A randomized, placebo-controlled, double-blind comparison of amlodipine and atenolol in patients with essential hypertension.

The efficacy and safety of amlodipine (2.5 mg, 5 mg, or 10 mg) once daily was compared with atenolol (50 mg to 100 mg) once daily in patients with mild-to-moderate essential hypertension in a randomized, double-blind, parallel, placebo-controlled study. One hundred and twenty-five patients were randomly allocated at the end of a 4-week run-in placebo period to 8 weeks' double-blind treatment with amlodipine (n = 41), atenolol (n = 43), or placebo (n = 41). The mean changes from baseline in blood pressure 24 h postdose for amlodipine (mean daily dose 8.8 mg) were -12.8/-10.1 mm Hg for supine and -11.5/-9.8 mm Hg for standing blood pressure (P < .001). For atenolol (mean daily dose 83.7 mg) the changes were -11.3/-11.7 mm Hg for supine and -13.3/-12.3 mm Hg for standing blood pressure (P < .001). There were no statistically significant differences between treatments. The responder rates for amlodipine, atenolol, and placebo were 61.1%, 64.9%, and 11.1%, respectively. Determinations taken over the 24-h period at the final visit revealed that amlodipine and atenolol maintained the group mean supine blood pressure at or below 140/90 mm Hg throughout the period of observation; the corresponding time-effect curve for the placebo group was clearly in the hypertensive range. Heart rate was significantly lowered by atenolol only. Both amlodipine and atenolol were well-tolerated. Only one patient was withdrawn because of the development of peripheral edema, arthralgia, and fatigue after treatment with amlodipine. This study demonstrates that once-daily administration of amlodipine or atenolol to mild-to-moderate hypertensive patients was well-tolerated and provided adequate blood pressure control throughout the 24-h dosing interval.