Short- and long-term effects of ramipril in hypertension

The effect of various doses of ramipril, a new converting enzyme inhibitor, was compared with that of placebo in patients with mild essential hypertension. After a single dose of 2.5 mg blood pressure was not significantly affected, despite a decrease in converting enzyme levels. Single doses of 5 or 10 mg did reduce blood pressure, although complete inhibition of the enzyme was apparent only with the higher dose. Despite partial recovery, both converting enzyme and blood pressure remained reduced for 48 hours. After 1 month of treatment with 10 mg of ramipril, renal vascular resistance had decreased and renal blood flow increased. Continued treatment for 1 year controlled blood pressure in 6 of 10 patients; in the remainder a diuretic needed to be added to maintain control of blood pressure.