Effects of lovastatin on the pharmacokinetics of nicardipine in rats

It has been reported that both nicardipine and lovastatin are substrates of both the cytochrome P450 (CYP) 3A subfamily and P‐glycoprotein (P‐gp), and P‐gp transport is unlikely to be a significant factor. Thus, the effects of oral lovastatin on the pharmacokinetics of intravenous and oral nicardipine were investigated in rats. Nicardipine was administered intravenously (4 mg/kg) and orally (12 mg/kg) with 0 (control), 0.3 and 1 mg/kg of oral lovastatin to rats. Lovastatin was administered 30 min before nicardipine administration. After intravenous administration of nicardipine with 0, 0.3 and 1 mg/kg of lovastatin, the total areas under the plasma concentration–time curve from time zero to infinity (AUCs) of nicardipine were not changed by lovastatin. However, after oral administration of nicardipine with 1 mg/kg of oral lovastatin, the AUC of nicardipine was significantly greater (by 67.4%), and the extent of absolute oral bioavailability (F) of nicardipine was increased (by 38.5%). The above data suggest that lovastatin did not considerably inhibit the metabolism of nicardipine via the hepatic CYP3A subfamily, but inhibited intestinal P‐gp and/or the CYP3A subfamily. Copyright © 2010 John Wiley & Sons, Ltd.