Writing pet prescriptions a pharmacy can fill: a vet guide

Why write with the pharmacist in mind

Many small-animal medicines are human generics, among them gabapentin, trazodone, fluoxetine, prednisolone, many 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 licensed pharmacy may dispense it on your prescription.

Human pharmacists are trained around human doses and products, and many see veterinary prescriptions only occasionally. A prescription that answers their likely questions up front saves a phone call to your clinic, gets the client’s pet started sooner, and reduces the chance that a dose is changed or a product is chosen that is unsafe for the animal.

What to put on every prescription

Write the prescription as you would for any outside pharmacy, and make sure it includes the following.

• The animal’s name and species, and the owner’s name and address, since the pharmacy label carries both.
• The animal’s current weight, so the pharmacist can check the dose.
• The drug, strength and dosage form, the dose per administration in milligrams, and the quantity.
• Directions written out in full, such as “give 1 tablet by mouth once daily”, rather than abbreviations.
• Refills, your name, clinic address and direct phone number, license details as your state requires, your signature and the date.
• For controlled substances, your DEA registration number and anything else your state requires.

Spell out frequency, route and units

Abbreviations that are routine in veterinary practice, such as SID for once daily, are rarely used in human pharmacy and can be misread. Writing “once daily”, “every 12 hours” or “every other day” in words removes the ambiguity. The same applies to routes and units: write “by mouth” and “mg”, avoid “cc”, and avoid trailing zeros, which can turn 1.0 mg into a tenfold error when the decimal point is missed.

If the dose is a fraction of a tablet, say so plainly, such as “give one half of a 10 mg tablet”, and check that the tablet is scored or can be split. For very small doses, a liquid or a compounded strength may be safer than splitting.

Doses that pharmacists may question

Some veterinary doses look wrong to a pharmacist used to human doses. Dogs need far higher doses of levothyroxine per kilogram than people do, and doses of several anticonvulsants, steroids and antibiotics differ between species. A short note such as “dose confirmed for a 30 kg dog” tells the pharmacist the dose is intentional. A pharmacist who is unsure should call you rather than change it, and a dose lowered to a human-typical amount can leave the animal undertreated.

Insulin is the clearest case for spelling everything out. Veterinary insulins such as Vetsulin and ProZinc are U-40 and use U-40 syringes, while human insulins are U-100 and use U-100 syringes. Write the insulin product, its concentration and the syringe type, so the client goes home with a matching pair; a mismatched syringe delivers the wrong dose.

Formulations to rule out

Human liquids and dissolving tablets sometimes contain xylitol, a sweetener that is toxic to dogs, and some gabapentin oral solutions are a known example. When you prescribe a liquid or dissolving form, write “no xylitol” or name an acceptable product, so the pharmacist checks the ingredients or arranges a compounded alternative.

Be specific with combination products, too. An antihistamine prescription could be filled with a product that also contains a decongestant such as pseudoephedrine, which is dangerous for pets, unless the plain product is named. Extended-release and enteric-coated tablets should not be split or crushed unless the product allows it.

Species dangers worth restating

Pharmacists know these, but they come up when owners ask about adding an over-the-counter product: 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, and dogs with the MDR1 gene mutation, common in herding breeds, can react badly to loperamide and some other drugs. Noting a known MDR1 status on the prescription helps the pharmacist protect the patient.

Controlled substances

To prescribe controlled substances you need DEA registration, and state rules govern how the prescription must be issued, including whether it must be sent electronically; those rules differ between states and sometimes treat veterinarians differently. Schedule II prescriptions cannot be refilled, and transfers between pharmacies are limited, so tell clients where a controlled prescription should be filled before they leave.

Gabapentin, widely used for pain and anxiety in dogs and cats, is a controlled substance in some states and not in others, which affects refills and transfers there. Our state-by-state gabapentin table shows where it is scheduled.

When a compounded preparation is the answer

When no approved product fits, such as a low-strength capsule for a cat, a flavored liquid or a transdermal methimazole gel, a compounding pharmacy can prepare a patient-specific preparation on your prescription. Under FDA’s Guidance for Industry #256, compounding from bulk drug substances for an individual animal is limited to situations where an approved drug cannot be used as labeled or extra-label, and the pharmacy must be licensed for compounding in the client’s state.

Office stock compounded from bulk substances is restricted to the substances FDA lists for that purpose and is ordered by the practice, not through a client’s prescription.

Getting the prescription to the client

Clients can take a written prescription to any pharmacy, or you can send it electronically to the pharmacy they choose. Some states require veterinarians to provide a written prescription when a client asks, and the AVMA’s policy supports honoring client requests for prescriptions.

On Script Unlock, a client uploads a photo or PDF of the prescription you wrote, and licensed pharmacies reply with their own cash price for exactly that prescription. The dispensing pharmacy verifies it with your clinic as it would any veterinary prescription, and the client pays the pharmacy. Nothing about your workflow changes, and you need no account.

Make pharmacist calls easy

Put a direct phone number on the prescription and make sure pharmacist calls about veterinary prescriptions reach a veterinarian or technician quickly. A two-minute call is usually enough to confirm a dose or agree an alternative product, and it keeps the client’s pet on schedule.