dicoumarol

Dicoumarol is a vitamin K antagonist belonging to the 4-hydroxycoumarin family of compounds. It was identified in the mid-20th century as the active anticoagulant component arising from spoiled sweet clover hay, which caused a hemorrhagic disease in cattle known as sweet clover disease. This finding helped establish dicoumarol as one of the first orally active anticoagulants used in humans, preceding the development of warfarin.

Mechanism of action and pharmacology

Dicoumarol inhibits the activity of the enzyme vitamin K epoxide reductase, reducing the regeneration of active, reduced vitamin K. This interferes with the gamma-carboxylation of glutamic acid residues on clotting factors II, VII, IX, and X, as well as anticoagulant proteins C and S, leading to impaired blood coagulation. The anticoagulant effect is dose-dependent and influenced by dietary vitamin K intake and interactions with other drugs.

Clinical use and status

Historically, dicoumarol was used as an oral anticoagulant in humans, but it was largely supplanted by warfarin due to more favorable pharmacokinetics and safety profiles. Today it is mainly of historical and research interest, though it may appear in veterinary contexts or laboratory studies as a reference compound for vitamin K antagonism.

Safety and reversal

Like other anticoagulants, dicoumarol increases bleeding risk. Reversal of its effects is achieved with vitamin K administration, and in acute bleeding situations with procedures such as plasma transfusion or coagulation factor concentrates as appropriate. Foods high in vitamin K can reduce its effectiveness.