A double-blind comparison of once-daily metoprolol controlled-release and atenolol in the treatment of Chinese patients with mild to moderate hypertension.
The efficacy and tolerability of controlled-release metoprolol (metoprolol CR/ZOK), 100-200 mg, and atenolol, 50-100 mg, once daily was compared in Chinese patients with mild to moderate essential hypertension. The study was of a randomized, double-blind, two-way crossover design. The active treatment periods lasted 4 weeks each and were preceded by a 4-week placebo run-in period. The two double-blind phases were separated by a 2-week washout period on placebo. Blood pressures and heart rates were measured at rest in each 2-week visit and during exercise at the end of each treatment period. Twenty-four patients (M/F = 14/10) were valid for efficacy analysis. Their ages ranged from 39 to 68, with a mean of 53.5 years. The rest supine blood pressure and heart rate before active treatment was 160 +/- 15/106 +/- 6 mmHg and 75 +/- 14 beats/min (mean +/- SD), respectively. A responder was defined as exhibiting a supine diastolic blood pressure < or = 90 mmHg or a supine diastolic blood pressure reduction of at least 10% of the baseline level. Both agents had high response rate: 88% and 92% of all patients responded to metoprolol CR/ZOK and atenolol, respectively. Both active treatments considerably reduced resting systolic and diastolic blood pressures and heart rates as compared with baseline (p < 0.001), respectively. With controlled-release metoprolol, a more pronounced beta 1 blockade was obtained than with atenolol, which was expressed as a significant reduction in exercise-induced heart rate at the highest comparable workload compared with placebo (p < 0.05). These findings are compatible with those reported from western populations.
Department of Internal Medicin (Cardiology), National Taiwan University Hospital, Taipei.
M F
MF
Chen
C Y
CY
Yang
W J
WJ
Chen
C M
CM
Lee
C C
CC
Wu
C S
CS
Liau
Y T
YT
Lee
D000284:Administration, Oral; D000293:Adolescent; D000319:Adrenergic beta-Antagonists / Q000008:administration & dosage* / Q000494:pharmacology; D000328:Adult; D000368:Aged; D000959:Antihypertensive Agents / Q000008:administration & dosage* / Q000494:pharmacology; D001262:Atenolol / Q000008:administration & dosage* / Q000494:pharmacology; D001794:Blood Pressure / Q000187:drug effects; D018592:Cross-Over Studies; D003692:Delayed-Action Preparations; D004311:Double-Blind Method; D004562:Electrocardiography / Q000187:drug effects; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D006973:Hypertension / Q000188:drug therapy*; D008297:Male; D008790:Metoprolol / Q000008:administration & dosage* / Q000494:pharmacology; D008875:Middle Aged; D013624:Taiwan
D000319:Adrenergic beta-Antagonists; D000959:Antihypertensive Agents; D003692:Delayed-Action Preparations; D001262:Atenolol; D008790:Metoprolol