Compounded medications for horses have been in the headlines in this and other publications a lot in recent years, especially in the wake of the 2020 federal indictments focusing on the use of misbranded drugs in racehorses. For a lot of horsemen though, it's not always clear from looking at a drug bottle or box what type of drug they're dealing with, and whether they should have concerns about its safety and legality.
Dr. Dionne Benson, chief veterinary officer for The Stronach Group and former executive director of the Racing Medication and Testing Consortium, presented a continuing education seminar for trainers in July to help them distinguish the different categories a drug may fall into and to determine if the product they're looking at is illegal.
When dealing with prescription (sometimes called “legend”) drugs, the first approved version of a new drug is called a pioneer drug. This is a substance that has been legally recognized by the Food and Drug Administration as a new animal drug and has been subjected to considerable testing to demonstrate its safety and efficacy, as well as the purity of its manufacturing process and the stability or shelf life of the drug. They also must show that the manufacturing process is consistent, and the concentration and purity of the drug doesn't change from batch to batch. Pioneer drugs also must show considerable research to validate their suggested doses and uses, and must meet rigorous requirements regarding their package labeling and advertising to be sure consumers are being presented with accurate and complete information.
The FDA approval process for new drugs is long, arduous, and expensive, so to give drug makers an incentive to go through it, they are permitted temporary patents on new substances. This means that for a limited number of years, the company that went through the approval process will be the only one that can legally produce the drug, allowing them to better recoup some of their expenditures in the approval process.
A generic medication is subject to all the same requirements regarding safety and efficacy, and may only be legally produced when the patent on the pioneer version of the drug has expired.
Both types of medications are also subject to adverse event reporting, so there is a public record of any negative side effects or bad reactions to a given drug or batch of drugs and those events can be investigated.
Compounded drugs aren't subject to any of that federal oversight.
Compounding may only be legally done in certain narrow parameters. A compounding pharmacy may only make a drug in response to a prescription a veterinarian has written to treat a specific condition in a specific animal, and it should only take place when there is no legend drug (either a pioneer or a generic) available to serve the patient's needs. Compounders can legally add flavoring to drugs to make them easier to administer, or take a drug traditionally offered in one form like a paste and make it into another, like a powder. In some limited circumstances, a compounder may legally mix two medications to reduce the amount of needle sticks a horse has to endure. In none of those situations should a compounder have large amounts of pre-formulated compounds sitting on the shelf awaiting an order – that, in the eyes of the FDA, is manufacturing. If an FDA-approved drug is no longer being manufactured or is on back order though, a compounder may make small batches of it but should not be in the business of mass manufacture.
“Compounded medications are legal under some circumstances,” said Benson. “Your vets use them every day and in the large majority of those cases they're using them appropriately.”
Benson has seen a number of examples of illegal compounds floating around the track however – sometimes sold online and sometimes peddled by sales reps.
One of the biggest areas of confusion seems to be what constitutes a generic drug. Compounded omeprazole products are a favorite of compounding pharmacies to produce in bulk, in part because horsemen are always looking for cheaper alternatives to the pioneer drug. But Benson said the patent on Gastrogard and Ulcergard, the pioneer form of the drug, hasn't run out yet, so all those “knock off” versions which people may think of as “generics” are actually illegal.
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Compounders are also fond of getting around this restriction by combining omeprazole with another ulcer drug like ranitidine, with the result often being priced more cheaply than pioneer omeprazole.
“The funny thing about that one is if you're combining omeprazole and ranitidine you're actually deactivating one of them,” said Benson.
Omeprazole works by reducing acid secretion, while ranitidine works by neutralizing acid. You don't need both, and they tend to be used in different types of ulcer cases.
Of course, Benson said, it's true that the FDA isn't likely to show up at your barn and ask to examine your prescription bottles (although, the federal case demonstrates they will take an interest in racing now and then). So why should horsemen worry about the technicalities of drug production?
Benson said that the illegal compounds she has seen often come along with safety concerns. Compounders mass producing a legend drug and selling it as a “generic” version aren't having their products tested like approved generic drug manufacturers, and testing by the RMTC suggests the amount of active ingredient in these illegal substances can be wildly mismatched to what's on the label. Benson recalled one bottle of clenbuterol that had ten times the labeled concentration of the drug, which was “getting into toxic ranges.” Another test of a triamcinolone bottle found it contained just .01 percent of its labeled concentration.
Another trouble with unauthorized mass manufacturers of prescription drugs is that there's no assurance of consistency from batch to batch of the medication, so just because a horseman has given a drug from a pharmacy once with no issue doesn't mean the next batch will be the same.
Many of these illegal substances can also be missing key safety information on their packaging. Benson cited Gastrotec, an omeprazole/misoprostol product which she said is still in circulation, despite FDA warnings about it.
“What's terrifying about this medication is the misoprostol,” she said, pointing out that drug is half of the abortion cocktail used in humans. “In veterinary school, you can't touch this stuff without gloves. All the women on the backside, they're given this to give to the horse, and what's the first thing we do? We put the tube in our mouth to pull off the cap and give it to the horse.”
There was no warning about these human health risks on the boxes or tubes of Gastrotec, Benson said.
Benson said she believes trainers have a responsibility to educate themselves about what is and isn't permissible in the drug-making world. Just acquiring a product from a sales representative or a veterinarian isn't a guarantee it is legal.
“Oftentimes we assume whatever the doctor or veterinarian says is right,” she said. “We don't want to make them mad; we just go along with it. But realistically it's your license on the line. Very rarely does a vet get called into a hearing or have to call an owner when a horse dies.”
The post Here’s The Difference Between Pioneer, Generic, And Compounded Medications For Horses – And Why It Matters appeared first on Horse Racing News | Paulick Report.
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