AIM: To evaluate quantitatively the influence of bioavailability and plasma unbound fraction (f(u)) on the extent of interaction between grapefruit juice (GFJ) and calcium antagonists. METHODS: The extent of drug-GFJ interaction was evaluated from reported clinical interaction studies of 11 calcium antagonists. The relationship between extent of interaction and bioavailability or f(u) was analysed. RESULTS: The following significant hyperbolic relationships were observed: [Extent] = 12.2/[bioavailability] + 1 and [Extent] = 0.718/[f(u)] + 1. CONCLUSIONS: Bioavailability and f(u) are major determinant factors of calcium antagonist-GFJ interaction: a drug with smaller bioavailability or lower f(u) is likely to exhibit a more potent interaction, and vice versa.
AIM: To evaluate quantitatively the influence of bioavailability and plasma unbound fraction (f(u)) on the extent of interaction between grapefruit juice (GFJ) and calcium antagonists. METHODS: The extent of drug-GFJ interaction was evaluated from reported clinical interaction studies of 11 calcium antagonists. The relationship between extent of interaction and bioavailability or f(u) was analysed. RESULTS: The following significant hyperbolic relationships were observed: [Extent] = 12.2/[bioavailability] + 1 and [Extent] = 0.718/[f(u)] + 1. CONCLUSIONS: Bioavailability and f(u) are major determinant factors of calcium antagonist-GFJ interaction: a drug with smaller bioavailability or lower f(u) is likely to exhibit a more potent interaction, and vice versa.
Authors: H Takanaga; A Ohnishi; H Murakami; H Matsuo; S Higuchi; A Urae; S Irie; H Furuie; K Matsukuma; M Kimura; K Kawano; Y Orii; T Tanaka; Y Sawada Journal: Clin Pharmacol Ther Date: 2000-03 Impact factor: 6.875
Authors: K Hashimoto; T Shirafuji; H Sekino; O Matsuoka; H Sekino; O Onnagawa; T Okamoto; S Kudo; J Azuma Journal: Eur J Clin Pharmacol Date: 1998 Nov-Dec Impact factor: 2.953