Reybrouck T, Amery A, Fagard R, Jousten P, Lijnen P, Meulepas E
Br Med J. 1978 May 27;1(6124):1386-8. doi: 10.1136/bmj.1.6124.1386.
In a double-blind, crossover trial 16 hypertensive patients were treated, in random order, with placebo, metoprolol 300 mg in a single daily dose, or metoprolol 300 mg/day in three doses. Both therapeutic regimens produced detectable plasma metoprolol concentrations and appreciable beta-blockade, estimated from exercise tachycardia, throughout the day. Fluctuations throughout the day in plasma drug concentrations and degree of beta-blockade were insignificant on the thrice-daily regimen, but they varied considerably on the single-dose regimen. Both therapeutic regimens also significantly lowered blood pressure throughout the day. Although the thrice-daily regimen again tended to produce a stronger and less fluctuating hypotensive action, the differences in hypotensive effect between the two regimens were not statistically significant. A single-dose of 300 mg of metoprolol can therefore be recommended if the only aim is to reduce blood pressure but not if a steady degree of beta-blockade is needed.
在一项双盲交叉试验中，16名高血压患者按随机顺序接受安慰剂、每日单次剂量300毫克美托洛尔或每日三次剂量300毫克美托洛尔治疗。两种治疗方案在一整天内均产生了可检测到的血浆美托洛尔浓度以及从运动性心动过速估计的明显β受体阻滞作用。每日三次给药方案下，全天血浆药物浓度和β受体阻滞程度的波动不显著，但单次给药方案下波动较大。两种治疗方案全天均显著降低了血压。虽然每日三次给药方案再次倾向于产生更强且波动较小的降压作用，但两种方案之间的降压效果差异无统计学意义。因此，如果唯一目的是降低血压，可推荐单次服用300毫克美托洛尔，但如果需要稳定程度的β受体阻滞作用则不推荐。
