Plasma pharmacokinetics after combined therapy of gemcitabine and oral S-1 for unresectable pancreatic cancer

Background. the combination of gemcitabine (gem) and s-1,an oral 5-fluorouracil (5-fu) derivative,has been shown to be a promising regimen for patients with unresectable pancreatic cancer. methods. six patients with advanced pancreatic cancer were enrolled in this pharmacokinetics (pk) study. these patients were treated by oral administration of s-1 30 mg/m2 twice daily for 28 consecutive days,followed by a 14-day rest period and intravenous administration of gem 800 mg/m2 on days 1,15 and 29 of each course. the pk parameters of gem and/or 5-fu after gem single- administration,s-1 single-administration,and co-administration of gem with pre-administration of s-1 at 2-h intervals were analyzed. results. the maximum concentration (cmax),the area under the curve from the drug administration to the infinite time (aucinf),and the elimination half-life (t1/2) of gem were not significantly different between gem administration with and without s-1. the cmax,aucinf,t1/2,and the time required to reach cmax (tmax) were not significantly different between s-1 administration with and without gem. conclusion. there were no interactions between gem and s-1 regarding plasma pk of gem and 5-fu. © 2010 nakata et al; licensee biomed central ltd.