It is pretty common knowledge that Warfarin can be difficult to regulate and if the blood gets too thin, we now have an antidote. There are two newer drugs where you can read below that Kcentra does not work as they are a different class of blood thinners. As the article states there are some other reversal agents but the new drug, Kcentra is stated to be much faster acting. BD
Ever since the drug warfarin was discovered to be a highly effective anti-clotting agent as well as a good rat poison in the early 1950s, it has been the frontline weapon in preventing stroke among those with atrial fibrillation. But its growing use has always raised the specter of dangerously hard-to-stanch bleeding if someone taking it is wounded or bleeds internally from a fall or a car accident.
Roughly six decades after its introduction, Kcentra has been approved by the Food and Drug Administration. It's a new product designed to quickly reverse the effects of warfarin. The prothrombin complex concentrate is made from the pooled plasma of healthy donors, and it joins a cluster of other "reversal agents" capable of restoring coagulation, including vitamin K and fresh-frozen plasma, in people who take warfarin.
The new agent does not, however, work to reverse the effects of two anticoagulants that are new to the market -- dabigatran (marketed as Pradaxa) or rivaroxaban (marketed as Xarelto). Last year, a case study in the Journal of Neurosurgery underscored that physicians still lack reversal agents that can restore coagulation in patients taking these new medications, with sometimes deadly results.