The safety profile of quinapril: is there a difference among ACE inhibitors?

The safety of quinapril hydrochloride, a new nonsulfhydryl angiotensin-converting enzyme (ACE) inhibitor with an intermediate duration of action, has been evaluated in 3,031 patients with hypertension and congestive heart failure (CHF) and has been compared with other ACE inhibitors. A comparison of double-blind studies showed quinapril to have a lower incidence of adverse effects and withdrawals than reported for captopril or enalapril. Analysis of onset of adverse events or withdrawals did not show either a time-dependent or dose-dependent relationship with quinapril. The proportion of patients who experienced orthostatic hypotension was less than that of patients on captopril or enalapril. Double-blind, long-term, and open-label studies with quinapril showed no increase in the incidence of events reported in patients with CHF compared with hypertensive patients. Quinapril produced minimal adverse effects on renal function in both patients with normal renal function and in those with pre-existing renal impairment. Age analysis of data from all studies showed no increase in total reporting of adverse events in older patients who did not take concomitant diuretics.