Case study of two methods for enteral phenytoin administration.

Phenytoin is a medication administered for the treatment or prophylaxis of seizures in head-injured patients. When enterally administered, serum phenytoin levels fall dramatically and are often subtherapeutic. The exact cause for this phenomenon has not been determined. The purpose in this case study was to evaluate the effect of two methods of administering phenytoin suspension in head-injured patients receiving concurrent enteral feedings by measuring subsequent serum phenytoin levels. Purposive sampling was used which included two female participants. For participant 1, data revealed dilution of the suspension and irrigation of the tube produced higher phenytoin levels than administering the suspension undiluted. Both serum phenytoin levels were profoundly subtherapeutic in participant 2. Factors such as simultaneous administration of other enteral medications to the second participant might have interfered with phenytoin absorption.