Ranolazine: (Major) Concomitant use of ranolazine and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Regular Insulin: (Moderate) Monitor blood glucose during concomitant insulin and hydroxychloroquine use; an insulin dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
Regular Insulin; Isophane Insulin (NPH): (Moderate) Monitor blood glucose during concomitant insulin and hydroxychloroquine use; an insulin dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
Relugolix: (Major) Concomitant use of relugolix and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Relugolix; Estradiol; Norethindrone acetate: (Major) Concomitant use of relugolix and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Remdesivir: (Major) Coadministration of remdesivir and hydroxychloroquine is not recommended. Based on data from cell culture experiments, the intracellular metabolic activation and antiviral activity of remdesivir may be antagonized by chloroquine phosphate in a dose-dependent manner.
Repaglinide: (Moderate) Careful monitoring of blood glucose is recommended when hydroxychloroquine and antidiabetic agents, including the meglitinides, are coadministered. A decreased dose of the antidiabetic agent may be necessary as severe hypoglycemia has been reported in patients treated concomitantly with hydroxychloroquine and an antidiabetic agent.
Ribociclib: (Major) Concomitant use of ribociclib and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Ribociclib; Letrozole: (Major) Concomitant use of ribociclib and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Rifampin: (Major) Avoid concomitant use of hydroxychloroquine and rifampin as lack of efficacy of hydroxychloroquine was reported when administered together. Coadministration may decrease the exposure of hydroxychloroquine. Hydroxychloroquine may be a CYP3A4 substrate in vitro, and rifampin is a strong CYP3A4 inducer.
Rilpivirine: (Major) Concomitant use of rilpivirine and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary. The degree of QT prolongation associated with rilpivirine is not clinically significant when administered within the recommended dosage range; QT prolongation has been described at 3 times the maximum recommended dose.
Risperidone: (Major) Concomitant use of risperidone and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Rituximab: (Moderate) The concomitant use of rituximab with other disease modifying anti-rheumatic drugs (DMARDs), such as hydroxychloroquine, may result in an increased risk of infection. Hydroxychloroquine itself does not increase immunosuppression or infection risk, but, is often used in DMARD regimens where infection risk is increased. Monitor patients closely for signs or symptoms of infection.
Rituximab; Hyaluronidase: (Moderate) The concomitant use of rituximab with other disease modifying anti-rheumatic drugs (DMARDs), such as hydroxychloroquine, may result in an increased risk of infection. Hydroxychloroquine itself does not increase immunosuppression or infection risk, but, is often used in DMARD regimens where infection risk is increased. Monitor patients closely for signs or symptoms of infection.
Romidepsin: (Major) Concomitant use of romidepsin and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Rosiglitazone: (Moderate) Monitor blood glucose during concomitant thiazolidinedione and hydroxychloroquine use; a thiazolidinedione dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
Rufinamide: (Moderate) Caution is warranted with the coadministration of hydroxychloroquine and antiepileptic drugs, such as rufinamide. Hydroxychloroquine can lower the seizure threshold; therefore, the activity of antiepileptic drugs may be impaired with concomitant use.
Saquinavir: (Major) Avoid coadministration of saquinavir and hydroxychloroquine due to an increased risk of QT prolongation. If no acceptable alternative therapy is available, obtain an ECG at baseline to assess initial QT interval and determine frequency of subsequent ECG monitoring, avoid any non-essential QT prolonging drugs, and correct electrolyte imbalances. Saquinavir boosted with ritonavir increases the QT interval in a dose-dependent fashion, which may increase the risk for serious arrhythmias such as torsade de pointes (TdP). Hydroxychloroquine prolongs the QT interval.
Saxagliptin: (Moderate) Monitor blood glucose during concomitant dipeptidyl peptidase-4 inhibitor (DPP-4) and hydroxychloroquine use; a DPP-4 dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
Selpercatinib: (Major) Concomitant use of selpercatinib and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Semaglutide: (Moderate) Monitor blood glucose during concomitant incretin mimetic and hydroxychloroquine use; an incretin mimetic dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
Sertraline: (Major) Concomitant use of hydroxychloroquine and sertraline increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary. The degree of QT prolongation associated with sertraline is not clinically significant when administered within the recommended dosage range; QT prolongation has been described at 2 times the maximum recommended dose.
Sevoflurane: (Major) Concomitant use of hydroxychloroquine and halogenated anesthetics increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
SGLT2 Inhibitors: (Moderate) Monitor blood glucose during concomitant SGLT2 inhibitor and hydroxychloroquine use; a SGLT2 inhibitor dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
Siponimod: (Major) Concomitant use of siponimod and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Sitagliptin: (Moderate) Monitor blood glucose during concomitant dipeptidyl peptidase-4 inhibitor (DPP-4) and hydroxychloroquine use; a DPP-4 dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
Sodium Bicarbonate: (Major) Hydroxychloroquine absorption may be reduced by antacids as has been observed with the structurally similar chloroquine. Administer hydroxychloroquine and antacids at least 4 hours apart. Of note, a study demonstrated no significant difference in hydroxychloroquine serum concentration in patients taking concomitant antacids (n = 14) compared to those not taking antacids (n = 495).
