Hydroxychloroquineinteractions
hydroxychloroquine sulfate 200 MG Oral Tablet [Plaquenil]
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
Drugs Prolonging QT Interval and Other Arrhythmogenic Drugs.
See FPI for more important drug interactions.
7.1 Drugs Prolonging QT
Interval and Other Arrhythmogenic Drugs PLAQUENIL prolongs the QT interval. There may be an increased risk of inducing ventricular arrhythmias if PLAQUENIL is used concomitantly with other arrhythmogenic drugs. Therefore, PLAQUENIL is not recommended in patients taking other drugs that have the potential to prolong the QT interval or are arrhythmogenic.
7.2 Insulin or
Other Antidiabetic Drugs PLAQUENIL may enhance the effects of insulin and antidiabetic drugs, and consequently increase the hypoglycemic risk. Therefore, a decrease in dosage of insulin and other antidiabetic drugs may be necessary.
7.3 Drugs that
Lower the Seizure Threshold PLAQUENIL can lower the seizure threshold. Co-administration of PLAQUENIL with other antimalarials known to lower the seizure threshold (e.g., mefloquine) may increase the risk of seizures.
7.4 Antiepileptics
The activity of antiepileptic drugs might be impaired if co-administered with PLAQUENIL.
7.5 Methotrexate
Concomitant use of PLAQUENIL and methotrexate may increase the incidence of adverse reactions.
7.6 Cyclosporine
An increased plasma cyclosporin level was reported when cyclosporin and PLAQUENIL were co-administered. Monitor serum cyclosporine levels closely in patients receiving combined therapy.
7.7 Digoxin
Concomitant PLAQUENIL and digoxin therapy may result in increased serum digoxin levels. Monitor serum digoxin levels closely in patients receiving combined therapy.
7.8 Cimetidine
Concomitant use of cimetidine resulted in a 2-fold increase of exposure of chloroquine, which is structurally related to hydroxychloroquine. Interaction of cimetidine with hydroxychloroquine cannot be ruled out. Avoid concomitant use of cimetidine
7.9 Rifampicin
Lack of efficacy of hydroxychloroquine was reported when rifampicin was concomitantly administered. Avoid concomitant use of rifampicin.
7.10 Praziquantel
Chloroquine has been reported to reduce the bioavailability of praziquantel. Interaction of praziquantel with hydroxychloroquine cannot be ruled out.
7.11 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. Interaction of antacids and kaolin with hydroxychloroquine cannot be ruled out.
7.12 Ampicillin
In a study of healthy volunteers, chloroquine significantly reduced the bioavailability of ampicillin. Interaction of ampicillin with hydroxychloroquine cannot be ruled out.
Text above is quoted in full from the FDA-approved drug label published by openFDA, effective April 9, 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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