Antibiotic Stewardship

Antimicrobial stewardship is the coordinated use of clinical, laboratory, pharmacy, infection-prevention, and system processes to optimise antimicrobial selection, dose, route, and duration. The aim is better treatment for the individual patient while limiting resistance, toxicity, *Clostridioides difficile* infection, and avoidable cost. It is not a policy of withholding antibiotics or choosing the cheapest drug. Resistance is selected, not created from nothing by a prescription. An antimicrobial suppresses susceptible bacteria and leaves resistant subpopulations in the patient’s flora or infecting population with a survival advantage. Mobile genetic elements such as plasmids, transposons, and integrons can then move resistance determinants between bacterial species. Broad-spectrum therapy also removes protective colonic anaerobes, allowing *C. difficile* to germinate and produce toxins A and B. The Canadian prescribing context makes this a community and hospital issue. PHAC reports that community antimicrobial use returned to approximately pre-pandemic levels after a 24% rebound between 2020 and 2024; more than 25% of hospital prescriptions are inappropriate or suboptimal, and most Canadian antimicrobial use by volume occurs in the community. More than 70% of community use is in the WHO...