Multidrug-resistant Acinetobacter baumannii infections: Current evidence on treatment options and the role of pharmacokinetics/pharmacodynamics in dose optimisation

Acinetobacter baumannii remains a difficult-to-treat pathogen that poses a significant challenge to clinicians and costs to the healthcare system. There is a lack of clinical efficacy data to aid in the selection of optimal treatment for multidrug-resistant (MDR) A. baumannii infections. This paper aimed to review recent literature on the treatment of MDR A. baumannii infections and novel agents in the pipeline and to discuss the clinical data supporting their use. Colistin has been widely studied as monotherapy or as part of combination therapy, but its use is limited due to nephrotoxicity. The clinical benefit of combination therapy, whether empirical or targeted, has yet to be demonstrated owing to a lack of definitive evidence from randomised controlled trials (RCTs). Most available clinical studies are retrospective and lack control groups, which offers low-grade evidence. Novel agents such as cefiderocol, plazomicin, eravacycline and sulbactam/ETX2514 combination are promising options for the treatment of different infectious pathologies caused by MDR A. baumannii, but these have yet to be evaluated in RCTs. A better understanding of the pharmacokinetics/pharmacodynamics of the 'old' antibiotics is required to optimise their dosing regimens in order to maximise bacterial killing, minimise toxicities and improve clinical outcomes.