HEROIN TREATMENT MAY RAISE RISK OF OVERDOSE

A CONTROVERSIAL treatment to help drug addicts kick heroin could put
them at risk of fatal overdoses, research has revealed.

When implanted in the body, naltrexone -- a drug that sends addicts
into immediate withdrawal -- was thought to prevent heroin overdoses
by blocking the effects of opiates.

But doctors from the Drug and Alcohol Research Centre at the
University of NSW found five drug-related deaths among people using
the implants in coronial records.

Four men and a women, with an average age of 26, died between 2002
and 2004. Two of them were from Victoria.

Researchers believe some addicts may have taken large doses of heroin
to overcome the "block" effect of the implant.

"The big thing that has been claimed is if you are actively in
treatment with naltrexone implants you can't overdose, and the fact
of the matter is these people did," one of the study's authors, Dr
Louisa Degenhardt, said.

Naltrexone, which has been used since the late 1990s in Australia as
an alternative heroin withdrawal method to methadone, has divided the
drug treatment community.

Normally used for alcoholism treatment, its effectiveness in heroin
addiction is untested. And although the oral tablet has been licensed
by the Therapeutic Goods Administration, the implant method has not
been clinically tested.

Two deaths occurred when users were undergoing implant treatment, one
happened soon after an implant was removed and two about six months
after insertion.

Addiction specialist Nick Lintzeris, from drug treatment agency
Turning Point, said it was possible some of the deaths had occurred
after naltrexone had worn off. "The problem is when you stop using it
(naltrexone) you become sensitive to the effects of heroin, so that
even much smaller doses of heroin than you used to use could be
potentially lethal," he said.

The research will be published today in The Medical Journal of Australia.