The Effect of Vancomycin and Piperacillin-Tazobactam on Incidence of Acute Kidney Injury in Patients With Obesity

Background: Increasing evidence suggests that administration of combination vancomycin and piperacillin-tazobactam (VPT) increases the incidence of acute kidney injury (AKI) beyond that of vancomycin alone. But these investigations have not evaluated AKI risk specifically in an increasingly prevalent obese population in whom VPT pharmacokinetics are altered. Objective: To evaluate AKI risk with VPT administration to patients with obesity. Methods: We conducted a multicenter retrospective study of obese patients admitted to 2 separate academic teaching hospitals from January 2010 to December 2021, who received VPT, or vancomycin plus either cefepime, meropenem, or ceftazidime. The primary outcome evaluated AKI when patients were treated with or without VPT. Results: A total of 227 patients were evaluated (114 in VPT, vs 113 in control group). Overall, body mass index (35.6 kg/m 2 ± 4.8vs 36.1 kg/m 2 ± 5.2; P = .44) was similar between the VPT and control groups respectively. Total vancomycin dose on day 1 of antibiotic therapy (3,432 mg ± 935 vs 2,732 mg ± 912; P < .01) and nephrotoxin administration (75.4% vs 62.8%; P = .04) were higher in the VPT group. Incidence of AKI was higher in the VPT group (37.7%vs 14.2%; P = .01) and on regression analysis VPT was predictive of developing AKI (OR = 3.9; 95% CI = 2.0-7.7; P < .01). Conclusion and Relevance: In this retrospective study, the incidence of AKI was increased in obese patients receiving therapy with VPT. Vancomycin combination therapy with ceftazidime, cefepime, and meropenem appeared to be safe and was associated with less nephrotoxicity. Cautious use of VPT and further investigation with larger studies are warranted in this area.