Venous thrombosis is a condition where clots are formed in
deep veins. These clots block the flow
of blood through the particular blood vessel.
Parts of the clots could dislodge and travel through the
circulation. These dislodged clots are
called emboli. Emboli can cause serious complications like stroke,
pulmonary embolism and heart attack.
The condition of clot and emboli formation in the deep veins is called
thromboembolism is currently treated using injectable heparin (or a low
molecular weight heparin) along with oral warfarin (an oral anticoagulant or
blood thinner that blocks the effect of vitamin K).
Heparin is stopped once warfarin shows its
effect. However, this current treatment has the following disadvantages:
Warfarin takes time to act; hence, hence patient is
initially given injectable heparin. This
means that he has to be admitted into a hospital.
The patient needs repeated tests for clotting of blood
done while taking warfarin to make sure that optimal anticoagulation is
achieved and the patient does not suffer from complications like bleeding.
Some food and drugs taken concomitantly could alter the
level of warfarin in blood and either lead to a decrease in effect or cause
Rivaroxaban is a
novel oral anticoagulant or blood thinner
and is currently undergoing
evaluation in the United
States. It has been approved for use in some
countries to prevent venous thromboembolism in patients undergoing planned hip
or knee surgery. It prevents clotting by
blocking the action of a clotting factor
. In contrast to warfarin, it does not need repeated laboratory
testing. Food does not affect its level
and it interacts with very few drugs.
A recent study showed that Rivaroxaban was similarly
effective as the standard treatment of enoxaparin (like heparin) and a vitamin
K blocker (like warfarin) in patients with confirmed deep venous thrombosis. The risk of bleeding was also similar in
both groups. Thus, one drug rivaroxaban
could replace the currently used two drugs.
Since rivaroxaban is taken
orally, it may be useful in treating patients of DVT on an outpatient basis.
The study also showed that rivaroxaban reduced chances of recurrence of clotting in patients with DVT or
pulmonary embolism who had already received 6 to 12 month prior anticoagulant
These patients had a
small risk of major bleeding.
Thus, rivaroxaban could
emerge as a simple treatment for deep vein thrombosis that is effective, easy
to administer and does not require regular monitoring.
The EINSTEIN Investigators. Oral Rivaroxaban for Symptomatic Venous
Thromboembolism N Engl J Med 2010; 363:2499-2510