Mirtazapine
Mirataz (transdermal ointment, veterinary) · Remeron (human) · generic mirtazapine
Mirtazapine is a human antidepressant that vets use as an appetite stimulant and anti-nausea drug in cats, especially those with kidney disease, and in dogs that will not eat. A veterinary ointment rubbed on the ear is approved for cats; the human tablets are the same drug and a pharmacy can fill a vet’s prescription for them.
What it is used for
Mirtazapine increases appetite and reduces nausea through its effects on histamine and serotonin receptors, and the effect in cats is marked and quick. It is used for cats losing weight with chronic kidney disease, liver disease, cancer or after surgery, and for dogs that stop eating during illness. Mirataz, a transdermal ointment applied to the inner ear once a day, was approved for weight loss in cats and avoids pilling an unwell animal.
The human tablets are dosed in very small amounts for cats, often a fraction of the smallest tablet given every other day or every third day, because cats clear the drug slowly. Dogs are dosed by weight once a day. Drowsiness, vocalising, restlessness and a fast heart can occur, more often when the dose is too high.
Safety points that differ from human use
- Cats are dosed far lower and less often than people or dogs; a human tablet given whole can cause agitation, tremor and a racing heart. Follow the vet’s fraction and interval exactly.
- It should not be combined with other serotonin-active drugs (fluoxetine, trazodone, tramadol) without the vet’s oversight.
- Wear gloves to apply the ointment, and keep the cat’s ear away from children and other pets until it has absorbed.
- Transdermal ointment (Mirataz, veterinary)
- Tablets and orally disintegrating tablets (human)
- Compounded transdermal gels and tiny capsules
- 7.5, 15, 30 and 45 mg human tablets
- Ointment 20 mg per gram
The 15 mg human tablet is scored; vets often prescribe a quarter or an eighth for a cat, which some owners find easier with a pill splitter than a compounded product.
Why the cash price varies
Human mirtazapine is a commodity generic and a cat uses a fraction of a tablet, so a month’s supply costs mostly the dispensing fee. Mirataz is a single-manufacturer veterinary product sold through vets and pharmacies that stock it, and compounded transdermal gels are made to order; both are conveniences for cats that cannot be pilled rather than savings.
How to pay less
- Ask the vet whether a split human tablet is practical for your cat before paying for the ointment or a compounded gel.
- If the ointment is needed, compare the clinic with a pharmacy that stocks veterinary products.
- Upload the prescription to Script Unlock so licensed pharmacies can quote. You pay the pharmacy directly.
Questions for your vet
- What dose and how often for my cat, exactly?
- Tablet fraction or the ear ointment?
- What signs mean the dose is too high?
- Is it safe with my pet’s other medicines?
- What is causing the poor appetite, and is that being treated too?
Rules on refills, transfers and controlled substances differ by state; see pharmacy rules by state.
How Script Unlock gets you a cash price for your pet’s mirtazapine prescription
Prices on this site come from pharmacies responding to a real prescription. We do not publish estimated, average or "typical" prices, because none of those would be your price.
- 1You upload your prescription
A photo of your your pet’s mirtazapine prescription prescription is enough. Nothing is sold on the site; you are asking pharmacies to quote.
- 2Licensed pharmacies respond
Pharmacies that Script Unlock has verified see the request and each can reply with its own cash price for your exact drug, strength and quantity.
- 3You choose and pay the pharmacy
You compare the responses, pick a pharmacy, and pay that pharmacy directly when you collect. Script Unlock never takes a patient payment and never sets the price.
Related pet medications
Sources
- FDA Approved Animal Drug Products (Green Book)
- Merck Veterinary Manual
- FDA Orange Book (approved generics and therapeutic equivalence)
- ASPCA Animal Poison Control
Written by the Script Unlock editorial team from the sources above. Not yet reviewed by a veterinarian or veterinary pharmacist. Last checked 2026-10-03. Nothing here replaces your vet\u2019s directions; doses for animals are set by weight and species.
Script Unlock is a marketplace that lets licensed pharmacies quote a cash price on your prescription. It does not prescribe, dispense or sell medication, does not process patient payments, and does not give medical advice. Always follow the instructions of your prescriber and pharmacist and read the medication guide supplied with your medicine.