Effects of fosenopril, a once-daily angiotensin-converting enzyme inhibitor, on resting and exercise-induced changes of blood pressure, hormonal variables, and plasma potassium in essential hypertension.

Fosenopril, a new angiotensin-converting enzyme (ACE) inhibitor, is a prodrug that is converted to its active diacid metabolite after intestinal absorption. Its excretion is equally divided between hepatic and renal routes. This study details the efficacy of fosenopril at rest and during exercise on blood pressure, plasma potassium, plasma renin activity, and plasma aldosterone in 11 hypertensive males, mean age 55 years. Individual subjects underwent an identical exercise protocol (bicycle ergometry) on placebo and on active treatment. Supine mean blood pressure fell from 116 to 100 mm Hg, P less than 0.005, and at 9 minutes of exercise mean blood pressure fell from 137 to 125 mm Hg, P less than 0.01 on fosenopril. Plasma potassium fell slightly at rest from 4.27 to 3.96 mmol/L and during exercise from 5.23 to 4.93 mmol/L, both P less than 0.025. Plasma renin activity (ng/mL/hr) rose on fosenopril, at rest 0.94 to 4.72, and during exercise 2.06 to 10.39, both P less than 0.005. Aldosterone changes on treatment were marginal and nonsignificant. The compound was well tolerated and free of subjective and routine laboratory side effects. Its antihypertensive action is broadly similar to the other ACE inhibitors currently available.