Jl. Mehta et al., DOUBLE-BLIND EVALUATION OF THE DOSE-RESPONSE RELATIONSHIP OF AMLODIPINE IN ESSENTIAL-HYPERTENSION, The American heart journal, 125(6), 1993, pp. 1704-1709
To determine the dose-response efficacy of once-daily administration o
f placebo or a new long-acting calcium channel blocker amlodipine in p
atients with mild to moderate hypertension, a randomized, multicenter,
placebo-controlled, double-blind trial was conducted. The study inclu
ded 210 patients with diastolic hypertension (blood pressure 95 to 114
mm Hg) without major hematologic, renal, hepatic, cardiac, or endocri
ne abnormalities. After a 4-week single-blind placebo run-in period, p
atients were given placebo or amlodipine (1.25, 2.5, 5, or 10 mg) dail
y for 4 weeks. To assess the antihypertensive effect of amlodipine ove
r a 24-hour period, blood pressure and pulse rate at weeks 0 and 4 wer
e recorded for 12 hours after the dose and then again at 24 hours. At
the end of the study patients treated with all doses of amlodipine gre
ater than 1.25 mg daily had significantly reduced diastolic blood pres
sure in both supine and standing positions. Amlodipine, 1.25 mg daily,
was also associated with a decrease in standing diastolic blood press
ure. Response to treatment was greater in all amlodipine-treated patie
nts than in those receiving placebo. Pulse rate in both the supine and
standing positions was not significantly affected by amlodipine. At d
oses of 2.5, 5.0, or 10.0 mg daily, amlodipine maintained blood pressu
re below values obtained with placebo throughout the 24-hour period. T
reatment with amlodipine was well tolerated and the incidence of side
effects was low. Once-daily dosing with amlodipine is effective in the
24-hour control of blood pressure in patients with mild to moderate h
ypertension. Because of its efficacy as monotherapy given once a day a
nd its low side effect profile, amlodipine may be well suited in the t
reatment of hypertension.