Several types of medications have the effect of slowing down blood clotting. As a group, these are called anticoagulants. Warfarin, also known as Coumadin, is a very powerful anticoagulant also found and rat poison. Heparin is another very strong anticoagulant.  Aspirin and other nonsteroidal anti-inflammatories also have a different anti-coagulation affect. Plavix is another anticoagulant often used in patients at risk for developing dangerous blood clots. These medications can be very dangerous and, as usual, their benefits must be carefully weighed against their possible and occasionally terrible side effects, which include stroke, excessive internal bleeding and even death. Prior to performing any spinal procedures, patients must be off of their anti-coagulation medications completely for the amount of time that it takes to restore their normal coagulation. Only then can their spinal procedure be performed without the risk of excessive bleeding into and around the spine. Patients should be sure that their physician is aware of any anticoagulants and all their other medications they are taking.