Dicumarol
Encyclopedia
Dicoumarol or dicumarol (USAN
) is an anticoagulant
that functions as a vitamin K
antagonist (similar to warfarin
, for which it was the inspiration). It is also used in biochemical experiments as an inhibitor of reductases.
Dicoumarol is a natural chemical substance of combined plant and fungal origin. It is a derivative of coumarin
, a bitter substance made by plants that does not itself affect coagulation, but which is (classically) transformed in mouldy feeds or silages by a number of species of fungi, into active dicoumarol. Dicoumarol does affect coagulation, and was discovered in mouldy wet sweet-clover hay, as the cause of a naturally occurring bleeding disease in cattle.
Identified in 1940, dicoumarol became the prototype of the 4-hydroxycoumarin derivative anticoagulant drug class. Dicoumarol itself, for a short time, was employed as a medicinal anticoagulant drug, but since the mid-1950s has been replaced by its simpler derivative warfarin
, and other 4-hydroxycoumarin drugs.
It is given only orally, and it acts within two days.
, preventing the formation of prothrombin. Administration of vitamin K is therefore the antidote for dicoumarol toxicity. The toxicity and the antidote effectiveness are measuring with the prothrombin time
(PT) blood test.
United States Adopted Name
United States Adopted Names are unique nonproprietary names assigned to pharmaceuticals marketed in the United States. Each name is assigned by the USAN Council, which is co-sponsored by the American Medical Association , the United States Pharmacopeial Convention , and the American Pharmacists...
) is an anticoagulant
Anticoagulant
An anticoagulant is a substance that prevents coagulation of blood. A group of pharmaceuticals called anticoagulants can be used in vivo as a medication for thrombotic disorders. Some anticoagulants are used in medical equipment, such as test tubes, blood transfusion bags, and renal dialysis...
that functions as a vitamin K
Vitamin K
Vitamin K is a group of structurally similar, fat soluble vitamins that are needed for the posttranslational modification of certain proteins required for blood coagulation and in metabolic pathways in bone and other tissue. They are 2-methyl-1,4-naphthoquinone derivatives...
antagonist (similar to warfarin
Warfarin
Warfarin is an anticoagulant. It is most likely to be the drug popularly referred to as a "blood thinner," yet this is a misnomer, since it does not affect the thickness or viscosity of blood...
, for which it was the inspiration). It is also used in biochemical experiments as an inhibitor of reductases.
Dicoumarol is a natural chemical substance of combined plant and fungal origin. It is a derivative of coumarin
Coumarin
Coumarin is a fragrant chemical compound in the benzopyrone chemical class, found in many plants, notably in high concentration in the tonka bean , vanilla grass , sweet woodruff , mullein , sweet grass , cassia cinnamon and sweet clover...
, a bitter substance made by plants that does not itself affect coagulation, but which is (classically) transformed in mouldy feeds or silages by a number of species of fungi, into active dicoumarol. Dicoumarol does affect coagulation, and was discovered in mouldy wet sweet-clover hay, as the cause of a naturally occurring bleeding disease in cattle.
Identified in 1940, dicoumarol became the prototype of the 4-hydroxycoumarin derivative anticoagulant drug class. Dicoumarol itself, for a short time, was employed as a medicinal anticoagulant drug, but since the mid-1950s has been replaced by its simpler derivative warfarin
Warfarin
Warfarin is an anticoagulant. It is most likely to be the drug popularly referred to as a "blood thinner," yet this is a misnomer, since it does not affect the thickness or viscosity of blood...
, and other 4-hydroxycoumarin drugs.
It is given only orally, and it acts within two days.
Mechanism of action
Like all 4-hydroxycoumarin drugs it is a competitive inhibitor of vitamin KVitamin K
Vitamin K is a group of structurally similar, fat soluble vitamins that are needed for the posttranslational modification of certain proteins required for blood coagulation and in metabolic pathways in bone and other tissue. They are 2-methyl-1,4-naphthoquinone derivatives...
, preventing the formation of prothrombin. Administration of vitamin K is therefore the antidote for dicoumarol toxicity. The toxicity and the antidote effectiveness are measuring with the prothrombin time
Prothrombin time
The prothrombin time and its derived measures of prothrombin ratio and international normalized ratio are measures of the extrinsic pathway of coagulation. This test is also called "ProTime INR" and "INR PT". They are used to determine the clotting tendency of blood, in the measure of warfarin...
(PT) blood test.