Prototype of the 4-hydroxycoumarin class of anticoagulants, which act as vitamin K antagonists, preventing formation of prothrombin. There are many reports that dicumarol also inhibits NADPH:quinone oxidoreductase (NQO(1)). In one, it inhibited NQO(1) in a pancreatic cancer cell line, causing increased formation of superoxide and inhibiting cell growth. Prototype of the 4-hydroxycoumarin class of anticoagulants, which act as vitamin K antagonists, preventing formation of prothrombin. There are many reports that dicumarol also inhibits NADPH:quinone oxidoreductase (NQO(1)). In one, it inhibited NQO(1) in a pancreatic cancer cell line, causing increased formation of superoxide and inhibiting cell growth.