Antihypertensive and hormonal effects of lisinopril, a new angiotensin converting enzyme (ACE) inhibitor in patients with renovascular hypertension.

The antihypertensive and hormonal effects of a new ACE-inhibitor, lisinopril (MK-521), was studied in 11 patients with renal arterial stenosis (bilateral in 1). Oral doses exceeding 5 mg a day significantly reduced blood pressure (BP), the maximum fall occurring 6 h after taking the drug. At higher doses (20-80 mg/day) sustained antihypertensive effects persisted for 24 h. Lisinopril was equally effective in lowering supine and standing BP. When the drug was given stepwise in increasing doses, (5, 10, 20, 40, and in 5 cases 80 mg/day) the BP was successively normalized in 10 of 11 patients (supine BP less than 90 mmHg). 3 patients with low renin hypertension (LRH) responded less well to monotherapy on long-term treatment with lisinopril than the others. A significant increase in heart rate was observed, initially and after 1 month of treatment. After 5 days treatment with increasing doses the plasma concentrations of angiotensin II (AII) and aldosterone (Aldo) fell significantly to very low concentrations. However, on long term treatment (3 months) suppression of AII and Aldo did not always take place. A concomitant decrease in 24 h urinary aldosterone excretion occurred. No changes in renal function or other biochemical tests except for a slight increase in S-K were observed. There were no adverse side-effects. We conclude that lisinopril is an effective and safe medication for renovascular hypertension.