Floxuridine (FUDR) is an antimetabolite, floxuridine inhibits thymidylate synthase, resulting in disruption of DNA synthesis and cytotoxicity.

Floxuridine exhibits higher affinity for PEPT1 than the corresponding 5'-O-mono amino acid ester prodrugs. [1] Floxuridine combined with Leucovorin results in synergistic inhibitory effects on growth of human T-lymphoblast leukemia cells. [2] Floxuridine significantly inhibits the uptake of both [(3)H]-inosine and [(3)H]-adenosine (60-70% of control), while its amino acid ester prodrugs including Val, Phe, Pro, Asp, and Lys esters exhibits markedly decreased inhibition potency (10-30% of control). [3] Floxuridine inhibits cell proliferation by more than 50% relative to the untreated control cells at 36 days, the cell numbers still increases fourfold compared with the initial cell density. Floxuridine results in prolonged effects on the proliferation of human Tenon's capsule fibroblasts in vitro. [4] Floxuridine (FUDR) is an ideal drug for hepatic arterial infusion (HAI) due to its short half life, steep dose response curve, high total body clearance, and high hepatic extraction. [5]