Compounded Drugs

By: Katie Jones, CVT

Every day we are bombarded with drug choices both in stores and through social media. coumponded drugsVeterinarian pharmacies are not any different. Adequan®, Banamine®, and GastroGuard® are all common names many have heard and learned about. A drug is classified by the U.S. Food and Drug Administration “as any substance, food, or nonfood intended for diagnosis, cure, mitigation, or prevention of disease in humans or other animals; any substance intended to affect body structure or function; or any substance administered by infection.”1 There are several different drug classifications a veterinarian can choose from when prescribing medication for their patients. The classifications are generic, brand name or patented drugs, and compounded drugs.

The first type of classification we will discuss is brand name drugs. Brand name drugs were developed and tested by their creating company. Once they are tested and approved by the FDA, the company holds the drug patent up to 12 years. After the patent expires, other manufactures are able to create their own version of the drug and sell it at a lower price; these new drugs are called generic drugs. Generic drugs are marketed under their chemical name but have the same dosage, strength, route of administration, quality, performance characteristics, and intended use as the brand name version. (For example: Acetaminophen is the generic name of Tylenol.) Both the brand and generic versions of a drug are FDA approved. The FDA approves all drugs through their testing for efficacy, quality, purity, strength, bioavailability, and stability before being available to the public. So why choose generic over the brand name version? Simply, PRICE.

Why are generic drugs so much cheaper when they are designed to be identical products to their brand name counterpart? The primary answer is generic drug developers have much less overhead invested into the drug. The original creators of the drug have invested large sums of money and time into the development, clinical trials, and marketing of the drug. By the time a specific drug is FDA approved, the creating company on average has invested 10 years and around $40 million into the product. These costs can skyrocket into the billions once the drug is in the hands of consumers.

Compounded drugsThe final type of drug classification is compounded drugs. Compounding is defined as “the art and science of mixing ingredients, which may be active, inactive, or both, to create a specific dosage form to meet a specific patient’s needs.”2 Many horse owners have used compounded drugs at one time or another. There are multiple reasons why drugs are compounded, here are a few: to add flavor, to combine two different drugs, to suspend a drug for oral administration, or to treat a horse with a drug not currently available with FDA approval. Due to the lower sale cost and the limited demand for certain drugs, drug developers have less incentive to invest millions into creating new drugs. This is where compounding comes in. Compounding allows veterinarians the ability to offer certain drugs as treatment options for horses. Though they are not regulated by the FDA, there are rules regarding the creation and prescription of compounded drugs:

  1. Compounded drugs can only be prescribed in circumstances where a valid veterinarian/client/patient relationship has been established.
  2. A drug can not be compounded if there is a FDA-approved drug available that will effectively treat the horse.
  3. The drug needs to be created from a FDA-approved commercially available drug; not from a bulk source.
  4. The compounding of the drug must be done by a licensed veterinarian or pharmacist.

Even with the previous rules and regulations there are risks associated with compound drug use. For one, mathematical errors can occur when ingredients are mixed. If the mixture doesn’t contain enough active ingredient, the drug will be ineffective; on the other hand, if too much is added, adverse reactions can be seen. Secondly, during the creation of the drug there is always a chance a chemical reaction will take place when multiple drugs are mixed together. Compounded drugs typically have a short shelf life which means they expire fairly quickly, making them a ‘use it or lose it’ drug. Finally, labeling errors can occur which can change the efficiency of the drug. Due to all these complications, it is very important to only purchase compounded drugs through a veterinarian.

Overall, compounded drugs are a great resource in situations where a horse requires treatment when otherwise there would not be one. Compounded drugs should only be used under veterinary direction and should not be purchased from pharmacies that are selling expensive drugs cheaply.


1. Food and Drug Administration-Center for Veterinary Medicine. FDA seeks to clear up confusion about compounding. Jam Vet Med Assoc 2003;223:1103-1106