- Azithromycin poses a similar risk to amoxicillin for cardiac events within 5 days of treatment administration, except in patients using concurrent QT-prolonging agents.
Why this matters
- Consider alternatives to azithromycin in patients taking QT-prolonging drugs.
- 2,141,285 episodes of each index therapy (n=4,282,570); mean age, 35.7 (standard deviation, 22.3) years.
- Treatment duration: 5 days (87.3% of azithromycin episodes),
- Prevalence of circulatory disease, respiratory disease, use of QT-prolonging drugs was similar between users.
- Overall cardiac events: 0.03%; most frequently syncope (70%), palpitations (22.5%).
- Number of cardiac events within 5 days: amoxicillin, 708; azithromycin, 766.
- Overall prevalence of events: within 10 days, 0.05%; within 30 days, 0.1%.
- Cardiac event odds were similar between groups within 5 days (OR, 1.08; 95% CI, 0.98-1.20) and up to 30 days (OR, 0.98, 95% CI, 0.92-1.04).
- Rates in azithromycin subgroups were higher but nonsignificant.
- Exception was among patients using QT-prolonging agents (OR, 1.40; 95% CI, 1.04-1.87) vs amoxicillin users.
- Retrospective cohort study, including prespecified subgroups (elderly with cardiovascular disease, patients using concurrent QT-prolongation drugs pre/post-2012 FDA warning, presence of previously identified risk factors).
- Funding: None disclosed.
- Unmeasured confounders.
- Administratively derived data.