Federal authorities plan to expand limits on who can buy antimicrobials for use in livestock and how long they can be used.
Authorities also will increase monitoring of antimicrobial use and resistance in agriculture and promote antimicrobial stewardship across veterinary medicine.
Under the Food and Drug Administration Center for Veterinary Medicine's plan published this fall, "Supporting antimicrobial stewardship in veterinary settings: Goals for fiscal years 2019-2023," farmers would need a prescription or a similar veterinary feed directive to access any of the antimicrobials that are in drug classes shared with human medicine. Agency officials also plan to develop recommended treatment times for those drugs for which guidance is absent.
The plan is a continuation of agency efforts to require veterinarian oversight of antimicrobials that are in the same drug classes as those used in human medicine. Under threat of regulatory action, pharmaceutical companies agreed to comply with an agency plan that removed over-the-counter access to such drugs delivered in feed and water.
That change, enacted in January 2017, affected about 95 percent, by weight, of all such medically important antimicrobials given to livestock. At the same time, the agreements also forbid use of those drugs for production purposes—such as growth promotion—rather than disease.
The changes proposed in the five-year plan would target the remaining medically important antimicrobials not already under veterinarian oversight, including over-the-counter injectable and intramammary products.
FDA officials also have been searching for ways to limit how long animals receive some approved antimicrobial treatments. A September 2016 Federal Register notice called for ideas on how to create proper and targeted treatment durations for instances when such guidance is absent from the labels, which sometimes contain instructions such as "feed continuously."
"Establishing defined durations of use for currently approved therapeutics will support FDA's efforts to foster stewardship of medically important antimicrobial drugs in food-producing animals and help preserve the effectiveness of these antimicrobials in animal and human medicine," the notice states.
The CVM's plan for fiscal years 2019-23 also includes drafting a strategy to promote antimicrobial stewardship in companion animal medicine.
"This includes a strategy to address potential development of antimicrobial resistant bacteria in companion animals," the plan states. "The development of antimicrobial resistant bacteria may impact the ability to effectively treat bacterial infectious disease in companion animals and increase the potential for transfer of antimicrobial resistant bacteria from companion animals to humans through direct or indirect contact."
Agency officials also plan to collect more data on antimicrobial uses in agriculture, evaluate antimicrobial resistance patterns in isolates from animals—including farmed aquatic animals—administered antimicrobials in drug classes shared with human medicine, encourage careful use of antimicrobials in all animals, improve access to drug label information for people who work with animals, identify illegal marketing of animal drugs, help other countries create their own stewardship programs, and share more data on antimicrobial use and resistance.