Loading...
Terfenadine (Seldane) is associated with dose-related QT prolongation and subsequent increased risk of ventricular arrhythmias. This risk is higher when terfenadine clearance is blocked by drugs like macrolide antibiotics or antifungal therapy. Fexofenadine (Allegra) is the main metabolite of terfenadine and is considered to be free of cardiac toxicity. However, this report from the Netherlands documents ventricular arrhythmia due to fexofenadine in a 67-year-old man.
The patient presented with syncope two months after starting fexofenadine (180 mg/day) for itch. His cardiogram on admission showed a prolonged QT interval, but this decreased gradually after the drug was stopped. The QT increased again when fexofenadine was reintroduced and th…