Dissociation of Pharmacokinetic-Pharmacodynamic Success and Clinical Failure of Tazobactam/Piperacillin in Escherichia coli Bacteremia: A Case Report

Hiroki Magarifuchi, Toshiharu Urakami, Hiroki Yamakuchi, Yohei Hamada, Yosuke Aoki

Abstract


An 84-year-old woman presenting with fever and the right lower guardant pain was found to have ischemic colitis and left renal abscess on CT scan findings, and started on empiric antimicrobial therapy with intravenous tazobactam/piperacillin (TAZ/PIPC) 4.5 g q8h. The blood culture prior to TAZ/PIPC grew Escherichia coli (E. coli) with MIC of 2 g/mL. The patient’s fever still continued; however, the follow-up blood cultures on another three occasions all demonstrated intermittent E. coli bacteremia despite continuation of TAZ/PIPC (MIC ranging from ≤ 2 to 16 g/mL). To make sure proper distribution of the drug, the pharmacokinetic parameters were quantitated after 18 dosing based on the serum concentration of TAZ/PIPC applied to the Sawchuk-Zaske equation: the serum peak/trough levels for PIPC and TAZ were 269/11 g/mL and 41/5 g/mL, with the time above MIC (T > MIC) of PIPC ranging from 70% to 100%. The volume of distribution of PIPC was 13.82 L, total clearance 98.89 mL/min, elimination rate constant (kel) 0.43 h-1, and resultant plasma half-life (0.693/kel) 1.6 h. Although T > MIC thus reflected optimal pharmacokinetics of TAZ/PIPC against Gram-negative blood stream infection, since blood cultures remained positive, the antimicrobial regimen was switched to intravenous pazufloxacin and tobramycin. The altered therapeutic regimen resulted in sterilization of the blood culture and gradual disappearance of the renal abscess. To the best of our literature search, this case report is the first to demonstrate on the basis of patient’s pharmacokinetic profile that the maximal attainment of pharmacological target of beta-lactam (T > MIC) does not always provide reassurance of successful treatment of blood stream infections.




J Med Cases. 2013;4(12):820-824
doi: https://doi.org/10.4021/jmc1494w

Keywords


Escherichia coli; Refractory bacteremia; Renal abscess; Tazobactam/piperacillin; Time above MIC

Full Text: HTML PDF
 

Browse  Journals  

 

Journal of Clinical Medicine Research

Journal of Endocrinology and Metabolism

Journal of Clinical Gynecology and Obstetrics

 

World Journal of Oncology

Gastroenterology Research

Journal of Hematology

 

Journal of Medical Cases

Journal of Current Surgery

Clinical Infection and Immunity

 

Cardiology Research

World Journal of Nephrology and Urology

Cellular and Molecular Medicine Research

 

Journal of Neurology Research

International Journal of Clinical Pediatrics

 

 
       
 

Journal of Medical Cases, monthly, ISSN 1923-4155 (print), 1923-4163 (online), published by Elmer Press Inc.                     
The content of this site is intended for health care professionals.
This is an open-access journal distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International License, which permits unrestricted
non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
Creative Commons Attribution license (Attribution-NonCommercial 4.0 International CC-BY-NC 4.0)


This journal follows the International Committee of Medical Journal Editors (ICMJE) recommendations for manuscripts submitted to biomedical journals,
the Committee on Publication Ethics (COPE) guidelines, and the Principles of Transparency and Best Practice in Scholarly Publishing.

website: www.journalmc.org   editorial contact: editor@journalmc.org
Address: 9225 Leslie Street, Suite 201, Richmond Hill, Ontario, L4B 3H6, Canada

© Elmer Press Inc. All Rights Reserved.