Merritt and Putnam1 found that while phenytoin sodium (sodium diphenyl hydantoinate, or dilantin sodium) was effective in protecting animals from electrically induced convulsions it produced little sedative effect. The effectiveness of this drug was then determined by them2 in a group of 200 patients who had been having frequent convulsive seizures for many years and who had obtained little or no benefit from the usually accepted treatment. Certain toxic effects were observed, among them dermatitis, nonthrombopenic purpura, tremors, ataxia and dizziness.
Although Fetterman3 reported that phenytoin sodium had a high degree of therapeutic value, he observed disquieting side actions such as itching, a cutaneous rash, swelling of the gums, tremors and ataxia, blurring of vision, loss of taste and dysesthesia in the mouth, restlessness, insomnia, irritability, paranoid state, anorexia, gastric distress and loss of weight. A study of the table published by Fetterman shows that 23 of
FINKELMAN I, ARIEFF AJ. UNTOWARD EFFECTS OF PHENYTOIN SODIUM IN EPILEPSY. JAMA. 1942;118(14):1209-1212. doi:10.1001/jama.1942.02830140039012