Comparison of Pharmacokinetics of 5-Fluorouracil and 5-Fluorouracil with Concurrent Thymidine Infusions in a Phase I Trial

摘要: The serum half-life of 5-fluorouracil (5-FUra) in humans is best described as a biexponential decay function, with t1/2 alpha = 7.8 +/- 2.6 (S.E.) min and beta 36.8 13.5 during initial courses this drug alone. Pharmacokinetics 5-FUra daily therapy (for 5 days) revealed prolongation both components the curve, which has not been previously reported. Despite efficacy thymidine (dThd) given continous i.v. infusion 8 g/sq m/day prevention high-dose methotrexate toxicity, continuous dThd at dose does prevent toxicity orreverse inhibition DNA RNA synthesis by 5-fura. On contrary, appears to increase remained stable through course days dThd. This protracted believed account least part for increased Dose-limiting mucositis, myelosuppression, gastrointestinal were observed doses ranging from one-half two-thirds customarily tolerated alone similar bolus days).