Filling veterinary prescriptions: a guide for pharmacists

How veterinary prescriptions reach you

Most small-animal prescriptions that come to a retail pharmacy are for human generics used extra-label, such as gabapentin, trazodone, fluoxetine, prednisolone, antibiotics, levothyroxine and insulin. Under the Animal Medicinal Drug Use Clarification Act and FDA’s regulations, a veterinarian may direct extra-label use of an approved human drug within a valid veterinarian-client-patient relationship, and a pharmacy may dispense it on that prescription.

Veterinary-only products, such as many flea, tick and heartworm preventives and some pain and allergy medicines, are usually distributed through veterinary channels, so a retail pharmacy can fill them only if it can lawfully obtain the product. Owners usually get those from the clinic or a veterinary pharmacy.

Verifying the prescription

Verify a veterinary prescription as you would any other, with a few differences.

• Confirm the prescriber holds a veterinary license, using the state veterinary board’s online lookup if needed.
• The patient is the animal. Record its name and species and the owner’s name and contact details, as your state and pharmacy system allow.
• For controlled substances, confirm the prescriber’s DEA registration and that the prescription meets your state’s format and electronic prescribing rules, which can treat veterinarians differently.
• Ask the clinic for the animal’s weight if it is missing, since every dose check depends on it.

Dosing: call, do not correct

Veterinary doses often look wrong by human standards. Dogs need far higher doses of levothyroxine per kilogram than people do, and doses of anticonvulsants, steroids, antibiotics and anti-nausea medicines differ between species. Cats handle many drugs differently from dogs because they metabolize them differently. When a dose looks unusual, call the veterinarian; changing it to a human-typical dose can leave an animal undertreated.

Check the dose in milligrams per administration against the weight given, and confirm the frequency. Veterinary abbreviations such as SID, meaning once daily, appear on handwritten prescriptions; when in doubt, confirm with the clinic rather than guess.

Formulations that can harm pets

Before dispensing a liquid, chewable or dissolving product for an animal, check the inactive ingredients and the product type.

• Xylitol is toxic to dogs and appears in some human liquids, dissolving tablets and chewables, including some gabapentin oral solutions.
• Combination cold and allergy products can contain decongestants such as pseudoephedrine, which are dangerous for pets; dispense the plain product prescribed.
• Extended-release and enteric-coated tablets should not be split or crushed for small animals unless the product allows it; ask the veterinarian about an alternative.
• Human flavored products are not always palatable to animals; a compounded flavored preparation may be the better option when the veterinarian agrees.

Insulin and syringes

Veterinary insulins such as Vetsulin and ProZinc are U-40 and need U-40 syringes or the matching pen, while human insulins are U-100. A syringe that does not match the insulin delivers the wrong dose. Confirm the product and syringe type against the prescription, show the owner the markings, and flag any change of product at refill.

Species toxicities to keep in mind

Acetaminophen is toxic to cats even in small amounts. Human anti-inflammatories such as ibuprofen and naproxen can cause ulcers and kidney failure in dogs and cats. Dogs with the MDR1 gene mutation, common in herding breeds, can react badly to loperamide and some other drugs. When an owner asks about adding an over-the-counter product for a pet, these are the conversations that prevent emergencies.

Controlled substances, PDMPs and refills

Federal rules apply to veterinary controlled substance prescriptions as to any other: Schedule II prescriptions cannot be refilled, and transfers between pharmacies are limited. States differ on whether and how pharmacies report veterinary prescriptions to the prescription drug monitoring program and how the owner is recorded, so follow your state’s rules.

Gabapentin is a controlled substance in some states and not in others, which matters for refills and transfers of a common veterinary prescription. Our state-by-state table shows where it is scheduled.

Compounding for animals

Compounding for an individual animal on a veterinarian’s prescription is permitted when no approved drug can be used as labeled or extra-label, and FDA’s Guidance for Industry #256 sets the conditions for compounding from bulk drug substances. Your pharmacy must be licensed for compounding in the owner’s state, and the preparation should be labeled for the specific animal.

Labeling and counseling the owner

Label the prescription for the animal, with its name and species and the owner’s name, and give directions exactly as the veterinarian wrote them. Counsel the owner on how to give the medicine, for example in a small amount of food unless the veterinarian said otherwise, and warn against peanut butter or treats that contain xylitol.

Remind owners to store pet medicines separately from the household’s own medicines, to keep chewables out of reach because animals may eat a whole bottle, and to call the clinic or an animal poison control center if a pet gets into a medicine.

Refills and renewals

Veterinary prescriptions carry refills like any other, within your state’s limits. When refills run out, contact the clinic as you would a physician’s office. Many clinics renew maintenance medicines only after a recent examination, because the veterinarian must maintain a current veterinarian-client-patient relationship, so tell the owner early that a recheck may be needed before the animal runs out.

Why a clear cash price matters

Human prescription insurance does not cover medicines for pets, so owners pay cash, and pet insurance, where they have it, reimburses the owner afterward. That makes a clear cash price important to them. Quoting your own price for the prescription as written, and explaining what is included, gives owners the straightforward answer they are looking for.