Industry groups plan to work closely with government agencies to comply with new guidance and rules for use of antibiotics in livestock production. Last week, the U.S. Food and Drug Administration issued its guidance, which calls for more veterinary oversight and voluntary suspension of the use of antibiotics for growth promotion. FDA also has asked drug companies to remove growth-promotion label claims from antibiotics important in human medicine.

Wednesday, representatives from the American Veterinary Medical Association, National Pork Producers Council and the Animal Health Institute discussed the transition with reporters in a news conference.

Dr. Rich Carnevale, AHI’s Vice President, Regulatory, Scientific and International Affairs, reminded participants that antibiotics used in livestock production are subject to the same review and approval process as those used in human medicine, requiring extensive testing to prove efficacy and safety. FDA allows four different claims for efficacy:

  1. Treatment of disease.
  2. Control of disease, such as during outbreaks when groups of animals require treatment.
  3. Prevention of disease, such as when a veterinarian determines an outbreak is likely.
  4. Growth promotion.

FDA considers treatment, control and prevention as therapeutic uses, while growth promotion is a sub-therapeutic use. The new guidance allows continued therapeutic uses, under oversight from a veterinarian.

Speaking for the American Veterinary Medical Association, Dr. Christine Hoang, Assistant Director, Scientific Activities, for the association, said AVMA supports the collaborative approach FDA has taken in developing the new guidance. The organization understands concerns over resistance and preserving the efficacy of antibiotics in human medicine, while also wishing to protect their judicious use in livestock production. The organization plans to work closely with FDA in specifying veterinary oversight provisions in the guidance.

Dr. Liz Wagstrom, Chief Veterinarian, National Pork Producers Council, expressed concerns over how FDA’s directive to drug companies to remove sub-therapeutic or growth-enhancement claims from their products over the next three years. Loss of these label claims, she says, will likely result in more health problems in pork operations and higher cost of production without any real public-health benefits.

NPPC supports the idea of veterinary oversight for antibiotic use, but also raises concerns that the requirements could cause hardships for smaller operations in remote areas that cannot afford or do not have access to veterinary support.

AHI’s Dr. Carnevale said the association and its members appreciate FDA’s concerns over the use of medically important antimicrobial products for growth promotion. He points out that the animal-health companies that make up AHI’s membership typically are divisions of companies that also market antibiotics for human medicine, and thus have a strong interest in preserving the efficacy of those products. AHI supports FDA’s position that claims for treatment, control and prevention qualify as therapeutic use, preserving those applications for veterinarians and producers.

AHI expects that companies will, over the next few years, pursue new therapeutic claims for products that lose their growth-promotion claims. In countries where sub-therapeutic uses have been banned, such as in Denmark, therapeutic use of antibiotics have increased. This suggests sub-therapeutic use helps suppress and prevent disease outbreaks, along with promoting growth.

Gaining approval for new label claims will, however, require extensive investment in research trials and data collection. Growth promotion, Carnevale says, is a relatively easy claim to demonstrate in research trials. Proving the efficacy of low-level feed-additive antimicrobials for suppressing sub-clinical disease is more complex.

Achieving  any new label claim will require companies to undergo a complete testing and approval process through FDA, assuring a specific use is efficacious and safe. Assuming FDA grants a therapeutic label claim for a low-dose application, it is likely the approval would include changes in label requirements such as a specific treatment interval, contrasting with longer-term feeding for growth promotion.