FDA issued a draft revised guidance for industry, “General Principles for Evaluating the Human Food Safety of New Animal Drugs Used In Food-Producing Animals” in July 2016 that “described the type of information that the Food and Drug Administration’s (FDA’s) Center for Veterinary Medicine (CVM) recommends sponsors provide [the agency] to address the human food safety of new animal drugs used in food-producing animals.”

In addition to proving that drugs are safe and efficacious in the targeted livestock species, drug companies (sponsors) face increasing hurdles to prove that “food derived from treated animals is safe for human consumption.”

FDA has already begun implementing other changes to “the way medically important antibiotics have been used in animal agriculture for decades.” See FDA’s Guidance #213.

As reported on its website, FDA explains:

“[o]nce the changes are fully implemented, it will be illegal to use these medically important antibiotics for production purposes, and animal producers will need to obtain authorization from a licensed veterinarian to use them for prevention, control or treatment of a specifically identified disease.”

Food animal veterinarians and livestock farmers are concerned about their ability to treat animals with antibiotics appropriately when needed. In response,

“[t]he FDA acknowledges the important role medically important antimicrobials play in treating, controlling, and preventing disease in food-producing animals. However, the agency has been actively engaging veterinary organizations, animal producer organizations and other stakeholders to express our position that medically important antibiotics labeled for continuous or undefined durations of use is not consistent with judicious use principles, as outlined in previously-released guidance documents.”

In “General Principles for Evaluating the Human Food Safety of New Animal Drugs Used In Food-Producing Animals” FDA “provides, in one document, an overview of the overall process for the human food safety evaluation of new animal drugs used in food-producing animals, including:

  • Determining an acceptable daily intake (ADI);
  • Calculating safe concentrations;
  • Assignment of a tolerance;
  • Calculation of a withdrawal period and a milk discard time; and
  • Evaluation of carcinogenic compounds.”

In addition to analyzing the appropriate withdrawal times for meat, milk, and eggs, the agency evaluates the proposed drugs for their potential to create additional pressures on antibiotic resistance in humans.

However, FDA has identified drugs that may not have to undergo this analysis if it (and its metabolites and excipients) are not:

  • “regularly considered to have properties that would exert pressure towards the emergence or selection of bacteria of public health concern;
  • used to treat zoonotic gastroenteritis or other bacterial diseases in humans;
  • under development to treat bacterial diseases in humans; or
  • indicated for a bacterial disease in food-producing animals (i.e., indication is instead antifungal, antiprotozoal, anthelminthic, etc.).”

With the emergence of new methods of disease treatment and prevention (using, for example, genetically immune livestock) hopefully veterinarians and farmers will not have to rely on antibiotics to treat animals and keep them healthy, since it will be increasingly difficult to obtain and retain the ability to use these drugs in livestock.