Clinical effects of grapefruit juice-nifedipine interaction in a 54-year-old Nigerian: a case report.

Grapefruit juice is known to increase the oral bioavailability of dihydropyridine calcium channel blockers, including nifedipine, by reducing presystemic clearance. The nature and magnitude of this interaction has not been studied in black Africans. Previous studies have reported reduced systemic clearance of nifedipine in this population, suggesting altered risk from the interaction of grapefruit juice and nifedipine. We report a case of a nifedipine-grapefruit juice adverse interaction in a Nigerian to draw attention to the problem and further sensitize practitioners.