Ichinohe T, Igarashi O, Kaneko Y
Tokyo Dental College, Chiba, Japan.
Anesth Prog. 1991 Nov-Dec;38(6):217-20.
The purpose of the present study was to determine how propranolol modifies the circulatory effects of epinephrine infused to produce plasma concentrations achieved during dental local anesthesia and to evaluate the effects of propranolol on the plasma clearance of epinephrine. The study was performed on six healthy male volunteers ranging in age from 25 to 34 yr. Five measurement series were performed on each of these subjects at the following times: pretreatment control, 15 min after the beginning of the first epinephrine infusion (10 ng/kg/min), 15 min after the cessation of the first epinephrine infusion, 3 min after the intravenous injection of propranolol 40 micrograms/kg, and 15 min after the beginning of the second epinephrine infusion. Plasma epinephrine clearance decreased to 54.7 +/- 9.3% of the control value after propranolol was given. Epinephrine showed initially a predominantly beta-adrenergic action, but this action was inhibited by propranolol. A relative alpha-dominant state may then occur, even when a routine volume of dental local anesthetic is administered to a chronic user of a nonselective beta blocker, and it is postulated that myocardial ischemia may develop in such patients.
本研究的目的是确定普萘洛尔如何改变肾上腺素的循环效应，该效应通过输注肾上腺素以产生牙科局部麻醉期间所达到的血浆浓度来实现，并评估普萘洛尔对肾上腺素血浆清除率的影响。该研究在6名年龄在25至34岁之间的健康男性志愿者身上进行。在以下时间对每个受试者进行了5个测量系列：预处理对照、首次肾上腺素输注开始后15分钟（10纳克/千克/分钟）、首次肾上腺素输注停止后15分钟、静脉注射40微克/千克普萘洛尔后3分钟以及第二次肾上腺素输注开始后15分钟。给予普萘洛尔后，血浆肾上腺素清除率降至对照值的54.7±9.3%。肾上腺素最初表现出主要为β-肾上腺素能作用，但该作用被普萘洛尔抑制。即使对非选择性β受体阻滞剂的长期使用者给予常规剂量的牙科局部麻醉剂，也可能会出现相对α优势状态，据推测此类患者可能会发生心肌缺血。
