Here is an actual description of what Warfarin which is the generic brand of COUMADIN is made of... (crystalline warfarin sodium) is an anticoagulant which acts by inhibiting vitamin K-dependent coagulation factors. Chemically, it is 3-(α-acetonylbenzyl)-4-hydroxycoumarin and is a racemic mixture of the R- and S-enantiomers. Crystalline warfarin sodium is an isopropanol clathrate. The crystallization of warfarin sodium virtually eliminates trace impurities present in amorphous warfarin.
Many people will say that you are taking "rat poison" when you are taking Coumadin/Warfarin. This is misleading. The compound was originally used to kill rats because it causes blood to thin. If it is given in overdose amounts it can cause bleeding out, and this is what killed the rats it was given to. For humans, Coumadin/Warfarin has important life saving uses. You are monitored carefully to stay within a range that is effective and safe. Thinner blood translates to fewer blood clots and less chance of stroke, especially for those who have atrial fibrillation, a type of irregular heartbeat. I hope this answer helps.