Mefloquine and Quinidine interaction
Mefloquine and Quinidine: both prescribing labels flag this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.
Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.
What the FDA labels say
From the Mefloquine (Mefloquine Hydrochloride) label · effective 2025-04-03
CONTRAINDICATIONS Use of mefloquine hydrochloride tablets is contraindicated in patients with a known hypersensitivity to mefloquine or related compounds (e.g., quinine and quinidine) or to any of the excipients contained in the formulation.
Other Antimalarial Drugs Concomitant administration of mefloquine and other related antimalarial compounds (e.g., quinine, quinidine and chloroquine) may produce electrocardiographic abnormalities and increase the risk of convulsions (see WARNINGS ).
Other Drugs that Prolong the QTc Interval Coadministration of other drugs known to alter cardiac conduction (e.g., anti-arrhythmic or beta-adrenergic blocking agents, calcium channel blockers, antihistamines or H 1 -blocking agents, tricyclic antidepressants and phenothiazines) might also contribute to a prolongation of the QTc interval.
Concomitant administration of mefloquine and quinine or quinidine may produce electrocardiographic abnormalities.
Substrates and Inhibitors of P-glycoprotein It has been shown in vitro that mefloquine is a substrate and an inhibitor of P-glycoprotein.
From the Quinidine (Quinidine Gluconate) label · effective 2024-08-27
Pediatric use In antimalarial trials, quinidine was as safe and effective in pediatric patients as in adults.
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Open in the checkerNot medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.