EQUIVALENT BLOOD-PRESSURE REDUCTION AND TOLERABILITY WITH CONTROLLED-RELEASE METOPROLOL 50MG ONCE-DAILY AND CONVENTIONAL METOPROLOL 50MG TWICE-DAILY - A DOUBLE-BLIND 8-WEEK COMPARISON IN HYPERTENSIVE PATIENTS
J. Scholze et G. Klein, EQUIVALENT BLOOD-PRESSURE REDUCTION AND TOLERABILITY WITH CONTROLLED-RELEASE METOPROLOL 50MG ONCE-DAILY AND CONVENTIONAL METOPROLOL 50MG TWICE-DAILY - A DOUBLE-BLIND 8-WEEK COMPARISON IN HYPERTENSIVE PATIENTS, Clinical drug investigation, 11(6), 1996, pp. 331-338
In a prospective, multicentre, double-blind, parallel group study, the
blood pressure-lowering effects of an oral 50mg once-daily dosage of
metoprolol CR/ZOK (controlled-release/zero-order kinetics), an agent w
ith 24-hour activity, were compared with those of conventional oral me
toprolol 50mg twice daily in patients with mild to moderate hypertensi
on. After a 2-week placebo washout phase, 54 patients were treated wit
h metoprolol CR/ZOK and 55 patients received conventional metoprolol f
or 8 weeks. The target variables of blood pressure and heart rate were
measured in the supine and standing positions at rest, under standard
ised conditions, in the morning and evening after 4 weeks' treatment a
nd at the end of the 8-week treatment phase. After 8 weeks, blood pres
sure and heart rate at the end of the respective dosage intervals were
significantly reduced from baseline in both treatment groups. Mean sy
stolic and diastolic blood pressures measured in the morning, 12 hours
after conventional metoprolol and 24 hours after metoprolol CR/ZOK, w
ere 16.8/11.0mm Hg and 16.2/11.2mm Hg, respectively, lower than baseli
ne values. Heart rate after 8 weeks' treatment was reduced by 9.0 beat
s/min with metoprolol CR/ZOK and by 9.3 beats/min with conventional me
toprolol. The small deviations in the 95% confidence intervals demonst
rate the equal efficacy of the 2 preparations. Approximately the same
number of patients in the 2 groups reported adverse events. Even thoug
h not significant, the total number of adverse events was 25% lower in
metoprolol CR/ZOK recipients. The results of this study confirm that
once-daily oral metoprolol 50mg administered as a controlled-release f
ormulation with 24-hour activity and zero-order kinetics constitutes a
n effective treatment for most patients with mild to moderate hyperten
sion. In addition, antihypertensive efficacy with this formulation is
achieved at half the dosage required with conventional metoprolol.