Chloroquine: uses, dosing, side effects & brands
Chloroquine is an antimalarial sold in the U.S. under one brand, for amebiasis, rheumatoid arthritis and discoid lupus erythematosus. Below: what the FDA label says, every product that contains it, what the pills look like, and its recall record.
Key facts
- Drug class
- Antimalarial
- Treats
- Amebiasis, Rheumatoid Arthritis and Discoid Lupus Erythematosus
- Available as
- Tablet
- Sold as
- Chloroquine Phosphate
- Prescription?
- Prescription only
- Generic available?
- Yes
How chloroquine is dosed
From the FDA label for Chloroquine Phosphate (application ANDA040516). Other chloroquine products — different forms, different strengths — are dosed differently. Follow the label for the one you were prescribed.
The dosage of chloroquine phosphate is often expressed in terms of equivalent chloroquine base. Each 500 mg tablet of chloroquine phosphate tablet contains the equivalent of 300 mg chloroquine base. In infants and children the dosage is preferably calculated by body weight. Prophylaxis against chloroquine-sensitive Plasmodium species Adult Dose: The dosage for prophylaxis is 500 mg (= 300 mg base) administered once per week on exactly the same day of each week. Pediatric Dose: The dosage for prophylaxis is 5 mg calculated as base, per kg of body weight, administered once per week on exactly the same day of each week. The pediatric dose should never exceed the adult dose regardless of weight. If circumstances permit, suppressive therapy should begin two weeks prior to exposure. However, failing this in adults, an initial double (loading) dose of 1 g (= 600 mg base), or in children 10 mg base/kg may be taken in two divided doses, six hours apart. The suppressive therapy should be continued for eight weeks after leaving the endemic area. Treatment of uncomplicated malaria due to chloroquine-sensitive Plasmodium species Adults: An initial dose of 1 g salt (= 600 mg base) followed by an additional 500 mg (= 300 mg base) after six to eight hours and a single dose of 500 mg (= 300 mg base) on each of two consecutive days. This represents a total dose of 2.5 g chloroquine phosphate or…
Chloroquine side effects
The following adverse reactions have been identified during post-approval use of chloroquine or other 4-aminoqunoline compounds. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Ocular disorders: Maculopathy and macular degeneration have been reported and may be irreversible. Irreversible retinopathy with retinal pigmentation changes (bull’s eye appearance) and visual field defects (paracentral scotomas) in patients receiving long-term or high-dosage 4- aminoquinoline therapy have been reported (see WARNINGS ). Visual disturbances (blurring of vision and difficulty of focusing or accommodation); nyctalopia; scotomatous vision with field defects of paracentral, pericentral ring types, and typically temporal scotomas (e.g., difficulty in reading with words tending to disappear, seeing half an object, misty vision, and fog before the eyes) have been reported. Reversible corneal opacities have also been reported. Immune system disorders: Urticaria, anaphylactic reaction including angioedema. Ear and labyrinth disorders: Nerve type deafness; tinnitus, reduced hearing in patients with preexisting auditory damage. Musculoskeletal and connective tissue-disorders: Sensorimotor disorders, skeletal muscle myopathy or neuromyopathy…
Who shouldn’t take chloroquine
Use of chloroquine phosphate tablets for indications other than acute malaria is contraindicated in the presence of retinal or visual field changes of any etiology. Use of chloroquine phosphate tablets are contraindicated in patients with known hypersensitivity to 4-aminoquinoline compounds.
Chloroquine drug interactions
Antacids and kaolin: Antacids and kaolin can reduce absorption of chloroquine; an interval of at least 4 hours between intake of these agents and chloroquine should be observed. Cimetidine: Cimetidine can inhibit the metabolism of chloroquine, increasing its plasma level. Concomitant use of cimetidine should be avoided. Insulin and other antidiabetic drugs: As chloroquine may enhance the effects of a hypoglycemic treatment, a decrease in doses of insulin or other antidiabetic drugs may be required. Arrhythmogenic drugs: There may be an increased risk of inducing ventricular arrhythmias if chloroquine is used concomitantly with other arrhythmogenic drugs, such as amiodarone or moxifloxacin. Ampicillin: In a study of healthy volunteers, chloroquine significantly reduced the bioavailability of ampicillin. An interval of at least two hours between intake of ampicillin and chloroquine should be observed. Cyclosporine: After introduction of chloroquine (oral form), a sudden increase in serum cyclosporine level has been reported. Therefore, close monitoring of serum cyclosporine level is recommended and, if necessary, chloroquine should be discontinued. Mefloquine: Co-administration of chloroquine and mefloquine may increase the risk of convulsions. The blood concentrations of chloroquine and desethylchloroquine (the major metabolite of chloroquine, which also has antimalarial properties) were negatively associated with log antibody titers. Chloroquine taken in the dose recommended for malaria prophylaxis can reduce the antibody response to primary immunization with intradermal human diploid-cell rabies vaccine. Praziquantel: In a single-dose interaction study, chloroquine has been reported to reduce the bioavailability of praziquantel. Tamoxifen: Concomitant use of chloroquine with drugs known to induce retinal toxicity such as tamoxifen is not recommended (see WARNINGS ).
