Grapefruit and Quinidine interaction
Grapefruit and Quinidine: the Quinidine prescribing label flags 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 Quinidine (Quinidine Gluconate) label · effective 2024-08-27
Although the clinical significance of this interaction is unknown, grapefruit juice should be avoided.
Grapefruit juice: Grapefruit juice inhibits P450 3A4-mediated metabolism of quinidine to 3-hydroxyquinidine.
Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.
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.