A Guide to Primidone - Brand Name Phenobarbital for Dogs and Cats

How This Brand Name Phenobarbital for Pets Treats Seizures and Epilepsy

By Sam Bourne.

  • Epilepsy
  • Poisoning

indications for Primidone

Primidone is an anticonvulsant medication used to help prevent dogs or cats with epilepsy from experiencing seizures. This drug makes it more difficult for one’s nervous system to fire off uncontrollably, which is one of the main causes of a seizure. Also used to help speed up the detoxification of chlorinated hydrocarbons insecticide poisoning, Primidone has a number of different applications. While the actual mechanism behind which this drug works is still not fully understood (many drugs working on our neural pathways are this way), we do know that it is incredibly effective as an anti-seizure drug.


Primidone should be taken with caution in patients with hypovolemia, anemia, hypoadrenocorticism, and kidney disease. Not to be given to patients with severe respiratory dysfunction, liver disease, or pets with a known sensitivity to drugs of this class. This drugs use in cats should be carefully monitored due to respiratory depression.

Primidone might decrease the effects of oral anticoagulants, beta blockers, corticosteroids, estrogen agents, progestins, and tricyclic antidepressants, while drugs like phenothiazine opiate agonists, CNS depressants, and antihistamines might increase the effects of Primidone.


Treatments should be given to you buy your consulting veterinarian, and should be followed. Dosage differs depending on species, breed, size, and age of your pet.

Brand/Generic equivalents


Side Effects

Primidone might cause anxiety, agitation, or depression during the first few therapeutic sessions, along with ataxia and sedation. Polyuria, polydipsia, polyphagia, liver changes, thrombocytopenia, neutropenia, and anemia are potential side effects as well, and should be mentioned to your veterinarian. On rare occurrences, anemia might occur.

For cats, ataxia, lethargy, polydipsia, polyuria, polyphagia, and weight gain have all been reported as side effects of Primidone. In some rare cases, immune mediated reactions and bone marrow hypoplasia can occur.

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Primidone at a glance

  • 1For dogs and cats
  • 2Anticonvulsant
  • 3Taken intravenously
  • 4Treats epilepsy and prevent seizures

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