zonisamide
Zonisamide is an antiepileptic medication that’s used to treat seizures in dogs and cats. It’s a human medication that’s used for pets since there’s no animal-only formulation. The vet might prescribe zonisamide alone to treat seizures, or they might add it to other seizure medications that aren’t working well enough. Zonisamide comes as capsules but can also be made into a liquid form by a compounding pharmacy. The dose is based on your pet’s weight, and it's usually given once or twice per day. Some side effects are sleepiness and low appetite.
What is Zonisamide for pets?
What is Zonisamide for pets used for?
How Zonisamide for pets works
Zonisamide is a type of antiepileptic medication. Experts don't know exactly how it works. But they believe it calms the electrical signals in the brain. This helps prevent seizures from happening.
Drug facts
More on Zonisamide essentials
Side effects of Zonisamide for pets
The following side effects might get better over time as your pet gets used to the medication. Let your veterinarian know immediately if your pet continues to experience these symptoms or if they worsen over time.
Common Side Effects
Dogs:
- Sleepiness
- Low energy
- Low appetite
- Trouble walking
Cats:
- Low appetite
- Diarrhea
- Vomiting
Less Common Side Effects
Zonisamide serious side effects
Contact your veterinarian immediately if your pet experiences any of the following.
- Liver damage: loss of appetite; vomiting; yellowing of the skin, gums, or eyes
- Allergic reaction: rash, hives, fever, swelling, trouble breathing, shock, collapse
- High acid levels in the body: panting, sleepiness, tiredness, muscle problems, irregular heartbeat, low blood pressure
The following Zonisamide 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
Discouragement
double vision
feeling sad or empty
irritability
lack of appetite
loss of interest or pleasure
mood or mental changes
shakiness or unsteady walking
tiredness
trouble with concentrating
trouble with sleeping
Less common
Agitation
bruising
delusions
hallucinations
large, flat blue or purplish patches on the skin
rash
Incidence not known
Blurred vision
change in near or distance vision
difficulty in focusing eyes
increase in frequency of seizures
swelling of the face
yellow eyes or skin
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
Abdominal or stomach pain
difficulty with memory
dizziness
double vision
headache
loss of appetite
restlessness
sleepiness
unusual drowsiness
unusual tiredness or weakness
Less common
Aching muscles or joints
acid or sour stomach
bad, unusual, or unpleasant taste in the mouth
belching
change in taste
chills
difficulty with speaking
difficulty with thinking
general ill feeling
headache
indigestion
mental slowness
nervousness
runny or stuffy nose
tingling, burning, or prickly feelings on the skin
uncontrolled, back and forth, or rolling eye movements
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.
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Pros and cons of Zonisamide for pets
Pros
- Can use alone or with other seizure medications to manage seizures in pets
- Liquid form can be made by some special pharmacies depending on your pet’s needs
- Usually well tolerated
Cons
- Will need to get your pet’s blood drawn a week after starting and also after each dose change
- Might have to give to your pet for the rest of their life
- Might cause allergic reaction if you or your pet has a “sulfa” allergy
Pharmacist tips for Zonisamide for pets
- If you’re pregnant, trying to get pregnant, or breastfeeding, be careful when you’re handling zonisamide. Wear gloves if you need to touch the medication and be sure to wash your hands afterwards. Zonisamide can cause harm to your baby.
- If you have a “sulfa” allergy, be careful while handling zonisamide. Or, you can ask someone else without the allergy to give your pet the medication. Zonisamide is a “sulfa” drug. So if you have this allergy, touching the medication could cause an allergic reaction.
- You can give zonisamide with or without food. If your pet has an upset stomach after taking the medication, try giving it with a small amount of food or a treat next time. Ask your vet about tips on how to get your pet to take pills.
- If your pet needs a zonisamide dose that isn’t easy to find or has trouble swallowing capsules, ask your vet about a liquid version of the medication that’s specially made by the pharmacy. Follow their instructions to measure and give the medication. Always use a dosing syringe or cup (not a household spoon) so your pet takes the right amount. Ask how to store the liquid properly.
- Keep a log of your pet’s seizures to track how well zonisamide is controlling their seizures. It also might be helpful to take a video of the seizure. Share any notes or videos with the vet. They can decide if zonisamide is right for your pet, if the dose should be changed, or if your pet needs a different medication to control seizures.
- Don’t stop giving your pet zonisamide suddenly. This can make seizures come back. If you want your pet to stop taking zonisamide, talk to your vet first. They’ll give you instructions on how to slowly lower the dose over time to stop the medication safely. Be sure to time refills well so your pet doesn’t suddenly run out of zonisamide.
