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Hydroxychloroquine (Monograph)

Brand name: Plaquenil
Drug class: Antimalarials
- Disease-Modifying Antirheumatic Drugs
- DMARDS
CAS number: 747-36-4

Medically reviewed by Drugs.com on Jun 10, 2024. Written by ASHP.

Introduction

Antimalarial; 4-aminoquinoline derivative.100

Uses for Hydroxychloroquine

Malaria

Prevention (prophylaxis) of malaria caused by Plasmodium malariae, P. ovale, chloroquine-susceptible P. vivax, and chloroquine-susceptible P. falciparum.100 115 121 Alternative when chloroquine is unavailable;115 121 134 may be better tolerated.115

Treatment of uncomplicated malaria caused by P. malariae, P. knowlesi, P. ovale, chloroquine-susceptible P. vivax, or chloroquine-susceptible P. falciparum.100 134 143 144 Alternative when chloroquine is unavailable;134 143 144 may be better tolerated.115

Do not use for prevention or treatment of malaria in areas where chloroquine resistance has been reported.115 121 143 (See Chloroquine-resistant Plasmodium under Cautions.)

Active only against asexual erythrocytic forms of Plasmodium (not exoerythrocytic stages) and cannot prevent delayed primary attacks or relapse of P. ovale or P. vivax malaria or provide a radical cure.100 115 143 144 Therefore, an 8-aminoquinoline antimalarial (14-day regimen of primaquine or single dose of tafenoquine) is indicated in addition to hydroxychloroquine prophylaxis if travelers were exposed in areas with P. ovale or P. vivax malaria and also is indicated in conjunction with hydroxychloroquine to eradicate hypnozoites and prevent relapse in patients being treated for P. ovale or P. vivax malaria.100 115 143 144

Information on risk of malaria in specific countries and mosquito avoidance measures and recommendations regarding whether prevention of malaria indicated and choice of antimalarials for prevention is available from CDC at [Web] and [Web].115

Information on recommended regimens for treatment of malaria is available from CDC at [Web].143 144 Assistance with diagnosis or treatment of malaria available by contacting CDC Malaria Hotline at 770-488-7788 or 855-856-4713 from 9:00 a.m. to 5:00 p.m. Eastern Standard Time or CDC Emergency Operation Center at 770-488-7100 after hours and on weekends and holidays.143 144

Lupus Erythematosus

Treatment of systemic lupus erythematosus and chronic discoid lupus erythematosus.100

Consider increased risk of serious adverse effects (e.g., retinopathy) if used for prolonged periods in treatment of lupus erythematosus.100 213

Rheumatoid Arthritis

Treatment of acute and chronic rheumatoid arthritis.100 103

One of several conventional disease-modifying antirheumatic drugs (DMARDs) that can be used when conventional DMARD therapy is appropriate.103

Consider increased risk of serious adverse effects (e.g., retinopathy) if used for prolonged periods in treatment of rheumatoid arthritis.100

Consult most recent guidelines available from the American College of Rheumatology (ACR) for information on use of hydroxychloroquine for the treatment of rheumatoid arthritis.103

Q Fever

Treatment of chronic Q fever† [off-label] caused by Coxiella burnetii when endocarditis, vascular infection, or non-cardiac organ disease is involved; used in conjunction with doxycycline.111 112 113 122

Porphyria Cutanea Tarda

Has been used in treatment of porphyria cutanea tarda† [off-label].114 116 117 123

Coronavirus Disease 2019 (COVID-19)

Was targeted for investigation as a potential option for treatment and prevention of coronavirus disease 2019 (COVID-19)† [off-label] caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) during early stages of the COVID-19 pandemic based on some evidence of in vitro activity against SARS-CoV-2,198 212 231 possibility that immunomodulatory activity of 4-aminoquinoline derivatives (chloroquine and hydroxychloroquine) might contribute to anti-inflammatory responses in patients with viral infections,193 198 213 215 216 231 and initial anecdotal reports and preliminary information from small trials.197 218 However, safety and efficacy for treatment or prevention of COVID-19 not established,230 and NIH231 and IDSA232 recommend against use of hydroxychloroquine or chloroquine (alone or in conjunction with other antivirals or other drugs) in the treatment or prevention of COVID-19.

