Pradaxa (dabigatran etexilate), an anticoagulant, has been approved in capsule form for the prevention of blood clots and strokes in individuals with atrial fibrillation by the US Food and Drug Administration (FDA). People with atrial fibrillation – abnormal heart rhythm – are more susceptible to developing blood clots which can lead to strokes.
A human heart has two upper chambers – the left atrium and the right atrium – and two lower chambers – the left ventricle and the right ventricle. When the left and right atria (plural of atrium is atria) contract at an excessively high rate and irregularly, the patient has atrial fibrillation. Atrial fibrillation is the most common condition with heartbeat rhythm or speed irregularity (arrhythmia), it is caused by a disorder in the electrical system of the heart.
Another way of describing atrial fibrillation is when the two upper chambers of the heart are not synchronized with the contractions of the two lower chambers.
Over two million Americans are affected with atrial fibrillation. Experts predict its incidence will double over the next four decades.
Norman Stockbridge, M.D., Ph.D., director of the Division of Cardiovascular and Renal Products in the FDA’s Center for Drug Evaluation and Research, said:
People with atrial fibrillation are at a higher risk of developing blood clots, which can cause a disabling stroke if the clots travel to the brain.
Pradaxa (dabigatran etexilate) is an anticoagulant from the class of direct thrombin inhibitors – it inhibits thrombin, a blood enzyme involved in the blood clotting process. Experts believe it will replace Warfarin as the preferred anticoagulant in many cases. In Europe it is marketed as Pradaxa and in Canada as Pradax. The medication was developed by Boerhinger Ingelheim, Germany. On March 18, 2008, the European Medicines Agency granted marketing authorization for dabigatran. It has been approved by the British National Health Service (NHS) for preventing blood clots in hip and knee surgery patients.
The FDA examined data on a clinical trial that compared Pradaxa with Warfarin. Among the results of the trial, clinicians reported a lower incidence of strokes in the Pradaxa patients.
One of the advantages of Pradaxa over Warfarin is periodic blood test monitoring, a requirement for those on Warfarin but not Pradaxa, Stockbridge explained.
Dr. Stuart Connolly, Director, Division of Cardiology at McMaster University and member of The Population Health Research Institute, Hamilton, Ontario said:
Warfarin has been the standard therapy for stroke prevention in AF for many years. However, it is a very difficult treatment to use because of its interaction with various drugs, food types and the need for continuous monitoring to ensure that the drug is at the right therapeutic level. Anticoagulant monitoring is particularly burdensome and it is often difficult to maintain therapeutic range with warfarin, which puts patients at a higher risk of stroke or major haemorrhage. The approval of dabigatran etexilate provides for the first time an effective, flexible and convenient treatment option in the U.S., which will be especially important for the large group of patients who currently do not take any treatment because they cannot tolerate or refuse to take warfarin, or are not adequately controlled under current treatment.
The most common adverse reactions to Pradaxa included bleeding (sometimes life threatening), as is the case with other approved anti-clotting medications, the FDA informs. Some patients may also experience dyspepsia (bloating and uncomfortable feeling in the stomach), stomachache, heartburn and nausea.
As one of the requirements of approval, Pradaxa’s Medication Guide includes details about a serious bleeding risk. Whenever a patient fills a prescription for the drug they will receive the guide.
Pradaxa will be available in 150 and 75 milligram capsules.
In September 2010 an FDA Advisory Committee voted unanimously to recommend the approval of Pradaxa for atrial fibrillation treatment.
Professor Andreas Barner, Chairman of the Board of Managing Directors and responsible for the Corporate Board Division Research & Development and Medicine, Boehringer Ingelheim, said:
This first approval of Pradaxa® for Stroke Risk reduction in Atrial Fibrillation in the US marks a new era for stroke prevention in atrial fibrillation. This is an important event in the 125-year history of Boehringer Ingelheim and is a very good example for Boehringer Ingelheim’s approach to provide “value through innovation”, i.e. through innovations in an area with high medical demand. This new treatment will improve the lives of many patients and with preventing stroke, will avoid suffering for a significant proportion of them. We expect that dabigatran etexilate will in the coming months become available to patients with atrial fibrillation in more countries, internationally.
The global market for anticoagulant medication is expected to grow significantly over the next ten years. According to Boehringer Ingelheim, atrial fibrillation causes approximately 3 million strokes each year worldwide. Strokes linked to atrial fibrillation tend to be especially severe and disabling – half of patients die within a year of having a stroke.
Sources: FDA, Boehringer Ingelheim
Written by Christian Nordqvist