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Drug Details

  • Drug Name: Phenobarbital
  • Common Name: Luminal®, Barbita®
  • Drug Type: Anticonvulsant
  • Used For: Seizures,
  • Species: Dogs, Cats
  • Administered: Injectable, Tablets, Capsules, Oral liquid
  • FDA Approved: No

General Description


Phenobarbital is used to control epilepsy in your pet. It may be used alone or in conjuction with other drugs to reduce the number and severity of your pet’s seizures.


How It Works


A seizure is a sudden surge in neuron activity in the brain, causing a change in feeling or behavior. Phenobarbital decreases and stabilizes neuron activity, decreasing the amount of seizures your pet experiences. Neurotransmitters, or brain chemicals, control the brain activity and phenobarbital tends to act on two. GABA is a neurotransmitter that has nerve-calming properties, and phenobarital increases this neurotransmitter. Glutamate is a neurotransmitter that has nerve-stimulating properties, and phenobarital decreases this neurotransmitter.


Phenobarbital’s neuron decreasing effects may also decrease other neurons, resulting in lethargy and other unwanted side effects. Closelt monitor your pet while they are on this drug.


Storage Information


Store in a tightly sealed container at room temperature.


Missed Dose?


Missing a dose may cause your pet to have a seizure! Try very hard not to miss any doses!


Give the dose as soon as possible. If it is almost time for the next dose, skip the missed dose, and continue with the regular schedule. Do not give the pet two doses at once.


Side Effects and Drug Reactions


Phenobarbital may result in these side effects:

  • Anxiety
  • Lethargy
  • Sedation
  • Increase in water intake
  • Increase in appetite
  • Increase in urination
  • Anemia
  • Weight gain


Phenobarbital may react with these drugs:

  • Anticoagulants
  • Antihistamines
  • Beta adrenergic blocker
  • Diazepam (and other central nervous system depressants)
  • Corticosteroids
  • Opiate agonists
  • Phenothiazine
  • Aminophylline
  • Chloramphenicol
  • Doxycycline
  • Furosemide
  • Griseofulvin
  • Metronidazole
  • Phenytoin sodium
  • Quinidine
  • Rifampin
  • Theophylline
  • Valproic acid




USE CAUTION WHEN ADMINISTERING THIS DRUG TO CATS - Risk and severity of side effects, mainly respiratory depression and labored breathing, increase when Phenobarbital is given to cats. Do not use without the approval of your veterinarian and use exactly the dose your veterinarian recommends.


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