Apixaban is an anticoagulant used to prevent blood clots. This medication is given to patients who have recently undergone surgery of the knees or hips and to those with atrial fibrillation. It is not available to the public yet, though initial studies show that it is an effective treatment.
Though apixaban is in the anticoagulant class, its mechanism of action is unlike other anticoagulants. There are a number of enzymes that play a part in the process of forming blood clots. Apixaban interferes with factor Xa, while other anticoagulants prevent blood clots by interfering with other enzymes.
Recent studies of the drug have shown apixaban to be as or more effective than competing drugs. When it was tested against a competing medication in 2007, it was shown to be as effective at preventing blood clots from forming following knee surgery. Further studies in 2010 showed that it is more effective than its competitors at preventing dangerous blood clots that can form as a result of hip surgery.
The main danger of taking an anticoagulant such as apixaban is that a patient can experience life-threatening bleeding. With the ability to create blood clots compromised, bleeding continues unchecked which can lead to severe blood loss. This is a risk associated with taking any anticoagulant, and, in most patients, apixaban has not been shown to cause more or less risk of bleeding than any other drug.
Though it seemed that apixaban was performing well in trials, it caused dangerous bleeding in patients who were suffering from acute coronary syndrome and who were receiving antiplatelet therapy in addition to apixaban. Studies were halted for these patients in November of 2010, though the medication is still considered to be safe for other groups of patients.
While clotting is necessary in order to control bleeding, under certain circumstances it can pose a serious risk to the life of the patient. Joint surgery on the knees or the hips can place a patient at particular risk for developing clots in the large blood vessels of the legs. These clots, if they become dislodged, can become trapped on the way to the heart or the brain, leading to stroke or heart attack. Many patients who undergo these types of surgeries are given anticoagulants, such as apixaban, to help reduce the risk of this.