Sodium Stibogluconate: (Major) Concomitant use of sodium stibogluconate and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Solifenacin: (Major) Concomitant use of solifenacin and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Sorafenib: (Major) Concomitant use of sorafenib and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Sotagliflozin: (Moderate) Monitor blood glucose during concomitant SGLT2 inhibitor and hydroxychloroquine use; a SGLT2 inhibitor dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
Sotalol: (Major) Concomitant use of hydroxychloroquine and sotalol increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Sulfonylureas: (Moderate) Monitor blood glucose during concomitant sulfonylurea and hydroxychloroquine use; a sulfonylurea dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
Sunitinib: (Major) Concomitant use of sunitinib and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Tacrolimus: (Major) Concomitant use of tacrolimus and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Tamoxifen: (Major) Concomitant use of tamoxifen and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Concomitant use may also increase the risk of retinal toxicity. Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Telavancin: (Major) Concomitant use of telavancin and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Tetrabenazine: (Major) Concomitant use of tetrabenazine and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Thiazolidinediones: (Moderate) Monitor blood glucose during concomitant thiazolidinedione and hydroxychloroquine use; a thiazolidinedione dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
Thioridazine: (Contraindicated) Avoid concomitant use of thioridazine and hydroxychloroquine due to an increased risk for torsade de pointes (TdP) and QT/QTc prolongation.
Tiagabine: (Moderate) Caution is warranted with the coadministration of hydroxychloroquine and antiepileptic drugs, such as tiagabine. Hydroxychloroquine can lower the seizure threshold; therefore, the activity of antiepileptic drugs may be impaired with concomitant use.
Tirzepatide: (Moderate) Monitor blood glucose during concomitant incretin mimetic and hydroxychloroquine use; an incretin mimetic dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
Tolazamide: (Moderate) Monitor blood glucose during concomitant sulfonylurea and hydroxychloroquine use; a sulfonylurea dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
Tolbutamide: (Moderate) Monitor blood glucose during concomitant sulfonylurea and hydroxychloroquine use; a sulfonylurea dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
Tolterodine: (Major) Concomitant use of tolterodine and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary. The risk for tolterodine-associated QT/QTc prolongation may be increased in poor CYP2D6 metabolizers.
Topiramate: (Moderate) Monitor persons with epilepsy for seizure activity during concomitant topiramate and hydroxychloroquine use. Hydroxychloroquine can lower the seizure threshold; therefore, the activity of antiepileptic drugs may be impaired with concomitant use.
Toremifene: (Major) Concomitant use of toremifene and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Trazodone: (Major) Concomitant use of hydroxychloroquine and trazodone increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Triclabendazole: (Major) Concomitant use of triclabendazole and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Trifluoperazine: (Major) Concomitant use of trifluoperazine and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Triptorelin: (Major) Concomitant use of triptorelin and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Valproic Acid, Divalproex Sodium: (Moderate) Caution is warranted with the coadministration of hydroxychloroquine and antiepileptic drugs, such as valproic acid. Hydroxychloroquine can lower the seizure threshold; therefore, the activity of antiepileptic drugs may be impaired with concomitant use.
Vandetanib: (Major) Concomitant use of vandetanib and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Vardenafil: (Major) Concomitant use of hydroxychloroquine and vardenafil increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Vemurafenib: (Major) Concomitant use of vemurafenib and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Venlafaxine: (Major) Concomitant use of hydroxychloroquine and venlafaxine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Vigabatrin: (Major) Vigabatrin should not be used with hydroxychloroquine, which is associated with serious ophthalmic effects (e.g., retinopathy or glaucoma) unless the benefit of treatment clearly outweighs the risks. Additionally, hydroxychloroquine can lower the seizure threshold; therefore, the activity of antiepileptic drugs may be impaired with concomitant use.
Voclosporin: (Major) Concomitant use of voclosporin and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary. The degree of QT prolongation associated with voclosporin is not clinically significant when administered within the recommended dosage range; QT prolongation has been described at 3 times the maximum recommended dose.
Vonoprazan; Amoxicillin; Clarithromycin: (Major) Concomitant use of hydroxychloroquine and clarithromycin increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Voriconazole: (Major) Avoid coadministration of voriconazole and hydroxychloroquine due to an increased risk of QT prolongation. If use together is necessary, obtain an ECG at baseline to assess initial QT interval and determine frequency of subsequent ECG monitoring, avoid any non-essential QT prolonging drugs, and correct electrolyte imbalances. Hydroxychloroquine prolongs the QT interval. Voriconazole has been associated with QT prolongation and rare cases of torsade de pointes (TdP).
Vorinostat: (Major) Concomitant use of vorinostat and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Ziprasidone: (Major) Concomitant use of ziprasidone and hydroxychloroquine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Zonisamide: (Moderate) Caution is warranted with the coadministration of hydroxychloroquine and antiepileptic drugs, such as zonisamide. Hydroxychloroquine can lower the seizure threshold; therefore, the activity of antiepileptic drugs may be impaired with concomitant use.