Hydroxychloroquine Dosage and Administration

Administration

Oral Administration

Administer orally with food or milk.100

Do not crush or divide the film-coated tablets.100

Dosage

Available as hydroxychloroquine sulfate; dosage expressed as hydroxychloroquine sulfate or as the base (hydroxychloroquine).100

Each 200-mg tablet of hydroxychloroquine sulfate contains 155 mg of the base.100

Pediatric Patients

Malaria
Prevention of Malaria in Areas Without Chloroquine-resistant Plasmodium
Oral

6.5 mg/kg of hydroxychloroquine sulfate (5 mg/kg of the base) once weekly on same day each week.100 115 Manufacturer states the tablets not recommended in pediatric patients weighing <31 kg.100

Initiate prophylaxis 1–2 weeks prior to entering malarious area and continue during stay and for 4 weeks after leaving the area.100 115 121

If exposure occurred in areas where P. ovale or P. vivax is endemic, terminal prophylaxis with an 8-aminoquinoline antimalarial (14-day regimen of primaquine or single dose of tafenoquine) also indicated.115

Treatment of Uncomplicated Chloroquine-susceptible Malaria
Oral

Initial dose of 13 mg/kg of hydroxychloroquine sulfate (10 mg/kg of the base) followed by 6.5 mg/kg of hydroxychloroquine sulfate (5 mg/kg of the base) given at 6, 24, and 48 hours after initial dose.100 144 Manufacturer states the tablets not recommended in pediatric patients weighing <31 kg.100

If hydroxychloroquine used for treatment of malaria caused by P. ovale or P. vivax, treatment with an 8-aminoquinoline antimalarial (14-day regimen of primaquine phosphate or single dose of tafenoquine) also indicated to provide a radical cure.143 144

Adults

Malaria
Prevention of Malaria in Areas Without Chloroquine-resistant Plasmodium
Oral

400 mg of hydroxychloroquine sulfate (310 mg of the base) once weekly on same day each week.100 115

Initiate prophylaxis 1–2 weeks prior to entering malarious area and continue during stay and for 4 weeks after leaving the area.100 115 121

If exposure occurred in areas where P. ovale or P. vivax is endemic, terminal prophylaxis with an 8-aminoquinoline antimalarial (14-day regimen of primaquine or single dose of tafenoquine) also indicated.115

Treatment of Uncomplicated Chloroquine-susceptible Malaria
Oral

Initial dose of 800 mg of hydroxychloroquine sulfate (620 mg of the base) followed by 400 mg of hydroxychloroquine sulfate (310 mg of the base) given at 6, 24, and 48 hours after initial dose.100 144

If hydroxychloroquine used for treatment of malaria caused by P. ovale or P. vivax, treatment with an 8-aminoquinoline antimalarial (14-day regimen of primaquine phosphate or single dose of tafenoquine) also indicated to provide a radical cure.143 144

Lupus Erythematosus
Oral

Systemic lupus erythematosus or chronic discoid lupus erythematosus: 200 mg of hydroxychloroquine sulfate once daily or 400 mg of hydroxychloroquine sulfate daily given as a single dose or in 2 divided doses.100

Rheumatoid Arthritis
Oral

Initial dosage: 400–600 mg of hydroxychloroquine sulfate daily given as a single dose or in 2 divided doses.100

Chronic maintenance dosage: 200 mg of hydroxychloroquine sulfate once daily or 400 mg daily given as a single dose or in 2 divided doses.100

Therapeutic effects are cumulative; maximum effects may require weeks to months of treatment.100

Q Fever† [off-label]
Chronic Q Fever† [off-label]
Oral

CDC recommends 200 mg of hydroxychloroquine sulfate every 8 hours in conjunction with doxycycline (100 mg every 12 hours).122

Base duration of treatment on serologic response and evidence of clinical improvement.122 Continue for at least 18 months in those with endocarditis.122

Prescribing Limits

Pediatric Patients

Malaria
Prevention of Malaria in Areas Without Chloroquine-resistant Plasmodium
Oral

Maximum 400 mg of hydroxychloroquine sulfate (310 mg of the base) once weekly, regardless of weight.100 115

Treatment of Uncomplicated Chloroquine-susceptible Malaria
Oral

Maximum 800 mg of hydroxychloroquine sulfate (620 mg of the base) for initial dose; maximum 400 mg of hydroxychloroquine sulfate (310 mg of the base) for each of the 3 subsequent doses.100

Special Populations

Hepatic Impairment

Dosage may need to be reduced;100 manufacturer makes no specific recommendations.100

Renal Impairment

Dosage may need to be reduced;100 manufacturer makes no specific recommendations.100

Detailed Hydroxychloroquine dosage information

Cautions for Hydroxychloroquine

Contraindications

Warnings/Precautions

Warnings

Cardiac Effects

Life-threatening and fatal cardiotoxicity, including cardiomyopathy, reported in patients receiving hydroxychloroquine.100 Signs and symptoms of cardiac compromise reported with both acute and chronic hydroxychloroquine treatment.100 Patients may present with ventricular hypertrophy, pulmonary hypertension, and conduction disorders including sick sinus syndrome; ECG findings include atrioventricular, right or left bundle branch block.100

