Ethotoin
Mechanism :
Ethotoin exerts an antiepileptic effect without causing general central nervous system depression. The mechanism of action is probably very similar to that of phenytoin, which appears to stabilize rather than to raise the normal seizure threshold, and to prevent the spread of seizure activity rather than to abolish the primary focus of seizure discharges.
Indication :
- Tonic-clonic and complex partial seizures
Contraindications :
Contraindicated in patients with hepatic abnormalities or hematologic disorders.
Dosing :
Start with doses upto 750 mg daily in 4-6 divided doses.
Maintain on 500 mg to 1 g orally once daily, although occasionally 2 or (rarely) 3 g daily may be necessary.
Adverse Effect :
Vomiting, nausea, ataxia, gum hypertrophy, nystagmus, diplopia, chest pain, dizziness, fever, diarrhea, headache, fatigue, numbness, insomnia, skin rash. Isolated cases of lymphadenopathy, Stevens-Johnson syndrome and systemic lupus erythematosus have been reported.
Interaction :
Combination with other drugs known to adversely affect the hematopoietic system should be avoided if possible.
Phenacemide: Paranoid symptoms have been reported during therapy with this combination.
phenytoin acts as a stimulator of coumarin metabolism and has been reported to cause decreased serum levels of the coumarin anticoagulants and increased prothrombin-proconvertin concentrations. Conversely, the coumarin anticoagulants have been reported to increase the serum levels and prolong the serum half-life of phenytoin by inhibiting its metabolism.
Hepatic Dose :
Ethotoin is extensively metabolized in the liver and reduction in the dose may be needed in liver dysfunction.