[Plasma concentrations after injection or infusion of phenytoin (author's transl)]

Intravenous injection of 3 mg/kg phenytoin produced plasma concentrations of 4.2 mug/ml in five volunteers, which were below the concentration of 10-20 mjg/ml necessary for effective antiarrhythmic and antiepileptic treatment. Intravenous injection of 250 mg phenytoin followed by infusion of 750 mg phenytoin in a mean dosage of 1.7 mg/kg x h in nine patients with epilepsy produced plasma concentrations of 10.2 resp. 15.1 mug/ml after 4 resp. 8h. An oral maintenance therapy of 5-6 mg/kg is suggested. Therapeutic plasma concentrations were rapidly reached with this regimen.