Objective: To examine whether short-term use of azithromycin increases the risk of sensorineural hearing loss (SNHL) in adults with uncomplicated infections.
Study design: A retrospective cohort study using Medicaid claims data, 1999 to 2010.
Patients: Adults (18-64 years old) who had continuous enrollment in Medicaid for the 12 months (baseline) before the date of first dispensation (index date) of oral azithromycin or amoxicillin ± clavulanate for uncomplicated infections.
Main outcome definition: We operationalized sensorineural hearing loss (SNHL) by a charge for audiometry and followed by a diagnosis of SNHL within 30 days.
Analysis: We adjusted for the baseline covariates through propensity score matching. Adults were followed for up to 120 days after the index date. The hazard of SNHL in azithromycin-exposed adults was compared with those who had amoxicillin ± clavulanate using a Cox proportional hazard model. We performed several sensitivity analyses by varying the follow-up time, SNHL definition, adjusting for cumulative antibiotic use, and switching exposure status during the follow-up period.
Results: A total of 493,774 patients entered the study cohort. The unadjusted incidence rates of SNHL were 38 and 41 cases per 10,000 patient-years following exposure to azithromycin and amoxicillin ± clavulanate, respectively. The adjusted (matched) hazard ratio (HR) of SNHL for azithromycin versus amoxicillin ± clavulanate was 0.91 (95% confidence interval [CI], 0.77-1.07). The sensitivity analyses findings were consistent with the primary analysis.
Conclusion: Azithromycin short-term use was not associated with an increased risk of SNHL in comparison to amoxicillin ± clavulanate.