doxifluridine doxifluridine doxifluridine is a second generation nucleoside analog prodrug developed by roche and used as a cytostatic agent in chemotherapy in several asian countries including china and south korea. doxifluridine is not fda-approved for use in the usa. it is currently being evaluated in several clinical trials as a stand-alone or combination therapy treatment. doxifluridineclinical dataother namesdoxyfluridine; doxifluridine; 5'-deoxy-5-fluorouridine; 5'-deoxy-5'-fluorouridine; 5'-fluoro-5'-deoxyuridine; 5'-dfurd; 5'-dfur; furtulon; ro 21-9738identifiers iupac name 1--5-fluoropyrimidine-2,4-dione cas number3094-09-5 ypubchem cid18343chemspider17322uniiv1jk16y2jpcomptox dashboard (epa)dtxsid2022967 echa infocard100.019.491 chemical and physical dataformulac9h11fn2o5molar mass246.194 g·mol−13d model (jsmol)interactive image smiles c1(((o1)n2c=c(c(=o)nc2=o)f)o)o inchi inchi=1s/c9h11fn2o5/c1-3-5(13)6(14)8(17-3)12-2-4(10)7(15)11-9(12)16/h2-3,5-6,8,13-14h,1h3,(h,11,15,16)/t3-,5-,6-,8-/m1/s1key:zwaohexosaujhy-ziyngmlesa-n biology 5-fluorouracil (5-fu), the nucleobase of doxifluridine, is currently an fda-approved antimetabolite. 5-fu is normally administered intravenously to prevent its degradation by dihydropyrimidine dehydrogenase in the gut wall. doxifluridine (5´-deoxy-5-fluorouridine) is a fluoropyrimidine derivative of 5-fu, thus a second-generation nucleoside prodrug. doxifluridine was designed to improve oral bioavailability in order to avoid dihydropyrimidine dehydrogenase degradation in the digestive system. within a cell, pyrimidine nucleoside phosphorylase or thymidine phosphorylase can metabolize doxifluridine into 5-fu. it is also a metabolite of capecitabine. high levels of pyrimidine-nucleoside phosphorylase and thymidine phosphorylase are expressed in esophageal, breast, cervical, pancreatic, and hepatic cancers. liberation of 5-fu is the active metabolite and leads to inhibition of dna synthesis and cell death. side effects high thymidine phosphorylase expression is also found in the human intestinal tract, resulting in dose-limiting toxicity (diarrhea) in some individuals. the most frequent adverse effects for doxifluridine were neurotoxicity and mucositis. brand names doxifluridine is sold under many brand names: brand name company country didox shin poong pharm. co., ltd. south korea doxyfluridine kwang dong doxifluridine cap myungmoon pharma co. ltd. ai feng hengrui china and japan doxifluridine xinshidai pharmaceutical furtulon roche, chugai ke fu zhaohui ke tuo southwest qi nuo bi tong wanjie high-tech shu qi team tan nuo xinchang medicine & chemical co ltd yi di an pacific