Antibiotic resistance is a growing public health problem. While there are many causes of resistance, one major reservoir for resistant bacteria is livestock. With more than 80 percent of the antibiotics used in this country administered to livestock, resistance arising from food-producing animals is of no small concern. Antibiotics are used in livestock for three main purposes. First, they are used to treat a sick animal. Secondly, they are used to prevent illnesses, diseases which are largely the result of the crowded agricultural conditions that are so common these days. Finally, antibiotics are used to promote faster growth so that animals may be taken to slaughter at younger ages, a practice which yields higher rates of profit for farmers.
Because antibiotic resistance develops when bacteria are exposed to antimicrobials intended to kill them, all three uses of these drugs can lead to problems. Some bacteria are stronger, often due to a genetic mutation. Antibiotics may kill the weaker bugs but these stronger bacteria will survive and flourish.
The consequences of increasing antimicrobial resistance are very real. Patients who become ill with a resistant infection will have to make choices about alternative drugs, which may be less effective or have more serious side effects.
In response to the problem of increasing drug resistance caused by livestock, the FDA recently issued a draft Guidance for Industry which set outs a new paradigm for reducing antibiotic use in livestock. Unfortunately, this new framework is entirely voluntary, meaning that manufacturers of these drugs get to decide whether or not they abide by FDA’s recommendations.
In formal comments filed with the FDA, NCL made the following recommendations for strengthening the program:
- Because disease prevention uses of antibiotics create the same selective pressures as growth promotion, FDA should move forward with withdrawing approvals for the use of antimicrobials for prevention of diseases. This is necessary as drug companies are unlikely to make this move on their own.
- The new system that FDA has proposed relies on a voluntary scheme for eliminating the use of antimicrobials for growth promotion. Because some companies may choose not to participate, a voluntary system is not sufficient for reducing the use of antibiotics. We encourage FDA to use its regulatory authority to create a mandatory reduction plan that will ensure compliance and increased public health.
- The FDA should choose a measure of success that is meaningful to public health. Because of our concerns that drug sponsors may add indications to their drugs for prevention uses, merely looking at whether sponsors do away with growth promotion uses of antimicrobials is an insufficient measure of whether the program is succeeding. A more appropriate measure of success would be to look at whether or not the amount of antibiotics used has decreased.
- Transparency in the implementation of this new process is essential. FDA has proposed a three year implementation period. FDA should publish detailed quarterly reports on proposed and finalized voluntary changes. These reports should facilitate the independent verification of progress made towards implementation as well as an assessment of the public health implications of these changes.
NCL urges FDA to implement mandatory reductions in antibiotic use in livestock. Without these changes, we face the very real possibility of losing our arsenal of drugs we use to treat human disease.