amantadine
Amantadine is an FDA-approved medication for people. But veterinarians often prescribe it off-label to treat chronic pain in cats and dogs. It’s an NMDA antagonist that works to block pain signals in pets. Amantadine comes as tablets, capsules, and a commercially-available liquid. Pets usually need to take the medication by mouth once or twice a day. Side effects for cats and dogs include gas and diarrhea. Amantadine is typically given with other pain medications.
What is Amantadine for pets?
What is Amantadine for pets used for?
Chronic pain conditions (e.g., arthritis, cancer, nerve pain) in cats and dogs
How Amantadine for pets works
Amantadine is an N-methyl-D-aspartate (NMDA) antagonist. It works by blocking the NMDA receptor. This helps stop nerves from sending pain signals to the brain, which reduces the feeling of pain.
Drug Facts
More on Amantadine essentials
Get your GoodRx coupon
What are the side effects of Amantadine for pets?
Common Side Effects
- Changes in behavior (e.g., restlessness, anxiety, aggression)
- Gas
- Diarrhea
Other Side Effects
The following side effects have also been reported
Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Check with your doctor immediately if any of the following side effects occur:
More common
Bladder pain
bloody or cloudy urine
blurred vision
confusion
difficult, burning, or painful urination
dizziness or lightheadedness
fainting
falls
frequent urge to urinate
lower back or side pain
seeing, hearing, or feeling things that are not there
swelling of the hands, feet, or lower legs
Less common
Inability to move the eyes
increased blinking or spasms of the eyelid
sticking out of the tongue
trouble breathing, speaking, or swallowing
uncontrolled twisting movements of the neck, trunk, arms, or legs
unusual facial expressions
Rare
Chills
decreased vision or any change in vision
difficulty in coordination
increased blood pressure
increase in body movements
irritation and swelling of the eye
loss of memory
mental depression
seizures
severe mood or mental changes
skin rash
slurred speech
thoughts of suicide or attempts at suicide
Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:
More common
Agitation
difficulty concentrating
headache
irritability
loss of appetite
nervousness
nightmares
purplish red, net-like, or blotchy spots on the skin
trouble with sleeping
Less common
Blindness
blurred vision
decrease in sexual desire
decreased vision
drowsiness
dryness of the mouth, nose, and throat
false sense of well-being
joint swelling
unusual tiredness or weakness
vomiting
Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.
Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.
Pros and cons of Amantadine for pets
Pros
Generally well tolerated when given as instructed
Can improve how well cats and dogs with osteoarthritic pain can move
Can give with other pain medications that are safe for cats and dogs
Cons
Need to give to pets carefully (even a little too much can cause serious side effects)
Can take about a week or longer for pain relief
Might not be safe for pets with kidney, liver, or heart problems; behavioral problems; or seizures
Pharmacist tips for Amantadine for pets
You can give amantadine to your cat or dog either once or twice a day. Studies show that twice-a-day dosing might work better for pain relief. Talk to your vet about how often your pet should take the medication.
You can give amantadine to your pet with or without food.
Amantadine can cause stomach upset and gas in animals. If your pet has these side effects, it might help to give amantadine with a small amount of food or a treat.
Call an emergency vet or a pet poison helpline right away if your pet shows signs of an amantadine overdose. These signs include vomiting, restlessness, shaking, and seizures. An overdose can happen if your pet accidentally takes even a little too much or if their dose is too high.
If you forget to give amantadine to your pet, give it to them as soon as you remember. But if there’s less than 8 hours left until the next scheduled dose, skip the dose. Wait to give the medication at the usual dose at the usual time. Don’t double up on the dose to make up for any missed doses because it can cause side effects and overdose.
Always ask a vet before giving amantadine to a pregnant or nursing cat or dog. It’s not clear if the medication is safe for them. In general, amantadine should only be used if the vet thinks the benefits are greater than the risks.
Tips for the liquid form of amantadine for cats and dogs:
Your vet might suggest a special liquid form of amantadine for your pet that’s made by a compounding pharmacy. This could be a good option if your pet doesn’t like the fruit flavor of the usual liquid form of amantadine. It could also be helpful if your pet needs a smaller dose than what’s usually available.
Use an oral syringe to measure out amantadine for your pet. Don’t use household spoons because they aren’t accurate. Using household spoons might make you give the wrong dose to your pet. Ask your vet or pharmacy for oral syringes.
For the commercially-available liquid form of amantadine: Place the bottle of liquid at room temperature (between 68 and 77 degrees Fahrenheit). Throw it away after the expiration date on the bottle, even if there’s still medication left.
For the compounded liquid form of amantadine: Follow your vet’s instructions on how to store the compounded liquid and when to discard it. This makes sure the medication stays safe for your pet to take.
Frequently asked questions about Amantadine for pets
How to save using GoodRx
What are the risks and warnings for Amantadine for pets?
Amantadine can cause some serious health issues. This risk might be even higher for certain pets. If this worries you, talk to your veterinarian about other options.
