AUTHOR=Chen Long , Qu Xingyi , Su Jingqian , Yao Haijun , Yuan Qiang , Wang Yu , Li Nanyang , Wu Gang , Liu Xiaofen , Hu Jin , Zhang Jing 

TITLE=The dilemma of antibiotic susceptibility and clinical decision-making in a multi-drug-resistant Pseudomonas aeruginosa bloodstream infection

JOURNAL=Frontiers in Pharmacology

VOLUME=Volume 14 - 2023

YEAR=2023

URL=https://www.frontiersin.org/journals/pharmacology/articles/10.3389/fphar.2023.1183332

DOI=10.3389/fphar.2023.1183332

ISSN=1663-9812

ABSTRACT=Objective: How to choose the appropriate antibiotics and dosage has always been a difficult issue during the treatment of multi-drug resistant bacterial infections. Our study aims to resolve this difficulty by introducing our multi-disciplinary treatment (MDT) clinical decision-making scheme based on rigorous interpretation of antibiotic susceptibility tests and precise therapeutic drug monitoring (TDM) guided dosage adjustment.
Method: The treatment course of an elderly patient who developed a multi-drug resistant Pseudomonas aeruginosa (MDRPA) bloodstream infection from a brain abscess was presented. 
Results: In the treatment process, ceftazidime-avibactam (CAZ-AVI) was empirically treated for the infection and clinical symptoms improved. However, the follow-up bacterial susceptibility test showed the bacteria was resistant to CAZ-AVI. Considering the low fault tolerance of clinical therapy, the treatment was switched to a 1 mg/kg maintenance dose of susceptible polymyxin B and TDM showed the AUC24h, ss of 65.5 mg·h/L had been achieved. But clinical symptoms were not improved after six days of treatment. Facing the complicated situation, the cooperation of physicians, clinical pharmacologists, and microbiologists was applied, and the treatment finally succeeded with the pathogen eradicated when polymyxin B dose increased to 1.4 mg/kg with the AUC24h, ss of 98.6 mg·h/L. 
Conclusions: MDT collaboration on the premise of scientific and standardized drug management is helpful to the recovery process of patients. The empirical judgment of doctors, the medication recommendations from experts in the field of TDM and pharmacokinetics/pharmacodynamics, and the drug susceptibility results provided by the clinical microbiology laboratory all provide the direction of treatment.