Effect of S-1 on blood levels of phenobarbital and phenytoin: A case report.
Ken ShiraiwaHiroyuki OnoRyota TanakaAtsuro FujinagaTakahiro HiratsukaRyosuke TatsutaMasafumi InomataHiroki ItohPublished in: Clinical case reports (2021)
Drug-drug interaction of fluorinated pyrimidine anticancer agents with phenytoin is well known, but interaction with phenobarbital is limited. We describe a case showing increases in plasma phenobarbital as well as phenytoin concentrations during preoperative S-1 (tegafur/gimeracil/oteracil) and radiation therapy for rectal cancer.