Pubdate: Sat, 21 Jun 2003
Source: State, The (SC)
Copyright: 2003 The State
Author: Linda H. Lamb


Hope for cocaine addicts desperate to conquer their cravings could lie in 
research at the Medical University of South Carolina.

In research, which eventually might help cigarette smokers and alcoholics 
as well, scientists at MUSC found that an amino acid compound you can buy 
in a health food store prevents cocaine cravings in laboratory rats.

Researchers hope studies in humans will provide solutions for people in the 
grip of addictions.

Cocaine addiction "produces long-term, if not permanent changes in the 
brain," said Peter Kalivas, who chairs the Department of Physiology & 
Neurosciences at MUSC.

"And these changes in the brain are what make it very difficult to avoid 
relapse," he said. "The craving becomes almost a compulsion."

Kalivas authored the MUSC study published in the July issue of Nature 
Neuroscience. The compound that proved so promising -- N-acetylcysteine -- 
is used as an antioxidant and as a remedy for acetaminophen overdose.

It doesn't reconstruct the affected parts of the brain, Kalivas said. But 
it restores cognitive control that enables the lab rats to resist cues 
enticing them back to cocaine use.

Before, he said, their pursuit of cocaine compelled them to put off eating, 
stop playing and forget about mating.

"When you give them a signal that they can go get cocaine, they rush off to 
get it," Kalivas said. "It dominates all other influences."

As those who live or work with addicts know, cocaine's effects on humans 
can be all too similar.

An estimated 40 percent of people who try cocaine -- often the potent form 
called crack -- will become addicted. By contrast, for example, about 10 
percent of people who drink alcohol will go on to become alcoholics.

"There are very few long-term 'social' cocaine users," said James Wilson, 
treatment consultant with the S.C. Department of Alcohol and Other Drug 
Abuse Services.

Wilson, 53, beat his own cocaine addiction 19 years ago. But some nights, 
he still dreams about using the drug.

For those trying to kick the habit, he said, there's a crucial period 
called "cocaine anhedonia," a depression caused by the drug's disturbance 
of the brain chemistry. People get anxious, irritable and increasingly 

"It's a very difficult period to get through," said Wilson, who has 
counseled addicts and now trains others to do counseling.

"They know that by getting high, they can feel better again."

Within four to six seconds, he said, the crack smoker gets a powerful, 
pleasurable jolt to the central nervous system.

The drug lowers levels of a neurotransmitter called glutamate in the part 
of the brain's frontal cortex that has been identified as important in 

What N-acetylcysteine does, Kalivas said, is restore the glutamate levels 
to normal. In practical terms, this can help recovering addicts by enabling 
them to stay drug-free long enough to hang on to their families, keep their 
jobs and rebuild their lives.

A second team of MUSC researchers is working on a clinical study with 
people who have been addicted to cocaine. Results are not expected until 
next year.

Dr. Robert Malcolm, MUSC psychiatrist and addiction specialist, is lead 
investigator in the clinical study. He wants to ensure the compound is safe 
as well as effective.

Volunteers who have used cocaine in the past are checked to see how they 
respond to cocaine cues after they have been given the compound. Cues 
include photos of cocaine paraphernalia and of people using the drug.

Researchers study subjects' responses such as blood pressure and pulse 
rates. They also look at magnetic resonance imaging (MRI) studies of the 
subjects' brains, to see whether they "light up" when exposed to the cues.

Malcolm said the compound researchers use is federally inspected and proven 
as pure -- which might not be true if one buys it in a store or online.

He said that while he's excited about the research, he worries about people 
trying the compound on their own. They could jeopardize the research or 
their own health, he said. While generally not seen as hazardous, 
N-acetylcysteine may cause allergic reactions and side effects.

"The last thing we want cocaine addicts to do, or smokers to do, is to run 
out, buy this stuff which may not even be pure, and use it in a dose that 
they don't know anything about," he said.

Cocaine is an expensive addiction, costing heavy users $500 to $800 a week. 
In South Carolina, 5.9 percent of residents surveyed in 2001 reported 
having used cocaine at least once, compared with 11 percent of the U.S. 
population in 2000.

But a 1997 study by Wilson's agency found that about 21 percent of people 
arrested in the state had cocaine in their urine.

"It's still a major problem," Wilson said.

Even if cocaine use doesn't lead to prostitution or other crimes, it has 
devastating effects on families, he said.

"Even if you can afford it, and few can, you're taking yourself away from 
your friends, your family, your job. If you're addicted to cocaine, there's 
no way you're going to be a good parent.

"You're robbing your loved ones of your best self."
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MAP posted-by: Larry Stevens