Mirataz is the first and only FDA-approved transdermal mirtazapine ointment for the management of weight loss in cats. Developed by Kindred Biosciences (now part of Elanco), Mirataz provides a convenient and effective way to stimulate appetite in cats experiencing weight loss from a variety of underlying conditions, including chronic kidney disease, cancer, hyperthyroidism, and other chronic illnesses.
Weight loss and poor appetite are among the most common reasons cat owners seek veterinary care, and Mirataz has become an important tool in feline medicine since its FDA approval in 2018.
What Is Mirataz Used For?
Mirataz is indicated for the management of weight loss in cats. It works as an appetite stimulant, encouraging cats to eat more and helping them regain or maintain body weight.
Common conditions where Mirataz may be prescribed include:
- Chronic kidney disease (CKD): One of the most common reasons for appetite loss and weight loss in older cats.
- Cancer: Many forms of cancer cause appetite suppression and cachexia (wasting).
- Hyperthyroidism: Can cause weight loss despite normal or increased appetite; treatment with methimazole may temporarily reduce appetite as thyroid levels normalize.
- Inflammatory bowel disease (IBD): Chronic GI inflammation can reduce appetite and nutrient absorption.
- Post-surgical or post-illness recovery: Cats recovering from surgery, hospitalization, or acute illness may need appetite support.
- Other chronic conditions: Any condition causing sustained appetite loss and weight decline.
Important: Mirataz addresses the symptom of weight loss and poor appetite but does not treat the underlying disease causing it. Your veterinarian will work to diagnose and manage the root cause alongside appetite support.
How Does Mirataz Work?
Mirtazapine, the active ingredient in Mirataz, was originally developed as a human antidepressant. In cats, its primary veterinary use is as an appetite stimulant. Mirtazapine works through several mechanisms:
- Alpha-2 adrenergic antagonism: Increases the release of norepinephrine and serotonin in the central nervous system, which stimulates appetite centers in the brain.
- Serotonin receptor antagonism (5-HT3): Blocks serotonin receptors involved in nausea and appetite suppression, reducing nausea and further promoting appetite.
- Histamine receptor antagonism (H1): Contributes to increased appetite and mild sedation.
The combined effect of these mechanisms makes mirtazapine one of the most reliable appetite stimulants available for cats. The transdermal formulation (Mirataz) delivers the drug through the skin of the inner ear, avoiding the need to give a pill to a cat that may already be nauseous or resistant to oral medication.
Dosage
Mirataz is applied topically to the inner surface of the cat’s ear pinna (ear flap). Your veterinarian will determine the appropriate dosing regimen for your cat.
| Parameter | Detail |
|---|---|
| Dose | 1.5-inch ribbon of ointment (approximately 2 mg mirtazapine) |
| Application site | Inner surface of the ear pinna (alternating ears each application) |
| Frequency | Once every other day (every 48 hours) |
| Duration | As directed by your veterinarian; typically ongoing while weight loss management is needed |
Important notes:
- Apply the ointment to the inner (hairless) surface of the ear pinna, not inside the ear canal.
- Alternate ears with each application (right ear one day, left ear the next application day).
- Your veterinarian may adjust the frequency or amount based on your cat’s response and any side effects.
- Mirtazapine is metabolized more slowly in cats than in humans or dogs. Every-other-day dosing with the transdermal formulation is important to avoid accumulation and toxicity.
- Do not apply more frequently than directed by your veterinarian.
How to Give Mirataz to Your Cat
Mirataz comes in a multi-dose tube with a dosing guide.
Application steps:
- Put on disposable gloves before handling the tube. Mirtazapine can be absorbed through human skin.
- Squeeze a 1.5-inch ribbon of ointment onto your gloved fingertip (use the dosing guide provided with the product).
- Gently apply the ointment to the inner surface of one ear pinna, spreading it in a thin layer.
- Alternate ears with each application.
- Dispose of gloves after application.
- Wash your hands thoroughly even after removing gloves.
- Avoid allowing other pets or family members to come in contact with the treated ear until the ointment is absorbed (approximately 15-30 minutes).
Tips:
- Apply when your cat is calm and relaxed.
- If your cat shakes its head immediately after application, some product may be lost. Try gently holding the ear still for a few seconds after applying.
- If the ear is visibly dirty, gently clean the inner ear surface before application per your veterinarian’s instructions.
- Do not apply to broken, inflamed, or infected skin on the ear.
