Dextromethorphan and quinidine and Grapefruit interaction
Dextromethorphan and quinidine and Grapefruit: the Dextromethorphan and quinidine prescribing label mentions this combination without an instruction to avoid it or change the dose.
Mentioned, no instruction to avoid. Worth knowing; rarely a reason to change anything on its own.
What the FDA labels say
From the Dextromethorphan and quinidine (Nuedexta) label · effective 2026-01-22
Strong and moderate CYP3A inhibitors include, but are not limited to, atazanavir, clarithromycin, indinavir, itraconazole, ketoconazole, nefazodone, nelfinavir, ritonavir, saquinavir, telithromycin, amprenavir, aprepitant, diltiazem, erythromycin, fluconazole, fosamprenavir, grapefruit juice, and verapamil.
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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.