Pubdate: Mon, 24 Oct 2005
Source: Inland Valley Daily Bulletin (CA)
Copyright: 2005 Inland Valley Daily Bulletin
Contact: http://www.dailybulletin.com/Stories/0,1413,203%257E23145%257E,00.html
Website: http://www.dailybulletin.com/
Details: http://www.mapinc.org/media/871
Author: Allan J. Comeau, Ph.D.

COCAINE VS. METHAMPHETAMINE

In the 2004 movie "Alien vs. Predator," teens (mostly) witnessed 
these film-favorite monsters in mortal combat, only to be stymied by 
a young (female, in this case) human scientist's raw determination 
and instinctual savvy.

While preparing for this column, in a bit of a mind-wandering 
fantasy, I somehow imagined that the part of the Alien could be 
played, metaphorically speaking, by the drug cocaine (it comes mostly 
from outside the United States), while the part of the Predator could 
go to methamphetamine (made by local drug pushers). Our hero is UCLA 
neuroscientist and addiction researcher Thomas F. Newton, with a 
strong supporting, albeit all-male, cast research team.

I'm sticking with the monster metaphor for good reason: surveys show 
that both methamphetamine and cocaine have a strong foothold on 
American users, especially teens. These drugs are destroying lives at 
this very moment. While less than 1 percent of teens have tried 
methamphetamine, nearly half of those are recent users, according to 
the National Survey on Drug Use and Health, released last month. 
About 2 million Americans 12 years and older are regular cocaine 
users, about one-fourth of them using the much more highly addictive 
form known as crack.

Based on the presumptive similarities between the cocaine and 
methamphetamine molecules and the fact that both are stimulants and 
utilize the dopamine (pleasure) circuitry -- with some exceptions -- 
scientists have tended to think of their effects as somewhat alike. 
In the article "Cocaine and Methamphetamine Produce Different 
Patterns of Subjective and Cardiovascular Effects," recently 
published in the journal Pharmacology, Biochemistry and Behavior, 
Drs. Newton and colleagues share the results of a controlled study 
conducted at the Jane and Terry Semel Institute for Neuroscience and 
Human Behavior at UCLA.

Newton et al found that, although both drugs are stimulants, cocaine 
and methamphetamine have distinctive patterns of subjective and 
cardiovascular arousal. The subjective effects of cocaine tend to 
peak and also tend to decline more rapidly than those caused by 
methamphetamine, whose subjective effects tend to rise more slowly 
and are more sustained than that of cocaine.

Also, the cardiovascular effects (heart rate and blood pressure) of 
both drugs were found to have similar initial patterns, but 
methamphetamine?s effects last longer.

I asked Dr. Newton to comment on the usefulness of this research.

"The significance of this study," he said, "is that it shows that 
drugs that we thought worked more or less alike actually produce 
quite different effects."

Newton added, "It underscores the importance of developing treatment 
aimed at specific medications as opposed to addiction generally."

There are a lot of reasons why researchers and clinicians would want 
to know this kind of information. One would be to explain reported 
differences in drug-taking patterns among cocaine and methamphetamine users.

The former, cocaine users, tend to binge, while methamphetamine users 
are more likely to consume on a daily basis, Newton writes. In this 
study, he points out that factors such as differences in drug 
half-life (the time it takes for one-half of the drug taken to be 
neutralized by the body) can make a difference.

"For example," he says, "the effects of cocaine are pretty much gone 
in 20 minutes to a half hour at the longest, whereas the half-life of 
cocaine is 90 minutes at the shortest, which means that you have 80 
percent of your blood level when your subjective effects have gone 
completely away. How that works is really not known."

"Another important significance of the study," he said, "is that the 
effects of methamphetamine lasted longer than we expected, compared 
to what we saw for cocaine. Why these two drugs differ, on a 
molecular level, is really not clear."

With each gain in knowledge, we can only hope that, somehow, there 
can be a parallel gain in lives saved and the quality of lives lived.

Allan J. Comeau, Ph.D., is a psychologist on the clinical faculty at 
UCLA and a former president of the Inland Southern California 
Psychological Association. Write him at 2001 S. Barrington Ave., 
Suite 304, Los Angeles, CA 90025, or visit 
(http://www.drcomeau.com)www.drcomeau.com
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MAP posted-by: Beth Wehrman