2019-2020 PT Rounds: 1: Beta-Lactam Antibiotics in Critically Ill Patients: Is TDM the Solution? - Gibbons

Over the last decade our understanding of pharmacokinetic (PK) changes that occur in critically ill patients has expanded exponentially.  Therapeutic drug monitoring (TDM) has been utilized for many years as a tool to decrease toxicity with antibiotics such as the aminoglycosides and vancomycin and its use has since evolved to optimize efficacy based on the pharmacokinetic profiles of these antibiotics.  B-lactam antibiotics have traditionally been considered highly efficacious at fixed doses, with minimal adverse effects, and because of this, TDM has not been explored in detail.  However, our current knowledge of PK changes in critically ill patients suggests significant changes compared to the “typical” patient.  In addition to this, the emergence of pathogens with higher MICs adds to the complexity of treating infections in critically ill patients and increases the likelihood of therapeutic failure.  Evidence of inadequate PK/PD target attainment in critically ill patients has emerged and dosing strategies such as extended and continuous infusion of B-lactams are utilized in attempt to combat this.  TDM of B-lactams has become an appealing potential tool to ensure adequate concentrations are maintained in critically ill patients and to avoid potential toxicity.  The rationale for this presentation is to review the evidence for TDM of B-lactams, describe situations in which TDM may be useful, and practical issues with the implementation of this practice.