Has potential to prolong QT interval.100 Ventricular arrhythmias (including torsades de pointes) reported.100 Because magnitude of QT prolongation may increase with increasing concentrations of the drug, do not exceed recommended dosage.100 Avoid use in patients with congenital or documented acquired QT prolongation and/or known risk factors for prolongation of QT interval, such as cardiac disease (e.g., heart failure, MI), proarrhythmic conditions (e.g., bradycardia [<50 bpm]), history of ventricular dysrhythmias, uncorrected hypokalemia and/or hypomagnesemia, and concomitant use of drugs known to prolong QT interval.100

Monitor cardiac function and avoid concomitant use with other drugs that have potential to prolong QT interval.100 Correct electrolyte imbalances prior to initiation of hydroxychloroquine.100

If cardiotoxicity suspected, discontinue hydroxychloroquine.100

Retinal Toxicity

Irreversible retinal damage has occurred in some patients treated with hydroxychloroquine; related to cumulative dosage and treatment duration.100

Risk factors for retinal damage include daily dosage ≥5 mg/kg of hydroxychloroquine sulfate, treatment duration >5 years, renal impairment, concomitant use of other drugs with ocular adverse effects (e.g., tamoxifen), and concurrent macular disease.100

In patients receiving long-term hydroxychloroquine treatment, a baseline ocular examinations recommended within the first year of treatment, including best corrected distance visual acuity (BCVA), automated threshold visual field (VF) of central 10 degrees (with retesting if abnormality noted), and spectral domain ocular coherence tomography (SD-OCT).100 For patients at higher risk of retinal damage, monitoring should include annual examinations that include BCVA, VF, and SD-OCT.100 For patients without significant risk factors, may usually defer annual retinal exams until 5 years of treatment.100 In patients of Asian descent, retinal toxicity may be noticed first outside the macula; therefore, perform visual field testing in central 24 degrees (instead of central 10 degrees).100

If ocular toxicity suspected, discontinue hydroxychloroquine and monitor closely; retinal changes and visual disturbances may progress even after the drug is discontinued.100

Dermatologic and Sensitivity Reactions

Serious adverse dermatologic reactions reported, including Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), drug reaction with eosinophilia and systemic symptoms (DRESS), and acute generalized exanthematous pustulosis (AGEP).100

Monitor for serious skin reactions, especially in those receiving other drugs associated with dermatitis.100 If a severe dermatologic reaction occurs, discontinue hydroxychloroquine.100

Patients with Psoriasis or Porphyria

May exacerbate psoriasis and precipitate a severe psoriasis flare-up in patients with the disease.100 Avoid use in patients with psoriasis unless benefits outweigh possible risks.100

May exacerbate porphyria.100 Avoid use in patients with porphyria unless benefits outweigh possible risks.100

Hematologic Effects

May cause myelosuppression, including aplastic anemia, agranulocytosis, leukopenia, or thrombocytopenia.100

Periodically monitor CBCs in patients receiving prolonged treatment.100 If myelosuppression occurs and is not attributable to disease being treated, discontinue hydroxychloroquine.100

Hemolysis reported in patients with glucose-6-phosphate dehydrogenase (G-6-PD) deficiency.100 Monitor for hemolytic anemia, especially in those receiving other drugs associated with hemolysis.100

Neuromuscular Effects

Skeletal muscle myopathy or neuromyopathy reported.100 May lead to progressive weakness and atrophy of proximal muscle group, depressed tendon reflexes, and abnormal nerve conduction.100 Muscle and nerve biopsies have demonstrated bodies and muscle fiber atrophy with vacuolar changes.100

Assess muscle strength and deep tendon reflexes periodically in patients receiving long-term hydroxychloroquine therapy.100

If muscular weakness occurs, discontinue hydroxychloroquine.100

Neuropsychiatric Events

Suicidal behavior reported.100

Advise patients to contact their healthcare provider if they experience new or worsening depression, suicidal thoughts or behavior, or mood changes.100 Assess risks and benefits of continued hydroxychloroquine treatment in patients who develop such symptoms.100

Hypoglycemic Effects

Severe and potentially life-threatening hypoglycemia reported in patients receiving or not receiving treatment with antidiabetic agents.100

Assess blood glucose in patients presenting with clinical symptoms suggestive of hypoglycemia; adjust antidiabetic treatment as necessary.100

