Azithromycin concurrent with QT-prolonging agents is linked to increased cardiac event risk

  • Patel H & al.
  • JAMA Netw Open
  • 1 Sep 2020

  • curated by Liz Scherer
  • Clinical Essentials
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Takeaway

  • 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.

Key results

  • 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.
  • 5-day-posttreatment:
    • 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.

Study design

  • 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.

Limitations

  • Unmeasured confounders.
  • Underpowered.
  • Administratively derived data.