STUDY LINKS COCAINE USE TO BLOOD CLOTS

If one needs another reason to say no to cocaine, here it is: Harvard
scientists have identified two nasty heart-damaging and potentially
life-threatening effects that explain why users are at risk for heart
disease and stroke every time they take cocaine.

"I hope this will be a wake-up call for people who use cocaine," said Dr.
Arthur Siegel, an assistant professor of medicine at Harvard Medical School
and director of internal medicine at McLean Hospital in Belmont, Mass.
"They should know how dangerous cocaine could be."

The findings, reported today in the Archives of Internal Medicine, provide
a biological explanation of how cocaine puts people at risk. There is no
telling how many people suffer these consequences, but doctors estimate
that cocaine-related emergency-room visits for chest pain are a major problem.

A medical study published earlier this year in Circulation by Harvard
researchers found that in the hour after cocaine use, there is an average
25-fold risk of having a heart attack. And others before Siegel have shown
that cocaine, a stimulant, constricts the arteries.

But Siegel's study of 21 McLean Hospital volunteers, who ingested cocaine
nasally or who were injected with it, found that cocaine also helps trigger
blood-clot formation.

When researchers looked at blood samples taken within minutes and then
again two hours after cocaine use, they found a thickening of the blood.

The reason: Cocaine causes constriction of the spleen, an organ on the
upper left side of the abdomen that manufactures red blood cells. This
constriction meant that the spleen had infused new blood cells into the
blood vessels. A high red-blood-cell count increases the risk of thrombosis
or clotting.

Siegel's study found a 4 percent to 6 percent increase in the number of red
blood cells after cocaine use.

Making matters worse, cocaine also caused an increase in a substance called
the von Willebrand factor, which triggers clotting by causing platelets to
stick to the lining of the blood vessels.

"This is a double-whammy to the blood-clotting system," said Siegel. "This
is very dangerous, even for people using it one time."

In a study of six men and six women, Siegel and his colleagues discovered
that cocaine causes von Willebrand factor to increase 40 percent in just a
few minutes.