Antimicrobial medicines have an important role in the treatment and prevention of disease in both humans and animals. The understanding of how antimicrobial resistance impacts humans, animals and the environment is called “one health”.

Although the side effects are usually investigated in thorough safety and toxicology studies, the potential environmental impacts of antimicrobial use, disposal and manufacturing are less understood and have only recently surfaced as a topic of concern.

Some of the effects of various compounds—most notably anthelmintics from veterinary medicine and antibacterial therapeutics—are already known, but there are many other substances that can affect organisms in the environment.

This is further complicated by the fact that some pharmaceuticals can cast effects on bacteria and animals well below the concentrations that are usually used in safety and efficacy tests. In addition, breakdown products and the combination of different biologically active compounds may have unanticipated effects on the environment.

In some countries, industrial animal farms commonly administer low doses of antibiotics and other antimicrobials (drugs that fight microorganisms like bacteria and viruses) to pigs, cows, chickens, sheep, and other food animal species for the purpose of growth promotion or weight gain. Typically, these subtherapeutic doses, which are generally not high enough to fight active diseases or infections, are given directly to animals in their feed or water.

In fact, it is common for feed to be pre-mixed with antimicrobial ingredients before it is purchased by livestock growers. The animals can receive additional, higher doses of these and other antimicrobial drugs again in their feed, water, or by injection for disease prevention and treatment. In Europe, antibiotics as growth promoters have been banned in the European Union and have not been used in the UK since 2006.

Pharmacists are the most accessible healthcare professionals and are fully competent in all aspects of medicines. They serve as communicators and educators on healthy behaviours and infection prevention. They are in a good position to explain the importance of using antimicrobials only when needed.

Pharmacists also provide effective medication management for both short- and long-term treatments.

They assess whether they can successfully treat a patient or whether the patient needs to be referred to another healthcare professional. Where pharmacists are legally allowed to prescribe antibiotics, fast and reliable diagnostic tests can support them in the proper diagnosis of common infections such as Chlamydia or Lyme Disease.

In hospitals, pharmacists lead antimicrobial stewardship programs and are competent in hygiene and sterilization. Pharmacists collect unused medicines, reducing the presence of antimicrobials in the environment.

As the world begins to acknowledge the importance of improving our stewardship efforts to protect these precious commodities in all three sectors of one health, pharmacists will play a vital role.