• Takeshi Yamagiwa, Mari Amino, Seiji Morita, Rie Yamamoto, Takeshi Saito, and Sadaki Inokuchi.
• Department of Emergency and Critical Care Medicine, Tokai University School of Medicine, 143 Shimokasuya, Isehara, Kanagawa, Japan. yamagiwa@is.icc.u-tokai.ac.jp
• Clin Toxicol (Phila). 2010 Feb 1; 48 (2): 149-52.

IntroductionEperisone hydrochloride is a centrally acting muscle relaxant, and triazolam is a short-acting benzodiazepine. Although commonly prescribed, cardiotoxicity induced by a single overdose of either drug is comparatively rare. A patient receiving nifedipine developed torsades de pointes (TdP) because of prolongation of the corrected QT (QTc) interval after an overdose of eperisone hydrochloride and triazolam.Case ReportA 60-year-old man receiving nifedipine was admitted in a comatose condition 3 h after ingesting 5,000 mg of eperisone and 2.5 mg of triazolam. Electrocardiogram showed sinus rhythm with prolongation of the QTc interval (820 ms). The serum electrolyte levels were as follows: potassium, 3.8 mEq/L; magnesium, 2.4 mg/dL. The serum drug concentrations were high: eperisone, 15,360 ng/mL; triazolam, 110.8 ng/mL. A temporary cardiac pacemaker was implanted immediately after the development of TdP, 11 h after the ingestion. The serum triazolam concentration normalized on day 2. The QTc interval and eperisone concentration normalized on day 6.ConclusionEperisone and triazolam overdose can cause life-threatening cardiotoxicity. Electrocardiographic monitoring and serial determination of QTc interval are likely the best way to observe these patients and evaluate the risk of cardiotoxicity.

28 keywords...

hide…