Eliquis is one of the newer treatments used to prevent blood clots and their related complications.

Also known by the generic name apixaban, it’s a relatively new addition to the available selection of anticoagulant drugs, having been first approved by the FDA in December 2012.

It’s frequently used to help prevent stroke in persons who have atrial fibrillation, a condition suffered by more than 3 million persons in the U.S.

In atrial fibrillation, an irregularity in the heart’s rhythm may allow blood clots to form that can travel to the brain and cause a stroke.

Eliquis helps reduce the risk of stroke by inhibiting the blood’s ability to clot, preventing dangerous blood clots from forming in the first place.

By reducing the formation of clots, Eliquis can also be useful to prevent pulmonary embolism (a blood clot in the lung) and deep vein thrombosis (a clot elsewhere in the body, usually in the leg).

Eliquis is one of a group of new anticoagulants that just recently entered a market that had been dominated by warfarin for years.

Since the 1950s, warfarin (sold under the brand names Coumadin and Jantoven) had been the only drug with FDA approval for the prevention of stroke in atrial fibrillation patients.

But warfarin requires regular blood testing to make sure the dosage is just right. Too much warfarin can create a risk of excessive bleeding. With too little, and it will fail to protect against stroke.

Eliquis and the other new anticoagulants were designed not to need this ongoing blood testing and dosage adjustment.

The good news is that Eliquis is effective at preventing blood clots and the strokes that can result from them.

In clinical trials involving over 50,000 patients from around the world, Eliquis was one of two new drugs that appeared to be at least as good as warfarin, if not better, at preventing strokes and other blood clot-related injuries.

Eliquis also caused fewer instances of hemorrhagic stroke, a type of stroke caused not by blood clots but by internal bleeding within the brain.

Eliquis and the Risk of Bleeding

The flip side of the protection from stroke that Eliquis can provide is that, as with all anticoagulants, the same mechanism that prevents blood from clotting also creates a greater risk of excessive and uncontrollable bleeding.

In the worst cases, that bleeding can be life-threatening.

Raising the stakes is the fact that Eliquis was released to the market without any available antidote that could reverse its anticoagulant effect in case of emergency.

In cases of spontaneous internal bleeding or where a patient on Eliquis may need emergency surgery, there may be no way to keep their bleeding under control.

The lack of an antidote has allowed warfarin to maintain at least one advantage over the new drugs. Warfarin can be reversed by administering vitamin K.

Eliquis patients, however, may simply have to wait for the body to finish metabolizing the drug.

While a new antidote for Eliquis is in the works, it will come too late for Eliquis patients who have already suffered excessive bleeding.