Trifluridine is a fluorinated pyrimidine nucleoside that is structurally related to idoxuridine and an active antiviral agent in ophthalmic solutions that is mainly used in the treatment of primary keratoxonjunctivitis and recurrent epithelial keratitis due to herpes simplex virus. It displays effective antiviral activity against Herpes simplex virus type 1 and 2. The mechanism of action of trifluridine as an antiviral agent has not been fully elucidated, but appears to involve the inhibition of viral replication. Trifluridine gets incorporated into viral DNA during replication in replacement of thymidine, which leads to the formation of defective proteins and an increased mutation rate. Less Viral DNA is transported into the nucleus, therefore, less viral DNA is integrated into the host DNA. Less viral proteins produced, fewer viruses can form. Trifluridine also mediates antineoplastic activities via this mechanism; following uptake into cancer cells, trifluridine is rapidly phosphorylated by thymidine kinase to its active monophosphate form. It is further phosphorylated into trifluridine triphosphate, which is readily incorporated into the DNA of tumour cells in place of thymidine bases to perturb DNA function, DNA synthesis, and tumour cell proliferation.

Trifluridine Pathway References