Effectiveness Of Pharmacokinetic/Pharmacodynamic-Guided Meropenem Treatment in Critically Ill Patients: A Comparative Cohort Study.

The proper dosage of antibiotics is a key element in the effective treatment of infection, especially in critically ill patients. This study aimed to evaluate the efficacy of optimized meropenem regimens based on pharmacokinetic/pharmacodynamic (PK/PD) criteria in patients admitted to the intensive care unit (ICU). This observational, naturalistic, retrospective, unicentric cohort study, was performed between May 2011 and December 2017. The clinical and bacteriologic responses of 77 control ICU patients receiving meropenem were compared with those of 77 propensity score-balanced patients who received meropenem dose-adjusted by therapeutic drug monitoring. The primary endpoint of clinical response was a reduction at the end of treatment of at least 80% of the maximum procalcitonin (PCT) value recorded during meropenem treatment. The primary endpoint was met by 55 patients (71.4%) in the adjusted group compared with 41 (53.3%) patients in the control group (mean difference 18.1%, p=0.02). Fifty-one patients (66.2%) in the adjusted group required a meropenem dose adjustment, being necessary in 46 of whom (90.2%) decrease the dose. dose. The reduction of PCT was greatest in the adjusted group compared with the unadjusted group (93 vs. 85%, p=0.004); a greater percentage of patients reached a PCT level < 0.5 ng/mL (63.6 vs. 41.6%, p=0.006), and there was a trend towards an improved bacteriologic response (Relative Risk=1.27; 95% confidence interval: 0.92-1.56). There were no differences in early mortality or safety between groups. Adjustment of meropenem therapy by monitoring is a useful strategy for improving meropenem effectiveness in the treatment of infection in critically ill patients, with no impact on safety.