[Pharmacokinetics and adverse event of TS-1 administered through gastrostomy]

We administered TS-1 to a patient with advanced oropharyngeal carcinoma who underwent a gastrostomy because of swallowing difficulties. TS-1 was dissolved in 50 degrees C water and administered through a gastrostogavage tube. The pharmacokinetics of TS-1 were then investigated. The plasma 5-FU level was measured, and adverse events appearing after administration were monitored. The highest plasma 5-FU concentration on day 1 was 138.7 ng/ml; this level was obtained in a sample drawn 2 hours after the administration of TS-1. The highest plasma 5-FU concentration of TS-1 on day 8 (159.8 ng/ml) was also drawn 2 hours after the administration of TS-1. No major adverse events were observed in the patient. In particular, no toxic effects on the digestive systems were observed. Furthermore, the administration of TS-1 through a gastrostomy was safe. Such a procedure could also be used in patients with naso-gastric feeding tubes. We conclude that the administration of TS-1 through either a gastrostomy or a naso-gastric feeding tube may be a new administration method that can improve the quality of life (QOL) of patients with advanced and/or recurrent head and neck carcinoma.