Comparison of Appropriate Piperacillin/Tazobactam Doses in Korean Obese Patients with Cancer Based on Different Body Size Descriptor Equations in a Tertiary Care Hospital

ABSTRACT

BACKGROUND: Piperacillin/tazobactam (TZP) is an antibiotic against a broad spectrum of gram-positive, gram-negative, and aerobic and anaerobic strains of bacteria. Due to changes in its pharmacokinetic and pharmacodynamic parameters by TZP-treated patients' renal functions and obesity, it is important to administrate and monitor TZP based on their renal functions and Body Mass Index (BMI) levels. The purpose of this study was to determine the appropriateness of administration doses of TZP based on renal functions of obese cancer patients in a tertiary hospital. METHODS: This study was retrospectively conducted with obese cancer patients with BMI ≥ 30 kg/m₂ in a tertiary hospital, Korea from September 2004 to August 2014. Data were collected through Electronic Medical Record (EMR) which contained laboratory data and TZP dosing of each patient. RESULTS: Among 7,058 patients during the study period, 102 prescriptions were selected based on inclusion and exclusion criteria and classified by their renal functions. Although TZP should be used based on patients' renal functions to adjust its dose, its initial dose and dosing interval were consistently used without considering patients' renal functions on a regular basis. Especially, in the comparison with FDA dosing standard of TZP, approximately twice patients with 20 mL/min ≤ CrCl ≤ 40 mL/min received domestically 4.5 g instead of 2.25 g as the TZP starting dose. CONCLUSION: The appropriate doses of TZP were administered to almost all of obese cancer patients; however, the recommended TZP dose was different between Korea and other countries by twice the amount. Further related studies are necessary to clearly determine the results, to optimize TZP treatment for obese patients with cancer in clinical practice, and to design and develop new TZP formulations for them in pharmaceutical industry.