Pharmacodynamic interaction between the new selective cholesterol absorption inhibitor ezetimibe and simvastatin

Aims The primary aims of these two single‐centre, randomized, evaluator‐blind, placebo/positive‐controlled, parallel‐group studies were to evaluate the potential for pharmacodynamic and pharmacokinetic interaction between ezetimibe 0.25, 1, or 10 mg and simvastatin 10 mg (Study 1), and a pharmacodynamic interaction between ezetimibe 10 mg and simvastatin 20 mg (Study 2). Evaluation of the tolerance of the coadministration of ezetimibe and simvastatin was a secondary objective. Methods Eighty‐two healthy men with low‐density lipoprotein cholesterol (LDL‐C) ≥130 mg dl−1 received study drug once daily in the morning for 14 days. In Study 1 (n=58), five groups of 11–12 subjects received simvastatin 10 mg alone, or with ezetimibe 0.25, 1, or 10 mg or placebo. In Study 2 (n=24), three groups of eight subjects received simvastatin 20 mg alone, ezetimibe 10 mg alone, or the combination. Blood samples were collected to measure serum lipids in both studies. Steady‐state pharmacokinetics of simvastatin and its β‐hydroxy metabolite were evaluated in Study 1 only. Results In both studies, reported side‐effects were generally mild, nonspecific, and similar among treatment groups. In Study 1, there were no indications of pharmacokinetic interactions between simvastatin and ezetimibe. All active treatments caused statistically significant (P