Antimicrobial stewardship and the role of pharmacokinetics-pharmacodynamics in the modern antibiotic era.

Antimicrobial stewardship, a term coined by Dale Gerding, is defined as the optimal selection, dose, and duration of an antimicrobial that results in the best clinical outcome for the treatment or prevention of infection, with minimal toxicity to the patient and minimal impact on subsequent resistance development. Methods to promote and ensure good antimicrobial stewardship have been implemented and studied, and have typically provided tangible benefits in terms of a reduction in overall or targeted antimicrobial usage and resistance emergence. Although most of the programmatic antimicrobial stewardship efforts have been conducted in acute care inpatient settings, some strategies usually involving education have been evaluated in the outpatient venue. In this review, we shall discuss issues related to why antimicrobial stewardship is of particular importance in the modern antibiotic era. In addition, general pharmacokinetic-pharmacodynamic (PK-PD) concepts will be reviewed and specific PK-PD analyses that support the optimal selection, dosing, and duration of therapy for beta-lactam antimicrobials will be provided.