Air Date: Week of March 7, 2003

Living on Earth’s Jessica Penney reports on how scientists may be able to improve drug absorption by stealing a trick from tapeworms.

Transcript

ROSS: Just ahead, fly fishing the route of Marco Polo and Genghis Kahn. But first, this environmental health note from Jessica Penney.

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PENNEY: For decades, drugmakers have faced the problem of how to improve the way we digest medicines. Most drugs taken by mouth are absorbed in the small intestine, but usually more than half of any pill will pass right through and end up in the sewer system. This becomes a problem for sewage treatment plants at the same time that it wastes medicine. But now scientists have discovered that the lowly tapeworm might provide a solution to this problem.

Researchers at the University of Wisconsin wondered how the worms manage to stay in the small intestine. That's because muscle contractions in the small intestine move food and medications through the digestive tract, but this doesn't happen to the tapeworm. After analyzing the dozens of chemicals the tapeworm secretes, the researchers found that one of these substances interacts with the nervous system and makes the contractions of the intestinal muscles ineffective. This allows the tapeworm to stay put inside our guts and eat at a more leisurely pace.

Researchers hope that drugmakers might one day be able to add this same chemical to drugs so they pass more slowly through the digestive system, allowing a greater amount to be absorbed into the body. This would not only help keep excess drugs out of wastewater, but allow for smaller, cheaper dosages.

That's this week's health note. I'm Jessica Penney.

ROSS: And you're listening to Living on Earth.

[MUSIC: Strunz & Farah “Bola” A World Instrumental Collection Putumayo World Music (1996)]