Long-term efficacy of angiotensin-converting-enzyme inhibition with captopril in mild-to-moderate essential hypertension.

1 Thirty-one patients with mild-to-moderate essential hypertension were treated with captopril for 30 months. 2 Captopril effectively lowered raised blood pressure in hypertensive patients with high, low, and normal renin concentrations. There was no significant change in heart rates. Captopril alone normalised blood pressure (diastolic pressure below 95 mm Hg) in 11 patients. In the other patients the addition of hydrochlorothiazide produced a further hypotensive effect. Blood pressure control could be maintained without any signs of tachyphylaxis. 3 Plasma concentrations of aldosterone and angiotensin II were significantly lower after 30 months of therapy than pretreatment values whether captopril was associated with diuretics or not. No relevant symptomatic or biochemical adverse reactions were observed. 4 These data establish the long-term potential of captopril for outpatient therapy in mild-to-moderate forms of essential hypertension.