Compounded Drugs Have Helped Horsemen For Ages

But a high-profile case has brought the safety of this practice under scrutiny.

When 21 polo horses died suddenly in Florida this April, an investigation revealed a fatal error in the amount of selenium contained in a compounded vitamin-mineral supplement. Many similar mishaps have occurred, including a situation in Louisiana in 2008, when several horses died after receiving a compounded clenbuterol product.

So what is a compounded drug and how can a trainer be sure to avoid a potential error in compounding?

The U.S. Food and Drug Administration regulates medications for humans and animals. Specific laws governing drug products, their manufacturing and use include the Food Drug and Cosmetic Act, the Animal Medical Drug Use Clarification Act, and the State Pharmacy Board Regulations in each individual state. The state boards have the authority to monitor within their state, but they answer to the FDA. There might be slight differences in interpretation of the rules, and the FDA may act on things it considers to be out of bounds.

Every new drug must go through rigorous testing before it can be approved for commercial use. It must be tested in and approved for the target species. A drug that is legal and labeled for use in dogs, for instance, might not be labeled for use in horses. And there are numerous drugs approved for horses or dogs that are not labeled for use in food animals.

According to James P. Morehead, DVM, drug manufacturing comes under the authority of the FDA and includes strict requirements related to Good Laboratory Practices, Good Manufacturing Practices, data demonstrating safety, efficacy and other parameters.

“Under strict interpretation of the law, all compounding is illegal,” said Morehead, of Equine Medical Associates in Lexington, Ky., and a member of the American Association of Equine Practitioners Professional Conduct and Ethics Committee.

Yet veterinarians have been compounding for a long time. Years ago, before the advent of drug manufacturers, medications were always compounded. Even today, there are not always appropriate approved, manufactured products to meet every medical need, and certain medications must be compounded.

Veterinarians often compound their own medications and mix their own formulas, their own oral and topical treatments. In the equine market especially, there are a limited number of approved drugs commercially available. Also, some medications that veterinarians relied upon in the past have been dropped by the manufacturer, perhaps due to profitability issues.

“Therefore the FDA recognizes the need for compounded products in specific situations, in both human and animal medicine, and has published some guidelines for compounding,” said Morehead.

The AAEP also recognizes the importance of drug compounding.

Hoyt Cheramie, DVM, MS, was a practicing equine surgeon before going to work as the manager of large animal veterinary services at Merial. He said that in certain instances it is necessary to compound medications to effectively treat horses.