Compounding Pharmacies

(original graphic by marvistavet.com)

A compounding pharmacy takes medications, usually in bulk form, and mixes them into capsules, chewables, oral liquids and even tablets in custom made doses and flavors. This allows your veterinarian to prescribe a tuna flavored oral liquid medication for your cat when no such product is manufactured by the parent pharmaceutical company. In the last 20 years, compounding pharmacies have emerged virtually everywhere as veterinary patient demand has grown.

(original graphic by marvistavet.com)

WHY COMPOUNDING IS GOOD

DOSING SIZE AND FORMAT FOR PETS

While there are plenty of veterinary medications, in the big picture of the pharmaceutical world, almost everything is made for human use. It takes millions of dollars to seek FDA approval of a drug and this approval includes the disease being treated by the drug, the species using the drug, proof the drug is safe, proof the drug works, and proof that every single pill in every single batch and lot has the amount of drug that the label says it has. Again, millions of dollars are required for approval so getting a medication with a broad human market re-approved for dogs or cats is probably not going to happen.

Because of the Minor Use Minor Species Act of 2004, your veterinarian can legally prescribe human medications for your pet as long as there is adequate science and pharmaceutical experience behind the prescription. The problem is frequently flavor, dosage and format.

The human patient who weighs 150 lbs may want a raspberry flavored-500 mg chewable tablet
so that is what the pharmaceutical company makes. The 5 lb cat may want a 15 mg tuna-flavored liquid.

Because of compounding, dogs and cats (and other animals as well) can get the medications they need in an appropriate size in an friendly flavor.

IS THERE A PROBLEM?

REGULATION, RULES AND OTHER PROBLEMS

Some Medications Don't Compound
Not every medication can be compounded effectively. Itraconazole, an important anti fungal, involves time release beads and these cannot be readily made into a compounded liquid as the beads must be crushed to do so. Crushing the beads vastly interferes with the effectiveness of the medication. This has not stopped compounding pharmacies from selling product. The introduction of a commercially manufactured oral liquid for pets has largely mooted this point for this drug in particular but there are probably other medications with similar issues. Transdermal medications (where the usual medication is oral but the compounded version is delivered as an ointment on the skin) do not always work well as not all medications are amenable to this format.

Batch Quality
Another issue is quality control between batches. A compounding pharmacy on the corner cannot possibly match the quality control of a pharmaceutical company factory. A batch of compounded medication will not be identical to the next batch of the same medication. In most situations, this is not a problem but there may be situations where minute changes could be an issue in a long term medication use situation. (It is generally not recommended to compound insulins, for example, as minute changes in concentrations can lead to big changes in the patient.)

State Law
Further, different states have different rules on compounding. For example, some states allow a veterinary hospital to stock compounded medications and dispense them the same as they do with conventional medications. Other states (like California) do not allow this and dispensed compounded medications must be for the sole use by a single individual patient. This means you are probably going to special order your pet's medication every time you need it. California also has special sterility requirements for certain medications which can delay their availability for weeks.

We have a good relationship with several reputable compounding pharmacies including our on-line pharmacy partner (Vet's First Choice) which can be accessed through our Home Page. If you expect a problem with your pet taking medications, a compounded product can be life-saving. Let us know if this is an option you hope to pursue.

Page last updated: 10/13/2021