Monday, November 24, 2008

Heroin treatment also works on cocaine: study

Methadone, a drug used for many years to treat heroin addiction, appears to work well in cocaine addiction, too, a new Canadian study suggests.

Psychologist Francesco Leri of the University of Guelph has been making rats addicted to cocaine, and then treating them with methadone.

Most of the rats responded well, he says. They lost their powerful urge for cocaine, and in addition, their brains "re-set" themselves into the same pattern that existed before they first used cocaine.

"It can be done tomorrow with humans, and should be done tomorrow," he said.

That's because methadone -- unlike a new drug -- already exists as a tested drug, with clear prescription rules and clinical staff trained in giving it out.

"There is an entire system that is already in place for the employment of methadone," that could be used for cocaine addicts.

Mr. Leri said the U.S. National Institute for Drug Abuse is looking into the use of methadone -- or a similar drug such as buprenorphine -- in a clinical setting.

The idea came up because in real life, people mix drugs.

There's no such thing as a "pure heroin addict," he said. "The norm is people who are addicted to opiates, so heroin or prescription opiates, and they co-abuse cocaine at the same time."

Researchers have wondered what happens to their cocaine problem when they start taking methadone for the heroin addiction.

But it's hard to tease apart the two addictions in humans. In his Guelph lab, Mr. Leri worked on rats with a cocaine addiction, but no exposure to heroin.

The cocaine-addicted rats in his lab didn't get a cocaine high on methadone, he said. Instead, "the methadone may be able to curb the desire that they have for that drug (cocaine)."

In addition, methadone actually reversed changes in the rats' brains that are caused by cocaine, and are known to play a key role in addictive behaviour.

"What's interesting is that, among the rats given cocaine and then methadone, these regions of the brain looked similar to how they appeared in the rats that were never exposed to cocaine.

"We feel we may have the hope of re-setting the brains of some individuals to a type of normality," he said. "I think it should be tried and I guarantee you there will be some individuals -- not everybody -- who will do better on methadone, who will be stabilized on methadone."

The study means a person who is motivated to stop taking cocaine may benefit from methadone as one tool to help, the psychologist says.

"You cannot give methadone left and right and hope that it is going to work. You need to work with individuals who in addiction to social support, in addition to cognitive therapy, will need something to curb their desire" for cocaine.

His study is published in European Neuropsychopharmacology, a research journal.
source: The Ottawa Citizen

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