Pimentel Laura, Mayo Douglas
University of Maryland School of Medicine, Baltimore, Maryland, USA.
J Emerg Med. 2008 Apr;34(3):287-90. doi: 10.1016/j.jemermed.2007.03.053. Epub 2007 Nov 26.
Methadone is commonly used by patients presenting to the Emergency Department (ED). The common, acute side effects of central nervous system depression and respiratory depression are easily recognizable by treating physicians as attributable to methadone; however, the cardiac toxicity of chronic methadone use recently has only been recognized. Both chronic use of large doses and a recent increase in the daily dose of methadone have been associated with QT prolongation and subsequent development of torsades de pointes. We describe the case of a 40-year-old woman whose methadone dose recently had been increased to 135 mg per day. She then presented to the ED with symptomatic torsades de pointes. She was stabilized in the ED by cardioversion and infusions of magnesium sulfate and lidocaine. The markedly prolonged corrected QT interval significantly shortened after discontinuing methadone. Inpatient cardiology evaluation found no other cause for the dysrhythmia. She was definitively treated with reduction of the daily methadone dose and an implanted cardioverter-defibrillator.
美沙酮常用于前往急诊科（ED）就诊的患者。中枢神经系统抑制和呼吸抑制等常见急性副作用很容易被治疗医生识别为美沙酮所致；然而，长期使用美沙酮的心脏毒性直到最近才被认识到。长期大剂量使用以及近期美沙酮日剂量增加均与QT间期延长及随后发生尖端扭转型室速有关。我们描述了一名40岁女性的病例，其美沙酮剂量最近已增至每日135毫克。随后她因有症状的尖端扭转型室速前往急诊科就诊。在急诊科，通过心脏复律以及输注硫酸镁和利多卡因，她的病情得以稳定。停用美沙酮后，明显延长的校正QT间期显著缩短。住院心脏科评估未发现心律失常的其他原因。她最终通过减少美沙酮日剂量并植入心脏复律除颤器得到了确切治疗。
