Kikuchi Kensuke, Tsukamoto Kei, Kikuchi Haruka, Saito Takashi, Mori Fumiaki
Cardiology, Yokohama Medical Center, Yokohama, JPN.
Cureus. 2024 May 19;16(5):e60581. doi: 10.7759/cureus.60581. eCollection 2024 May.
A 37-year-old woman was admitted to our hospital due to a loss of consciousness. She had been taking 2 mg of tizanidine for two months to manage shoulder muscle pain at night. On admission, an electrocardiogram showed sinus bradycardia with a heart rate of 30 bpm and QT prolongation (QTc 495 msec). She had a temporary pacemaker inserted in the catheterization room, after which an improvement in her level of consciousness was observed. There were no apparent endocrine disorders or structural heart diseases. The administration was discontinued after admission, and 12 hours after admission, her heart rate normalized to a sinus rhythm of 70-100 bpm, and QTc improved to 431 msec. Therefore, she was diagnosed with tizanidine-induced bradycardia. Although reports of tizanidine-induced bradycardia are rare, tizanidine's central α2 agonistic effects can cause bradycardia, necessitating caution.
一名37岁女性因意识丧失入住我院。她因夜间肩部肌肉疼痛服用替扎尼定2毫克，已持续两个月。入院时，心电图显示窦性心动过缓，心率为30次/分钟，QT间期延长（QTc 495毫秒）。她在导管室插入了临时起搏器，之后意识水平有所改善。没有明显的内分泌紊乱或结构性心脏病。入院后停用该药物，入院12小时后，她的心率恢复正常，窦性心律为70 - 100次/分钟，QTc改善至431毫秒。因此，她被诊断为替扎尼定诱发的心动过缓。虽然替扎尼定诱发心动过缓的报道很少见，但替扎尼定的中枢α2激动作用可导致心动过缓，需谨慎使用。
