erythromycin and prolonged QT

Erythromycin has been associated with events secondary to QT interval prolongation such as cardiac arrest and ventricular fibrillation. Erythromycin should not be given to patients with a history of QT interval prolongation or ventricular cardiac arrhythmia, including torsades de pointes, or patients with electrolyte disturbances. A potential drug interaction between rivaroxaban and erythromycin resulting in increased risk of bleeding has also been identified.

Advice for healthcare professionals:

• be aware of reports of cardiotoxicity (QT interval prolongation) with macrolide antibiotics, in particular with erythromycin and clarithromycin
• erythromycin should not be given to patients with:
  • a history of QT interval prolongation (congenital or documented acquired QT interval prolongation) or ventricular cardiac arrhythmia, including torsades de pointes
  • electrolyte disturbances (hypokalaemia or hypomagnesaemia due to the risk of arrhythmia associated with QT interval prolongation)
• consider the potential benefit of treatment against the cardiac risks when prescribing in patients at increased risk of a cardiac event; patients in whom caution is needed are those with:
  • cardiac disease or heart failure
  • conduction disturbances or clinically relevant bradycardia
  • those concomitantly taking other medicines associated with QT interval prolongation
• direct patients to the patient information leaflet and remind at-risk patients of the importance of seeking medical attention if they develop signs or symptoms of a cardiac event
• erythromycin is widely used in children, some of whom may have QT interval prolongation; therefore, consider the child’s medical history and balance the treatment benefits against the potential risks
• erythromycin may interact with rivaroxaban and increase the risk of bleeding – consider this interaction when prescribing antibiotics and follow precautions in the product information if concomitant use is necessary

Reference:

• Drug Safety Update volume 14, issue 5: December 2020: 2.