Since 2005, the WHO has produced a regularly updated list of all antimicrobial drugs currently used for human medicine. Most are also used in veterinary medicine. They are grouped into 3 categories (critically important, highly important and important) based on their importance to human medicine. The list is intended to assist in managing drug-resistant infections, ensuring that all antimicrobial drugs, especially critically important antimicrobials, are used prudently in human and veterinary medicine.

In 2019, the sixth revision of Critically Important Antimicrobials for human medicine was released by the WHO.[1]  The conclusions from the expert workshops organized by WHO are:

1. There is clear evidence of adverse human health consequences due to antimicrobial-resistant organisms, resulting from non-human usage of antimicrobials.

2. The amount and pattern of non-human usage of antimicrobials affect the occurrence of resistant bacteria in animals and food commodities, thereby exposing humans to these drug-resistant bacteria.

The consequences of antimicrobial resistance are particularly severe when pathogens are resistant to antimicrobials that are critically important in humans.

It is noteworthy that some drugs used in animals, for example tilmicosin, are not used in humans but are also considered critically important antibiotics. This is because tilmicosin is in the same class (macrolides) as other antibiotics used in humans, to which bacteria that develop resistance to tilmicosin may also be resistant. Overuse and misuse of tilmicosin in animal agriculture may lead to the emergence and spread of macrolide-resistant bacteria.

Colistin is commonly used in animals; however, colistin is now considered a last resort antibiotic to cure human infections caused by multidrug-resistant bacteria. China recently banned the use of colistin as a growth promoter and released a mandate to control colistin use in the treatment of disease in animals.

Check out this video about “critically important antibiotics”:

References

1 WHO. (2019). Critically important antimicrobials for human medicine, 6th revision. ISBN 978-92-4-151552-8

2 Branswell, H. (2016, May 26). The world's worst superbug has made its way to the US. Retrieved from http://www.businessinsider.com/superbug-resistant-to-colistin-found-in-us-2016-5