Association of antibiotic use and acute kidney injury in patients hospitalized with community-acquired pneumonia.

Background: Acute kidney injury (AKI) is common among hospitalized patients with community-acquired pneumonia (CAP). We aimed to estimate and compare the risk of AKI for various antibiotic combinations in adults hospitalized for CAP.
Methods: We conducted a retrospective cohort study of the Premier Healthcare Database containing all admissions for 660 US hospitals from 2010 to 2015. We included adults aged ≥18 years hospitalized with CAP and considered 6 different antibiotic combinations based on continuous use in the first 3 hospital days. The primary outcome was incident AKI, defined by ICD-9 codes 584.5-584-9. We evaluated associations of AKI with in-hospital mortality and length-of-stay. We excluded patients who were admitted directly to the intensive care unit, had AKI codes present on admission or had dialysis in the first 2 days. We used generalized linear mixed models with the hospital as a random effect and covariate adjustment for patient demographics, comorbidities, other treatments on day 0/1, and hospital characteristics.
Results: The total sample included 449,535 patients, 3.15% of whom developed AKI. All other regimens but fluoroquinolones exhibited higher AKI odds than 3rd generation cephalosporin with or without macrolide. The combination of piperacillin/tazobactam and vancomycin with or without other antibiotics was associated with the highest AKI odds (OR = 1.89; 95% CI: 1.73-2.06). Patients with incident AKI had an increased odds of hospital mortality (OR = 6.37; 95% CI: 6.07-6.69) and longer length-of-stay (mean multiplier = 1.84; 95% CI: 1.82, 1.86).
Conclusion: Compared to 3rd generation cephalosporin with or without macrolide, piperacillin/tazobactam, vancomycin, and their combination were associated with higher odds of developing AKI, which in turn were associated with worse clinical outcomes.