By David Brown
Washington Post Staff Writer
Thursday, March 18, 1999; Page A01
The active substances in marijuana may be "moderately" useful for treating such problems as pain, nausea and appetite loss, but smoked marijuana has little future as a medicine, a panel of experts advising the federal government said yesterday.
The long-awaited review comes after several states have legalized marijuana for medical use, and was immediately seized upon by marijuana's advocates as an endorsement of their position.
"We are very pleased with this report, which clearly shows there is scientific evidence that marijuana has bona fide therapeutic effects for some patients," said Chuck Thomas, the director of the Washington-based Marijuana Policy Project. "Patients already using marijuana should be given the benefit of the doubt, and should not be arrested."
The report, prepared by 11 scientists convened by the National Academy of Sciences' Institute of Medicine, specifically warned against smoked marijuana because of risks of lung damage. Therapeutic marijuana smoking should be permitted only in a few short clinical trials designed to assess claims for marijuana's usefulness as a pharmaceutical.
White House drug control policy director Barry R. McCaffrey, who requested the report, said he endorsed it "thoroughly" and called it a "significant contribution to discussing the issue from a scientific and medical viewpoint." He said he would not oppose limited studies of smoked marijuana until a less harmful way of inhaling the substance's active ingredients is found.
"I would note, however, that the report says 'smoked marijuana has little future as an approved medication,' " McCaffrey said. "You should not expect to go into an ICU [intensive care unit] in 15 years and find someone with prostate cancer with a 'blunt' stuck in his face as a pain management tool."
The 250-page report was prepared over the last year at a cost of $896,000. The panel reviewed published medical studies on marijuana's physiological effects and possible clinical benefits, and took testimony from researchers and patients.
The claims for marijuana are very broad. People have used it as treatment for nausea caused by chemotherapy, appetite loss arising from AIDS, the painful spasms of multiple sclerosis, the pain of migraine headache, the sight-threatening condition known as glaucoma and the memory loss of Alzheimer's disease.
Reliable data on the drug's benefits, however, have been hard to get. The Drug Enforcement Administration places marijuana -- along with heroin and several other addictive drugs -- in the category reserved for substances with "a high abuse potential." This has made research on patients unusually difficult. Many of the claims for marijuana are based on small, poorly designed studies, or on "clinical anecdotes," the recounted experiences of individuals.
The body produces a marijuana-like substance naturally -- its evolutionary purpose is uncertain -- which stimulates specific receptors on nerve cells distributed widely in the brain. Marijuana contains about 30 active ingredients, collectively known as "cannabinoids," that also activate these receptors. One cannabinoid drug, dronabinol, is licensed in the United States for use in appetite stimulation in AIDS patients, and to prevent nausea and vomiting caused by chemotherapy.
"There is remarkable consensus about the science -- the science suggests the potential of cannabinoid drugs for medical use," said John A. Benson Jr., the former dean of the Oregon Health Sciences University School of Medicine, who was one of the two heads of the panel. "There is far less convincing data about actual medical benefits."
Most studies suggest there are existing drugs that do what marijuana is reputed to do, but better. This was especially true in the case of glaucoma treatment and nausea prevention, the panel found. Nevertheless, a few patients who do not respond to those pharmaceuticals are helped by marijuana.
The panel advocated research aimed at isolating marijuana's ingredients and testing them in randomized controlled trials. An inhalation device is a high priority because it will allow patients to take in the drug as quickly as when it's smoked, without delivering tar and other unwanted substances. In the meantime, studies of smoked marijuana are warranted, the panel said. They should last six months or less, and enroll patients, such as those with terminal cancer, for whom the long-term risks of smoking are relatively unimportant.
The panel found no evidence that closely controlled medical marijuana use would be a "gateway" to illicit drug use, either in ill patients or in society at large.
In the last three years, seven states have passed referenda allowing the medical use of marijuana. Several, however, have run into legal problems, and the statutes have not taken effect.
In the District, a marijuana legalization measure appeared on the ballot in November. Ballots were counted, but the results were not released because Congress prohibited the spending of public money on the legalization effort. The matter is now in federal court.
© Copyright 1999 The Washington Post Company
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