 For the eye drops, trifluridine absorption is negligible, rendering interactions basically irrelevant.It is a nucleoside analogue, a modified form of deoxyuridine, similar enough to be incorporated into viral DNA replication, but the –CF3 group added to the uracil component blocks base pairing, thus interfering with viral DNA replication.Trifluridine passes the cornea and is found in the aqueous humour.