Lancet 1991 Feb 2;337(8736):268-9
Interaction of citrus juices with felodipine and
nifedipine.
Bailey DG, Spence JD, Munoz C, Arnold JM.
Department of Medicine, Victoria Hospital, University of Western Ontario, London, Canada.
Six men with borderline hypertension took felodipine 5 mg with water, grapefruit juice, or orange juice. The mean felodipine bioavailability with grapefruit juice was 284 (range 164-469)% of that with water. The dehydrofelodipine/felodipine AUC ratio was lower, diastolic blood pressure lower, and heart rate higher with grapefruit juice than with water. Vasodilatation-related side-effects were more frequent. Orange juice had no such effects. Six healthy men took nifedipine 10 mg with water or grapefruit juice; the bioavailability with grapefruit juice was 134 (108-169)% of that with water.