Hydroxychloroquine/Hydroxychloroquine Sulfate/Plaquenil/Quineprox Oral Tab: 100mg, 200mg, 300mg, 400mg

800 mg/dose (620 mg base/dose) PO for malaria up to a total of 2,000 mg (1,550 mg base) PO in 48 hours; 400 mg/week (310 mg base/week) PO for malaria prophylaxis; 600 mg/day (465 mg base/day) PO for rheumatoid arthritis; 400 mg/day (310 mg base/day) PO for systemic lupus erythematosus and chronic discoid lupus erythematosus

800 mg/dose (620 mg base/dose) PO for malaria up to a total of 2,000 mg (1,550 mg base) PO in 48 hours; 400 mg/week (310 mg base/week) PO for malaria prophylaxis; 600 mg/day (465 mg base/day) PO for rheumatoid arthritis; 400 mg/day (310 mg base/day) PO for systemic lupus erythematosus and chronic discoid lupus erythematosus

weighing 31 kg or more: 13 mg/kg/dose (10 mg base/kg/dose) [Max: 800 mg (620 mg base)] PO for malaria up to a total of 32.5 mg/kg (25 mg base/kg) [Max: 2,000 mg (1,550 mg base)] PO in 48 hours; 6.5 mg/kg/week (5 mg base/kg/week) [Max: 400 mg/week (310 mg base/week)] PO for malaria prophylaxis.
weighing less than 31 kg: 13 mg/kg/dose (10 mg base/kg/dose) PO for malaria up to a total of 32.5 mg/kg (25 mg base/kg) PO in 48 hours has been used off-label; 6.5 mg/kg/week (5 mg base/kg/week) PO for malaria prophylaxis has been used off-label.

weighing 31 kg or more: 13 mg/kg/dose (10 mg base/kg/dose) [Max: 800 mg (620 mg base)] PO for malaria up to a total of 32.5 mg/kg (25 mg base/kg) [Max: 2,000 mg (1,550 mg base)] PO in 48 hours; 6.5 mg/kg/week (5 mg base/kg/week) [Max: 400 mg/week (310 mg base/week)] PO for malaria prophylaxis.
weighing less than 31 kg: 13 mg/kg/dose (10 mg base/kg/dose) PO for malaria up to a total of 32.5 mg/kg (25 mg base/kg) PO in 48 hours has been used off-label; 6.5 mg/kg/week (5 mg base/kg/week) PO for malaria prophylaxis has been used off-label.

13 mg/kg/dose (10 mg base/kg/dose) PO for malaria up to a total of 32.5 mg/kg (25 mg base/kg) PO in 48 hours has been used off-label; 6.5 mg/kg/week (5 mg base/kg/week) PO for malaria prophylaxis has been used off-label.

Safety and efficacy have not been established.

