Plasma Propranolol Levels in the Quantitative Assessment of β-adrenergic Blockade in Man
Plasma Propranolol Levels in the Quantitative Assessment of β-adrenergic Blockade in Man
复制标题
血浆普萘洛尔水平在人体 β-肾上腺素能阻断定量评估中的应用
作者：
D. Coltart;D. Shand
在正常人中测定与内源性和外源性心脏β刺激减少相关的血浆普萘洛尔水平。与运动诱发心动过速的给定程度的阻滞相关的水平在静脉给药后比口服给药后高约3倍。这表明普萘洛尔的活性代谢物仅在口服药物后形成。剧烈运动的心动过速的最大减少与血浆水平40 ng相关。ml.口服给药，100 ng./ ml.静脉注射普萘洛尔静脉注射普萘洛尔后对异丙肾上腺素诱导的心动过速的影响表明，异丙肾上腺素的剂量比约为30，血浆水平为100 ng/ml。ml. 10-20纳克/升。ml.这些血浆水平可100%和20-30%阻断运动诱发的心动过速。这些结果表明，普萘洛尔的某些治疗作用可能与β-肾上腺素能阻滞无关。
Plasma propranolol levels associated with reductions in endogenous and exogenous cardiac β-stimulation were determined in normal people. The levels associated with a given degree of blockade of exercise-induced tachycardia were about three times greater after intravenous administration than after oral administration. This shows that an active metabolite of propranolol is formed only after the drug is taken by mouth. The greatest reduction in the tachycardia of strenuous exercise was associated with plasma levels of 40 ng./ml. with oral administration and 100 ng./ml. with intravenously administered propranolol. The effect on isoprenaline-induced tachycardia following intravenously administered propranolol showed that the dose ratio for isoprenaline was about 30 with plasma levels of 100 ng./ml. and 10 with levels of 10-20 ng./ml. These plasma levels give 100% and 20-30% blockade of exercise-induced tachycardia. These findings suggest that some of the therapeutic effects of propranolol may be unrelated to β-adrenergic blockade.