ABSTRACT

Gastrointestinal A N TIEM ETIC S DROPERIDOL: INTERACTIO N W ITH C YC LO BENZAPRINE AND FLUOXETINE: TO RSADE DE POINTES

Approximately two hours postsurgery for Achilles tendon repair, a 59year-old woman developed polymorphic ventricular tachycardia (torsade de pointes) which progressed into ventricular fibrillation. Preadmission medica­ tions included amlodipine (5 mg daily), cyclobenzaprine (10 mg daily), diclo­ fenac (100 mg daily), fluoxetine (30 mg daily), and triamterene/HCTZ (37.5 mg/25 mg daily). Preoperative medications included intravenous cefazolin (1 g three hours preop), droperidol (0.625 mg, 45 min prior to surgery), and metoclopramide (10 mg, 45 min prior to surgery). Cardiopulmonary resuscita­ tion also included intravenous atropine (1 mg), lidocaine bolus (50 mg) and infusion (2 mg/min), and magnesium sulfate (4 mg). An ECG revealed a prolonged QTc (500 msec) without ischemic event. One day post-surgery the QT was 440 msec, and ECG revealed normal sinus rhythm, and electrolytes and thyroid panel were within normal range. Although total creatine phosphokinase was elevated (629 U/L), the MB fraction was not (0%). The patient was discharged on post-operative day six without further event. All preoperative medications except cyclobenzaprine were restarted.