COMPARISON OF THE EFFECTIVENESS OF 2 ORAL PHENYTOIN PRODUCTS AND CHRONOPHARMACOKINETICS OF PHENYTOIN

A cross-over study was carried out in 14 epileptic patients to compare the steady-state serum phenytoin concentrations produced by two pheny toin formulations (Phenytoin Sodium(R) and Epanutin(R)). Differences i n steady-state phenytoin concentrations following a change from one pr oduct to the other were not significant, indicating that the two brand s manifest equivalent therapeutic efficacy. The results suggest that n o overall dosage adjustments are required when switching from one bran d to the other. Chronopharmacokinetic parameters of a single 300-mg do se of phenytoin, given at 08.00 and 20.00 hours, were studied in 10 he althy, male volunteers under controlled conditions. No evidence was fo und that circadian rhythms influenced absorption and disposition.