TROUGH-PEAK RATIO OF THE BLOOD-PRESSURE RESPONSE TO ANGIOTENSIN-CONVERTING ENZYME-INHIBITORS

Short- versus long-acting angiotensin converting enzyme (ACE) inhibito rs: Although ACE inhibitors are widely used in the treatment of hypert ension, there are few data on trough:peak ratios and the data are cont radictory. Part of the explanation for this lies in differences In pha rmacological properties. Depending on the kinetics of elimination, the trough:peak ratio of short- and long-acting ACE inhibitors has to be evaluated according to a dose regimen of twice or once a day, respecti vely, and must take account of the dose used, since long-acting ACE in hibitors appear to have a dose-dependent trough : peak effect. Further explanations for the contradictory trough:peak ratios reported for AC E inhibitors include measurement methods (clinic blood pressure versus ambulatory monitoring) and study design. Trough:peak ratio: Data from randomly allocated, placebo-controlled studies indicate that both the short-acting ACE inhibitors captopril and quinapril given twice a day and the long-acting ACE inhibitors enalapril, lisinopril, benazepril and cilazapril given once a day have an acceptable trough:peak ratio ( >50%). The evidence suggests that when chemically different ACE inhibi tors with similar kinetics of elimination are administered at equipote nt doses, similar trough:peak ratios are obtained.