Consensus Guidance for Beta-Lactam Antibiotic Dose Individualization in Acutely Ill Patients: Endorsed by the American College of Clinical Pharmacy, European Society of Clinical Microbiology and Infectious Diseases, European Society of Clinical Microbiology and Infectious Diseases PK/PD of Anti-Infectives Study Group, Infectious Diseases Society of America, International Association of Therapeutic Drug Monitoring and Clinical Toxicology, Society of Critical Care Medicine, and the Society of Infectious Diseases Pharmacists.

Beta-lactam antibiotics (beta-lactams) are first-line treatments for most major infectious syndromes in acutely ill patients, with in vitro activity against common pathogens, demonstrated efficacy in trials, and a perceived low risk of adverse effects. The current dosing approach, informed by population-level data, tends to be simplistically reduced to a "one size fits all" dosing method which only accounts for body weight (i.e., in pediatrics) and end organ function to estimate drug clearance (e.g., estimated glomerular filtration rate); this approach results in substantial variability in observed serum concentrations in acutely ill patients, which can compromise real-world effectiveness and safety. Beta-lactam dose individualization, therefore, defined as a dosing regimen for one patient informed by measured concentrations from that patient, has been recommended in international clinical guidelines. Comprehensive guidance on best practices for beta-lactam dose individualization is lacking. To address this knowledge gap and develop guidance, a multidisciplinary panel of international experts was assembled from the disciplines of infectious diseases, critical care, pharmacometrics, and laboratory medicine, representing both adults and pediatrics. The panel systematically evaluated the literature, using the GRADE approach where feasible, to address broad thematic questions pertaining to whether beta-lactam dose individualization should be pursued, for what indications beta-lactam dose individualization is warranted, and the most critical considerations and best practices for implementation of beta-lactam individualization. The resultant consensus recommendations will equip healthcare professionals caring for acutely ill patients treated with beta-lactam therapy with the evidence and tools necessary to guide optimal use of beta-lactam dose individualization.