Pubdate: Tue, 01 May 2001
Source: Vancouver Sun (CN BC)
Copyright: 2001 The Vancouver Sun
Contact:  http://www.vancouversun.com/
Details: http://www.mapinc.org/media/477
Author: Pamela Fayerman

THE HEALING POWERS OF PUFFER FISH

Vancouver Company Hopes Infamous Toxin Can Help Heroin Addicts, Cancer Patients

Clinical trials sponsored by a Vancouver company on a poisonous toxin found 
mainly in the ovaries of puffer fish may lead to a drug therapy to help 
addicts kick their heroin habit and to block pain in cancer patients.

Best known in Japan as a potentially lethal culinary delight enjoyed by 
people who get a thrill out of tempting fate, the puffer fish, or fugu, is 
now the object of scientific scrutiny by International Wex Technologies, 
Inc. of Vancouver

Dr. Edward Sellers, a University of Toronto professor of pharmacology, 
medicine and psychiatry is leading the clinical trials into the drug called 
Tetrodin (the purified form of tetrodotoxin). He said that although there 
are numerous deaths reported in humans who have consumed the fish when 
improperly prepared, the doses being used in the clinical trials are safe 
and low.

The toxin, found also in the liver and intestines, but most concentrated in 
the ovaries of puffer fish, is believed to protect them from predators.

Specially certified chefs know how to clean the fish to carefully separate 
the organs and tissue carrying the toxin before serving it to wealthy 
customers who obviously enjoy not only the bittersweet taste, but the 
Russian Roulette allure of the experience.

It is not uncommon in Japan to see chefs test the waters, so to speak, 
before offering the fish in its raw sushi or soup form to their customers. 
The chefs will eat the meat and skin of the fish before the paying 
customers do.

As a drug treatment, the toxin may lessen the nervous strain addicts 
experience during withdrawal. "It might also decrease cravings for heroin," 
said Sellers, who is conducting clinical trials through Ventana Clinical 
Research, based at Sunnybrook and Women's Health Sciences Centre in Toronto.

Currently, heroin addicts are provided with methadone as a heroin 
substitute but it is an expensive, addictive and lengthy treatment. 
International Wex maintains Tetrodin would be far cheaper since it may work 
in only two weeks and is non-addictive.

Researchers will also look at the drug's potential as a non-narcotic 
painkiller.

Donna Shum, chief operating officer of the company, said puffer fish are 
plentiful in Asia, found both in the South China Sea and also cultivated in 
fish farms.

"The fishermen are only too happy to supply us with the innards the 
restaurants don't want," she said.

Sellers said it would be difficult to synthesize the toxin found in the 
fish since its chemical makeup is so complex, but it's not necessary 
anyway, since one fish can yield 600 doses of the drug therapy.

Through the Health Canada approved trials, Sellers has first tested safe 
doses of the drug. A trial involving 71 people who took a single small dose 
to prove it had no detrimental effects is said to have accomplished that. 
In the second part, involving 56 participants, several doses of the drug 
over a week are being given through intramuscular injections. Shum hopes an 
oral form of the therapy, which melts under the tongue, will also be developed.

Sellers said it's not unusual to be studying a potentially toxic substance 
as a helpful therapy. "It's done in medicine all the time ... almost every 
drug can be toxic depending on the dose."

Shum, who is from China but has lived in Vancouver for the past decade, 
said there are an estimated 10 million heroin addicts in China alone 
"because of the proximity to the Golden Triangle and the fact it is much 
cheaper there."

Because of that, the company recently presented its application for 
clinical trials in China to officials there. She noted that China embraces 
Eastern therapies like herbal or homeopathic remedies more readily than 
new, Western based drugs. The company, International Wex, derives its name 
from the concept of exchange between Western and Eastern therapies.

The first phase of clinical trials, estimated to cost $1.5 million, are 
expected to be completed in the summer.

Phase-two trials, which must focus on the effectiveness of the therapy, 
will begin after that.
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MAP posted-by: Beth