CHAPEL HILL - Doctors at the University of North Carolina at Chapel Hill are seeking adults with acute pulmonary embolism or deep-vein thrombosis to participate in studies aimed at improving treatments for blood clots.
Dr. Stephan Moll, director of the thrombophilia program at the UNC School of Medicine's Center for Thrombosis and Hemostasis, said the studies will help determine the best way to prevent blood clot recurrence.
Coumadin, known generically as warfarin, is the standard blood-thinning medication doctors use to treat patients during the first six months after a blood clot is diagnosed, Moll said. However, the drug presents risks, and it topped UNC's recent list of medications with the most reported side effects.
"We don't like to give Coumadin long-term," he said. "It carries the risk of bleeding and can have side effects that range from mild bruising to death through bleeding in the head. On the other hand, we know that 25 percent of blood clot patients develop a second clot, and we want to avoid that. We're forced to weigh this risk against the risk of serious side effects from Coumadin, and that's not an optimal answer."
The first study, called PREVENT, is a randomized, double-blind trial that involves two groups of patients, Moll said. One group will receive no more Coumadin after the first six months but instead an inactive compound. A second group will follow the six months' regular treatment with a smaller maintenance dose of the drug. Both groups will be monitored for four years.
"We want to know if the lower dose, which we think decreases the risk of bleeding, actually prevents the recurrence of clots," Moll said. "If so, that dose should be the standard of care for patients with a first blood clot."
Moll is following 10 patients in the PREVENT study and would like to enroll as many as 50 more. Those eligible are age 30 and older who have had a blood clot -- not from surgery or trauma -- and who are either still on Coumadin or have come off the drug in the last two years.
The second study, called THRIVE V, is a phase III trial (the final stage before the FDA approves a drug for routine use) of a promising new medication for treating blood clots. The drug doesn't require the monitoring that Coumadin does, and researchers say it works fully and immediately, while Coumadin requires between five and seven days to build up to the appropriate level in the body.
Until that buildup occurs, patients must also take Heparin, Moll said. Heparin is inconvenient, since it requires either hospital admission for intravenous therapy or injections under the skin.
"If, as we expect, this new drug is as effective as Coumadin and causes fewer side effects and lowers the risk of bleeding, it could make specialized blood testing to determine the appropriate dose of Coumadin obsolete," he said.
Another benefit of the new drug is that it allows patients to be less vigilant about diet, the physician said. Coumadin interferes with vitamins, and so patients have to watch what they eat.
"With the new pill, they can eat what they like," he said.
Finding appropriate candidates for the study for the THRIVE V study is more difficult than for PREVENT, Moll said. For THRIVE V, clinicians need to see patients within the first 24 hours of an acute deep-vein thrombosis or pulmonary embolism. "This almost limits those enrolled to being at UNC Hospitals, but we might be able to work with local physicians who have patients with newly diagnosed clotting," he said.
Besides specific research, public awareness and education are critical for improving blood clot treatment for the millions, young and old, afflicted by the problem, he said.
"With patients with blood clots being taken care of by different practitioners -- family physicians, hematologists, cardiologists -- and care is not being coordinated," Moll said. "When coordination between physicians does not take place, opportunities for better care and education are lost."
Until a few years ago, doctors didn't know why patients developed blood clots, he said. Now there are tests that can find an inherited abnormality. "This is valuable information," Moll said. "For example, if a woman knows she has the inherited tendency to clot, she will be better able to make decisions about taking contraceptives or hormone replacement drugs, both of which are associated with clotting."
While treatment centers for bleeding disorders in hemophilia exist where different specialists work together, very few options exist for patients with thrombosis, he said.
"We need to encourage Congress to fund centers in thrombophilia," Moll said. "Currently, no government-funded centers exist in this country. Canada, the Netherlands and Belgium have used these centers very successfully to improve the health of patients, save health-care money and even prevent clots that can lead to significant disability and death."
To be considered for enrollment in one of the studies, contact Moll by e-mail, Smoll@med.unc.edu, or call Susan Jones, thrombosis research nurse, at 919-843-7371. Details on the PREVENT study can be found at www.nhlbi.nih.gov/studies/prevent1.htm. Jones also can provide information about free patient education meetings.
Note: Moll can be reached at 919-966-3311.