Adverse events associated with azithromycin and clarithromycin in adults aged ≥65: a disproportionality analysis of the FDA Adverse Event Reporting System (FAERS) database.

Background: Azithromycin and clarithromycin are commonly used to treat community-acquired pneumonia in adults aged ≥ 65, such as mycoplasma pneumonia. This study aims to evaluate adverse events (AEs) associated with azithromycin and clarithromycin in this age group by analyzing the FDA Adverse Event Reporting System (FAERS), providing insights for clinical use and management of AEs in this population.

Research design and methods: We retrieved reports of AEs related to azithromycin and clarithromycin from the FAERS database. Disproportionality analysis was conducted using the Reporting Odds Ratio (ROR), Proportional Reporting Ratio (PRR), Bayesian Confidence Propagation Neural Network (BCPNN), and Multi-Gamma Poisson Shrinkage (MGPS) to identify AEs associated with azithromycin and clarithromycin in adults aged ≥ 65.

Results: A total of 2,019 adverse event reports were retrieved for azithromycin, and 2,392 for clarithromycin. Off-label use (n = 349) and drug interactions (n = 487) were the most reported AEs in adults aged ≥ 65 for azithromycin and clarithromycin, respectively. Prolonged QT interval showed the strongest signal among AEs for azithromycin in this age group. Drug interaction-related medication errors had the strongest signal for clarithromycin. Seven signals not explicitly included in the azithromycin package insert were identified in adults aged ≥ 65. Fourteen signals not explicitly included in the clarithromycin package insert were identified.

Conclusions: Among adults aged ≥ 65, cardiac-related adverse events are more closely associated with azithromycin than with clarithromycin. Conversely, AEs related to drug interactions and psychiatric symptoms are more associated with clarithromycin. Additionally, clinicians should be vigilant regarding AEs not specified in the package inserts. The findings of this study may help optimize the selection of azithromycin and clarithromycin based on patient circumstances and assist clinicians in focusing on relevant AEs for early intervention.