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 aerobicand anaerobic strains of bacteria. Due to changes in its pharmacokinetic and pharmacodynamic parameters by TZP-treatedpatients' renal functions and obesity, it is important to administrate and monitor TZP based on their renal functions and Body MassIndex (BMI) levels. The purpose of this study was to determine the appropriateness of administration doses of TZP based on renalfunctions of obese cancer patients in a tertiary hospital. Methods: This study was retrospectively conducted with obese cancerpatients with BMI ≥ 30 kg/m2 in a tertiary hospital, Korea from September 2004 to August 2014. Data were collected throughElectronic Medical Record (EMR) which contained laboratory data and TZP dosing of each patient. Results: Among 7,058 patientsduring the study period, 102 prescriptions were selected based on inclusion and exclusion criteria and classified by their renalfunctions. Although TZP should be used based on patients' renal functions to adjust its dose, its initial dose and dosing intervalwere consistently used without considering patients' renal functions on a regular basis. Especially, in the comparison with FDAdosing standard of TZP, approximately twice patients with 20 mL/min ≤ CrCl ≤ 40 mL/min received domestically 4.5 g instead of2.25 g as the TZP starting dose. Conclusion: The appropriate doses of TZP were administered to almost all of obese cancerpatients; however, the recommended TZP dose was different between Korea and other countries by twice the amount. Furtherrelated studies are necessary to clearly determine the results, to optimize TZP treatment for obese patients with cancer in clinicalpractice, and to design and develop new TZP formulations for them in pharmaceutical industry.