Chloroquineinteractions
chloroquine phosphate 500 MG Oral Tablet
This is the interactions section of this product’s FDA label — what the manufacturer documented for this drug. It is not a check of your medication list, and a drug missing from it has not been cleared: licensed clinical databases list far more interactions than any single label does. Before combining medicines, ask a pharmacist, who can check everything you take at once and will do it for free.
Named on this label
Every name above is printed in the text below. This is not the full set of drugs that interact with this one — it is the set this manufacturer wrote down.
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 ).
Text above is quoted in full from the FDA-approved drug label published by openFDA, effective July 2, 2026. Matched to this product by RxNorm code. Cross-references to other sections of the full prescribing information have been removed, since they point to a document not shown here. Nothing else is changed: no sentence is shortened, reworded or summarised.
This page reproduces regulatory text for reference. It is not medical advice, and KenyRx is not a pharmacy or a prescriber. Talk to a doctor or pharmacist about whether a medicine is right for you.
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