The effect of sodium phenytoin on central nervous system oxygen toxicity.

The effect of sodium phenytoin on hyperbaric oxygen (HBO) induced central nervous system (CNS) toxicity was studied in rats. The latency of the epileptic electroencephalographic discharges was measured in 20 phenytoin-treated rats exposed to 6 ATA of 100% oxygen, and compared with that of 20 saline-injected rats exposed to the same pressure of pure oxygen. No statistically significant difference was found in the latency between the two groups. In addition, phenytoin failed to suppress or to modify the clinical seizures. Sodium phenytoin failed to suppress or to modify the clinical seizures. Sodium phenytoin blood levels were determined in the rats, and were found to be within the therapeutic range. We conclude that sodium phenytoin is ineffective in suppressing HBO induced CNS oxygen toxicity.