Amantadine and Quinidine interaction

Amantadine 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.

Major

Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.

What the FDA labels say

From the Quinidine (Quinidine Gluconate) label · effective 2024-08-27

Major

Quinidine is also contraindicated in patients who, like those with myasthenia gravis, might be adversely affected by an anticholinergic agent.

Contraindicationsby drug classView label on DailyMed
Moderate

Altered pharmacodynamics of other drugs: Quinidine's anticholinergic, vasodilating, and negative inotropic actions may be additive to those of other drugs with these effects, and antagonistic to those of drugs with cholinergic, vasoconstricting, and positive inotropic effects.

Drug interactionsby drug classView label on DailyMed

From the Amantadine (AMANTADINE HYDROCHLORIDE) label · effective 2026-04-08

Moderate

Coadministration of quinine or quinidine with amantadine hydrochloride was shown to reduce the renal clearance of amantadine hydrochloride by about 30%.

Drug interactionsnames QuinidineView label on DailyMed

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Not 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.