Duration of the antihypertensive action of atenolol, enalapril and placebo: a randomized within-patient study using ambulatory blood pressure monitoring.

Atenolol (A) and enalapril (E), two agents widely used as first-line monotherapy in arterial hypertension, have never been compared in their potency and duration of action by using 24-h ambulatory blood pressure monitoring (ABPM). Twelve out-patients (mean age 48.6 years - SD 7) with mild-to-moderate hypertension and supine diastolic blood pressure (Hawksley Random Zero Manometer) greater than 100 mmHg at the end of a 3-week placebo wash-out received, in double-blind and random order, A 100 mg daily, E 20 mg daily and placebo for 4 weeks each, according to a 3 x 3 latin square design. A 24-hour non-invasive ABPM (Spacelabs ICR 5200) was performed at the end of each of the 3 periods. In respect to placebo, both A and E produced a 24-h antihypertensive effect. The frequency of diastolic blood pressure values above 90 mmHg was 50.0% after placebo, 24.5% after A and 28.9% after E (a 51% reduction after A and a 42.3% reduction after E in respect to placebo - both p less than .05). Systolic blood pressure profiles differed less than 5 mmHg between placebo and A, as well as between placebo and E, between 9:30 and 10:30. Diastolic blood pressure profiles differed less than 5 mmHg between placebo and A over 2 h (between 2:30 and 3:30, and between 10:30 and 11:30), and between placebo and E over 2 other h (between 9:30 and 10:30, and between 11:30 and 12:30). None of the routine hematochemical parameters differed between placebo, A and E.(ABSTRACT TRUNCATED AT 250 WORDS)

RCT Entities:   Population Interventions Outcomes