New Anti-Diarrhea Medication Produced from Amazonian Tree


Two international pharmaceutical partnerships are working to simultaneously develop and commercialize crofelemer, the name for the anti-diarrheal preparation extracted from the latex of a South American tree. On July 6, Napo Pharmaceuticals Inc., a specialty pharmaceutical company based in South San Francisco, signed a partnership with Glenmark Pharmaceuticals Ltd. of Mumbai, India, to develop and commercialize the crofelemer compound for the Indian market and 140 countries,[ 1] excluding the United States, Europe, Japan, and China.[ 2] On June 15, Napo signed a similar deal with AsiaPharm of the People's Republic of China (PRC) to launch crofelemer in China, Hong Kong, and Macau.[ 3] These partnerships are part of Napo's global strategy to expand crofelemer's potential uses and to brine the drug to new markets.[ 1]

"This collaboration will allow Napo to bring a novel therapy to these debilitating and sometimes deadly diseases, to both traditional Western markets and resource constrained areas of the world," said Napo CEO Lisa Conte in a press release.[ 1] The international partnerships have licensed crofelemer in various countries to treat pediatric and acute infectious diarrhea and chronic diarrhea in people living with HIV/AIDS.[ 1] According to Napo, crofelemer has shown significant anti-diarrheal activities in multiple clinical trials of over 1000 patients.[ 1]

"Crofelerner works by normalizing water flow in the gut. It is not absorbed into the blood, but acts in the intestines to treat diarrhea and prevent dehydration. Because it is not absorbed and acts locally, it has a positive safety profile," explained Steven King, PhD, vice-president of Ethnobotany and Conservation of Napo (oral communication, July 21, 2005). The drug's capacity to treat diarrhea by blocking the secretion of chloride ions, and still allowing bowel movements, makes this useful for treating chronic diarrhea, explained King. (Note: Dr. King is also a member of the American Botanical Council Advisory Board.)

This novel mechanism is important to people livingwith chronic diarrhea, so much so, that the US Food and Drug Administration (FDA) gave Napo a fast-track designation for the crofelemer drug for use in treating AIDS-related diarrhea.[ 2] According to King, the plan is to be completed with clinical trials and gain FDA approval for a new drug application (NDA).

Crofelerner is extracted and purified from the latex of a South American tree called dragon's blood (Croton lechleri Mull. Arg., F.uphorbiaceae). Each indigenous group has a different common name for this tree, but the most common name is the Spanish sangre de drago (dragon's blood), because of the red color of the latex that oozes from the bark when it is cut. According to Dr. King, who has studied this tree for over 15 years, the species of sangre de drago that produces a large amount of latex is found in the Amazon region of Bolivia, Columbia, Ecuador, and Peru. "This is a novel mechanism of action for the treatment and management of diarrhea, and it has been brought to us by indigenous knowledge," added Dr. King.

PHOTO (COLOR): Dragon's blood Croton lechieri.

1. Conte L, Bertrand B. Napo Pharmaceuticals, Inc. Adds Glenmark Pharmaceuticals of India to Global Team to Develop and Commercialize a Novel Treatment for Diarrhea [press release], San Francisco, CA: Napo Pharmaceuticals Inc; July 7, 2005.

2. Jankiraman V, Conte LA, Bertrand D. Glenmark Pharmaceuticals Ltd and Napo Pharmaceuticals Inc announce collaboration agreement on Napo's novel anti-diarrheal product Crofelemer [press release]. Mumbai, India: Glenmark Pharmaceuticals Ltd.; July 7, 2005.

3. Conte L, Bertrand B. Napo Pharmaceuticals signs development, commercialization alliance with Asiapharm of China [press release). San Francisco, California: Napo Pharmaceuticals Inc; June 15, 2005.


By Katherine Purcell

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