Phenytoin therapy

I wish to point out a significant error in the article by Peter W. Mullen, “Optimal phenytoin therapy: A new technique for individualizing dosage,” which appeared on page 228 of the February, 1978, issue of the J ournal . In Table I, the serum phenytoin concentrations he predicted by using the method described by Ludden and colleagues (C lin . P harmacol . T her . 21 :287–293, 1977) for Patient C are given as 9.7 and 24.3 mg/L for the 200 and 300 mg/day doses, respectively. I obtain 7.6 and 31.5 mg/L, respectively, using Ludden and co‐workers' method.