This information is generalized and not intended as specific medical advice. Consult your healthcare professional before taking or discontinuing any drug, changing your diet or commencing any course of treatment.
Important. Possible changes in your diet, medicine, or dosage should be discussed with your doctor or pharmacist.
How the interaction occurs:
Grapefruit juice slows down the absorption of quinidine from the gut. It also slows down the breakdown of quinidine by your liver. This results in a delayed effect of the drug.
What might happen:
Quinidine might not be able to control problems associated with your hear rate and rhythm.
What you should do about this interaction:
While you are taking this medicine, you should avoid eating grapefruit or drink grapefruit juice. You may choose an alternative citrus beverage (such as orange juice).In the event that you are instructed by a healthcare professional (e.g., doctor, pharmacist, or dietitian) to eat grapefruit or drink grapefruit juice, you should immediately discuss with doctor the effects of grapefruit on the blood levels of this medicine. If you notice an increase in any side effect from your medicine, contact your doctor.Your healthcare professionals may be aware of this interaction and may be monitoring you for it. Do not start, stop, or change your medicine or diet before checking with them first.
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3.Min DI, Ku YM, Geraets DR, Lee H. Effect of grapefruit juice on the pharmacokinetics and pharmacodynamics of quinidine in healthy volunteers. J Clin Pharmacol 1996 May;36(5):469-76.