lisinopril and grapefruit

A:Lisinopril (an ACE inhibitor) and hydrochorothiazide (a thiazide diuretic) are not affected by grapefruit juice and the potassium present would actually be beneficial with the diuretic. A glass a day is ok. For future reference, orange juice does not interact with any drugs. Grapefruit juice can affect certain liver enzymes and can lead to a number of interactions with drugs, often increasing the effective potency of compounds. Grapefruit contains naringin and bergamottin, which inhibit the cytochrome P450 isoform CYP3A4 in the intestine. It is via inhibition of this enzyme that grapefruit increases the effects of buspirone (Buspar), carbamazepine, caffeine, several statin drugs (such as simvastatin), terfenadine, felodipine, nifedipine, verapamil, estradiol, tacrolimus, dextromethorphan (significant only at recreational doses), benzodiazepines, and cyclosporin. In rare instances death has occured from this interaction. I hope this helps. Be well. Rick the Pharmacist