2440. Weight-adjusted Piperacillin-Tazobactam (PIP/TAZ) Therapy in Obese Patients versus Optimized Doses in Non-obese Patients: a Retrospective Cohort Study
Session: Poster Abstract Session: Treatment of AMR Infections
Saturday, October 6, 2018
Room: S Poster Hall
Background: Dose optimized PIP/TAZ utilizing prolonged infusion has been shown to improve clinical outcomes. Previous pharmacokinetic studies of these prolonged infusion PIP/TAZ doses that achieve adequate time above minimum inhibitory concentration (T>MIC) in non-obese patients do not achieve similar concentrations in obese patients. Due to this higher doses are necessary in obese patients to achieve adequate T>MIC. Our institution utilizes weight-based dose optimization of PIP/TAZ in obese patients. The purpose of this study is to investigate clinical outcomes and adverse events with these dosing strategies compared to optimized doses in non-obese patients

Methods: A retrospective single-center cohort study was conducted in patients ≥18 years old with culture-confirmed non-urinary tract Pseudomonas aeruginosa infections. Patients with positive cultures and PIP/TAZ treatment ≥24 hours were classified in groups as obese (≥120 kg) or non-obese (<120kg).

Results: 44 patients were studied in each arm with mean age 56 ± 13.8 and 65 ± 17.5, median weight 144 {132-170] and 77 [65-99] and median BMI 48 [40.5-56.2] and 26.4 [21.8-29.7] in the obese and non-obese groups respectively. Outcomes in obese compared to non-obese included composite clinical cure/improvement 86.4% and 77.2%, length of stay 8 and 10 days, ICU length of stay 10 and 8 days, hospital mortality 9.1% and 11.3%, 30 day mortality 15.9% and 18.2%, respectively. Adverse events in obese and non-obese groups occurred at 34.1% and 27.3% including AKI at 27% and 16% and thrombocytopenia at 7.1% and 12.8%, respectively. PIP/TAZ was discontinued due to safety concerns in 1 obese patient and 2 non-obese patients.

Conclusion: Weight-adjusted PIP/TAZ doses in obese patients produce similar clinical outcomes to optimized doses in non-obese patients.

Sarah Moore, PharmD, Pharmacy, Franciscan Health Indianapolis, Indianapolis, IN, Chad Knoderer, PharmD, Pharmacy Practice, Butler University College of Pharmacy and Health Sciences, Indianapolis, IN and S. Christian Cheatham, PharmD, Pharmacy, Franciscan St. Francis Health, Indianapolis, IN


S. Moore, None

C. Knoderer, None

S. C. Cheatham, None

Findings in the abstracts are embargoed until 12:01 a.m. PDT, Wednesday Oct. 3rd with the exception of research findings presented at the IDWeek press conferences.