Trifluridine is a fluorinated pyrimidine nucleoside analog which interferes with DNA synthesis of herpes simplex virus, type 1 and 2 and vaccinia virus. It stops replication of herpes viral DNA in 3 ways:
i) competitive inhibition of viral DNA polymerase,
ii) incorporation into and termination of the growing viral DNA chain and
iii) inactivation of the viral DNA polymerase.