Every chloroquine product we track (1)
Same active ingredient — different manufacturer, form, price and FDA recall record. That last one is what our independent score measures.
Only one: Chloroquine Phosphate.
What chloroquine pills look like
Imprint codes, colour and shape from the FDA’s labelling data. Match the imprint on your pill — or search any imprint.
Combination products containing chloroquine
A combination is a different drug — different dosing, different warnings. It is listed here so you can find it, not so you can substitute it.
How long chloroquine keeps
No chloroquine label we read sets a separate limit for after opening, but they do specify how it must be stored — and the stability behind any date assumes those conditions.
Does chloroquine expire? The in-use limits and storage rules from its labelsChloroquine and breastfeeding
From LactMed, the US National Library of Medicine’s Drugs and Lactation Database — quoted, not rewritten.
Full LactMed record for chloroquine: levels in milk, effects in breastfed infants, and the drugs it would consider insteadOnly small amounts of chloroquine are excreted in breast milk; when given once weekly, the amount of drug is not sufficient to harm the infant nor is the quantity sufficient to protect the child from malaria. United Kingdom malaria treatment guidelines recommend that weekly chloroquine 500 mg be given until breastfeeding is completed and primaquine can be given. Breastfeeding infants should receive the recommended dosages of chloroquine for malaria prophylaxis. In HIV-infected women, elevated viral HIV loads in milk were decreased after treatment with chloroquine to a greater extent than other women who were treated with the combination of sulfadoxine and pyrimethamine. Because no information is available on the daily use of chloroquine during breastfeeding, hydroxychloroquine or another agent may be preferred in this situation, especially while nursing a newborn or preterm infant.
National Institute of Child Health and Human Development, record revised June 15, 2025. LactMed states its information is not a substitute for professional judgement.
What people report to the FDA about chloroquine
The FDA Adverse Event Reporting System (FAERS) collects reports from patients and clinicians. It holds 679 reports naming chloroquine, and the FDA flagged 93% of those reports as serious. The effects reported most often — leaving out reports about overdose, misuse or the condition being treated, which dominate the raw list for common medicines:
- vomiting52 reports
- nausea51 reports
- headache43 reports
- pyrexia43 reports
- hypertension42 reports
- fatigue40 reports
- pneumonia40 reports
- hypoxia33 reports
Read these as a signal, not a rate. A report does not mean chloroquine caused the effect — anyone can file one, and many describe people taking several medicines for several conditions. Crucially there is no denominator: FAERS does not record how many people took the drug, so these counts cannot be turned into “X% of patients” — a bigger number often just means a more widely used or more talked-about drug. Duplicates exist, and publicity drives reporting. For what is actually established, read the FDA label section above.
Source: openFDA drug/event (FAERS), retrieved July 25, 2026.
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Frequently asked questions
What is chloroquine?
Chloroquine Phosphate is an antimalarial used to treat Amebiasis, Rheumatoid Arthritis, Discoid Lupus Erythematosus, Avian Malaria.
What kind of drug is chloroquine?
The FDA classifies chloroquine as an antimalarial. If you are checking whether it is safe to combine with something else, the class is what matters — two drugs from the same class usually should not be stacked.
Can you take chloroquine with other medicines?
It depends on the medicine. We check it against the FDA labels rather than guessing: our interaction checker searches each drug's own label for the other and quotes what it says, naming the section it came from. Run chloroquine against whatever else you take — and remember that a label not naming a drug is not the same as that combination being safe.
What forms does chloroquine come in?
Across the brands we track, chloroquine is currently marketed as tablet, per the FDA's National Drug Code Directory. Each form is dosed differently — follow the label for the exact product you were prescribed.
Is there a generic chloroquine?
Yes. Our catalog lists 1 generic chloroquine product alongside the brand versions. A generic has the same active ingredient and must meet the FDA's bioequivalence standard; it usually costs less. Ask your pharmacist which one your plan covers.
Cite this page
- APA
- pharmaranks. (2026, July 24). Chloroquine: uses, dosing, side effects & brands. https://pharmaranks.com/drugs/chloroquine
- MLA
- “Chloroquine: uses, dosing, side effects & brands.” pharmaranks, 24 July 2026, https://pharmaranks.com/drugs/chloroquine.
We summarise public FDA and NIH sources — for a clinical claim, cite the primary source we link to as well.
Sources: FDA openFDA drug label, National Drug Code Directory, and Enforcement (recall) database. This page reproduces public FDA data and is not medical advice. Dosing is set by your prescriber.
Read the full FDA label for chloroquine on DailyMed (NIH) ↗.