Gatifloxacin and prolonged QT interval

We report the case of a 54-year-old woman who, while being treated for acute sinusitis with gatifloxacin, presented with syncope and was found to have a markedly prolonged QT interval. After stopping gatifloxacin, the QT interval normalized. We speculate that her episode of syncope was caused by a ventricular arrhythmia that resulted from an increased QT interval.