Sotalol-induced torsades de pointes precipitated during treatment with oseltamivir for H1N1 influenza.

BACKGROUND

Striking prolongation of the QT interval and the morphologically distinctive polymorphic ventricular tachycardia torsades de pointes can occur in patients treated with antiarrhythmic drugs and certain non-cardiovascular medications. However, there have been no reported cases of QT prolongation and torsades de pointes associated with the antiviral agent oseltamivir.

OBJECTIVE

To determine whether exposure to oseltamivir is associated with increased risk of QT prolongation and torsades de pointes in patients treated for H1N1 influenza.

METHODS

Two unusual case histories of patients exposed to oseltamivir who developed marked QT prolongation and torsades de pointes were examined.

RESULTS

Two patients on stable doses of sotalol for atrial fibrillation developed marked QT prolongation and torsades de pointes following administration of the antiviral agent.

CONCLUSIONS

The recent H1N1 pandemic has necessitated treatment of suspected or confirmed cases of H1N1 influenza with oseltamivir. Although the precise mechanism for this drug-drug interaction is not clear, given the large number of people expected to receive oseltamivir this winter, it is important to highlight this potentially adverse event.