Comparison of sodium valproate and phenytoin as single drug treatment in epilepsy.

Thirty-three epileptic patients were randomly divided into two treatment groups. One group of 18 patients was given sodium valproate; the other 15 patients were given phenytoin. Periods of treatment ranged from 9 t0 48 months (mean, 30 months). Any patient who developed a seizure while on the first drug was changed to the other drug, provided the serum level of the first drug was in the accepted therapeutic range. Six required the change from phenytoin to sodium valproate, and three from sodium valproate to phenytoin. Side effects were not a major problem with either drug during the trial period. Phenytoin has been widely prescribed alone; our results indicate that sodium valproate may also be used as a single drug in the treatment of several types of epilepsy.