Warfarin (a form of rat poison still sold as Coumadin) has been the standard anticoagulant for going on six decades. It is far from a perfect treatment: determining the correct dosage can be difficult, and patients must go on a restricted diet and undergo constant monitoring because of numerous interactions (frequently an issue with elderly patients on numerous prescriptions).
Administering Xarelto (rivaroxaban) is far easier, and requires much less in the way of patient monitoring. Both medications can cause serious bleeding. However, such episodes with warfarin are easily corrected by administering high doses of Vitamin K, a key component of blood clotting factors.
However, as of the present, Xarelto has no antidote, since it acts directly on the clotting factor, not Vitamin K. Because of this, episodes of bleeding can be fatal. The only recourse is to have the patient undergo emergency dialysis in order to remove the drug from the system. An antidote has been developed, but has not yet gained FDA approval.
Given these facts, how did Xarelto, and its only slightly less dangerous competitor, Eliquis, become so popular? Last year, Xarelto was a major driver behind drugmaker Johnson & Johnson's growth in earnings, increasing by well over 22%.
Part of it is no doubt due to slick advertising and promotion, including major celebrity endorsements. There are also claims that both Xarelto and Eliquis are safer than warfarin. Those claims are based on facts – but they do not take into account the lack of an antidote.
The cause of action in Xarelto lawsuits is the allegation that drugmaker Johnson & Johnson was aware of the dangers of its product and failed to warn patients and doctors of those risks. In September of 2011, Bayer, which was a partner in the development of Xarelto, funded its own studies to “prove” the safety and efficacy of Xarelto when compared to warfarin. Neither study took into account the lack of an antidote. Furthermore, there have been serious questions about the studies, particularly the one known as “ROCKET-AF,” including faulty data and the use of substandard equipment.
Fortunately, physicians are aware of these problems, and are hesitant to prescribe Factor Xa inhibitors to elderly patients with health issues – at least until the antidote is approved. In the meantime, patients at risk for deep vein thrombosis or experiencing atrial fibrillation are urged to learn all the facts about Factor Xa inhibitors such as Xarelto before allowing their physicians to prescribe some medications for them.