Definition

The disodium salt form of raltitrexed, a quinazoline folate analogue, with potential antineoplastic activity. Upon administration of raltitrexed, this agent is taken up by cells via the reduced folate carrier, undergoes intracellular polyglutamation, and blocks the folate-binding site of thymidylate synthase (TS). This inhibits the conversion of deoxyuridine monophosphate (dUMP) into deoxythymidine monophosphate (dTMP) and thus increases dUMP levels and decreases the amount of deoxythymidine triphosphate (dTTP) available for DNA synthesis. This prevents DNA replication and repair, and leads to DNA fragmentation and cell death, and results in reduced tumor cell ‘proliferation.