Compounding, by definition, is tailor-made preparation of a drug to meet the needs of a specific patient when an approved drug can’t fit the bill. This can be done by modifying an approved product to make it more palatable by adding flavoring, creating an oral suspension by crushing tablets and mixing them with fluid, etc. A licensed pharmacist can compound drugs on the prescription of a licensed veterinarian with a valid veterinary-client-patient relationship, or the veterinarian can do the compounding.

Scarlet Thomas, RPh (registered pharmacist), director of pharmacy at Hagyard Equine Medical Institute in Lexington, Ky., says compounding can be performed legally only when there is not an approved animal or human drug available in the correct dosage, form, and concentration to appropriately treat the patient according to its diagnosis. It is not legal to create something that merely duplicates an already existing FDA-approved product.

“There are a number of instances in which compounding could be beneficial or necessary,” she explains. “In the equine market, particularly, there are a limited number of drugs commercially available for horses.” She said there are more com-mercial options for the small animal population, probably due to the greater number of cat and dogs in this country, as op-posed to horse owners.

“When there is not an appropriate commercially available product, or when a certain medication is discontinued or unavailable from the pharmaceutical compa-nies, then compounding becomes necessary,” Thomas says.

When products are pulled off the market, for whatever reason (as long as it’s not a safety issue), that might be an appropri-ate instance to compound that medication, she adds. “You still have the same horses with the same illnesses or need for the medication–animals that were being treated by commercially available products. The horse owner and veterinarian must have some means to continue to obtain the medications, to continue the therapy.” In rare instances equine patients are aller-gic to certain preservatives, dyes, fillers, or carriers that exist in commercially available products, so compounding might be used to design a treatment without the allergen. Also, certain patients require tailored dosage strengths to meet a unique need.

“If you are trying to use a human product or a small animal product for a horse, and the product is geared toward a 25-pound dog or a 150-pound human and you are dealing with a 1,300-pound horse, the logistics of this can be challenging,” says Thomas.

There also is the challenge with pediatric or elderly patients that might not be able to ingest the medication in its commer-cially available form. “It may be a human product that is not palatable for them to take, or not feasible for a horse to be given 200 tablets of human medication in order to meet the needs of the equine patient,” she says. “In those instances it may be ne-cessary, and certainly beneficial, to manipulate the drug product into a different formulation or dosage form, or add flavoring. In many instances we add flavoring (such as banana, apple, or vanilla) to make it smell and taste better for the animal, so it can be given orally.”

What’s Legal?

Anne Gresham, RPh, a pharmacist at Rood & Riddle Equine Hospital, also in Lexington, says in her experience the use of compounding for animal medications has increased in recent years for two reasons. “One, we are treating more animals–equines and small animals–for illnesses and conditions now that we might not have treated in earlier years because of financial costs and lack of awareness by owners,” says Gresham. “Two, improved diagnostic testing as well as more extensive medical care afforded by owners has improved medical treatment of animals and has allowed them to have a higher quality of life. However, because not all of the drugs that are being used for these treatments are available commercially in the veteri-nary industry, there is a true medical need for compounding.”

Pharmacies legally cannot compound products that are very similar to or identical to products approved by the FDA and commercially available in an acceptable form that can be used to treat the particular species. “They should only compound to fill a true need,” says Gresham.

“Legal compounding requires a valid veterinarian-client-patient relationship,” says Thomas. “Veterinarians should limit the use of compounded drugs to specific needs in specific patients, when there is no other method or route of drug delivery that is practical for that patient. If there is a commercial product available, and it’s reasonable to be given to that particular horse, that’s the first line of treatment.”

The commercial product might be available over the counter or by prescription, but it is the legal first choice.

“Compounded medications would be the next option, but would require a valid prescription from a veterinarian, and it must be patient-specific,” says Thomas.

The veterinarian has to have seen the animal and have diagnosed the condition to be treated. Then he or she must look at what’s available for treating that horse. If there is nothing commercially available to treat the horse’s particular problem, or if there’s something unique about this particular patient that makes it impossible for the commercial product to be appropriate, then a compounded product would be suitable.

“Compounding is merely a niche to augment the practice of veterinary medicine,” says Thomas. “It is not an exclusive source of medication, but rather an alternative to be considered when there are no commercially available products that meet the needs of a particular patient/case.” She advises horse owners first to consult with a veterinarian they are comfortable with and whose judgment they trust–a veterinarian they know well and who knows their animals.

“Talk with the veterinarian if a compounded product is going to be necessary for a certain animal,” says Thomas. The vete-rinarian should know the source of that compounded product and whether it’s a reputable, trustworthy pharmacy, she says.

Among the facts your veterinarian will know about the compounded drug are which FDA-approved drug(s) will be used to compound the prescribed medication, and the ingredients and potency of the compounded product.

As previously mentioned, commercial products that are already on the market for the horse should not be compounded.

“An example would be omeprazole paste with the same active ingredient and dosage form as Gastrogard,” says Thomas. “This has been one of the hugely controversial products.” Compounding Gastrogard is illegal, and many veterinarians hold that it’s ineffective, because the drug’s efficacy is based on its formulation, and compounders don’t have access to the formula.

If medications are being compounded in the same dosage formulation as patented products and marketed as “look-alikes,” or “generics,” it’s usually not truly for the health and welfare of the horse, but merely to offer a less expensive product, she explains. The horse owner or veterinarian might choose a compounded substitute because it’s cheaper, but they could be get-ting something less effective and illegal.

This is often where the controversy over compounding comes into the picture. It is neither ethical nor legal to compound something just to save money. Compounding should only be done for the health and welfare of the horse, not to pirate a man-ufacturer’s patent to produce something cheaper because the horse owner or veterinarian does not want to purchase an ap-proved product.

Compounded or Generic?

“There is some misconception in the public mind, including horse owners, that compounded medications are the same as generic medications, and that’s not true,” says Thomas. “Compounded medications are manipulations of a drug product to produce a dosage or formulation specifically tailored to address a certain need in an individual patient. A generic drug has gone through FDA approval channels just like the brand name product and is the same as the brand name product in terms of potency and bioavailability. However, it is usually less expensive to purchase.”

As an example, she says, when Gastro-Gard goes off patent with Merial at some point in the future, at that point other drug manufacturers may submit an abbreviated new animal drug application (ANADA) to the FDA for approval to make a generic of this product, explains Thomas. At that point the formula for the product is no longer protected by patent and anyone can use it.

Phenylbutazone is a good example of a product that came off patent and has legal generics on the market. “It’s been around a long time and now has generic equivalents available from numerous manufacturers (pharmaceutical companies),” says Thomas. “It’s like in human pharmacy, you can choose to buy a certain brand-named drug or its generic. FDA-approved ge-neric drugs have met the same standards as the brand name drug; they are not compounded.”

It’s important to note that the practice of compounding is FDA-regulated, but the final products produced by compounding are not, so there is no oversight to whether the product contains what the label says it contains.

The ANADA process does not require the applicant to repeat costly clinical research on ingredients already proven safe and effective, explains Thomas. Thus, generics generally are less costly to produce than the brand-name product was.

Take-Home Message

Admittedly, compounding has gotten a bad name in recent years because of a few “renegade” compounders who do not fol-low the rules. Compounding in veterinary medicine is necessary to provide proper treatments to specific animals when a need arises, and legitimate compounding pharmacies are available. If your veterinarian prescribes a compounded medication, he or she should strive to ensure it is from a reputable pharmacy and created specifically for your animal