Ask Dr. H: Coumadin and aspirin curb clotting differently

Question:

How many 325 mg aspirin tablets are equivalent to one 2.5 mg Coumadin tablet?

Answer: That's really like comparing apples and oranges. They're both so-called blood thinners, but they work in different ways. Technically, neither aspirin nor Coumadin makes the blood any thinner. They just affect the ability of blood to clot.

Aspirin interferes with the ability of platelet clot cells to stick together and form a temporary plug in an injured blood vessel. When we get a cut, platelets stick to the inner lining of the blood vessel. But this can't permanently repair the damage, and it sure can't hold forever. For that, a clot needs to form. Platelets are key to this, triggering a series of reactions in which proteins in the blood called fibrinogens convert into a stringy, mesh-like material called fibrin. This fibrin mesh traps blood cells, forming what we know as a clot. Then, long fibers of fibrin form a tight mesh to create a permanent patch over the tear in the blood vessel.

Coumadin acts to interfere with clotting by inhibiting the vitamin-K dependent clotting proteins involved in the formation of fibrin mesh. Since the life span of a platelet is about seven days, the effect of aspirin on clotting is seven days. Coumadin's effect on the overall process of clotting is more powerful (with a less predictable effect on clotting) than that of aspirin, which is why doctors will use Coumadin over aspirin for patients who are at high risk of developing a blood clot.

Aspirin is still quite effective in helping to decrease the risk of a heart attack when taken daily. It also is helpful in folks who have carotid artery disease or circulation disease. And it is helpful in preventing strokes. What's more, it doesn't require the frequent blood monitoring of Coumadin.

Q: A friend of mine was telling me about a bizarre medical procedure in which stool from one person is put in the bowels of another person. Is this for real? Why would someone want to do that?

A: "Fecal transplantation," as it's called, is being used by doctors as an alternative treatment for the management of refractory cases of antibiotic-associated diarrhea as well as inflammatory bowel disease (e.g., ulcerative colitis and Crohn's). If you're familiar with "probiotics" such as Acidophilus and Lactobacillus, you already have an understanding of the concept of infusing healthy bacteria into the colon to help restore balance between bad bacteria in the gut that make us sick and the good bacteria in the colon that keep us well.

The effectiveness of fecal transplantation in curing antibiotic-associated diarrhea is said to be about 95 percent, even in the most stubborn cases. A recent study of six patients with severe ulcerative colitis showed that fecal transplantation completely reversed all symptoms of disease after four months of treatment.

The stool is best obtained from a close relative who has been tested negative for a wide variety of infectious organisms.