Phenytoin

Name

• Phenytoin sodium.

Class of drug

• Anticonvulsant

Uses

Action

• An anti-epileptic drug which diminishes the spread and propagation of focal neural discharges in the cerebral motor cortex by reducing/stabilizing synaptic junction excitability.

Indications

• It is used to control most forms of epilepsy in human medicine.
• Metabolized very rapidly in dogs such that very high doses need to be given often , whereas cats metabolize the drug very slowly and toxicity easily develops.
• These undesirable pharmacokinetc properties make it a secondary agent in veterinary medicine.
• Its use in the cat cannot be recommended.

Adverse reactions

Other reported reactions

• Ataxia.
• Vomiting.
• Peripheral neuropathy.
• Liver failure.
• Toxic epidermal necrolysis.
• Pyrexia.
• Lupus erythematosus.
• Delirium.

Investigation of adverse reaction

• Monitoring of serum levels is useful in cases when either efficacy or toxicity are in question.
• Monitor liver function yearly in patients on chronic therapy.