Safety issues during antihypertensive treatment with angiotensin converting enzyme inhibitors.

When captopril was first introduced, it was used in high doses for severe hypertension, often in the presence of renal insufficiency, and side effects such as proteinuria, rash, neutropenia, and altered taste sensation were noted. Upon analysis, these effects were most commonly seen in patients with renal disease, autoimmune disease, or collagen vascular disease. These complications usually reversed rapidly upon discontinuation of treatment. In contrast, the growing use of the angiotensin converting enzyme inhibitors, captopril and enalapril, for treating mild to moderate hypertension and the trend toward the use of lower doses has shown these agents to be well tolerated with a low frequency of troublesome adverse effects. In fact, the original spectrum of adverse effects has virtually disappeared with the use of lower doses in patients with uncomplicated hypertension. In low doses, the converting enzyme inhibitors produce remarkably few incidences of symptomatic discomfort; the most common is skin rash, which often responds to dosage reduction. Cough and rare occurrences of angioedema have also been reported. Moreover, evidence is evolving that indicates that the converting enzyme inhibitors may sometimes decrease proteinuria and improve renal function; these effects may be especially important in diabetic hypertensive patients. Of note, these drugs can also attenuate the unwanted metabolic side effects of concurrent diuretic treatment.