Hydroxychloroquine dosage, forms, and strengths

Hydroxychloroquine is a generic prescription drug that treats malaria, rheumatoid arthritis, and lupus. It’s also available as two brand-name drugs, Plaquenil and Sovuna. People usually take one tablet daily, but doses can be split into two daily doses when necessary. However, people only need to take once-weekly doses to prevent malaria.

Hydroxychloroquine forms and strengths

Hydroxychloroquine is only available as a tablet. 

• Tablets: 100 mg, 200 mg, 300 mg, 400 mg

Hydroxychloroquine dosage for adults

Hydroxychloroquine is approved by the U.S. Food and Drug Administration (FDA) to treat or prevent malaria infections. It’s also an anti-inflammatory drug approved to treat rheumatoid arthritis, systemic lupus erythematosus, and chronic discoid lupus. People who can’t safely take this drug include those with allergies to drugs like hydroxychloroquine, called 4-aminoquinolines. Prescribers may also avoid using the drug in people with psoriasis or porphyria because it can worsen these conditions.

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Hydroxychloroquine dosage for malaria

Malaria is a parasitic infection of the blood that is common in many parts of the world. It’s rare in the U.S., affecting mostly people who travel to malaria-endemic areas, about 2,000 to 2,500 people per year. 

Hydroxychloroquine is an antimalarial drug used to both treat and prevent malaria infections. However, it’s not as useful as it used to be. Some species of malaria parasites are resistant to drugs like hydroxychloroquine. One malaria species that can be eradicated by hydroxychloroquine is Plasmodium falciparum (P. falciparum) in regions without resistance. However, it’s also approved to treat different species in combination with other drugs, such as P. vivax. 

Treatment of an active malaria infection involves a 2,000 mg total dose delivered in four separate doses over two days. Prevention involves taking a 400 mg weekly dose before, during, and after travel to a malaria-endemic area. 

• Standard hydroxychloroquine dosage for the treatment of malaria: 800 mg initial dose followed by a 400 mg dose taken 6, 24, and 48 hours after the first dose

• Standard hydroxychloroquine dosage for the prevention of malaria: 400 mg taken once per week starting two weeks before travel, during travel, and until four weeks after leaving a malaria-endemic area

Hydroxychloroquine dosage for rheumatoid arthritis

Rheumatoid arthritis is an autoimmune disease in which the immune system attacks soft tissues in the joints, causing swelling, pain, and damage. Hydroxychloroquine is a disease-modifying antirheumatic drug (DMARD) that suppresses the immune response, helping to control the symptoms and minimize the damage of rheumatoid arthritis flare-ups. 

Hydroxychloroquine is not often used alone unless the disease is mild. Instead, it’s most often prescribed as part of a combination, including “triple therapy” for rheumatoid arthritis that consists of the DMARDs sulfasalazine and either methotrexate or leflunomide. 

Treatment may require several weeks to improve symptoms.

• Standard hydroxychloroquine dosage for rheumatoid arthritis: 400–600 mg daily to start (usually four to 12 weeks); 200–400 mg daily as long-term maintenance treatment

Hydroxychloroquine dosage for lupus

Lupus is an autoimmune disease that can affect the skin or organs throughout the body. Systemic lupus erythematosus (SLE) is the most common type. During a systemic lupus flare-up, inflammation can occur anywhere in the body and affect multiple organs. Cutaneous lupus erythematosus (CLE) involves just the skin. Discoid lupus is a type of CLE characterized by disc-shaped skin rashes. 

Hydroxychloroquine acts as an immunomodulator to control symptoms of systemic or chronic discoid lupus. Cumulative research has shown that hydroxychloroquine significantly reduces SLE flare-ups and decreases mortality rates by 50%.

• Standard hydroxychloroquine dosage for systemic lupus erythematosus or chronic discoid lupus: 200–400 mg daily

Hydroxychloroquine dosage for children

Children weighing more than 31 kg (68 pounds) can take hydroxychloroquine for malaria. Pediatric doses are calculated by body weight, and the maximum pediatric dosages are the FDA-approved adult dosages.

• Standard hydroxychloroquine dosage to treat malaria in children weighing 31 kg or more: Total dose is administered over two days: 

  • 13 mg/kg as a first dose (up to 800 mg)

  • 6.5 mg/kg (up to 400 mg) at 6 hours, 24 hours, and 48 hours after the first dose

• Standard hydroxychloroquine dosage to prevent malaria in children weighing 31 kg or more: 6.5 mg/kg (up to 400 mg) taken once per week starting two weeks before travel, during travel, and ending four weeks after returning

Hydroxychloroquine dosage restrictions

The FDA prescribing information indicates that dosage reductions may be required for people with kidney (renal) disease or liver (hepatic) dysfunction. However, these dosage modifications have not been defined.

How to take hydroxychloroquine 

• Take this medicine as directed.

• Swallow the tablet whole. Do not crush, chew, or divide the tablet. 

• Take the tablets with a glass of milk or food to help prevent stomach problems.

• Store hydroxychloroquine at room temperature in a light-resistant, tightly closed container.

• Keep hydroxychloroquine tablets securely out of the reach of children.

Hydroxychloroquine dosage FAQs

How long does it take hydroxychloroquine to work?

Hydroxychloroquine works very quickly in fighting off malaria for treatment. It takes two weeks of once-weekly hydroxychloroquine tablets to ensure protection has started against malaria. 

For rheumatoid arthritis or lupus, it may take several weeks of daily hydroxychloroquine doses before people notice symptom improvement.

