Advocacy in action

AMDUCA under assault

As you are hopefully all aware by now, the US Food and Drug Administration’s (FDA’s) Center for Veterinary Medicine has proposed a ban on the extra-label use of the cephalosporin class of antimicrobials in food-producing animals. According to the Center for Veterinary Medicine, the agency is taking this action after “considering a broad set of information, including scientific literature, antimicrobial resistance surveillance data collected as part of the US National Antimicrobial Monitoring System, antimicrobial resistance surveillance data collected in other countries, as well as unpublished data collected as part of FDA inspectional activities.” This action, which follows the recent approval of Baytril^ for use in swine, but the continued ban on the extra-label use of fluoroquinolones in food-producing animals, raises the concern of food-animal veterinarians and the AASV. This decision flies in the face of the intent of regulations allowing for the extra-label use of approved antimicrobials and ignores the ability of veterinarians to determine appropriate and judicious use of antimicrobials in the treatment of their food-animal patients.

In 1994, Congress passed the Antimicrobial Medicinal Drug Use Clarification Act (AMDUCA) to delineate the circumstances under which a veterinarian could prescribe the use of an antimicrobial in food-producing animals in a manner other than that specifically described on the product label. The utilization of antimicrobials in this manner is referred to as extra-label drug use. AMDUCA recognizes the training, experience, and expertise of the veterinarian in determining an appropriate treatment regimen to alleviate pain and suffering in food-producing animals while insuring continued public safety. The regulation places very stringent controls on who may decide to use a drug in an extra-label manner, as well as which drugs may be used extra label and under what conditions. The practitioner is uniquely qualified to accept this responsibility and understand its implications.

AMDUCA defines extra-label use as the administration of a drug in any manner not specifically approved on the product label. This includes using the product to treat a pathogen or condition not described on the label and administering the product via a route or dosage other than that approved on the label, or to a species other than those listed on the label. Extra-label use is illegal in all cases except when prescribed by a licensed veterinarian within the context of a veterinarian-client-patient relationship and requires additional labeling and extended withdrawals. There is no approved extra-label use of feed-grade antimicrobials. Extra-label use is approved for treatment only when there is no veterinary product approved for the condition being treated in that species, or when the approved dosage or route of administration is ineffective. Drugs may not be used in an extra-label manner for production purposes or simply because they are cheaper alternatives to approved products.

Food-animal veterinarians have relatively few approved drugs available to treat the myriad of conditions they encounter in the field on a daily basis. In many instances, there are no approved drugs to treat these conditions, or the approved dosages or routes of administration are ineffective. In order to treat and control diseases, alleviate animal suffering, and ensure food safety, veterinarians often must utilize antimicrobials in an extra-label manner. Retaining our ability to utilize these products in a responsible manner is imperative to enable practitioners to effectively treat our patients and protect public health.

While the FDA has the authority and the responsibility to evaluate the use of antimicrobial compounds and the impact of that use on public and animal health, their decisions must be based on sound science. Their response should be constrained to effectively address any concerns that arise without unduly restricting the appropriate and necessary utilization of approved products by licensed veterinarians. The recent decision to ban the extra-label use of products approved for use in food animals, namely the fluoroquinolones and cephalosporins, is based on limited and questionable interpretation of scientific studies, agency inspections of practices being conducted in certain segments of the food-animal industry, and international experiences not subject to the controls mandated by AMDUCA. This action circumvents the intent of AMDUCA and ignores the ability of the practitioner to utilize approved veterinary products in a prudent and safe manner.

When considering restricting the extra-label use of a product or class of products, the agency should first identify whether or not the utilization of those products in animals results in a real risk of promoting antimicrobial resistance and then determine if there are specific practices (eg, use in certain species, dosages, routes of administration) that increase this risk. The agency should then ban or modify those specific practices rather than jeopardizing all food-animal species by disallowing veterinarians’ access to these compounds.

The leadership of the AASV and members of the Pharmaceutical Issues Committee, along with the AVMA, the National Pork Board, the National Pork Producers Council, and other food-animal veterinary and producer organizations, are actively engaging FDA on this issue. At the time of this writing, FDA has agreed to extend the deadline for public comments regarding this final rule, but is currently scheduled to enact this prohibition effective November 30, 2008.

-- Harry Snelson, DVM