Erythromycin-induced torsades de pointes and ventricular fibrillation in a patient with Legionella pneumonia.

Several case reports of erythromycin-induced torsades de pointes (TDP) arrhythmia have been reported in the literature. However, this potentially lethal side-effect of a frequently prescribed drug is not generally known. We report a patient who developed TDP followed by ventricular fibrillation during rapid infusion of erythromycin lactobionate. Although the patient used diuretics, probably predisposing her to arrhythmias due to hypokalaemia, several ECG abnormalities predisposing to TDP, all related to erythromycin infusion, occurred during observation in the ICU, establishing the precipitating role of erythromycin. The diagnosis was made only after QT prolongation, TDP and ventricular fibrillation were observed during rapid intravenous infusion of erythromycin lactobionate, one of the reasons no doubt being the assumed lack of serious side-effects of this frequently prescribed drug.