Effect of bile acids on absorption of nitrendipine in healthy subjects

Abstract

Aims To examine whether bile acids such as ursodeoxycholic acid (UDCA) and chenodeoxycholic acid (CDCA) can influence the absorption of nitrendipine, a highly lipophilic calcium channel blocker. Methods Six healthy subjects received nitrendipine (10 mg) with and without UDCA (50 mg) and CDCA (200 and 600 mg) with an interval of 1 ∼ 2 weeks between study phases. Results Bile acids decreased the Cmax (ng ml-1) [control 10.9±5.8 (mean±s.d.), UDCA 5.0±4.7 (95% confidence interval for difference; 3.9, 7.8, P=0.0006), CDCA (600 mg) 5.0±3.9 (2.6, 9.2, P=0.0059)] and AUC (ng ml-1 h) [(control; 60±36, UDCA 15±13 (20, 73, P=0.0064), CDCA (600 mg) 19±19 (21, 63, P=0.0038)] of nitrendipine, while elimination half-life remained unchanged. Conclusions: These results suggest that the amount of nitrendipine absorbed was decreased when the drug was administered with UDCA and CDCA.