Pill may help break cocaine addiction
By LAURAN NEERGAARD
Milwalkee Sentinal, May 7, 2006
may help break cocaine addiction - Washington - The
hottest topic in cocaine addiction is another drug - a
medicine already sold to wake up narcoleptics.
Hundreds of cocaine users are
testing whether that legal pill, called modafinil, could
help them kick the addiction, and there's early evidence
that it may.
In addition to blunting
cocaine's notorious cravings, modafinil might also counter
the damage that cocaine wreaks on users' brain circuits -
damage that in turn fuels the cycle of addiction.
The prospect of that
double-whammy has the National Institutes of Health spending
$10.8 million researching modafinil as a potential cocaine
treatment. Results from the first of three key clinical
trials could arrive by year's end.
Scientists are cautious: In a
hunt spanning two decades, no one has found a medication to
help treat cocaine addiction, and there's no guarantee that
modafinil will pan out.
But for Nora Volkow, director
of NIH's National Institute on Drug Abuse, the narcolepsy
medicine tops the list of promising potential therapies. It
may help restore proper function of a crucial brain
chemical, dopamine, that addiction hijacks.
And in describing why he's
hopeful, one leading researcher recounts the man who accused
his drug dealer of selling bad coke before realizing
modafinil had kept him from getting high - and several other
modafinil testers who told of flushing cocaine down the
"I've been treating cocaine-
addicted patients for something like 25 years, more, and
I've never heard of anybody throwing away cocaine," says
Charles Dackis of the University of Pennsylvania, who led a
pilot study that suggested modafinil more than doubled
addicts' chances of going cocaine-free for at least three
That study enrolled just 62
people, but the results were significant enough for NIH to
fund new research - at Pennsylvania, the University of
Texas-Houston, Boston University and other sites - enrolling
about 650 cocaine users to see if modafinil really does
The main side-effect so far:
insomnia, not surprising as modafinil is sold today to help
narcolepsy patients fend off that neurologic disease's
sudden sleep attacks.
Addiction specialists gave it
a look because modafinil triggered something in the brain to
also improve patients' mood, energy levels and ability to
concentrate - effects that might counter cocaine withdrawal.
Then came the surprises:
• Cocaine intensely
stimulates the brain's pleasure centers, producing not just
a "buzz" or a "rush" but outright euphoria. In a small
safety study to ensure that modafinil didn't make cocaine
worse, some users found the once-a-day pill blocked that
high. "We didn't expect that at all," Dackis says.
• Potentially more important,
he says, modafinil seems to increase activity in the
prefrontal cortex, the brain's decision-making command
center and the spot that allows reasoning to override
impulse or emotion. Cocaine reduces activity in that key
brain region, making it even harder for would-be quitters to
ignore cravings and resist another hit.
• Modafinil also increases
the ability to think strategically, a means of weighing
variables and risks to make decisions, says Frank Vocci,
NIDA's pharmacotherapy chief.
"The effects on cognitive
processes are very subtle, and very interesting," Vocci
says, and that's the reason that of half a dozen medications
being studied as potential cocaine treatments, the
government's biggest emphasis is on modafinil.
Cocaine is highly addictive:
About 16% of people who try it become hooked, often rapidly.
In 2003, the latest data, the government estimated that more
than 1.5 million Americans were dependent on or abusing
cocaine, and more reported recently experimenting with it.
Addictions in general rewire
the brain, says Volkow. Drugs cause a feel-good rush by
increasing amounts of the brain chemical dopamine. The brain
reacts by tamping down regular dopamine production, making
users feel lousy between hits and setting up the cycle of
At the same time, the
dopamine surge also creates memory circuits that eventually
establish so-called "cue-induced cravings": If an addict
passes the crack house or sees friends he did drugs with,
his brain literally sends a strong impulse to use again.
Modafinil seems to affect
chemicals that in turn regulate dopamine production, a
different pathway than cocaine takes in altering normal
dopamine, and thus one that might counter it, adds Dackis.
A drug that could help
cognition instead of just numb cravings would be "a big
benefit in treatment," he says.