Where do the drugs that you give your horse come from? Unless you've asked your veterinarian or you've carefully scrutinized the label affixed to the bottle or box, you're probably not aware of the name and location of the firm that manufactured the product. After all, as long as the preparation produces the desired effect to support your horse's health and well-being, it hardly seems essential for you to know much more than how often the drug should be administered and in what amount. Nevertheless, learning just how a pharmaceutical is made and by whom can save you from giving your horse ineffective or even dangerous medications.
Brand-name and generic drugs approved by the Food and Drug Administration (FDA) are supplied to veterinarians by the manufacturers, who must comply with strict regulations regarding product safety, efficacy and the manufacturing process. As a result, consumers who use pharmaceuticals that are FDA approved generally are confident of the products' drug content and quality.
In some cases, however, there is no FDA-approved preparation readily available or conveniently formulated to treat a horse--and that's where the services of a compounding pharmacy come in. For example, if a veterinarian wants to administer a particular drug intravenously but only the tablet version has been approved by the FDA, he may ask a compounding pharmacy to produce the medication in intravenous form. In other instances, a compounding pharmacy can make a drug that is not FDA approved in any form. For example, a veterinarian may want to use an antibiotic that is reported to work on a particular infection in laboratory studies but which is not FDA approved for that particular purpose. The compounding pharmacy can use bulk raw chemicals and produce the preparation at the veterinarian's request.
Compounding pharmacies provide an invaluable service because there are not enough FDA-approved drugs to treat all equine diseases. However, the pharmacies that produce compounded drugs are not held to the same standards that the manufacturers of FDA-approved drugs must meet.
In the absence of stringent government oversight, the use of compounded medications is bounded ethically by several stipulations that include, but are not limited to, the observance of the restrictions that govern the dispensing of prescription drugs, the need for the compounded preparation in the treatment of disease or to improve the welfare of the animal, and the lack of an FDA-approved product in a suitable dosage form to treat the condition.
Yet, even when these stipulations are satisfied, there is no guarantee that the formulation created by a compounding pharmacy is safe and effective. There are, however, some specific questions your veterinarian can ask to assure that a compounding pharmacy is doing its best for you and your horse.
Does the compounding pharmacy have a licensed pharmacist on staff? Some compounders do not have a pharmacist on staff, or they maintain only a loose association with a pharmacist. Pharmacists have the training, as well as the legal and ethical responsibility, to follow good compounding practices as prescribed by the practice of pharmacy and as outlined by state pharmacy boards. Through their training, pharmacists understand the issues of drug quality, strength, purity and stability, which are essential to the rational use of drugs. Your veterinarian can verify a pharmacist's name and license number with the appropriate state agency.
Are high-quality raw materials used? Obviously, the individual ingredients that go into a drug formulation must be of high quality for the resultant compounded product to be of high quality. When drugs are not FDA approved, there is no assurance that the raw materials are of acceptable quality. Raw materials used by reputable compounding pharmacies are accompanied by a valid certificate of analysis. A reputable compounding pharmacy will not hesitate to provide that information to veterinarians. At the least, a veterinarian can--and should--ask the compounder if the wholesaler of the raw materials is licensed or registered with the state pharmacy board.
What type of quality testing is performed? Ideally, each individual drug preparation would be quality tested before it was shipped to a veterinarian. However, this is impractical in many situations. At a minimum, a compounding pharmacy can test batches of any formulation that is produced regularly. Such analysis will detect any loss of quality of calculation errors.
How stable is the compounded drug? The nature of equine practice leads me to stress the importance of the stability of compounded products. Equine practitioners tend to work outdoors, so the medications that we administer to horses often are kept in uncontrolled climates, which can lead to the breakdown of unstable compounds. The compounding pharmacy should provide some storage instructions with the medication.
In contrast to FDA-approved formulations that undergo rigorous tests under various environmental conditions to define the limits of storage conditions, the true expiration date for many compounded drugs isn't known. As a result, the expiration date of a compounded formulation should not exceed the length of time it will take for the medicine to be properly administered. For instance, the expiration date on a five-day course of an antibiotic that is scheduled to begin on September 15 would be September 20.
The bottom line is that the use of compounded drugs cannot be taken lightly. Approved drugs give the veterinary community the highest assurance of quality, strength, purity and stability, as well as the best opportunity for accurate dosing. Compounded drugs, while useful--and sometimes even essential to the care of horses--come with no such assurances. As a result, veterinarians must take responsibility for the use of compounded drugs, collecting information on the practices of individual compounding firms and using only license pharmacists when seeking compounded drug formulations. Likewise, horse owners must become informed consumers and ask questions about the nature and quality of the substances prescribed for their horses.
This article is reprinted from EQUUS 263.