- If you forget to give your pet zonisamide, don’t double their dose or give extra medication. Wait until the next time they usually take the medication to give the regular dose to your pet. Giving too much zonisamide raises the risk of side effects.
- If your pet gets pregnant while taking zonisamide, talk to your vet about whether to keep giving the medication to them. Zonisamide isn’t usually recommended for pregnant animals because it can harm the unborn babies. Your vet can discuss the risks and benefits for your pet.
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Risks and warnings for Zonisamide for pets
Zonisamide 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 harm to the liver
- Risk factors: Dogs | High zonisamide dose | Taking zonisamide for a long time
The risk for liver toxicity from zonisamide is low. But talk to your vet if you know your pet already has liver problems to make sure this medication is safe for them. If your pet has signs of liver damage while taking zonisamide, talk to a veterinarian immediately. Look out for signs like not eating, vomiting, overly tired, and yellowing of the skin, eyes, or gums.
Allergic reaction
- Risk factors: Pets with a sulfonamide (“sulfa”) allergy | Doberman pinscher breed of dogs
Tell the vet if your pet has a sulfonamide or “sulfa” allergy before giving zonisamide. Pets with this allergy shouldn’t take this medication unless the benefits are greater than the risks. Some dog breeds, like Doberman pinschers, are more likely to be sensitive to sulfonamides like zonisamide. These dogs should avoid taking zonisamide if possible to be safe.
A mild allergic reaction to zonisamide can look like hives or a fever. More serious reactions include swelling, blood problems, or anaphylaxis (e.g., trouble breathing, shock, collapse). Get help from a veterinarian right away if your pet has an allergic reaction to zonisamide.
Higher acid levels in the body
Although rare, zonisamide can lower how well your pet’s kidneys can remove acid from the body. Too much acid can build up, which can lead to a medical emergency called metabolic acidosis. Signs of metabolic acidosis in pets include heavy panting, being very sleepy or tired, sleepiness, an irregular heartbeat, and low blood pressure. Call your vet right away if you see any signs of metabolic acidosis while your pet is taking zonisamide.
Withdrawal seizures
- Risk factors: Lowering the dose or stopping zonisamide too suddenly | Missing zonisamide doses
If you lower the dose or stop giving zonisamide suddenly, your pet might have seizures again. Talk to your vet before changing or stopping your pet’s medication to make sure it’s safe. The vet might slowly lower the dose over time to do this safely.
Harm to unborn puppies or kittens
- Risk factors: Pregnant pets
Zonisamide isn’t recommended for pregnant dogs and cats. This is because it can harm the unborn babies and cause heart problems. But sometimes, the vet might decide that controlling your pet’s seizures outweighs the risk of harming the puppies or kittens. Talk to your vet if your pet is pregnant or could become pregnant before starting zonisamide.
Zonisamide dosage forms for pets
Capsule| Dosage | Quantity | Price as low as | Price per unit |
|---|---|---|---|
| 100mg | 120 capsules | $22.22 | $0.19 |
| 25mg | 60 capsules | $11.95 | $0.20 |
| 50mg | 60 capsules | $9.00 | $0.15 |
Typical dosage for Zonisamide
The dose is based on your pet’s weight.
-
Dogs
-
Taking zonisamide alone: The typical starting dose is 5 mg/kg by mouth every 12 hours.
-
Taking zonisamide with phenobarbital: The recommended starting dose is 10 mg/kg by mouth every 12 hours.
-
-
Cats: The typical starting dose is 5 mg/kg to 10 mg/kg by mouth every 24 hours. Some vets might prefer to give this medication every 12 hours.
The vet might change the dose based on the zonisamide levels in your pet’s blood. This helps make sure the medication is safe and works well to control your pet’s seizures.
Interactions between Zonisamide and other drugs for pets
Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking this medicine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.
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.
- Methenamine
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.
- Calcifediol
- Methotrexate
- Orlistat
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.
- Aminolevulinic Acid
- Ginkgo
How much does Zonisamide cost?
Zonisamide contraindications for pets
Contraindications are specific health conditions or situations in which a pet should not take a medication due to safety concerns. If your pet has any of the following conditions or if any of the following apply to your pet, let your veterinarian know because Zonisamide will not be safe for your pet to take.
- Allergy to sulfonamides (“sulfa” drugs)
What are alternatives to Zonisamide for pets?
Zonisamide images
