Make sure you understand all the do’s and don’ts of compounding. View our recorded webinar. (AVMA members only.)
Q: What is compounding?A: Simply put, compounding is any manipulation of a drug beyond that stipulated on the drug label. Veterinary drugs should only be compounded based on a licensed veterinarian's prescription, and to meet the medical needs of a specific patient.
Manipulation might include mixing, diluting, concentrating, flavoring, or changing a drug's dosage form.
Some states allow veterinarians to prescribe compounds for administration to patients in the practice; but depending on state rules, it is typically not legal to dispense medications previously compounded by a pharmacy to leave the veterinary practice with clients, so state rules should be reviewed and followed.
View a compounding brochure that was developed by the Animal Health Institute, the American Veterinary Distributors Association, and the AVMA.
Q: Are compounded drugs the same as generic drugs? A: No, they are not the same as generic drugs. A generic drug is a non-brand-name version of a drug: for example, Tylenol® is the brand name for this drug used in human medicine, but acetaminophen is the generic name. In general, buying a generic drug with the same ingredient and same strength as the brand name is equivalent to (but often cheaper than) buying the brand name version. Veterinary extralabel use of human generic drugs in animals is allowed under specific conditions delineated within federal law.
Generic drugs are approved by the FDA. They have to be shown to be safe and effective; their label has to be approved by FDA; their manufacturing facilities have to follow certain FDA specifications; and the manufacturer is required to continually ensure the shelf stability of the product. FDA assigns an equivalency rating to human generic drugs which states whether the generics are therapeutically equivalent (achieve the same therapeutic goal) as compared to the branded product. Generic animal drugs have an Abbreviated New Animal Drug Application (ANADA) number assigned by the FDA, which you can typically find on the container. Compounds and unapproved drugs lack an ANADA number.
When a drug is compounded, the new form of that drug no longer performs in the same manner as the approved drug. Yes, the compound still incorporates the same drug ingredient, but the composition of the dosage form has been changed and you can't expect it to be identical in every way to the original drug. Compounding may cause changes in stability, bioavailability, metabolism and elimination of the drug.
Q: When is compounding necessary? A: Compounding for non-food animals may be necessary when approved drugs need to be modified to sufficiently treat the patient (e.g. flavoring, diluting, or changing the form of medications from tablet to suspension).For example, if you need to prescribe methimazole (Felimazole®) for a hyperthyroid cat but the owner tells you the cat will not allow the owner to “pill” it, you might need to have the product compounded into a liquid form so the cat can be adequately treated.
Compounding for non-food animals might also be necessary when no approved drug exists, or if the approved drug isn’t commercially available to treat a pet’s diagnosed condition. There are two general sets of circumstances in which the AVMA believes compounding from bulk ingredients (i.e., “raw” active ingredients) may be necessary:
Otherwise the AVMA believes drugs should be compounded only from FDA-approved drugs to fulfill the regulations written to implement the Animal Medicinal Drug Use Clarification Act (AMDUCA).
The status of drug shortages can be checked on the FDA website.
Q: When is compounding legal? What criteria must be met? A: Compounding is considered legal when federal and state rules are followed. Veterinarians can inquire about state licensure from the relevant state boards of pharmacy prior to prescribing compounds. Federal extralabel drug use regulations specifically permit compounding from FDA-approved drugs when a veterinarian believes there is a need to alter the approved drug to adequately medicate a non-food animal with a diagnosed medical condition. This means that there an established Veterinarian-Client-Patient Relationship (VCPR); the individual patient has a medical condition for which a prescribed medication is needed; and the veterinarian determines that a compounded drug is needed for the animal. To be in line with FDA’s Extralabel Drug Use Rules, compounding should be performed using the FDA-approved drug.
For example, let’s say you need to prescribe a particular FDA-approved antimicrobial for an ear infection in a dog, but the antimicrobial only comes in an injectable form. Following the FDA’s rules, you could mix the antimicrobial – for example, amikacin – with normal saline for instilling into the ear.
Q: When is compounding illegal or unethical? A: According to the FDA’s Compliance Policy Guide (CPG), examples of situations where FDA might use enforcement action include: