Story URL: http://news.medill.northwestern.edu/chicago/news.aspx?id=227245
Story Retrieval Date: 4/17/2015 11:16:04 AM CST
Medill File Photo
The Food and Drug Administration allowed the potentially risky use of antibiotics in animal feed for years despite internal safety reviews showing that the practice could expose humans to antibiotic resistant bacteria, according to a report released by the Natural Resource Defense Council this week.
“The evidence is quite clear that feeding some of these antibiotic additives [to animals] did lead to increased antimicrobial resistance,” said Carmen Cordova, NRDC microbiologist and lead author of the report.
“There is enough evidence that they can and should pursue a regulatory approach,” Cordova said.
The NRDC’s review looks at drug safety studies submitted to the FDA by pharmaceutical companies. The analysis of documents acquired through the Freedom of Information Act reveals that 30 antibiotics, including many on the market today for use in animal feed, would not meet approval requirements for additives if submitted to the FDA today.
All of the 30 antibiotics were penicillin and tetracycline-based, categories that the FDA itself had proposed to withdraw from use in animal feed in 1977 after studies showed their routine use in animal feed could lead to antibiotic resistance in humans.
But approval for the use of these drugs was never withdrawn.
In 2012, the NRDC won a lawsuit against the FDA for failing to do so. The FDA appealed to the United States Court of Appeals for the Second Circuit in New York, where the case is still pending.
“The Agency chose to employ a strategy that would more broadly address the concerns about the production use [as a growth stimulant] of medically important antimicrobials in food-producing animals,” reported the FDA in a statement responding to NRDC report.
This FDA strategy was unveiled on December 11, 2013, when the FDA announced its plan to curb the use of “medically important antimicrobials” in animal feed for production (growth) purposes.
Medically important antimicrobials are antibiotics and other drugs important for treating infections in humans. Farmers have been putting low doses of these drugs in animal feed since the 1950s because it helps animals grow faster and gain weight despite being fed less. Antimicrobials also prevent and treat diseases in animals. It is estimated that between 70 and 80 percent of medically important antibiotics sold in North America annually are used in animal feed.
The FDA plan calls for animal pharmaceutical companies to voluntarily remove growth or feed efficiency uses from drug labels and change the marketing status of drugs from over the counter to Veterinary Feed Directive. A VFD is the equivalent of a prescription, issued by a veterinarian for feed that contains these drugs.
Cordova called the FDA’s current strategy for phasing out all medically important antibiotics inadequate, adding that it “doesn’t sufficiently address the human health risk brought on by routine disease prevention use.”
The label changes requested by the FDA will still allow the use of medically important antibiotics for “disease prevention” purposes, but the labels don’t distinguish between routine disease prevention – the precautionary feeding large groups of healthy animals antibiotics in the absence of disease– and feeding antibiotics to animals on a farm where a the presence of a threatening bacterial strain or pathogen has actually been identified.
Cordova said these vague disease prevention guidelines allow antibiotic misuse to continue because the industry can keep dosing healthy animals with antibiotics under a different label.
The NRDC wants the FDA to remove routine disease prevention from the approved uses for these medically important antibiotics.
“We believe that antibiotics should be used in sick animals for treatment of disease and also in rare cases when there is a disease outbreak.”
According to the FDA website, the agency has been working with pharmaceutical companies to implement the changes and is confident they will support the plan. Two of the largest animal pharmaceutical companies, Zoetis and Elanco, have already said they will, according to the FDA.
Currently, almost all of the medically important drugs being used in animal feed are available over the counter without a prescription or veterinary supervision.
“These new rules are pushing us in the direction of closer relationships and closer consultation between the animal producers and the veterinarian,” said Professor Emeritus James Pettigrew, in a webinar offered by the University of Illinois Department of Animal Sciences Tuesday to explain the FDA ruling to livestock producers and industry professionals.
“There may be cases where that becomes a problem, where there simply are not enough veterinarians in a geographic area.” Pettigrew said this will be particularly true in aquaculture (the production of shrimp and other seafood) because there are so few aquaculture veterinarians for the industry to go to.
The FDA has given drug companies until March 12th to confirm whether or not they will voluntarily undertake the changes and will release a report letting the public know the results.
Advocacy groups have criticized the voluntary aspect of ruling as not going far enough to protect the efficacy of antibiotics important to treating humans but according to an FDA guidance document on their website, they believe it is the fastest way to change drug labels and over the counter statuses.
If pharmaceutical companies do not make the changes voluntarily, the FDA could take regulatory action to change labels on a product-by-product basis. This would, however, take additional time and resources.
“The request for voluntary change likely does not impact the FDA’s authority to exercise regulatory action,” Pettigrew said.
“Withdrawal or modification of a label would require FDA to show evidence that there is the likelihood of harm from use of the drug as described in the label," Pettigrew said. "Then the burden of proof of safety shifts to the sponsor (manufacturer) of the drug. It would probably be a long process, but FDA appears confident they can win.”
While the drug company’s choice to change labels and over the counter status would be voluntary, complying to the listed label uses once they are changed is the law under the Federal Food, Drug and Cosmetic Act.