Inappropriate Use

CDC issued a health advisory concerning inappropriate use of hydroxychloroquine and chloroquine.222 Advise patients and the public to not ingest aquarium products or any other chemical products that contain chloroquine since these products are not intended for human consumption and can lead to serious health consequences, including death.222

Advise patients and the public that hydroxychloroquine and chloroquine should be used only under supervision of a healthcare provider.222 Inappropriate uses include taking any commercially available non-pharmaceutical preparations of the drugs, taking the drugs without a prescription or without supervision of a healthcare provider, and taking additional doses of the drugs not recommended by a healthcare provider.222

Chloroquine-resistant Plasmodium

Chloroquine-resistant P. falciparum confirmed in all areas with P. falciparum malaria, except the Caribbean and Central America west of the Panama Canal.115

Chloroquine-resistant P. vivax confirmed in Papua New Guinea and Indonesia;115 143 rare cases also reported in Burma (Myanmar), India, and Central and South America.143

Do not use for prevention of malaria in individuals traveling to malarious areas where chloroquine-resistant P. falciparum or chloroquine-resistant P. vivax malaria reported.115 134

Do not use for treatment of uncomplicated P. falciparum malaria or uncomplicated malaria caused by unidentified plasmodial species if the infection was acquired in areas with chloroquine resistance.143 144

Specific Populations

Pregnancy

Manufacturer states that decades of clinical experience with use of hydroxychloroquine and data available from published epidemiologic and clinical studies have not identified a drug-associated risk of major birth defects, miscarriage, or adverse maternal or fetal outcomes.100

There are risks to the mother and fetus associated with untreated or increased disease activity from malaria, rheumatoid arthritis, and systemic lupus erythematosus during pregnancy.100

Hydroxychloroquine readily crosses the placenta with cord blood concentrations corresponding to maternal plasma concentrations.100 Manufacturer states no retinal toxicity, ototoxicity, cardiotoxicity, or growth and developmental abnormalities observed in children exposed to hydroxychloroquine in utero.100

CDC states that pregnancy is not a contraindication to use of hydroxychloroquine when indicated for prevention of malaria.115 In addition, CDC states that recommendations for use of hydroxychloroquine for treatment of uncomplicated malaria in pregnant women are the same as those for other patients.143

Encourage pregnant women exposed to hydroxychloroquine to enroll in the pregnancy registry by calling 877-311-8972.100

Lactation

Distributed into milk in low concentrations.100 Not known whether the drug affects milk production.100

Manufacturer states no adverse reactions reported in breast-fed infants of mothers who received hydroxychloroquine and no retinal toxicity, ototoxicity, cardiotoxicity, or growth and developmental abnormalities observed in children exposed to hydroxychloroquine through breast milk.100

Consider developmental and health benefits of breast-feeding along with the mother’s clinical need for hydroxychloroquine and any potential adverse effects on the breast-fed child from the drug or from the underlying maternal condition.100

Amount of drug present in human milk is insufficient to provide protection against malaria in breast-feeding infants.115 If prevention of malaria indicated, such infants should receive recommended dosages of appropriate antimalarial agent(s).115

Pediatric Use

Safety and efficacy established in pediatric patients for treatment of uncomplicated malaria caused by susceptible P. malariae, P. ovale, P. vivax, or P. falciparum and for prophylaxis of malaria in geographic areas where chloroquine resistance not reported.100 Manufacturer states that hydroxychloroquine film-coated tablets not recommended in pediatric patients weighing <31 kg because the tablets cannot be crushed or divided.100

Safety and efficacy not established in pediatric patients for treatment of systemic lupus erythematosus or juvenile idiopathic arthritis.100

Geriatric Use

Insufficient numbers of patients ≥65 years of age in clinical trials to determine whether they respond differently from younger patients.100

Substantially eliminated by the kidneys; risk of toxic reactions may be greater in patients with impaired renal function.100 Because geriatric patients more likely to have decreased renal, hepatic, or cardiac function and concomitant disease or other drug therapy, select dosage starting with the lowest recommended dosage.100

Hepatic Impairment

Reduced dosage may be needed.100

Renal Impairment

Reduced dosage may be needed.100

Common Adverse Effects

The most common adverse reactions are nausea, vomiting, diarrhea, abdominal pain.100

Drug Interactions

Drugs that Prolong QT Interval

Concomitant use with drugs known to prolong QT interval may increase risk of QT interval prolongation and ventricular arrhythmias;100 concomitant use not recommended.100

Specific Drugs

Drug

Interaction

Comments

Ampicillin

Reduced ampicillin bioavailability reported with chloroquine;100 similar interaction with hydroxychloroquine cannot be ruled out100

