T wave alternans and Torsades de Pointes after the use of intravenous pentamidine.

We report the case of a patient in whom dramatic T wave alternans with brief bouts of torsades de pointes and QT prolongation occurred in association with intravenously administered pentamidine. This ECG marker of a potentially fatal side effect, although uncommon, should be looked for in patients requiring the use of this drug.