Pentopril‐Cimetidine Interaction Caused by a Reduction in Hepatic Blood Flow

Abstract
The interactive effects of the coadministration of steady‐state Cimetidine and single‐dose pentopril, an angiotensin converting enzyme inhibitor, on the pharmacokinetic disposition of each other were studied in humans. Cimetidine reduced the clearance of pentopril by 11 to 14%. This reduction in clearance was shown to be caused by a reduction in liver blood flow probably mediated through H2 receptor blockade. Meanwhile pentopril induced the oral clearance of Cimetidine by 21%, presumably by a reduction in the bioavailable fraction of Cimetidine. The mechanism of this interaction is unknown.