How meaningful is FDA's latest move on antibiotics in livestock?

Yesterday, the FDA announced a new program that has the potential to slash the routine use of antibiotics by livestock producers. The routine administration of antibiotics to livestock with no signs of sickness helps animals grow more quickly, but it's also a significant contributor to the rise of antibiotic-resistant bacteria. An estimated 70% of the antibiotics sold in the US are given to non-human animals, and most of them are the same drugs that humans rely on to treat our illnesses.

Gardiner Harris's New York Times article about FDA's announcement bears the exciting (to me, anyway) headline "US Tightens Rules on Antibiotics Use for Livestock," but FDA's press release strikes a less dramatic note, announcing, "FDA takes steps to protect public health: Agency working with animal, drug and medical communities to promote judicious antimicrobial use." And here's the agency's description of what it's doing:

Today, the FDA is issuing three documents that will help veterinarians, farmers and animal producers use medically important antibiotics judiciously in food-producing animals by targeting their use to only address diseases and health problems. Under this new voluntary initiative, certain antibiotics would not be used for so-called "production" purposes, such as to enhance growth or improve feed efficiency in an animal. These antibiotics would still be available to prevent, control or treat illnesses in food-producing animals under the supervision of a veterinarian.

... The FDA is publishing three documents today in the Federal Register.

• A final guidance for industry, The Judicious Use of Medically Important Antimicrobial Drugs in Food-Producing Animals, that recommends phasing out the agricultural production use of medically important drugs and phasing in veterinary oversight of therapeutic uses of these drugs.
• A draft guidance, open for public comment, which will assist drug companies in voluntarily removing production uses of antibiotics from their FDA-approved product labels; adding, where appropriate, scientifically-supported disease prevention, control, and treatment uses; and changing the marketing status to include veterinary oversight.
• A draft proposed Veterinary Feed Directive regulation, open for public comment, that outlines ways that veterinarians can authorize the use of certain animal drugs in feed, which is important to make the needed veterinary oversight feasible and efficient.

The repeated use of the word "voluntary" always makes me a little nervous. So far, suggestions to US livestock producers that they stop using antibiotics to promote animal growth haven't resulted in widespread abandonment of the practice. If drug companies change their antibiotics labels to remove production use of the drug and to require a veterinarian's prescription, that would indeed be a big step -- but all FDA is doing is issuing a draft guidance to assist the companies to do this voluntarily. So how likely is it to happen?

One reason drug companies might change their labels voluntarily is if they think FDA might withdraw its approval of growth-promoting antibiotic use some time in the near future, anyway. FDA approved low-dose antibiotics for growth promotion in livestock in the 1950s, but by the 1970s had concluded that this use of the drugs is not in the interest of public health. In 1977, FDA's Bureau of Veterinary Medicine issued notices of opportunity for hearing on proposals to withdraw approval of subtherapeutic doses of penicillin in animal feed and nearly all subtherapeutic uses two kindds of tetracyline. Several drug companies and other organizations requested hearings, and FDA apparently intended to schedule them ... but then three Congressional committee reports urged the agency to postpone the hearings to do more research, and the hearings never ended up happening.

More than two decades later, in December 2011, FDA rescinded the 1977 notices of opportunity for hearing. The Natural Resources Defense Council and four other organizations (Center for Science in the Public Interest, Food Animal Concerns Trust, Public Citizen, and Union of Concerned Scientists) sued the agency. Last month, Judge Theodore Katz of the US District Court for the Southern District of New York ordered FDA to:

... reissue a notice of the proposed withdrawals (which may be updated) and provide an opportunity for a hearing to the relevant drug sponsors ... If ... the drug sponsors fail to show that the use of the drugs is safe, the Commissioner must issue a withdrawal order.

Maryn McKenna at Superbug as more about the case and its background here and here, and she's posted a copy of the decision on Scribd.

Once FDA reopens this process, it's unlikely to find that growth-promoting use of penicillin and tetracycline in livestock is safe, and it'll likely withdraw its approval for these uses. In January, FDA issued an order prohibiting extra-label uses of cephalosporin in cattle, swine, chickens, and turkeys -- though, in response to public comments, they included permission for veterinarians to prescribe it for limited extra-label use.

In his article, Harris explains the rationale behind FDA's voluntary approach:

Initially, the F.D.A. is asking drug makers to voluntarily change their labels to require a prescription; federal officials said that drug makers had largely agreed to the change. If some fail to impose the restrictions, the agency will consider a more forceful ban, Mr. Taylor said.

The reason for the reliance on voluntary efforts is that the F.D.A.'s process for revoking approved drug uses is lengthy and cumbersome, officials said. The last time the F.D.A. banned an agricultural use of a medically important antibiotic against the wishes of its maker, legal appeals took five years. In this case, hundreds of drugs are involved, each with myriad approved uses in various animals.

I hope the drug makers follow through on their agreement to change antibiotics labels voluntarily. Curing disease in humans is far more important than making livestock slightly cheaper to produce.