Warfarin, sold under the brand name Coumadin among others. It is used as an anticoagulant medication. It is commonly used to prevent deep vein thrombosis and pulmonary embolism, and to protect against stroke in people who have atrial fibrillation, valvular heart disease and prosthetic heart valves. Warfarin is a vitamin K antagonist that inhibits the vitamin K epoxide reductase complex VKORC1 in the liver, reducing gamma carboxylation and activation of clotting factors II, VII, IX and X and anticoagulant proteins C and S. Clinically it is administered orally with dose titration guided by INR monitoring because of a narrow therapeutic index, significant interpatient variability driven by CYP2C9 and other hepatic metabolism, dietary vitamin K interactions and multiple drug interactions; knowledge of enantiomeric activity is relevant because the S enantiomer is pharmacologically more potent than the R enantiomer.
Parent: Warfarin / Warfarin Sodium
Warfarin active substance and finished products are controlled for a set of process related and degradant impurities including coumarin-related precursors, reduced alcohol forms, diketone species, positional isomers and dimeric coumarins, as well as residual solvents and elemental impurities. Typical quality specifications used by manufacturers and pharmacopeias set limits to control safety and stability, for example individual related compounds commonly limited to about 0.5 percent or less and total related compounds typically limited to the 1.5 to 2.0 percent range depending on the monograph and risk assessment, with specific reporting thresholds for genotoxic impurities and residual solvents set separately. Analytical methods for impurity profiling include HPLC with UV or MS detection, chiral separation to quantify enantiomeric purity and orthogonal methods to confirm identity of key degradants.
Warfarin is used to reduce blood clot formation and is commonly prescribed to prevent and treat deep vein thrombosis and pulmonary embolism and to reduce stroke risk in patients with atrial fibrillation, valvular heart disease or mechanical heart valves.
Yes. Warfarin is a vitamin K antagonist anticoagulant that interferes with the vitamin K cycle by inhibiting VKORC1, which decreases activation of several clotting factors.
Warfarin acts primarily in the liver where it inhibits gamma carboxylation of clotting proteins and is also extensively metabolized by hepatic cytochrome P450 enzymes.
The most serious side effect is major bleeding, particularly intracranial hemorrhage, which can be life threatening and is the primary risk driving close INR monitoring and dose adjustments.
