Re: Thanks for the responses on Coumadin

[Guest guest]

(AP) -- A new, easier-to-use blood thinner pill offers the first potential

alternative in 50 years to warfarin, the standard treatment given to millions of

people to prevent blood clots.

The new drug has been tested in 17,000 patients for a number of uses and has

shown to work as well as or, in some cases, better than warfarin at preventing

dangerous blood clots. It acts more quickly and does not require the frequent

blood testing of warfarin, also known as Coumadin.

In Thursday's New England Journal of Medicine, researchers report on two of

the latest tests of the drug, Exanta. The studies showed it reduced the risk of

blood clots by one-quarter after knee replacement surgery, and substantially

cut the long-term risk of another clot developing in patients who had a blood

clot in a leg or lung.

The drug maker, AstraZeneca, which paid for the studies, has filed for

approval of Exanta in Europe and expects to apply for U.S. approval this year.

" I think in most cases it will replace warfarin because it is much easier and

seems safer also, " said Dr. Sam Schulman, who is at the Karolinska Hospital

in Stockholm, Sweden, and led the long-term study of Exanta. " It will take some

time, but I think that gradually patients will be switched. "

Warfarin, originally developed as a rat poison, was first used as a blood

thinner in the 1950s. It is still the only oral blood thinner available to

protect against clots that can block blood vessels. It is widely prescribed

after

strokes, heart attacks and orthopedic surgery and is also given to prevent

recurring clots in the legs or lungs.

But warfarin, which takes time to kick in, interacts with other drugs and

foods containing vitamin K. It requires regular blood tests to adjust the dose.

Doctors are wary of using it for more than a few months because of the risk of

bleeding.

Exanta, also known as ximelagatran, works by targeting one coagulation

factor; warfarin affects many. Exanta acts faster and does not have the

monitoring

or diet drawbacks.

" Everyone has Coumadin patients who aren't doing very well, so they'll

probably try this, " said Dr. W. Francis who led the knee-replacement

study

at the University of Rochester Medical Center. " And if the experience is

positive and patients do well, they'll use more and more of it. "

Looking at the liver problem

The cost of Exanta has not been determined yet, according to AstraZeneca

spokesman Bruell. While warfarin itself is cheap -- $1 or less a day -- the

required lab tests cost much more.

The Swedish study of 1,223 patients in 18 countries tested Exanta for the

prevention of recurrent clots in people who had a leg or lung clot. They entered

the study after getting warfarin for six months. For the next 18 months they

got Exanta or a dummy pill.

RAT POISON ROOTS

Warfarin, a widely prescribed drug for the prevention of blood clots, was

first developed as a rat poison at the University of Wisconsin.

Professor Karl Link identified an anticoagulant in spoiled sweet clover

while trying to figure out why cows were bleeding to death after eating it. He

developed it into a rat poison and it was patented in 1948. Warfarin is still

used in some rat poison.

At the time, warfarin was considered too dangerous for humans. Researchers

reconsidered after a farmer tried to commit suicide with it but survived. It was

first used as blood thinner in the 1950s.

Recurrent clots were found in 12 patients in the Exanta group and 71 in the

comparison group, a reduction of 84 percent. Major bleeding was low in both

groups. Six patients died in the Exanta group and seven in the comparison,

including three of suffered fatal lung clots.

In about 6 percent of the Exanta group, there was an unexplained increase in

liver enzymes, which has been seen in other studies of the drug. Schulman said

levels increased in the first four months and then returned to normal without

any apparent damage to liver function.

Dr. Sandor S. Shapiro, who wrote an accompanying editorial in the journal,

said the liver problem is worrisome and needs to be followed.

" What's going to happen to those liver functions when people are on it for

three, or four or five years? Is it possible that something will pop up again? "

said Shapiro of Jefferson Medical College in Philadelphia.

The second study examined whether a higher dose of Exanta would be more

effective in preventing blood clots after knee replacement surgery. About 2,300

patients in five countries received either one of two doses of Exanta or

warfarin

for up to 12 days after surgery.

About 20 percent developed clots in the high-dose group; 25 percent in the

lower-dose group; and 28 percent for warfarin. There was no significant

difference in bleeding.

In a third study in the journal, researchers reported that a daily injection

of the blood thinner Arixtra works as well as standard intravenous heparin in

treating blood clots in the lung. Arixtra, also known as fondaparinux, does

not require monitoring like heparin, and that can shorten hospital stays.

The manufacture-sponsored study involved 2,213 patients. Arixtra is approved

for use after hip and knee surgery.