Atrial Fibrillation Health Center

Atrial Fibrillation Stroke 'Tragedy'

Coumadin: Lifesaver and Nuisance continued...

Coumadin is a brand name for the drug warfarin. Warfarin was originally invented to kill rodents. Later was it discovered that tiny doses of the drug act as a powerful blood thinner. But the therapeutic window -- the difference between no effect, a helpful effect, and a harmful effect -- is relatively small. And many factors, including other medical conditions or other drugs and dietary supplements, can drastically alter Coumadin's effect.

"Warfarin is known as rat poison for a reason," William O'Neill, MD, professor of medicine and cardiology at the University of Miami Miller School of Medicine, tells WebMD. "I am afraid patients at the highest risk of stroke are also those at highest risk of bleeding complications from Coumadin. It is very hard to maintain patients at the correct level long term. It is a real nuisance."

O'Neill's University of Miami colleague, electrophysiologist Robert Myerburg, MD, agrees with O'Neill that Coumadin is hard to manage.

"It is a nuisance for the patients. But the way I see it is that stroke is a bigger nuisance," Myerberg tells WebMD. "I don't know if Coumadin is underused. I agree with what this and other studies have shown: that atrial fibrillation patients inadequately anticoagulated or not on anticoagulants are at high risk of stroke."

Coumadin is a nuisance for doctors, too. It takes a lot of a doctor's time to manage Coumadin treatment, to assess elderly patients' risk of a fall (Coumadin ups the risk of deadly bleeding in elderly patients who fall) and to help patients go on and off the drug when they need a dental or surgical procedure.

Worthington agrees that Coumadin has suffered a poor reputation among patients and doctors. But he passionately argues that this poor reputation is undeserved.

"Warfarin is an inconvenient truth. Warfarin is inconvenient because regular blood tests are inconvenient," he says. "The truth, too, is inconvenient: We can reduce the chance of stroke and we do not always do this. Until we do what the evidence suggests -- that is, start more people over age 65 with atrial fibrillation on Coumadin -- individuals will suffer avoidable strokes and our health services will carry an avoidable [and] expensive burden of sick and disabled stroke patients."

Worthington and colleagues' editorial accompanies the Gladstone report in the January 2009 issue of the journal Stroke, published ahead of print on Aug. 28.