How long does hydroxychloroquine stay in your system?

With an elimination half-life of 40 to 50 days, hydroxychloroquine stays in the body for a very long time. A single dose is detectable in the urine up to three months later. 

What happens if I miss a dose of hydroxychloroquine?

For daily hydroxychloroquine doses, take a missed dose when remembered. If it’s almost time for the next dose, skip the missed dose and take the next dose as scheduled. Do not take two doses to make up for a missed dose.

When taking hydroxychloroquine to prevent a malaria infection, take the missed dose as soon as you remember. Hydroxychloroquine levels in the blood can prevent malaria for one or two days after a missed dose, so don’t wait too long.

How long can you take hydroxychloroquine?

Hydroxychloroquine is a time-limited treatment for malaria. However, for rheumatoid arthritis and lupus, people will need to take hydroxychloroquine for weeks, months, or longer.

Long-term use of hydroxychloroquine does have risks. These risks are less likely when the doses are limited to maintenance doses. 

In the body, hydroxychloroquine concentrations are higher in tissues like the retina. When taken at high doses for years at a time, hydroxychloroquine can cause irreversible retina damage. The incidence of retina damage increases the longer people take hydroxychloroquine, so the American Academy of Ophthalmology recommends regular retinal exams starting with a baseline evaluation for people on long-term hydroxychloroquine. 

Chronic use of hydroxychloroquine can, in rare cases, also cause muscle damage, nerve damage, low blood cell counts, and serious heart problems (cardiomyopathy and heart rhythm changes), particularly in people with pre-existing heart disease, abnormal heartbeats, or other risk factors.

How do I stop taking hydroxychloroquine?

Hydroxychloroquine can be stopped at any time without causing withdrawal. Do not stop taking hydroxychloroquine to prevent or treat malaria unless a doctor instructs you to. For autoimmune conditions, get medical advice before stopping treatment.

There are several complications of hydroxychloroquine that may make it necessary to switch to another drug, including allergic reactions, skin reactions, anemia, nerve damage, muscle damage, muscle weakness, heart problems, psychiatric changes, retinal damage, and psoriasis flare-ups. 

If the doctor needs to switch medications, choices include other antimalarial drugs or antibiotics like doxycycline. For rheumatoid arthritis or lupus, a doctor can use other immune modulators such as methotrexate or corticosteroids.

What is the maximum dosage for hydroxychloroquine?

Most people will take single doses of 400 mg of hydroxychloroquine sulfate tablets (about 310 mg base hydroxychloroquine). The largest single dose anyone will take is 800 mg. Adult dosages are the maximum dosages allowed for children.

Can you overdose on hydroxychloroquine?

People can overdose on hydroxychloroquine either by taking too many tablets or taking the drug without a doctor’s prescription, like for a coronavirus infection. An overdose can be fatal and requires immediate medical care. Symptoms appear one to three hours after an overdose and include life-threatening low blood pressure, racing heartbeats, heart attack, seizures, central nervous system depression, vision changes, blindness, coma, and death.

What interacts with hydroxychloroquine?

To avoid drug interactions, make sure to tell the doctor about all prescription drugs, over-the-counter medications, vitamins, and dietary supplements you are taking. The doctor will be concerned about drugs that change the way the heart beats because the concomitant use of hydroxychloroquine may worsen those effects. Other drugs the doctor should know about include:

• Insulin and diabetes medications

Hydroxychloroquine can cause low blood sugar (hypoglycemia)

• Seizure medications

• The immunosuppressants cyclosporine and methotrexate

• The antibiotic rifampicin

• The heart drug digoxin

• The stomach acid reducer cimetidine

• Antacids

• Kaolin

What happens when you mix hydroxychloroquine and alcohol?

Hydroxychloroquine is not known to interact with alcohol.

Is it safe to take hydroxychloroquine during pregnancy?

Healthcare professionals consider hydroxychloroquine to be safe to use in pregnant women. There is no evidence that the drug can cause major birth defects with available studies. The drug does cross the placenta, and the drug levels in the cord blood are equal to those in the mother, but no serious side effects have been found in babies exposed to the drug while in the uterus.

Is it safe to take hydroxychloroquine while breastfeeding?

Hydroxychloroquine is present in low amounts in breast milk, but there is no evidence of serious adverse effects of hydroxychloroquine or other problems in nursing infants.

Sources

• 2021 American College of Rheumatology Guideline for the Treatment of Rheumatoid Arthritis, American College of Rheumatology 

• Appendix A: Malaria in the United States: Treatment Tables, Centers for Disease Control and Prevention (CDC)

• Clinical efficacy and side effects of antimalarials in systemic lupus erythematosus: A systematic review, Annals of the Rheumatic Diseases

• Hydroxychloroquine: An old drug with new relevance, Cleveland Clinic Journal of Medicine

• Hydroxychloroquine sulfate tablet prescribing information, DailyMed (NIH National Library of Medicine)

• Malaria CDC Yellow Book 2024, Centers for Disease Control and Prevention (CDC)

• Medicines for the prevention of malaria when traveling: Hydroxychloroquine (Plaquenil), Centers for Disease Control and Prevention (CDC)

• Plaquenil hydroxychloroquine sulfate drug summary, Prescriber’s Digital Reference (PDR)

• Recommendations on Screening for Chloroquine and Hydroxychloroquine Retinopathy (2016 Revision), Ophthalmology

• What to know about malaria in the U.S., Johns Hopkins Bloomberg School of Public Health