Antacids

Reduced GI absorption of chloroquine;100 similar interaction with hydroxychloroquine cannot be ruled out100

Antidiabetic agents (insulin, other antidiabetic agents)

Possible enhanced hypoglycemic effects if used with hydroxychloroquine100

May need to decrease dosage of insulin or other antidiabetic agents100

Antiepileptic agents

Hydroxychloroquine may impair antiepileptic agents100

Cimetidine

Studies using chloroquine indicate twofold increase in chloroquine exposure;100 similar interaction with hydroxychloroquine cannot be ruled out100

Avoid concomitant use100

Cyclosporine

Increased cyclosporine concentrations reported100

If use concomitantly, monitor cyclosporine concentrations100

Digoxin

Possible increased digoxin concentrations if used with hydroxychloroquine

If used concomitantly, monitor digoxin concentrations100

Mefloquine

Increased risk of seizures if used with hydroxychloroquine; both drugs lower seizure threshold100

Methotrexate

Concomitant use with hydroxychloroquine not studied; possible increased risk of adverse effects100

Praziquantel

Decreased bioavailability of praziquantel reported with chloroquine;100 similar interaction with hydroxychloroquine cannot be ruled out100

Rifampin

Concomitant use has resulted in lack of hydroxychloroquine efficacy100

Avoid concomitant use100

Tamoxifen

Concomitant use may increase risk of retinal damage100
Hydroxychloroquine drug interactions (more detail)

Hydroxychloroquine Pharmacokinetics

Absorption

Following single 200-mg oral dose of hydroxychloroquine sulfate in healthy males, peak concentrations in whole blood of 129.6 ng/mL attained at 3.3 hours and peak plasma concentrations of 50.3 ng/mL attained at 3.7 hours.100 Mean fraction of the dose absorbed was 0.74 (compared to an IV dose of 155 mg of hydroxychloroquine).100

Patients with rheumatoid arthritis receiving oral hydroxychloroquine: Fraction of dose absorbed is highly variable (30–100%); mean hydroxychloroquine concentrations significantly higher in those with less disease activity.100

Distribution

Extent

Large volume of distribution; extensively distributed to tissues.100

Readily crosses placenta;100 distributed into milk.100 102

Elimination

Metabolism

Partially metabolized.100 Major metabolite is desethylhydroxychloroquine (DHCQ); other metabolites are desethylchloroquine (DCQ) and bidesethylhydroxychloroquine (BDCQ).100

Elimination Route

Hydroxychloroquine and its metabolites slowly excreted by the kidneys.100

Still detectable in urine after 3 months; approximately 10% of dose eliminated as the parent drug.100

Half-life

Mean elimination half-life of about 40 days;100 106 considerable interindividual variation.106

Following single 200-mg dose in healthy males, plasma half-life of 123.5 days observed.100 Following chronic oral administration, absorption half-life reported to be approximately 3–4 hours and terminal half-life ranged from 40–50 days.100

Stability

Storage

Oral

Tablets

Room temperature ≤30°C in tight, light-resistant container;100 may be exposed to 15–30°C.100

Actions and Spectrum

Advice to Patients

Additional Information

The American Society of Health-System Pharmacists, Inc. represents that the information provided in the accompanying monograph was formulated with a reasonable standard of care, and in conformity with professional standards in the field. Readers are advised that decisions regarding use of drugs are complex medical decisions requiring the independent, informed decision of an appropriate health care professional, and that the information contained in the monograph is provided for informational purposes only. The manufacturer’s labeling should be consulted for more detailed information. The American Society of Health-System Pharmacists, Inc. does not endorse or recommend the use of any drug. The information contained in the monograph is not a substitute for medical care.

Preparations

Excipients in commercially available drug preparations may have clinically important effects in some individuals; consult specific product labeling for details.

Please refer to the ASHP Drug Shortages Resource Center for information on shortages of one or more of these preparations.

* available from one or more manufacturer, distributor, and/or repackager by generic (nonproprietary) name

Hydroxychloroquine Sulfate

Routes

Dosage Forms

Strengths

Brand Names

Manufacturer

Oral

Tablets, film-coated

200 mg (155 mg of hydroxychloroquine base)*

Hydroxychloroquine Sulfate Tablets

Plaquenil

Concordia

AHFS DI Essentials™. © Copyright 2024, Selected Revisions June 10, 2024. American Society of Health-System Pharmacists, Inc., 4500 East-West Highway, Suite 900, Bethesda, Maryland 20814.

† Off-label: Use is not currently included in the labeling approved by the US Food and Drug Administration.

References

Only references cited for selected revisions after 1984 are available electronically.

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