Hydroxychloroquine, a 4-aminoquinolone antimalarial, is a weak base and may exert its antimalarial effect by concentrating in the acid vesicles of the plasmodia and by inhibiting the polymerization of heme. It can also inhibit certain enzymes by its interaction with DNA. Organisms with reduced susceptibilities to chloroquine also show reduced susceptibilities to hydroxychloroquine.[41806]
 
Although the mechanisms underlying the antiinflammatory and immunomodulatory effects of hydroxychloroquine in the treatment of rheumatoid arthritis, chronic discoid lupus erythematous, and systemic lupus erythematosus are not fully known, several possible mechanisms of action have been proposed. It is unclear if these mechanisms work similarly for rheumatic and autoimmune diseases. Potential mechanisms include reduced cytokine production, inhibition of immune effector cells, inhibition of platelet function, protection of the cell surface from external disturbances, competitive binding to nucleic acid ligands or toll-like receptors (TLRs), interference with lysosomal function, reduction of leakage of lysosomal enzymes, and interference with endosomal NADPH oxidase (NOX).[41806] [61727] [61728] [61729]

Hydroxychloroquine is administered orally. It is widely distributed into body tissues, with high concentrations in the bone marrow, liver, kidneys, lungs, adrenal gland, and pituitary gland. Hydroxychloroquine has a high affinity for melanin and thus is concentrated in the choroid and ciliary body of the eye, which may account for the retinal toxicity. Cellular concentrations have been shown to be higher in mononuclear cells than in polymorphonuclear leukocytes.[41806] [61731] [61732]
 
Hydroxychloroquine is partially metabolized in the liver to 3 metabolites. These include the major metabolite, desethylhydroxychloroquine (DHCQ), as well as desethylchloroquine (DCQ) and bidesethylhydroxychloroquine (BDCQ). Renal clearance of unchanged drug ranges from 16% to 30% and does not change with chronic dosing. A half-life of 123.5 days in plasma were observed after a single 200 mg dose in healthy male volunteers. Urine hydroxychloroquine levels were still detectable after 3 months with approximately 10% of the dose excreted as parent drug. Results after a single 200 mg oral dose versus a single 155 mg IV dose demonstrated a half-life of about 40 days and large volume of distribution. After chronic oral administration, the absorption half-life was approximately 3 to 4 hours and th terminal half-life ranged form 40 to 50 days.[41806]
 
Affected cytochrome P450 isoenzymes and drug transporters: CYP2C8, CYP2D6, CYP3A4, P-gp
In vitro data suggest that hydroxychloroquine is metabolized primarily by CYP2C8 and CYP3A4, and to a much lesser extent, by CYP2D6.[65236] [65239] It has also been shown to be an inhibitor of the drug transporter P-glycoprotein (P-gp).[65237]

Prolonged clinical experience over decades of use and available data from published epidemiologic and clinical studies with hydroxychloroquine use in pregnant women have not identified a drug-associated risk of major birth defects, miscarriage, or adverse maternal or fetal outcomes. Hydroxychloroquine readily crosses the placenta with cord blood levels corresponding to maternal plasma levels. No retinal toxicity, ototoxicity, cardiotoxicity, or growth and developmental abnormalities have been observed in children who were exposed to hydroxychloroquine in utero. Available epidemiologic and clinical studies have methodological limitations including small sample size and study design. There are risks to the mother and fetus associated with untreated or increased maternal disease activity from malaria, rheumatoid arthritis, and systemic lupus erythematosus (SLE) during pregnancy that should be considered. There is a pregnancy exposure registry that monitors pregnancy outcomes in women exposed to hydroxychloroquine during pregnancy. Encourage patients to register by contacting 1-877-311-8972. Hydroxychloroquine is considered to be compatible for use during pregnancy in some anti-rheumatic guidelines, and may be continued in pregnancy for maintenance of remission or treatment of a disease flare. Hydroxychloroquine may also be appropriate for pregnancies complicated by lupus. Guidelines also recommend hydroxychloroquine as an alternative to chloroquine as a treatment option for acute malaria and for prophylaxis in pregnant women during all trimesters. Animal reproductive studies have not been conducted.

Data regarding the use of hydroxychloroquine during breast-feeding report that hydroxychloroquine is present in human milk at low levels. No adverse reactions have been reported in breastfed infants. No retinal toxicity, ototoxicity, cardiotoxicity, or growth and developmental abnormalities have been observed in children who were exposed to hydroxychloroquine through breastmilk. There is no information on the effect of hydroxychloroquine on milk production. Hydroxychloroquine is considered to be compatible for use during breast-feeding in some anti-rheumatic guidelines, and may be continued during lactation for maintenance of remission or treatment of a disease flare.  During lactation studies, breast milk concentrations ranged from 10.6 to 1,392 mcg/L  and breast-fed infants would likely receive 0.2 mg/kg or less of hydroxychloroquine. In infants monitored for up to at least 1 year of age, careful follow-up found no adverse effects on growth, vision, or hearing. The developmental and health benefits of breast-feeding should be considered along with the mother's clinical need for the medication and any potential adverse effects on the breastfed child from hydroxychloroquine exposure or from the underlying maternal condition.