Enalapril in moderate to severe hypertension: a comparison with atenolol.

Abstract 1 Patients with moderate to severe essential hypertension (mean untreated supine blood pressure 190/112 mm Hg) received once daily enalapril 20-40 mg or atenolol 50-100 mg, supplemented if required by hydrochlorothiazide 25-100 mg, in a randomized observerblind trial. 2 Both regimens produced a highly significant reduction in supine and standing blood pressure. 3 There was no significant difference in the antihypertensive effects of enalapril and atenolol when they were used as monotherapy. After hydrochlorothiazide was added to patients not achieving `target' blood pressure, the fall in systolic pressure was significantly greater in the enalapril group than in the atenolol group, despite similar dosage of hydrochlorothiazide in the two groups. 4 At the end of 6 months' treatment, a supine diastolic blood pressure of 90 mm Hg or below was achieved in 74% of patients on enalapril plus hydrochlorothiazide and 56% of patients on atenolol plus hydrocholorothiazide. This difference was not statistically significant. 5 A small rise in plasma urea and creatinine was observed in the enalapril group and a small rise of urea only in the atenolol group. These changes were statistically significant but of uncertain clinical importance. 6 This study confirms that once daily enalapril and atenolol, both alone and in combination with hydrochlorothiazide, are effective drugs in the management of moderate to severe hypertension.