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Information |
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Drug Groups
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approved |
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Description
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Acenocoumarol is a coumarin derivative used as an anticoagulant. Coumarin derivatives inhibit the reduction of vitamin K by vitamin K reductase. This prevents carboxylation of vitamin K-dependent clotting factors, II, VII, XI and X, and interferes with coagulation. Hematocrit, hemoglobin, international normalized ratio and liver panel should be monitored. Patients on acenocoumarol are prohibited from giving blood. |
| Indication |
For the treatment and prevention of thromboembolic diseases. More specifically, it is indicated for the for the prevention of cerebral embolism, deep vein thrombosis, pulmonary embolism, thromboembolism in infarction and transient ischemic attacks. It is used for the treatment of deep vein thrombosis and myocardial infarction. |
| Pharmacology |
Acenocoumarol inhibits the reduction of vitamin K by vitamin K reductase. This prevents carboxylation of certain glutamic acid residues near the N-terminals of clotting factors II, VII, IX and X, the vitamin K-dependent clotting factors. Glutamic acid carboxylation is important for the interaction between these clotting factors and calcium. Without this interaction, clotting cannot occur. Both the extrinsic (via factors VII, X and II) and intrinsic (via factors IX, X and II) are affected by acenocoumarol. |
| Toxicity |
The onset and severity of the symptoms are dependent on the individual's sensitivity to oral anticoagulants, the severity of the overdosage, and the duration of treatment. Bleeding is the major sign of toxicity with oral anticoagulant drugs. The most frequent symptoms observed are: cutaneous bleeding (80%), haematuria (with renal colic) (52%), haematomas, gastrointestinal bleeding, haematemesis, uterine bleeding, epistaxis, gingival bleeding and bleeding into the joints. Further symptoms include tachycardia, hypotension, peripheral circulatory disorders due to loss of blood, nausea, vomiting, diarrhoea and abdominal pains. |
| Affected Organisms |
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Humans and other mammals |
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| Biotransformation |
Extensively metabolized in the liver via oxidation forming two hydroxy metabolites and keto reduction producing two alcohol metabolites. Reduction of the nitro group produces an amino metabolite which is further transformed to an acetoamido metabolite. Metabolites do not appear to be pharmacologically active. |
| Absorption |
Rapidly absorbed orally with greater than 60% bioavailability. Peak plasma levels are attained 1 to 3 hours following oral administration. |
| Half Life |
8 to 11 hours. |
| Protein Binding |
98.7% protein bound, mainly to albumin |
| Elimination |
Mostly via the kidney as metabolites |
| Distribution |
The volume of distribution at steady-state appeared to be significantly dose dependent: 78 ml/kg for doses < or = 20 microg/kg and 88 ml/kg for doses > 20 microg/kg respectively |
| References |
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Cesar JM, Garcia-Avello A, Navarro JL, Herraez MV: Aging and oral anticoagulant therapy using acenocoumarol. Blood Coagul Fibrinolysis. 2004 Oct;15(8):673-6.
[Pubmed]
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Lengyel M: [Warfarin or acenocoumarol is better in the anticoagulant treatment of chronic atrial fibrillation?] Orv Hetil. 2004 Dec 26;145(52):2619-21.
[Pubmed]
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Ufer M: Comparative pharmacokinetics of vitamin K antagonists: warfarin, phenprocoumon and acenocoumarol. Clin Pharmacokinet. 2005;44(12):1227-46.
[Pubmed]
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Montes R, Ruiz de Gaona E, Martinez-Gonzalez MA, Alberca I, Hermida J: The c.-1639G > A polymorphism of the VKORC1 gene is a major determinant of the response to acenocoumarol in anticoagulated patients. Br J Haematol. 2006 Apr;133(2):183-7.
[Pubmed]
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Girard P, Nony P, Erhardtsen E, Delair S, Ffrench P, Dechavanne M, Boissel JP: Population pharmacokinetics of recombinant factor VIIa in volunteers anticoagulated with acenocoumarol. Thromb Haemost. 1998 Jul;80(1):109-13.
[Pubmed]
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