5-fluorouracil + raltitrexed

This is a combination chemotherapy regimen consisting of two antimetabolite agents, 5-fluorouracil (5-FU) and raltitrexed. Both drugs inhibit thymidylate synthase, an enzyme essential for DNA synthesis, but through distinct mechanisms. 5-FU is converted intracellularly to active metabolites that inhibit thymidylate synthase and can also be incorporated into RNA and DNA, disrupting their function. Raltitrexed is a quinazoline folate analogue that selectively inhibits thymidylate synthase by mimicking the natural folate cofactor required for the enzyme's activity. The combination has demonstrated schedule-dependent synergism in preclinical studies—raltitrexed should precede administration of 5-FU for optimal effect—and has been investigated primarily in advanced colorectal cancer as well as other solid tumors such as head and neck cancer. The main dose-limiting toxicity is neutropenia; other toxicities include mucositis and diarrhea[1][2][3][8]. This regimen remains investigational or off-label in many regions.

Other names

5-FU + raltitrexedfluorouracil + raltitrexed