Adverse Effect of Phenobarbital in Dogs

Phenobarbital is a long-acting anti-convulsive medication used for the treatment of seizures and epilepsy in dogs. Phenobarbital has a sedative effect, which helps to lessen the frequency and severity of seizures.

Initial Side Effects

During the initial stages of treatment with phenobarbital, your dog might experience restlessness, anxiety, lethargy, depression, increased appetite, increased thirst and increased urination.

Ongoing Side Effects

Once your dog's body becomes accustomed to the phenobarbital, which usually takes about two weeks, many of the side effects begin to diminish. However, increased hunger and thirst as well as increased urination will be ongoing.

Long-Term Side Effects

Many times phenobarbital is prescribed on a long-term basis for the treatment of epilepsy. Prolonged use can cause severe irreversible damage to the liver; your veterinarian might need to change medications if symptoms appear.

Drug Interactions

Some medications might cause additional complications when used in conjunction with phenobarbital. Be sure to alert your veterinarian before mixing medications.

Overdose

Since phenobarbital is a sedative, an overdose could cause the nervous system to shut down, resulting in death. Although this is rare, care should be taken to follow dosing instructions carefully.

References

• Phenobarbital
• The Side Effets of Phenobarbital for Dogs
• Phenobarbital (CIV)

Resources

• Phenobarbital