Procedures: When Dilantin levels are in the therapeutic range for 2 consecutive days on interrupted feedings (baseline), the patient will be switched to continuous feedings uninterrupted for the medication, for 7 days. Dilantin levels will be checked daily and if the levels become subtherapeutic an IV bolus of Dilantin will be given and the enteral dose will be increased (doses determined by primary caregiver). Serum albumin will be measured at baseline and at the beginning and end of each week, in order to calculate free Dilantin.