Background: Clarithromycin is a commonly used macrolide antibiotic. It is known to cause QT prolongation. Medication induced QT prolongation is a major risk factor for the development of torsade de pointes.
Methods: A 79-year-old lady presented with frequent episodes of torsade de pointes following commencement of clarithromycin. This was noted to be in association with a prolongation of the QT interval.
Conclusion: Knowledge of medications which prolong the QT interval is important to minimize the risk of ventricular arrhythmias, which may lead to sudden death. This is essential in patients with a congenitally long QT interval.