Impact of piperacillin/tazobactam on nephrotoxicity in patients with Gram-negative bacteraemia

Piperacillin/tazobactam (TZP) has been associated with nephrotoxicity in patients receiving vancomycin. Its impact on nephrotoxicity in patients with Gram-negative bacteraemia (GNB) is unclear. This study evaluated the impact of TZP on nephrotoxicity in patients with GNB. This retrospective cohort included patients aged >= 18 years receiving >= 48 h of therapy for bacteraemia due to Escherichia coli, Pseudomonas aeruginosa, Enterobacter, Klebsiella, Acinetobacter or Stenotrophomonas maltophilia from 1/01/2008-8/31/2011. Patients with baseline serum creatinine (SCr) >= 3.5 mg/dL, polymicrobial infection or recurrent bacteraemia were excluded. Nephrotoxicity was defined as a >= 0.5 mg/dL increase in SCr or >= 50% increase from baseline for >= 2 consecutive days. Any variable demonstrating a 10% change in exposure effect was retained in the final model. All variables biologically reasonable causes of nephrotoxicity were also considered for inclusion. The median age of the cohort (n = 292) was 76 years; 38.0% had a cancer diagnosis and ICU residence was common (21.9%). There was no difference in nephrotoxicity incidence based on days of TZP received (0 days, 13.6%; 1-2 days, 14.7%; 3-4 days, 6.9%; >= 5 days, 16.7%; P = 0.71). In multivariable analysis, baseline SCr, total body weight and vasopressor use were independently associated with nephrotoxicity. Duration of TZP was not associated with nephrotoxicity in multivariable analysis (1-2 days, OR = 0.91, 95% CI 0.39-2.12; 3-4 days, OR = 0.48, 95% CI 0.10-2.46; >= 5 days, OR = 0.57, 95% CI 0.11-3.02). In this cohort of GNB patients, duration of TZP was not associated with nephrotoxicity. (c) 2018 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.