1. Some sodium channel blockers, such as Dilantin (diphenylhydantoin), have been clearly shown to have adverse effects on cognition.

2. 1 Pretreatment doses of Barbitone, pentoBarbitone, ethanol, and phenytoin (diphenylhydantoin) in non-tolerant rats produced increases in operant responding at low doses and at higher doses resulted in decreases in responding.