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Two
Medical Studies Find Vaporized Medical Marijuana is Safe and Effective
by Marijuana Policy
Project (19 Apr, 2007)
Vaporization Avoids Exposure to Contaminants in Smoke; Associated With Reduced Respiratory Symptoms
SAN FRANCISCO, CALIFORNIA - Two new studies, one from the
University of California, San Francisco, and the other from the University at
Albany, State University of New York, provide strong evidence that technology
now allows medical use of marijuana with the rapid action and easy dose
adjustment of inhalation, but without the respiratory hazards associated with
smoking. This is considered highly important, as the risks associated with smoke
inhalation have been cited by both government officials and independent experts
as a major argument against medical marijuana.
The San Francisco study, conducted by Dr. Donald Abrams and colleagues at UCSF
and just published online by the journal Clinical Pharmacology and
Therapeutics, compared a commercially available vaporizer called the Volcano
to smoking in 18 volunteers.
The subjects inhaled three different strengths of marijuana either as smoked
cigarettes or vaporized using the Volcano. Unlike smoking, a vaporizer does not
burn the plant material, but heats it just to the point at which THC and the
other active components, called cannabinoids, vaporize. The vapors are collected
in a detachable plastic bag with a mouthpiece for inhalation.
The researchers then measured the volunteers' plasma THC levels and the amount
of expired carbon monoxide (CO), which is considered a reliable marker for the
unwanted combustion products contained in smoke. The two methods produced
similar THC levels, with vaporization producing somewhat higher levels, and were
judged equally efficient for administration of cannabinoids.
The big difference was in expired CO. As expected, there was a sharp increase in
CO levels after smoking, while "little if any" increase was detected
after vaporization. "This indicates little or no exposure to gaseous
combustion toxins," the researchers wrote. "Vaporization of marijuana
does not result in exposure to combustion gases, and therefore is expected to be
much safer than smoking marijuana cigarettes."
A second study, by Dr. Mitch Earleywine at the University at Albany, State
University of New York and published in the Harm Reduction Journal,
involved an Internet survey of nearly 7,000 marijuana users.
Participants were asked to identify their primary method of using marijuana
(joints, pipe, vaporizer, edibles, etc.) and were asked six questions about
respiratory symptoms. After adjusting for variables such as age and cigarette
use, vaporizer users were 60 percent less likely than smokers to report
respiratory symptoms such as cough, chest tightness or phlegm. The effect of
vaporizer use was more pronounced the larger the amount of marijuana used.
"Our study clearly suggests that the respiratory effects of marijuana use
can be decreased by use of a vaporizer," Earleywine said. "In fact,
because we only asked participants about their primary means of using marijuana,
it's likely that people who exclusively use vaporizers will get even more
benefit than our results indicate, because no doubt some in our study used
vaporizers most of the time but not all of the time."
"Ten years ago, the Institute of Medicine's landmark, White
House-commissioned report found that marijuana has medical value," said Rob
Kampia, executive director of the Marijuana Policy Project in Washington, D.C.
"In its report, the Institute of Medicine also called for the development
of a non-smoked delivery system before making medical marijuana widely
available. Now that we have such a delivery system, the prohibitionists' final
arguments against medical marijuana have been reduced to rubble."
The Earleywine study is available online at www.harmreductionjournal.com/content/pdf/1477-7517-4-11.pdf.
References
- Abrams DI et al. Vaporization as a Smokeless Cannabis Delivery System: A
Pilot Study. Clin Pharmacol Ther. 2007, Apr 11; [Epub ahead of print].
- Earleywine M and Barnwell SS. Decreased Respiratory Symptoms in Cannabis Users
Who Vaporize. Harm Reduction Journal. 2007, 4:11.
Article from www.mpp.org