Risk of amantadine overdose
Risk factors: Giving too much amantadine to your pet | Cat or dog with kidney problems
If your cat or dog takes too much of amantadine, even by a little, it can lead to a dangerous overdose. This can happen if you accidentally give your pet too much medication.
An amantadine overdose can also happen if you give the medication to a cat or dog with kidney problems. When the kidneys don’t work properly, the body can’t get rid of amantadine. This can lead to too much medication in the body. Talk to your vet before giving this medication to your pet if they have kidney problems.
Signs of an amantadine overdose in pets include vomiting, restlessness, and seizure. Call a vet or a pet poison helpline right away if you think your pet has taken too much amantadine.
Possible fluid buildup and swollen legs
Risk factors: Cats or dogs with heart problems (e.g., heart failure) | Cats or dogs with kidney problems
Amantadine might make the body hold onto extra fluid, which can cause swelling in your pet’s legs. The risk of complications from this fluid buildup is higher if your cat or dog has heart or kidney problems.
Tell your vet if your pet has any heart or kidney issues to make sure amantadine is safe. Call your vet if you notice that your pet’s legs swell after they start taking the medication.
Possible behavior changes
Risk factors: Cats or dogs with behavior problems
Some cats and dogs might act differently while they’re taking amantadine. They might seem anxious, nervous, aggressive, restless, or want more attention than usual. Talk to your vet if your pet’s behavior changes in a way that worries you.
Caution use in cats and dogs with liver problems
Talk to your vet before giving amantadine if your pet has liver problems. Cats and dogs with a liver condition should take this medication with caution. We don’t know whether amantadine is safe for pets with liver problems. But in people, this medication has a rare risk of raising liver enzyme levels, which can be a sign of liver damage.
Amantadine dosage forms
Typical dosing for Amantadine for pets
Your pet’s amantadine dose will be based on their weight. The typical dose for cats and dogs is 3 mg/kg to 5 mg/kg by mouth every 12 or 24 hours.
Interactions between Amantadine and other drugs for pets
Using this medicine with any of the following medicines is not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.
Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
- Amifampridine
- Bupropion
- Donepezil
- Glucagon
- Memantine
- Methacholine
- Metoclopramide
- Quetiapine
- Secretin Human
Using this medicine with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
- Betel Nut
- Bromperidol
- Triamterene
- Trimethoprim
How much does Amantadine cost?
Amantadine contraindications for pets
Pets with some types of glaucoma
What are alternatives to Amantadine for pets?
Chronic pain conditions (e.g., arthritis, cancer, nerve pain) in cats and dogs
Amantadine images
Get savings updates for Amantadine
Receive price alerts, news, and other messages from GoodRx about Amantadine and other healthcare topics and relevant savings offers.By providing your email, you consent to receive marketing communications from GoodRx, which may include content and/or data related to men’s health, women's health, reproductive care, or sexual health. You agree to the GoodRx Terms of Use and acknowledge the Privacy Policy. You can unsubscribe at any time.
References
Best studies we foundActavis Pharma, Inc. (2023). Amantadine hydrochloride tablet [package insert]. DailyMed.
Allweiler, S. (2024). Analgesics used in animals. Merck Manual Veterinary Manual.
Allweiler, S. (2024). Chronic pain in animals. Merck Manual Veterinary Manual.
American Veterinary Medical Association. (n.d.). Cancer in pets.
Bionpharma Inc. (2023). Amantadine HCl- amantadine hydrochloride capsule, liquid filled [package insert]. DailyMed.
British Small Animal Veterinary Association. (2020). Amantadine.
Burns, K. (2020). Getting ahead of osteoarthritis in pets. JAVMAnews.
Gelatt, K. N. (2024). Glaucoma in dogs. Merck Manual Veterinary Manual.
Grubb, T. (2018). Gabapentin and amantadine for chronic pain: Is your dose right? Today’s Veterinary Practice.
Gruen, M. E., et al. (2022). 2022 AAHA pain management guidelines for dogs and cats. American Animal Hospital Association.
Hamor, R. E. (2024). Glaucoma in animals. Merck Manual Veterinary Manual.
Lascelles, B. D. X., et al. (2008). Amantadine in a multimodal analgesic regimen for alleviation for refractory osteoarthritis pain in dogs. Journal of Veterinary Internal Medicine.
Mercer, M. A. (2024). Purine nucleosides used in animals. Merck Manual Veterinary Manual.
PAI Holdings, LLC dba PAI Pharma. (2024). Amantadine hydrochloride solution [package insert]. DailyMed.
Plumb’s Veterinary Medication Guides. (2021). Amantadine.
Shipley, H., et al. (2021). Owner evaluation of quality of life and mobility in osteoarthritic cats treated with amantadine or placebo. Journal of Feline Medicine and Surgery.
Browse medications
View AllResearch prescriptions and over-the-counter medications from A to Z, compare drug prices, and start saving.