右美托咪啶在临床医学中应用的新进展

Progress in Study on the Clinical Application of Dexmedetomidine

右美托咪啶为新型高选择性a2肾上腺素能受体激动剂,其激动a2与a1的比例为1620:1。其分布半衰期约为6分钟,消除半衰期约为2小时,主要在肝脏进行代谢。大量的实验室实验,动物研究及健康志愿者和临床病人的临床应用表明了它的药理作用。它具有剂量依赖性的镇静催眠作用,还具有镇痛、抑制交感活性、无呼吸抑制等药理性质。其发挥镇静催眠等的作用是通过调节抑制蓝斑核和髓核的去甲肾上腺素神经元的超极化,抑制其神经元冲动的产生和减少去甲肾上腺素的释放以及激活中枢的a2ARs受体等机制而产生的。本药于1999年在美国批准用于重症监护病房(ICU)成人的镇静,镇痛。由于右美托咪啶具有上述特性,现在本药已用于术前用药,全麻辅助药,锥管内麻醉,术后镇痛等诸多临床实践中。现就其临床应用作一综述。

Dexmedetomidine is a potent and highly selective a2-adrenoceptor agonist. It has the ratio of a2/al is 1620：1. Its half-life of distribution is about 6 minutes and the elimination half-life is about 2 hours. Dexmedetomidine is mainly dissolved by the liver. A large number of laboratory and animal studies have been performed, as have clinical trials enrolling healthy volunteers or patients with the aim of shedding shed light on the main pharmacological features of dexmedetomidine. It provides dose-dependent sedation, analgesia, anxiolysis and sympatholysis with less and light side-effects. The hypnotic and supraspinal analgesic effects of dexmedetomidine are me- diated by the hyperpolarization of noradrenelgic neurons, which suppresses neuronal firing in the locus ceruleus along with inhibition of norepinephrine release and activity in the descending medullospinal noradrenergic pathway, secondary to activation of central a2-ARs. It was proved for adult sedation and analgesia use in the intensive care unit （ICU）in the USA in 1999. As a result of these properties, it has been successfully used in the Premedication, intrathecal anesthesia, postoperative analgesia and as an adjunct to general anesthesia. This review focuses on the advances of its clinical use.