Verapamil/Grapefruit Juice
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.
Medical warning:
Important. Possible changes in your diet, medicine, or dosage should be discussed with your doctor or pharmacist.
How the interaction occurs:
When grapefruit or grapefruit juice is taken with verapamil, it may increase the amount of this medicine absorbed into your bloodstream.
What might happen:
Your blood levels of verapamil may increase. Increased blood levels may cause a lower-than-desired blood pressure or an undesirable change in heart rate.
What you should do about this interaction:
While you are taking this medicine, you may want to consider avoiding eating grapefruit or drinking 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 your doctor the effects of grapefruit on the blood levels of this medicine.Tell your doctor immediately if symptoms of low blood pressure (such as rapid heartbeat or dizziness) occur. Also report an irregular or unusually slow heartbeat. Contact your healthcare professional for more information.Your healthcare professional 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.
References:
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2.Zaidenstein R, Dishi V, Gips M, Soback S, Cohen N, Weissgarten J, Blatt A, Golik A. The effect of grapefruit juice on the pharmacokinetics of orally administered verapamil. Eur J Clin Pharmacol 1998 Jun;54(4):337-40.
3.Fuhr U, Muller-Peltzer H, Kern R, Lopez-Rojas P, Junemann M, Harder S, Staib AH. Effects of grapefruit juice and smoking on verapamil concentrations in steady state. Eur J Clin Pharmacol 2002 Apr;58(1):45-53.
4.Covera-HS (verapamil hydrochloride) US prescribing information. G.D. Searle LLC November, 2011.
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6.Bailey DG, Malcolm J, Arnold O, Spence JD. Grapefruit juice-drug interactions. Br J Clin Pharmacol 1998 Aug;46(2):101-10.
7.Pillai U, Muzaffar J, Sen S, Yancey A. Grapefruit juice and verapamil: a toxic cocktail. South Med J 2009 Mar;102(3):308-9.
