WHO definitions for reserve antibiotics

The World Health Organization (WHO) Access, Watch, Reserve (AWaRe) classification of antibiotics is closely linked to the essential medicines concept and the WHO Model lists of essential medicines, which inform national essential medicines lists.1,2 These national lists are a fundamental strategy in health- care systems to ensure effective use of constrained resources. Furthermore, by focusing on essential antibiotics, health- care systems can better meet the health needs of their populations and mitigate the risk of antibiotic resistance. The AWaRe classification categorizes antibiotics into three groups: Access, Watch or Reserve. This classification, developed in 2017 by the Expert committee on the selection and use of essential medicines, has a twofold objective: prioritizing the most important antibiotics for human health; and supporting stewardship and surveil- lance activities.1 As of 2025, WHO has assigned 268 antibiotics used in humans to one of the AWaRe groups. Since 2019, the expert committee defines reserve antibiotics as last-resort antibiotics that are only to be used in patients with confirmed or suspected life-threatening infection due to multi drug-resistant (MDR) bacteria.3 The AWaRe classification also states that reserve antibiotics should only be used when other therapeutic alternatives have failed or are unsuitable.3 Finally, only reserve antibiotics with proven activity against critical or high priority pathogens identified by the WHO priority pathogens list can qualify for inclusion on the WHO essential medicines list (Box 1).3 The 2025 WHO essential medicines list includes 50 antibiotics, 10 of which are in the reserve group.....