A Clinical Study on the Antihypertensive Effects of Enalapril

ABSTRACT

A new angiotensin converting enzyme inhibitor, enalapril, was administered in 20 hypertensive patients (7 mild, 6 moderate and 7 severe hypertensives) for 8 weeks or longer in order to see the blood pressure lowering effects. Additionally the left ventricular mass index was measured by 2-D guided M-mode echocardiography before and after enalapril therapy, and subjective symptoms and laboratory findings were also followed. The results were as follows 1) After 8 weeks of enalapril treatment (the doses form 10 mg to 20mg once a day) blood pressure were lowered markedly in 10, moderately in 4, mildly in 4 cases, but the blood pressures were not lowered in 2 cases with severe hypertension. The means of the blood pressures of the group were lowered form 182.1+/-19.2 to 148.0+/-26.0mmHg in systolic and from 111.9+/-14.7 to 95.1+/-17.1mmHg in diastolic after 8 weeks of treatment (p<0.001). 2) Heart rates were not changed significantly with enalapril. 3) The symptoms of insomnia and headache were reported to be improved after enalapril in 13 cases. 4) No discernable changes in CBC and serum level of creatinine were observed. But the random urine protein was decreased in 6 cases with proteinuria in routine urinalysis. The serum lipid profile was not significantly changed, but in the 2 cases in which the ratio of total to HDL-cholesterol was above 5.0, the ratio fell to below 5.0. 5) There was no significant EKG change after enalapril. 6) In 9 cases out of 13 cases with the left ventricular mass index (LVMI) above 125g/m2 BSA, LVMI was followed by echocardiography after enalapril. LVMI was significantly decreased in 8 of 9 cases and mean values after enalapril was decreased from 183.1+/-88.0g/m2 BSA to 150.8+/-61.3g/m2 BSA (p<0.0025). 7) Side effects after enalapril administration were transient dizziness in 4 cases and ageusia in 2 cases. Above results suggest that the enalapril could be an initial choice in the treatment of essential hypertension as a single oral agent in once a day regimen resulting in good antihypertensive effects, improvement of subjective symptoms, regreassion of the left ventricular hypertrophy and few side effects.