Side Effects
Most cats tolerate Mirataz well. Side effects are generally mild and may diminish with continued use.
| Common Side Effects | Serious Side Effects (Contact Your Vet) |
|---|---|
| Behavioral changes (increased vocalization, hyperactivity, or restlessness) | Serotonin syndrome (tremors, rapid heart rate, agitation, elevated temperature) |
| Skin irritation at application site (redness on ear) | Persistent vomiting or diarrhea |
| Mild increase in affection or attention-seeking behavior | Severe lethargy or unresponsiveness |
| Weight gain (desired effect, but excessive weight gain should be monitored) | Significant behavioral changes (aggression, disorientation) |
| Signs of mirtazapine toxicity (tremors, vocalization, disorientation, rapid breathing) |
Mirtazapine toxicity can occur if too much product is applied, if the product is applied more frequently than prescribed, or if the cat ingests the ointment. Signs of toxicity may include vocalization, agitation, vomiting, tremors, rapid heart rate, and disorientation. If you suspect toxicity, contact your veterinarian or an emergency animal poison control center immediately.
Drug Interactions
Mirtazapine may interact with several other medications:
- Serotonergic drugs (fluoxetine, tramadol, ondansetron, amitriptyline): Combining mirtazapine with other serotonin-affecting drugs increases the risk of serotonin syndrome, a potentially life-threatening condition. Inform your veterinarian if your cat is taking any of these medications.
- MAO inhibitors (selegiline/Anipryl): Should not be used with mirtazapine due to the risk of serotonin syndrome.
- Cyproheptadine: May reduce the effectiveness of mirtazapine, as both drugs affect serotonin pathways.
- Other CNS depressants: May increase sedation when combined with mirtazapine.
Always provide your veterinarian with a complete list of all medications and supplements your cat is receiving.
Contraindications
- Do not use in cats with known hypersensitivity to mirtazapine or any component of the Mirataz formulation.
- Do not use concurrently with MAO inhibitors.
- Use with caution in cats with liver disease, as mirtazapine is metabolized by the liver and clearance may be reduced.
- Use with caution in cats with severe kidney disease; your veterinarian may adjust the dosing schedule.
- The safety of Mirataz has not been evaluated in breeding, pregnant, or lactating cats.
Storage
- Store at room temperature (68-77 degrees F / 20-25 degrees C).
- Replace the cap tightly after each use.
- Keep the tube in its carton to protect from light.
- Keep out of reach of children and pets.
- Discard the tube 30 days after first opening (or per the expiration date, whichever comes first).
Cost & Availability
Mirataz is a prescription medication available through veterinary clinics and authorized pharmacies.
| Product | Approximate Cost |
|---|---|
| Mirataz tube (5 g, ~30 applications) | $50-$90 |
| Monthly cost (approximately 15 applications/month) | $25-$45 |
- Cost varies by clinic and pharmacy.
- Compounded oral mirtazapine (non-transdermal) is also available and may be less expensive, but it is not FDA-approved and requires oral dosing, which can be challenging in cats with nausea.
- The FDA-approved transdermal formulation (Mirataz) offers the advantage of consistent dosing and avoids the need for oral administration.
- No generic transdermal mirtazapine for cats is currently available.
FAQ
Q: How quickly will Mirataz improve my cat’s appetite? A: Many cat owners notice increased appetite within 1-2 days of starting Mirataz. Some cats show improvement after the first application. If your cat does not show improvement after 5-7 days of consistent use, contact your veterinarian to reassess.
Q: Can I use oral mirtazapine instead of Mirataz? A: Oral mirtazapine (human tablets or compounded veterinary formulations) has been used off-label in cats for appetite stimulation for many years. However, oral dosing can be difficult in nauseous cats, and the oral dose used in cats differs from the transdermal dose. Mirataz is the only FDA-approved transdermal formulation, offering a studied and standardized delivery method. Discuss the options with your veterinarian.
Q: Is Mirataz safe for humans to handle? A: Mirtazapine can be absorbed through human skin. Always wear disposable gloves when applying Mirataz, and wash your hands after handling. Avoid contact with your eyes, mouth, or mucous membranes. If you are pregnant, nursing, or taking medications that affect serotonin, take extra care and consult your physician if you have accidental skin exposure.
Q: Can Mirataz be used long-term? A: Mirataz may be used for extended periods under veterinary supervision, particularly for cats with chronic conditions like kidney disease. Your veterinarian will periodically reassess whether continued appetite stimulation is needed and monitor your cat’s weight, overall condition, and any side effects.
Q: My cat gained too much weight on Mirataz. What should I do? A: While weight gain is the goal for underweight cats, excessive weight gain should be reported to your veterinarian. The dosing frequency or amount may be adjusted. Do not change the dosing schedule on your own.
Sources & References
- FDA - Mirataz (Mirtazapine Transdermal Ointment) Approval
- Merck Veterinary Manual - Appetite Stimulants in Small Animals
- VCA Animal Hospitals - Mirtazapine for Cats
- Cornell Feline Health Center - Managing Your Cat’s Weight
- Journal of Feline Medicine and Surgery - Mirtazapine Transdermal Ointment in Cats
- Elanco - Mirataz Product Information
This content is for informational purposes only and is not a substitute for professional veterinary advice. Always consult your veterinarian before starting, changing, or stopping any medication for your cat.