Falliers C J, Vincent M E, Medakovic M
J Asthma. 1986;23(5):251-60. doi: 10.3109/02770908609073169.
The effects of labetalol, metoprolol, and placebo on pulmonary function and their interaction with isoproterenol were evaluated in 18 patients with reversible bronchial asthma [isoproterenol-induced increase in forced expiratory volume in 1 second (FEV1) of greater than or equal to 15%]. Two dose levels of each medication were studied (on consecutive days), with the lower doses of these drugs given randomly. When the lowest values during the 2-hour postdrug evaluation period were considered, FEV1 significantly increased (10.9%; 15.4%) following labetalol (200 and 400 mg, respectively), significantly decreased (-11.2%; -5.4%) after metoprolol (100 and 200 mg, respectively), and was unchanged after placebo. The effects of the three treatments on forced vital capacity (FVC) and maximal midexpiratory flow (MMEF) were qualitatively similar to those observed in FEV1. When isoproterenol was administered following labetalol (200 and 400 mg), FEV1 further increased with a resulting combined increase of 18.9 and 19.7%, respectively, indicating an additive interaction. The effect of isoproterenol was blunted by metoprolol (100 and 200 mg) (p less than 0.01, difference from the effect observed after labetalol and isoproterenol), indicating antagonistic interaction between these two drugs. Labetalol may be a safer antihypertensive than metoprolol in patients with concomitant bronchial asthma.
在18例可逆性支气管哮喘患者（异丙肾上腺素诱发的一秒用力呼气量增加大于或等于15%）中评估了拉贝洛尔、美托洛尔和安慰剂对肺功能的影响及其与异丙肾上腺素的相互作用。每种药物研究了两个剂量水平（连续两天给药），这些药物的低剂量随机给予。当考虑给药后2小时评估期内的最低值时，拉贝洛尔（分别为200和400毫克）给药后一秒用力呼气量显著增加（分别为10.9%；15.4%），美托洛尔（分别为100和200毫克）给药后显著降低（分别为-11.2%；-5.4%），安慰剂给药后无变化。三种治疗对用力肺活量（FVC）和最大呼气中期流速（MMEF）的影响在性质上与一秒用力呼气量中观察到的相似。拉贝洛尔（200和400毫克）给药后给予异丙肾上腺素时，一秒用力呼气量进一步增加，结果分别联合增加18.9%和19.7%，表明存在相加相互作用。美托洛尔（100和200毫克）使异丙肾上腺素的作用减弱（p<0.01，与拉贝洛尔和异丙肾上腺素给药后观察到的作用不同），表明这两种药物之间存在拮抗相互作用。在合并支气管哮喘的患者中，拉贝洛尔可能比美托洛尔是更安全的抗高血压药物。
