Primidone is used to for long-term control of convulsions, seizures, and epilepsy in dogs. It’s rarely used in cats. Primidone requires a prescription from your veterinarian, and is sold per tablet.
For: Dogs, and rarely with Cats
Controls severity and frequency of seizures associated with epilepsy
Also provides an effective means of controlling convulsions associated with infectious neuropathies such as virus encephalitis and distemper
How it works: When Primidone is ingested, it’s converted to phenobarbital which is an anticonvulsant. It works by decreasing nerve impulses in the nervous system, which helps to reduce seizures
Cautions: Primidone should not be used in pregnant or nursing animals. Other drugs, as well as vitamins and supplements, may have an adverse interaction with Primidone, so disclose to your veterinarian what other products you are giving to your pet. Primidone may cause drowsiness, dizziness, hives, swelling or other side effects. Contact your vet at the onset of any of abnormal physical or behavioral change in your pet. It is very important not to miss giving your pet a dose, as this can cause a seizure.
Brand Name Neurosyn (Boehringer Ingleheim), Mysoline (Athena Neuroscience)
Generic Name Primidone (prim-ih¿-doen)
What is the most important information I should know about Primidone: Do not stop giving this medication. It is important to continue giving primidone to prevent seizures from recurring. Primidone may cause drowsiness or dizziness.
What is Primidone: Primidone is used to control seizures in dogs. It is believed that Primidone alters the chemical impulses in the brain that cause seizures. Primidone is a prescription medication available as 250mg scored tablets. The usual dose in dogs is 2.3-6.8 mg/pound per day in 2 or 3 divided doses. Primidone may be also be used for purposes other than those listed in this guide.
What should I discuss with my veterinarian before giving primidone to my pet: Discuss with your veterinarian any other medical conditions your pet may have and any medications your pet is being given, including over the counter medications. Tell your veterinarian if your pet is pregnant, lactating or if you intend to breed your pet.
How should this medication be given: Give this medication exactly as directed by your veterinarian. If you do not understand these directions ask your pharmacist or veterinarian to explain them to you. Primidone can be given with food. Allow plenty of water for your pet to drink. Do not stop giving the medication. It is important to continue giving primidone to prevent seizures from recurring. Store primidone at room temperature away from moisture and heat. Keep out of the reach of children and other pets.
What happens if I miss giving a dose: Give the missed dose as soon as you remember. However, if it is almost time for the next dose, skip the dose that was missed and give only the next regularly scheduled dose. Do not give a double dose of this medication.
What happens if I give my pet an overdose: Seek emergency veterinary medical treatment. Symptoms of overdose may include dizziness, drowsiness, incoordination, nausea, vomiting, blurred vision, and irregular, rapid eye movements.
What should I avoid while giving primidone to my pet: Do not give primidone to dogs allergic to Phenobarbital. Primidone should not be given to cats. Primidone may cause dizziness or drowsiness. Use caution when giving other medications that may cause dizziness or drowsiness.
What are the possible side effects of primidone: If your pet develops any of the following serious side effects, stop giving primidone and seek emergency veterinary medical attention; an allergic reaction (difficulty breathing, closing of the throat, swelling of the lips, tongue, face, or hives); a rash; worsening of seizures; fever. Other less serious side effects may occur. Continue to give primidone and talk to your veterinarian if your pet experiences dizziness, poor coordination, or drowsiness; blurred vision; irregular back and forth movements of the eyes; or nausea and vomiting. Side effects other than those listed in this guide may also occur. Talk to your veterinarian about any side effect that seems unusual or that is especially bothersome to your pet.
What other drugs will affect primidone: Acetazolamide (Diamox), carbamazepine (Tegretol), ethosuximide (Zarontin), and methsuximide (Celontin) may decrease the effects of primidone and require a higher primidone dose. Phenytoin (Dilantin), ethotoin (Peganone), mephenytoin (Mesantoin), and isoniazid may increase the effects of primidone and require a lower primidone dose. Carbamezepine (Tegretol) blood levels may increase when given with primidone. The carbamazepine dose may need to be adjusted lower. CNS depressants, valproic acid and chloramphenicol may increase the effect of primidone. Primidone may decrease the effect of coumadin, corticosteroids (such as prednisone), beta blockers (such as atenolol), theophylline and metronidazole. Use with caution when giving primidone with furosemide, griseofulvin or rifampin.
Where can I get more information: Your pharmacist has additional information about primidone written for health professionals that you can read.
Call your veterinarian for medical advice about any side effects to your pet. You may report side effects to the FDA at 1-800-FDA-1088.
Primidone is a prescription medication used to control seizures and epilepsy in dogs. It is believed that Primidone alters the chemical impulses in the brain that cause seizures.
Primidone should not be given to cats.
Primidone may cause drowsiness and dizziness.
Tip: Do not stop giving this medication. It is important to continue giving Primidone to prevent seizures from recurring.
The usual dose in dogs is 2.3-6.8 mg per pound of pet’s body weight per day in 2 or 3 divided doses. Primidone can be given with food. Allow plenty of water for your pet to drink
Storage: Store this product at room temperature, away from moisture and heat.
Your veterinarian would need to make the decision whether primidone could be used instead of phenobarbital elixir. If the decision was made to use primidone, your veterinarian would determine the correct dose to use. Primidone and phenobarbital are not directly substitutable.
I don't know. I don't know how much your pet weighs nor do I know what strength phenobarbital your pet took. I would suggest you contact your veterinarian or a veterinary emergency room because of the potential for an overdose.
Our vet has our whippet-like 40 lb. dog taking 400 mg of Zonisamide a day...two at each meal. (She'd been having seizures about once a month.) She is NOT eating. We have tried a chicken/rice dog food and now she's not eating that either. Everything I've read says that's way too big a dosage for her. Help?
3 years, 6 months ago
Cedar Park, TX
A typical dose of zonisamide for a 40 lb dog is 200 mg every 12 hours. I can't say that 400 mg every 12 hours is too much because I don't know your pet's condition. Loss of appetite is a common side effect for this medication.
She gets very excited, restless. What she took was Pheno. Please help me with this. P.S. She has seizure.
3 years, 6 months ago
This medication can cause your dog to have trouble breathing. This typically happens if the animal has an allergic reaction to the primidone. Getting excited and restless can both be caused by taking this drug.
This information sheet is for educational purposes only and is intended to be a supplement to, and not a substitute for, the expertise and professional judgment of your veterinarian. The information is NOT to be used for diagnosis or treatment of your pet. You should always consult your own veterinarian for specific advice concerning the treatment of your pet. The information is not intended to cover all possible uses, directions, precautions, warnings, allergic reactions, drug interactions or adverse effects, nor should it be construed to indicate that use of a particular drug is safe, appropriate or effective for your pet. It is not a substitute for a veterinary exam, and it does not replace the need for services provided by your veterinarian. Note: Any trademarks are the property of their respective companies.