Meropenem for the Pharmacological Treatment of Severe Infections in Critically Ill Pediatric Patients: Breakthrough Standard Treatment Strategies Based on PK/PD

Meropenem, as a carbapenem antibiotic, is commonly used in critically ill pediatric patients with severe infection because of its broad antimicrobial spectrum, high penetration into tissues, and favorable safety profile. Due to pathophysiological changes in critically ill children, the available evidence has demonstrated that the standard dosage regimens of meropenem could not meet an appropriate pharmacodynamic (PD) target attainment in severely infected children. Therefore, we reviewed the pharmacokinetic (PK) profile of meropenem in critically ill children, therapeutic drug monitoring (TDM), and dose optimization based on PK/PD. Meropenem kills bacteria in a timedependent manner and its efficacy is positively correlated with the percentage of the time of dosing interval during which the free serum concentration of meropenem remains above the minimum inhibitory concentration (MIC) of the pathogen (%fT>MIC), which is related to PK/PD targets. For critically ill children, TDM-based dosage optimization and setting even higher PK/PD targets seem necessary to be considered. The currently available studies have revealed that increasing the dose and the application of the extended or continuous infusion of meropenem were able to achieve better PK/PD targets. According to limited clinical data on efficacy and safety, these treatment measures cannot yet be adopted as routine regimens only when serious infections caused by drug-resistant bacteria or strains with high values of MIC are suspected. Further high-quality randomized controlled trials (RCTs) or observational studies with sufficient sample sizes are required to confirm the efficacy and safety of these modes of administration.