A brief trial of phenytoin therapy for thalamic pain.

Phenytoin was given in full dosage to eight patients with thalamic pain and two others with intractable pain resistant to other forms of treatment. Serum levels were monitored and correlated with dosage levels. Three patients improved markedly, two improved only minimally, two were unchanged, and three were worse. Those patients who had improved noted return of original pain on stopping phenytoin. The results indicate the need for a further study of the drug in thalamic and other chronic pain states.