Phenobarbital Overdose in Dogs

Phenobarbital is a medication that is commonly prescribed by veterinarians to treat seizures in dogs. Phenobarbital is inexpensive, is effective in controlling seizures and has few side effects. It is important to follow your veterinarians directions exactly when giving your dog this medication. The correct dosage is important to control seizures in dogs and will help to avoid an overdose of medication.

  1. Identification

    • Phenobarbital is in the barbiturate family of drugs and is an anti-epileptic drug. It is prescribed in the treatment of seizures in dogs as well as humans. Phenobarbital was first introduced for use in humans in 1912, and was the first synthetic drug used to treat epilepsy.

    Dosage

    • The dosage of phenobarbital for seizures in dogs is originally based on the body weight of the dog. Each dog metabolizes medication differently and most veterinarians begin treatment in dogs with the lowest recommended dosage. This dosage is gradually increased when the tolerance and response to the drug is determined. Dogs that have severe or frequent seizures may begin with a slightly higher dose. Never increase your dog's dosage without consulting your veterinarian. Doing so may cause an overdose of medication, which may be fatal.

    Side Effects

    • There are some side effects that can be expected in dogs that are taking phenobarbital for seizures. Normal side effects that may be associated with phenobarbital in dogs is lethargy, sedation, increase in thirst, increase in urination, hyperactivity and loss of coordination. Dogs that take this medication for an extended period of time may experience liver damage. Liver damage may change the way phenobarbital is metabolized by the body and may result in an overdose of medication or may require a higher dosage of medication in order to control your dog's seizures. Your veterinarian will monitor your dog's liver function while taking phenobarbital for seizures with regular blood tests.

    Symptoms

    • The symptoms associated with an overdose of phenobarbital in dogs are sedation, ataxia, low blood pressure and stupor. Phenobarbital may suppress the respiratory system, making breathing shallow. An overdose of this medication may lead to acute kidney failure as well. If the dog is in a stupor, it may be necessary to remove as much phenobarbital from the stomach as possible using gastric lavage.

    Considerations

    • While phenobarbital may be successful in controlling seizures in dogs, it is a potent barbiturate. It is important to follow all dosage instructions as provided by your veterinarian. If your dog seems extremely lethargic or cannot walk, contact an emergency professional to rule out a phenobarbital overdose. Keep this medication out of the reach of other dogs and children to avoid accidental ingestion and overdose.