A heart problem wasn't about to keep Sally Eckard from doing what she loves.
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Sally Eckard of McCandless is on Coumadin for a heart problem, but she's looking forward to using an easier drug to manage the problem. (Matt Freed, Post-Gazette) |
So when she was diagnosed with an irregular heartbeat five years ago, the retired secretary from McCandless kept on competing in a traveling women's paddle tennis league, just as she had done for years. She also followed the advice of her doctor, Joseph E. Calhoun, who prescribed warfarin to prevent blood clots from forming in her heart.
The drug, sold under the name Coumadin, requires careful management, and Eckard began regular blood testing to track it in her system. Needle sticks and blood draws became a way of life.
Depending on test results, the dose of warfarin Eckard takes may change every other week. She records the new orders, but is sometimes confused, especially when she has to split tablets to make a new dosage. Worst of all is the inconvenience of blood testing.
"The problem is I don't live handy to the doctor's office, so sometimes I forget about it," she says, adding that she wouldn't think of switching doctors. "Needles don't bother me -- it's just not convenient."
The inconvenience doesn't end with patients. For doctors, regulating warfarin is a little like driving a car forward while only looking in the rearview mirror. Too little warfarin and the drug fails to prevent potentially devastating blood clots; too much and the patient risks bleeding in the brain or gut that can be fatal. Multiply the monitoring chore by the rising number of patients who need warfarin, and the problem can be daunting.
An end to needles
All this may change soon. New blood thinners, which doctors call anticoagulants, are making their way to the market. What's more, a new oral anticoagulant promises to be painless. For millions of Americans like Eckard, routine blood testing may become a thing of the past.
Among the more promising drugs is new oral anticoagulant ximelagatran, which will be sold as Exanta by British pharmaceutical giant AstraZeneca. Company spokesman Gary Bruell says Exanta could be available by late 2004. The drug is the first new oral anticoagulant in more than 50 years. Results of early trials have been encouraging and testing is now in its final stages.
"If this agent succeeds, it would be an extraordinary advance," says Dr. Steven B. Deitelzweig, head of hospital-based internal medicine at Ochsner Clinic Foundation in New Orleans.
Dr. James E. Muntz, clinical associate professor of medicine and orthopedic surgery at Baylor College of Medicine in Houston agrees, calling the new drug a "major breakthrough.
"It could mean big savings" in health-care costs, says Muntz, who has directed studies of Exanta's effectiveness when compared to warfarin.
Eckard is among 2 million Americans who are at risk of developing blood clots from an irregular heartbeat called atrial fibrillation, according to the American Heart Association. Blood clots can cause a number of problems, including stroke. In fact, people with atrial fibrillation are up to six times as likely to have a stroke as those without the condition.
Strokes, a leading cause of death in America, occur when a vessel in the brain bursts, or a clot lodges in the brain, cutting off blood and oxygen and causing brain tissue to die.
Clots also arise from leg veins. If these clots break free, they float toward the heart where they can block blood flow. Between 60,000 and 200,000 deaths annually are caused by this kind of clot, which is called a pulmonary embolism.
Burgeoning market
Warfarin has long been a big gun in preventing and treating blood clots. The drug works through a broad assault on the clotting process. Warfarin is also inexpensive, costing patients about $1 a day. But dosing can be tricky.
The drug's effectiveness can be influenced by diet, such as extra helpings of green, leafy vegetables, which are rich in vitamin K. Alcohol, tuna and over-the-counter pain relievers can also reduce warfarin's effectiveness.
Unlike warfarin, Exanta targets a key enzyme involved in clot formation and growth, and is not affected by eating habits, Deitelzweig says. AstraZeneca hasn't priced Exanta for consumers yet. Still, the drug is expected to be cost-effective in savings from blood testing, return doctor's office visits and complications such as bleeding.
One concern is that Exanta caused an increase in liver enzymes in early studies, Calhoun says, which indicates inflammation. But evidence also suggests the problem may be temporary and more studies are under way.
Exanta may work well in treating clots from other causes, such as knee and hip replacement surgery. And in recent years, doctors have begun to recognize the risk of blood clots in people hospitalized for other conditions, including heart failure, blood poisoning and cancer. Even immobility may cause clots.
Because of all this, the market for anticoagulants is expected to increase to $6.71 billion by 2008 from $3.72 billion in 2001, according to market consultant Frost & Sullivan of New York. The growth is fueled in part by an aging American population, which will experience increased risk of heart problems and serious hip and knee problems.
Still, a big chunk of that growth may come from people like Eckard, who are on long-term anticoagulant therapy. This group is where Exanta is expected to have the biggest impact.
At his Richland clinic, Calhoun treats about a dozen patients a day who take warfarin. Generally, this involves calling patients with results of blood tests and adjusting dosages accordingly. A new oral blood thinner could greatly simplify care for these patients, he says.
"If it pans out, no blood work will be needed," says Calhoun. "It's a quality of life issue for patients."
Kris Mamula is a free-lance journalist who lives in Pittsburgh.
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