ANTIEPILEPTIC MEDICATIONS

CARBAMAZEPINE

Mechanism of Action :

Carbamazepine reduces polysynaptic responses and blocks post-tetanic potentiation. It is effective in partial and generalised convulsions as well as in mixed types but not in petit mal seizures. It reduces or abolishes pain in trigeminal and glossopharyngeal neuralgia.

Indication, Dosage and Frequency :

Oral
EPILEPSY
Adult: Initially, 100-200 mg once or bid gradually increased by increments of 100-200 mg every 2 wk. Maintenance: 0.8-1.2 g daily in divided doses. Max dose: 2 g daily.
Child: ≤1 yr: 100-200 mg daily, 1-5 yr: 200-400 mg daily, 5-10 yr: 400-600 mg daily, 10-15 yr: 0.6-1 g daily. Alternatively, 10-20 mg/kg daily in divided doses.

TRIGEMINAL NEURALGIA
Adult: Initially, 100 mg once or bid gradually increased as necessary. Maintenance: 400-800 mg daily in 2-4 divided doses. Max: 1.2 g daily.

PROPHYLAXIS OF BIPOLAR DISORDER
Adult: Initially, 400 mg daily in divided doses gradually increased if necessary. Maintenance: 400-600 mg daily. Max: 1.6 g daily.

Rectal
EPILEPSY
Adult: 250 mg every 6 hr for patients incapable of oral treatment

Interactions :

Reduces tolerance to alcohol; shortens T½ of doxycycline. Decreased efficacy of oral contraceptives when used with carbamazepine. Increased plasma concentrations of carbamazepine by propoxyphene. Serum level decreases with phenytoin, phenobarbital, primidone