A pharmaceutical composition including an active anticonvulsant drug and an effective amount of at least one metabolite of dextromethorphan sufficient to potentiate the anticonvulsant activity of the anticonvulsant drug. The metabolites and in particular dextrorphan are effective in potentiating the activity of anticonvulsants including phenytoin and carbamazepine. A method of treating epilepsy and other forms of convulsions comprising administration either simultaneously or sequentially and of an effective amount of an anticonvulsant drug and at least one of the dextromethorphan metabolites in an amount sufficient to potentiate the action of the anticonvulsant drug.
DEXTRORPHAN POTENTIATOR FOR ANTICONVULSANT COMPOSITION AND METHOD