'Real-life' approach to applying PK/PD principles in infectious diseases clinical practice without access to prompt TDM

Introduction: Infectious disease treatments are transitioning from a one-size-fits-all approach to a more tailored approach. The increasing adoption of therapeutic drug monitoring (TDM) of antimicrobials is a clear example of this trend. Routine antimicrobial TDM in critically ill patients should be mandatory. Unfortunately, nowadays, only expert centers can provide it. Given the crucial nature of the first hours/days for achieving a favorable clinical outcome, empirical antibiotic therapy with an adequate choice of drug, dose and administration modalities is fundamental. Areas covered: We outline common scenarios encountered in clinical practice, such as in edematous patients, hypoalbuminemia, patients with liver and renal diseases, patients under renal replacement therapy or extracorporeal membrane oxygenation (ECMO), over or under-weight patients, in old adults and cases of infections caused by relatively high minimum inhibitory concentration (MIC) pathogens. Various clinical situations were analyzed with the help of the available literature (PubMed/MEDLINE/Google Scholar and books written by experts in pharmacology and infectious diseases). Expert opinion: In these different scenarios, we reported common examples of optimizing drug utilization to maximize therapeutic outcomes, reduce incorrect prescriptions and limit the emergence of antimicrobial resistance.