Antibiotics, Farm Animals, and the FDA

On Wednesday, the Food and Drug Administration announced that 25 pharmaceutical companies that manufacture animal drugs will participate in voluntarily phasing-out the use of antibiotics for growth promotion purposes in farm animals.

The companies are acting in response to voluntary guidelines that the FDA issued in December, requesting that the companies change their labeling of “medically important” antibiotics in two ways: (1) removing production uses (e.g., animal growth promotion) from the approved indications for the drugs; and (2) requiring veterinary oversight, rather than allowing over-the-counter distribution, for the remaining therapeutic uses.

Of the 26 companies targeted by these guidelines, 25 have agreed to comply by either revising their labels or withdrawing the drugs from animal use completely.   The FDA did not name the one company that has not agreed to comply.

While this is undoubtedly an important step forward in the FDA’s efforts to reduce non-necessary uses of antibiotics in livestock production—and hopefully slow the evolution of drug-resistant bacteria—it is important to note that there are potential loopholes in the FDA’s approach, as I have previously discussed.

Most importantly, the “therapeutic” uses of drugs that are allowed to continue under the FDA’s guidelines include the use of drugs not just to treat disease, but also to prevent disease.   Thus, it is possible that some of the indiscriminate uses of antibiotics for production purposes will merely be re-characterized as being for the purposes of disease prevention and continue unchanged.   In fact, the FDA’s guidance document explicitly notes that “there could be a therapeutic benefit associated with the production use of a drug,” and that in these situation, “sponsors could wish to seek new therapeutic indications to fill the therapeutic needs of animals.”    In other words, when preventing a disease will help an animal grow (which seems likely to often be the case), the required changes in labeling will not necessarily result in a change in practice.

Furthermore, although the changes to labeling would require increased veterinary oversight, the FDA has concurrently proposed a change to the regulations that govern veterinary oversight.   The proposed rule would revise the requirements that veterinarians are to follow when authorizing the use of certain animal drugs in feed.   Under the current regulations, a veterinarian may only prescribe antibiotics “if a valid veterinarian-client-patient relationship exists.”   The proposed rule would replace this with a more general requirement that the veterinarian provide supervision or oversight  “in compliance with all applicable veterinary licensing and practice requirements.”   Whether this change will take the teeth out of the increased veterinary oversight is something that I hope will become clear when the FDA responds to the comments it has received.