A new experimental anti-clotting drug called Apixaban has
been found to be efficient in reducing the risk of stroke in these patients. It
was found to be far superior to aspirin.
The condition is
typically treated by using a type of anticoagulant known as a Vitamin K antagonist. Warfarin
is the most common vitamin K antagonist. A patient on vitamin K antagonists
requires serious monitoring owing to a marked variation in its effect both from
one patient to another and within the individual patient. Its use is further
limited by a narrow therapeutic window, i.e. doses have to be precisely titered
so as to avoid danger of bleeding and not all patients are suitable for vitamin
K antagonist therapy. The use of vitamin K antagonists is generally difficult.
Aspirin continues to be used in treating patients with atrial fibrillation for
whom vitamin K antagonist therapy is unsuitable but it is less effective. The
search for better drugs has been a challenge but a recent trial called the
AVERROES study tested the effect of Apixaban and this brings some promise.
Apixaban is a drug that inhibits one of the
components that take part in the body's clotting mechanism (called factor Xa).
At a dose of 2.5 mg twice daily, Apixaban,
an anti-thrombotic drug to be precise, was known to be effective and safe for
the prevention of venous thromboembolism after elective orthopedic surgery. The
AVERROES study conducted at 522 centers in 36 countries evaluated the efficacy and
safety of apixaban, at a dose of 5 mg twice daily, as compared with aspirin, at
a dose of 81 to 324 mg daily, for the treatment of patients with atrial
fibrillation for whom vitamin K antagonist therapy was considered unsuitable.
The results were published in the New England Journal of Medicine (NEJM).
patients for whom vitamin K antagonist therapy was considered unsuitable,
apixaban, as compared with aspirin, reduced the risk of stroke or systemic
embolism by more than 50%, without a significant increase in the risk of major
bleeding', reported NEJM. Apixaban did not bring any significant increase in
the risk of major bleeding such as intracranial bleeding. Apixaban and was
found to be superior to aspirin.
approved, Apixaban will offer an effective alternative to warfarin, whose
limitations have already been discussed. The approval of the drug will bring a
revolutionary change in medical practice.
: New England Journal of Medicine