Case Study 4

1. E.A., (37y, 70 kg, male), had been taking 300mg/day of sodium phenytoin; however, his dose was increased to 350 mg/day because his reported plasma phenytoin concentration was only 8 mg/L. Now his reported plasma phenytoin concentration is 20 mg/L. Both of the reported plasma concentrations represent steady-state level. Calculate a new daily dose of sodium phenytoin that will result in a steady state level of 15 mg/L (Salt factor = 0.92).