Indication |
Used for the prevention and treatment of thromboembolic disease
including venous thrombosis, thromboembolism, and pulmonary embolism as
well as for the prevention of ischemic stroke in patients with atrial
fibrillation (AF). |
Pharmacodynamics |
Phenprocoumon, a coumarin anticoagulant, thins the blood by
antagonizing vitamin K which is required for the production of clotting
factors in the liver. Anticoagulants such as phenprocoumon have no
direct effect on an established thrombus, nor do they reverse ischemic
tissue damage (damage caused by an inadequate blood supply to an organ
or part of the body). However, once a thrombus has occurred, the goal of
anticoagulant treatment is to prevent further extension of the formed
clot and prevent secondary thromboembolic complications which may result
in serious and possibly fatal sequelae. |
Mechanism of action |
Phenprocoumon inhibits vitamin K reductase, resulting in depletion
of the reduced form of vitamin K (vitamin KH2). As vitamin K is a
cofactor for the carboxylation of glutamate residues on the N-terminal
regions of vitamin K-dependent proteins, this limits the
gamma-carboxylation and subsequent activation of the vitamin K-dependent
coagulant proteins. The synthesis of vitamin K-dependent coagulation
factors II, VII, IX, and X and anticoagulant proteins C and S is
inhibited. Depression of three of the four vitamin K-dependent
coagulation factors (factors II, VII, and X) results in decreased
prothrombin levels and a decrease in the amount of thrombin generated
and bound to fibrin. This reduces the thrombogenicity of clots. |
Absorption |
Bioavailability is close to 100% |
Volume of distribution |
Not Available |
Protein binding |
99% |
Metabolism |
Phenprocoumon is stereoselectively metabolized by hepatic
microsomal enzymes (cytochrome P-450) to inactive hydroxylated
metabolites (predominant route) and by reductases to reduced
metabolites. Cytochrome P450 2C9 is the principal form of human liver
P-450 responsible for metabolism. |
Route of elimination |
Not Available |
Half life |
5-6 days |
Clearance |
Not Available |
Toxicity |
50=500 mg/kg. Symptoms of overdose includes suspected or overt
abnormal bleeding (e.g., appearance of blood in stools or urine,
hematuria, excessive menstrual bleeding, melena, petechiae, excessive
bruising or persistent oozing from superficial injuries). |