Meropenem in the Management of Severe Multidrug-Resistant Bacterial Infections

Abstract

Background: The multidrug-resistant (MDR) Gram-negative bacterial infections are a significant health problem worldwide, with high morbidity and mortality. Meropenem has long been a first-line treatment in the treatment of serious infections, but its presence in the treatment has changed as a result of the expanding resistance to antimicrobials and the development of new therapeutic agents. Objective: To critically analyse the modern role of meropenem in the treatment of severe cases of MDR bacterial infections, focusing on clinical effectiveness, pharmacokinetic/pharmacodynamic (PK/PD) optimization, pathogen-specific use, and the development of new methods of treatment. Methods: The literature review was carried out in PubMed, Scopus, and Web of Science databases to find out the studies published since 2018 and up to 2025. Included were eligible studies randomized controlled trials, observational studies, systematic reviews, and clinical guidelines that covered the use of meropenem in MDR Gram-negative infections. Results: Meropenem is also very effective in severe infections by extended-spectrum beta-lactamase (ESBL)-producing Enterobacterales, with good clinical evidence. Nevertheless, its effectiveness is much lower in carbapenem-resistant organisms, especially carbapenem-resistant Enterobacterales (CRE) and Acinetobacter baumannii where other agents show better results. In multidrug-resistant Pseudomonas aeruginosa, it becomes variable and relies on the susceptibility and dosing. Optimization of PK/PD, such as high-level resistance, may improve clinical outcome in critically ill patients but not overcome high-level resistance, including prolonged infusion and therapeutic drug monitoring. The development of new 2-lactam/2-lactamase combinations of inhibitors has further changed the paradigm of treatment towards the targeted therapy. Conclusion: Meropenem is also a useful but less selective therapeutic agent in MDR infections. To be utilized optimally, pathogen-specific susceptibility, resistance mechanisms, and PK/PD principles should be integrated. To optimize the clinical outcome and reduce the development of antimicrobial resistance, strategic implementation within a precision-based treatment framework is needed.