Amitriptyline for Cats: Dosage, Side Effects, and How It Works for Anxiety and Stress

If you have a stressed-out cat, you may be wondering how you can help ease their anxiety. There are a number of things you can do at home, such as improve your cat’s environment and give them plenty of playtime. But that isn’t always enough. 

In that case, your veterinarian may recommend an anxiety medication. One option is amitriptyline (Elavil).

Read on to learn about amitriptyline for cats, including its dosage, side effects, and medication interactions.

Amitriptyline for cats at a glance

What is amitriptyline for cats, and what is it used for?

Amitriptyline is a tricyclic antidepressant (TCA) used to treat a variety of behavioral issues in cats, including: 

• Anxiety

• Excessive grooming

• Aggression

• Litter box problems 

• Urine spraying 

• Nerve pain 

• Feline lower urinary tract disease (FLUTD), stress cystitis, or interstitial cystitis

• Pica (eating nonedible items)

Amitriptyline is prescribed extra-label, or off-label, to cats since it isn’t FDA approved for pets. Off-label prescribing is common in veterinary medicine and safe.

Amitriptyline is most effective at treating stress and anxiety-related disorders in cats when combined with environmental modifications and enrichment. For example, if amitriptyline is prescribed to a cat for stress-related urinary problems, it will be most effective when used alongside litter box best practices. 

How does amitriptyline work for cats?

Amitriptyline and most TCAs work in a few ways to treat behavioral disorders and nerve pain in cats. 

One major way TCAs function is by increasing the levels of dopamine and serotonin in the brain. By increasing the levels of these “feel-good” brain chemicals, they stabilize mood and reduce pain. TCAs do this by blocking chemical receptors and transporters on the surface of brain cells. 

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• Recognizing anxiety: Think you know all the signs that point toward cat anxiety? Check out this list of anxiety symptoms in cats to find out.

• Other medication options: Amitriptyline (Elavil) is only one anxiety medication for cats. Here are other common anxiety medications your veterinarian may suggest for a scaredy cat.

• Is your cat not using the litter box? It’s not to spite you, but it could be a sign that something is wrong. Learn more about why your cat may avoid the litter box and what to do.

TCAs also function as alpha-1 adrenergic receptor blockers, which can reduce fear.

How is amitriptyline given to cats, and what is the dosage?

Amitriptyline for cats comes in tablets ranging from 10 mg to 25 mg that can be split if necessary. Amitriptyline can also be compounded into an oral liquid, a chewable treat or tablet, or a transdermal lotion that can be rubbed into a cat’s ear. 

Unless your cat gets amitriptyline as a lotion, it is best to give them the medication with food to increase absorption and minimize stomach upset. Wash your hands after handling the medication, and use gloves if you’re applying the transdermal lotion.

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Dosage

Your veterinarian will determine the appropriate amitriptyline dosage for your cat. Often, dosages for cats range from 2.5 mg to 12.5 mg taken once or twice a day. The exact dosage of amitriptyline for your cat will depend on several factors, including: 

• The condition or issue being treated

• Your cat’s weight and overall health

• Any other medications your cat takes 

It is important to accurately follow all dosage instructions, as amitriptyline can be easily overdosed. Your veterinarian will likely start your cat at a lower dosage to reduce negative side effects. If there is no improvement or if your cat experiences side effects, your vet will adjust the dosage of amitriptyline. 

This adjustment process may take several weeks. So be patient and communicate with your veterinarian during this time to get the best results. 

What are the common side effects of amitriptyline in cats?

Amitriptyline can significantly improve the quality of life of cats with anxiety or other behavioral disorders. But pet parents must be aware of the potential negative side effects. 

The most common side effects of amitriptyline in cats include:

• Drowsiness, low energy, or sleeping more

• Dry mouth, resulting in increased thirst and urination

• Drooling after administration  

• Increased or decreased appetite

• Constipation

• Hyperactivity and agitation (rare paradoxical effects)

Allow your feline friend to rest as necessary and provide constant access to fresh, clean water. 

When to talk to a veterinarian

If your cat seems to be spending more time in the litter box or if you notice any changes to their poop, contact your veterinarian for advice. You should also reach out to your vet if you're concerned about changes in your cat’s appetite or if they are gaining or losing weight. 

Most side effects associated with amitriptyline are usually temporary, mild, and go away on their own. But if you have concerns, talk to your veterinarian.

Discontinuing the medication

Since amitriptyline alters the levels of chemicals in your cat’s brain, it is best not to stop it suddenly. If you think you need to stop giving your cat amitriptyline, talk to your veterinarian first. They can give you instructions on how to slowly lower the dosage of the medication safely.

What are the most serious risks of amitriptyline in cats?

The most serious side effects of amitriptyline in cats are associated with an overdose. That’s why it’s important to work closely with your veterinarian if your cat is prescribed this medication. 

Signs of an amitriptyline overdose in cats include:

• Vomiting

• Severe incoordination or falling down

• Collapse

• Pale gums 

If you notice any of these signs of overdose while your cat is taking amitriptyline, call your veterinarian or a pet poison hotline for advice immediately. 

Precautions to consider before giving your cat amitriptyline

Amitriptyline can cause changes in a cat’s blood levels. It should be given with caution to cats with liver or kidney disease. In addition, amitriptyline can cause heart arrhythmias in some cats. 

Before prescribing amitriptyline, your veterinarian may want to run blood work and recommend an electrocardiogram (EKG) that shows heart rhythm and echocardiogram, or an ultrasound of the heart. They may then request follow-up checks periodically (every 6 months) while your cat is taking the medication to ensure that your cat’s health is not negatively impacted. 

Does amitriptyline interact with any other cat medications?

There are many medications that can interact with amitriptyline, including:

• Amantadine

• Azole antifungals, such as fluconazole and itraconazole

• Benzodiazepines, including alprazolam and diazepam 

• Buspirone

• Cetirizine

• Cimetidine

• Cisapride

• Clomipramine

• Diltiazem

• Enrofloxacin

• Estrogens

• Levetiracetam

• Metronidazole

• Nonsteroidal anti-inflammatory drugs (NSAIDs), such as meloxicam

• Ondansetron

• Opioids, including buprenorphine

• Phenobarbital

• Rifampin

• Selective serotonin reuptake inhibitors (SSRIs), such as fluoxetine and sertraline

• Selegiline

• Tramadol

• Trazodone

• Warfarin

Let your veterinarian know about any medications, vitamins, or supplements your cat takes. They will be able to determine if any of your cat’s existing medications could interact with amitriptyline. 

What should you do if your cat misses a dose of amitriptyline?

Amitriptyline is typically given to cats once a day. So, if you miss a dose of amitriptyline, give your cat the medication as soon as possible. Then, resume their regular medication schedule the next day. Never give two doses of amitriptyline at the same time to “catch up” — or give two doses within 12 hours of each other. 

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Written by:

Sarah J. Wooten, DVM, CVJ

Dr. Sarah Wooten, DVM, CVJ, is a well-known international influencer in the veterinary and animal healthcare spaces. She has 16 years of experience in private practice and more than 15 years experience in veterinary media work.

Edited by:

Renée Fabian, MA

Renée Fabian is the senior pet health editor at GoodRx. She’s worked for nearly 10 years as a journalist and editor across a wide range of health and well-being topics.

Reviewed by:

Ghanasyam Bey, DVM

Ghanasyam Bey, DVM, is from Cleveland, Ohio, and attended Princeton University for undergraduate studies. After a year of biology research at Duke University, he attended Ohio State College of Veterinary Medicine.

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