The rumors are true. As of June 11, 2023, farmers will no longer be able to purchase antibiotics over the counter or through mail order without a veterinarian’s prescription.
Dr. Hayley Springer, Extension veterinarian and assistant clinical professor, Penn State, explained the reason for the change. “The underlying reason is antibiotic resistance,” she said. “The CDC defines antibiotic resistance as the ability of a bacteria to resist the effects of an antibiotic that would otherwise kill it or stop its growth.”
Resistance develops because of changes within bacteria. Antibiotic resistance is not an issue on a single farm and can spread beyond the farm. “Bacteria are everywhere, and within every bacterial population, there are a few resistant organisms,” Springer said. “When we treat with antibiotics, we kill off the susceptible organisms and leave the resistant organisms that are no longer impacted by the antibiotic. When the bacterial population grows back, it is much more resistant, so a greater portion of that population is resistant.”
An interesting phenomenon can potentially contribute to resistance – bacteria can pass drug resistance from one species to another, not just between individuals of the same species. “Salmonella can pass resistance genes to an E. coli, making that E. coli resistant to the same things the salmonella was resistant to,” said Springer.
Resistance can cause human health problems, which means farm families and employees are at risk. “If animals have an antibiotic-resistant infection or are harboring antibiotic-resistant pathogen like salmonella or E. coli, they could pass that on to people working in close contact with them,” said Springer.
Prescription products, which will include all antibiotics, will require a valid veterinary client patient relationship (VCPR). Within the relationship, the veterinarian is responsible for clinical judgements, ensuring sufficient knowledge of the owner, animals and facility and being available for follow-up. The livestock owner holds responsibility within the VCPR, which involves agreeing to follow the vet’s advice. The VCPR definition may vary among states and urged livestock owners to determine how their state defines the term.
Having a VCPR allows access to more medications and provides solutions when no labeled products are available. Springer said it’s important to understand that when a product is used in a way other than the way the product label states, it’s considered extra-label use and a veterinarian must determine the withdrawal period.
The federal definition of extra label use is “actual or intended use of a drug in an animal in a manner that is not in accordance with the approved labeling.” “That means we might use it for a different species, use it more frequently than labeled, in a different route (subcutaneously versus intravenously),” said Springer. “We might use a different dosage than what’s listed on the label or for a different disease than listed. Any time we use a drug in this manner, it has to come with a valid VCPR.”
The vet must identify that there’s a need for extra label use and no other products can be used, provide a prescription for the extra-label use and provide a withdrawal time for the extra-label use.
“There is no extra label use allowed on all feed or water antibiotics, and restricted products cannot be used extra label use,” she said. “These are typically antibiotics that are important in human health. Some products have limited extra-label use, such as ceftiofur products (Naxcel®), and we cannot use those off label except for the type of disease we are treating as long as we keep everything else exactly on label.” Such drugs cannot be administered to other species or given using alternate routes of administration.
While developing the new rule, the FDA worked with doctors and veterinarians to determine a list of antibiotics considered important in human health. “There are three categories: important, highly important and critically important,” said Springer. “All three are considered medically important because they are antibiotics used to treat human diseases.” Non-medically important antibiotics are not used in human medicine and include ionophores such monensin products (Rumensin) and lasalocid products (Bovatec).
The group of products impacted by the rule change are medically important antibiotics that are currently available over the counter (OTC). “There were 93 products that are impacted by these changes,” said Springer. “Seventy of those products are pioneer products, meaning they are the name brand product. There are 34 unique drug and route combinations. This [new rule] impacted 22 ingredients and eight different antibiotic classes.”
Springer focuses on the 70 pioneer products because the generics don’t differ significantly from the pioneer versions. “The 70 pioneer products can be labeled for more than one species,” she said. “A lot of these products are labeled for cattle, so the beef and dairy category is for non-lactating cattle. Another group is lactating dairy and swine with about 22 products impacted. Some dog, equine and cat products are impacted, as well as seven sheep products and five poultry products. No goat products are impacted.”
Four types of products are impacted, including intramammary antibiotics for lactating or dry cow treatments, injectable antibiotics, oral antibiotics (bolus or liquid) and topical/eye antibiotics. OTC non-antibiotic products such as dewormers and vaccines are not impacted by the changes.
One set of label changes involves implant labels but will have little impact on the livestock industry. Implants currently fall into three categories. “We have beef implants labeled to be used more than once within one of those periods and beef implants that are labeled to not be re-implanted within those periods,” Springer said. “We also have some that aren’t labeled for re-implantation but are not labeled for not re-implanting. These are going to be impacted by upcoming changes. FDA has requested that if a product is not labeled for re-implantation that it would become illegal to use as a re-implant.”
Springer explained that the rule change is about veterinary oversight, with the intention of improving judicious use of antibiotics. The change is one aspect of the One Health concept that includes the relationships between animal health, environmental health and human health.
“Animal agriculture is part of this story, and also part of the solution,” said Springer. “Antibiotic stewardship includes judicious use of antibiotics and minimizing the need for antibiotics. Judicious use means good veterinary oversight, making sure the right antibiotics are being used and the antibiotic that makes the most sense for fixing the disease without using high-powered antibiotic we might need for important human diseases. The key to minimizing the use of antibiotics is disease prevention.”
by Sally Colby