Long-Term Enalapril-A New Converting Enzyme Inhibitor-in the Treatment of Mild to Moderate Essential Hypertension, Results of a worldwide Multiclinic Study. Subtitle: Comparing Two Ways of Analyzing Data

The antihypertensive effect of enalapril maleate, a new converting enzyme inhibitor, was evaluated in a multiclinic, double-blind, randomized study in patients with mild to moderate essential hypertension. The analyses were done in two ways, with patients who violated the entry criteria of the protocol excluded, and according to the intention to treat principle. Enalapril in dosages of 10 to 40 mg daily administered alone or concomitantly with hydrochlorothiazide was compared to propranolol (80 to 240 mg daily) alone or concomitantly with the diuretic. The study showed that enalapril significantly lowered both systolic and diastolic blood pressure. At each timepoint measured in the course of 26 weeks of therapy, the patients in the enalapril group consistently had greater decreases in blood pressure than patients in the propranolol group although not always significantly. The enalapril treatment group had a decrease in the mean arterial blood pressure of 22.2 mmHg compared to the propranolol group of 17.9 mmHg at the end of the study. These results were similarly independent of the way the data were analyzed. Fewer patients in the enalapril group required the addition of hydrochlorothiazide to maintain optimal control of blood pressure. Enalapril was found to be safe and well tolerated over the long-term of 48 weeks. Side effects such as leukopenia and taste perversions believed to be sulfhydryl-related were not encountered. The occurrence of rash and proteinuria was rare. Thiazide-induced hypokalemia, hyperuricemia and hyperglycemia appeared to be attenuated by enalapril. The favorable efficacy and side-effect profile provide the basis for enalapril to be a drug of choice when initiating antihypertensive therapy.