Comparative effects of combination drug therapy regimens commencing with either losartan potassium, an angiotensin II receptor antagonist, or enalapril maleate for the treatment of severe hypertension

Objective To compare the efficacy and safety of a regimen of losartan potassium (losartan) and a regimen of enalapril maleate (enalapril) in a randomized trial of patients with severe hypertension in which the initial treatments were blinded.Design and methods Seventy-five patients, 23-74 years of age, with sitting diastolic blood pressure of 15- 130mmHg, were enrolled in a 12-site multicenter study. The primary efficacy parameters were the change in trough systolic and diastolic blood pressure,as well as response to treatement in terms of categories of hypertensive response.Results A gradual reduction in mean sitting diastolic blood pressure was observed in all patients treated from week 1 to 12 (10-29mmHg for the losartan regimen and 14- 32mmHg for the enalapril regimen). At week 4, a substantial number of patients remained on monotherapy at either the initial dose or double the dose of losartan (52%) or enalapril (72%). The blood pressure curves for each treatment were parallel over time. The enalapril-based regimen elicited a statistically significantly greater reduction in blood pressure than the losartan-based regimen, although the mean differences in the blood pressure response between the two treatment groups was small. Based on sitting diastolic blood pressure