Major
Established
الوصف
Both azithromycin and hydroxychloroquine independently prolong the cardiac QT interval; concurrent use substantially raises the risk of torsades de pointes and sudden cardiac death.
الآلية
Both drugs block cardiac hERG (IKr) potassium channels, prolonging ventricular repolarization in an additive or supra-additive manner.
الأهمية السريرية
This combination received global attention during the COVID-19 pandemic when pharmacovigilance data showed excess arrhythmia-related deaths.
التدبير
Avoid concurrent use; obtain baseline and follow-up ECG if co-prescription is unavoidable, correct electrolytes, and avoid other QT-prolonging drugs.