Nordt S P, Clark R F
San Diego Regional Poison Center, University of California, USA.
J Emerg Med. 1997 May-Jun;15(3):357-65. doi: 10.1016/s0736-4679(97)00022-x.
Midazolam is a familiar agent commonly used in the emergency department to provide sedation prior to procedures such as laceration repair and reduction of dislocations. Midazolam is also effective in the treatment of generalized seizures, status epilepticus, and behavioral emergencies, particularly when intravenous access is not available. Midazolam is often employed as an induction agent for rapid sequence endotracheal intubation. Midazolam has a rapid onset of action following intravenous, intramuscular, oral, nasal, and rectal administration. Only 50% of an orally administered dose reaches the systemic circulation due to extensive first-pass metabolism. Midazolam is metabolized by the cytochrome P450 enzyme system to several metabolites including an active metabolite, alpha-hydroxymidazolam. Cytochrome P450 inhibitors such as cimetidine can profoundly reduce the metabolism of midazolam. Midazolam has a half-life of approximately 1 h, but this half-life may be prolonged in patients with renal or hepatic dysfunction. Midazolam has been associated with respiratory depression and cardiac arrest when used in combination with an opioid, particularly in the elderly, although all ages are at risk for respiratory depression. Midazolam is relatively free of side effects when used alone and offers several advantages over traditional pharmacological agents such as chloral hydrate and the combination of meperidine, chlorpromazine, and promethazine. Hiccups, cough, nausea, and vomiting are the most commonly reported adverse effects. Many of the adverse effects associated with midazolam can be reversed rapidly by the administration of flumazenil, a competitive benzodiazepine receptor antagonist. Midazolam is a safe and effective agent for providing sedation in the emergency department.
咪达唑仑是急诊科常用的一种药物，常用于在诸如伤口缝合和脱位复位等操作前提供镇静作用。咪达唑仑在治疗全身性癫痫、癫痫持续状态及行为紧急情况时也有效，尤其是在无法建立静脉通路时。咪达唑仑常被用作快速顺序气管插管的诱导药物。静脉、肌肉、口服、鼻腔及直肠给药后，咪达唑仑起效迅速。由于广泛的首过代谢，口服剂量仅有50%到达体循环。咪达唑仑经细胞色素P450酶系统代谢为多种代谢产物，包括活性代谢产物α-羟基咪达唑仑。西咪替丁等细胞色素P450抑制剂可显著降低咪达唑仑的代谢。咪达唑仑的半衰期约为1小时，但在肾功能或肝功能不全患者中，该半衰期可能会延长。尽管各年龄段均有呼吸抑制风险，但咪达唑仑与阿片类药物合用时，尤其是在老年人中，曾出现过呼吸抑制和心脏骤停的情况。单独使用时，咪达唑仑相对副作用较少，与传统药物如水合氯醛以及哌替啶、氯丙嗪和异丙嗪的组合相比具有多个优势。呃逆、咳嗽、恶心和呕吐是最常报告的不良反应。许多与咪达唑仑相关的不良反应可通过使用竞争性苯二氮䓬受体拮抗剂氟马西尼迅速逆转。咪达唑仑是急诊科提供镇静作用的一种安全有效的药物。
