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Despite Research, FDA Says Marijuana Has No Benefit
The Food and Drug Administration issued a statement in April that no sound scientific studies support the medicinal use of marijuana for treatment. This conclusion left some researchers puzzled.
"I don't understand where that came from," said John Benson, M.D., a professor of medicine at the University of Nebraska in Omaha, who chaired an Institute of Medicine panel that wrote a 267-page report, Marijuana and Medicine, Assessing the Science Base, published in 1999. "We found sufficient evidence that [smoking marijuana] had benefits for some patients, such as to help with nausea and chemotherapy for cancer treatment. We recommended that further research be done, but it hasn't been."
These researchers say that such studies do exist and point to benefits both from smoked marijuana and its derivatives. Although everyone agrees that more research is needed, some who want to study smoked marijuana charge that new work has been hampered by federal agencies, which have increasingly limited the amount of marijuana that can be legally be used in research. At the same time, the issue of medical marijuana has become a battleground between the federal government, which argues that it has the right to arrest anyone who uses an illegal drug, and several states, which have passed laws permitting the use of medical marijuana. Recent Supreme Court decisions have not clarified the issue.
The FDA announcement, labeled an "interagency advisory," specifically focused on smoked marijuana rather than agents based on derivatives and stressed that the agency has not approved its use for any condition or disease. Still, it added, "a growing number of states"—11 so far—have legalized medicinal use of marijuana.
"These measures are inconsistent with efforts to ensure that medications undergo the rigorous scientific scrutiny of the FDA approval process and are proven safe and effective under the standards of the [Federal Food, Drug and Cosmetic] Act," the advisory said.
It concluded that the FDA, along with the Drug Enforcement Agency (DEA), and the Office of National Drug Control Policy "do not support the use of smoked marijuana for medical purposes."
Some researchers who study medical marijuana, as well as a few patient advocacy groups, claim that the FDA decision was based on political pressure from Congress rather than on scientific merit. Some members have been asking the FDA for years to issue an opinion on medical marijuana. One example is Rep. Mark Souder, a Republican from Indiana, who says on his congressional Web page that the argument for medicinal use of marijuana "is simply a red herring for the legalization of marijuana for recreational use.
"Studies have continually rejected the notion that marijuana is suitable for medical use because it adversely impacts concentration and memory, the lungs, motor coordination, and the immune system," the Web site says.
The FDA spokesperson on this issue didn't return several calls or e-mail messages for comment. But in other media reports the representative said the agency issued the statement in response to many inquiries from Capitol Hill but would probably do nothing to enforce it, because that responsibility falls to the DEA.
Limited Studies and Government Regulation
The FDA position does not surprise Donald Abrams, M.D., who says he is one of the few U.S. researchers who have recently studied the benefits of smoked marijuana. "It seems that every 10 years since the 1940s, a government commission comes up with the same kind of report, and we were about due for another one," he said. "So, in my opinion, this clearly seems to be politically motivated."
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Abrams, a professor of clinical medicine at the University of California in San Francisco, has just received funding from the National Institute on Drug Abuse (NIDA) to study whether smoked marijuana in cancer patients can increase the pain-relieving effects of opioid pain control substances like morphine. He says that animal data suggest that cannabinoids (the 66 cannabis chemicals that bind to specific human tissue receptors) and opioids have synergistic effects, "so it may be possible that patients using marijuana can get away with using lower doses of opioids for longer periods before they become immune to them."
But Abrams can't predict where the study will lead, citing constraints by regulations governing marijuana research. For example, his study can only be a safety study, because NIDA did not fund a study designed to detect a benefit for smoked marijuana given the agency's mission, Abrams says. So he can only look to see if cannabinoids can increase blood levels of opioids. Other funding agencies also say there isn't a good body of evidence that shows a benefit, yet legal access to marijuana for study can be difficult. Even if they do find a benefit—which Abrams has for treatment of human immunodeficiency virus symptoms—peer reviewers have argued that it is impossible to design a randomized, placebo-controlled study of marijuana because the differences between the two substances would be obvious.
Cannabis has been used medicinally for centuries, and cannabis products were widely prescribed for pain and other symptoms by physicians until 1937, when the Marijuana Tax Act was passed—over the objections of the American Medical Association.
Most of the research on the use of smoked marijuana for treatment of cancer and several diseases was conducted in the 1970s and 1980. For example, six state-sponsored clinical studies established that smoked marijuana is an effective antinausea treatment for cancer chemotherapy. But the Controlled Substance Act subsequently prohibited all medicinal use of marijuana by placing it in the most restrictive category of schedule I, and in 1992, marijuana testing through the FDA's compassionate investigational new drug program was closed.
The medical community remained interested in the potential medical uses of the drug. In March 1996, the American Public Health Association formally urged the U.S. administration and Congress "to move expeditiously to make cannabis available as a legal medicine where shown to be safe and effective and to immediately allow access to therapeutic cannabis through the [investigational new drug] program."
An expert panel formed by the NIH in 1997 found that research showed some patients, especially those receiving chemotherapy to treat cancer, could be helped by the drug. The 1999 Institute of Medicine report concluded that although some newer drugs can effectively help symptoms of cancer and cancer treatment, some patients still benefit. "The critical issue is not whether marijuana or cannabinoid drugs might be superior to the new drugs, but whether some groups of patients might obtain added or better relief from marijuana or cannabinoid drugs," it said.
Two years later, the AMA urged the NIH "to implement administrative procedures to facilitate grant applications and the conduct of well-designed clinical research into the medical utility of marijuana."
Angst and Frustration Limit Research
Although several states were legalizing the medical use of marijuana, and were funding studies, the DEA began conducting raids on medical marijuana distribution centers in California and other states, according to a 2003 Congressional Research Service report. Their response came from a study that estimated 30,000 California patients and another 5,000 in eight states possess physician's recommendations to use marijuana medically, the report said.
In two 2005 rulings, the U.S. Supreme Court said that states have the prerogative to legalize marijuana for medicinal purposes, but it also reaffirmed federal authority to prosecute patients in those states who use it, along with anyone else.
To many researchers, conducting research on the medical effects of smoked marijuana is becoming nearly impossible. Not only is it difficult to address the position, expressed by Rep. Souder, that allowing marijuana to be used as medicine would allow opportunities for recreational use, but other researchers question the value of offering patients a substance to smoke that could logically cause lung disease, as cigarettes do. For example, Benson said that he and the IOM panel "did not like smoke as a way of delivering a therapeutic substance because of the possible risks." However, a new study presented in late May at the American Thoracic Society's annual meeting may mollify Benson somewhat. The study, by researchers at the University of California at Los Angeles, found that smoking marijuana did not increase the risk of developing cancer compared with nonsmokers, even among users who reported smoking up to a cumulative 22,000 marijuana cigarettes. Although other health issues may come from smoking marijuana, such as repression of the immune system, cancer isn't one of them, the researchers concluded.
Be that as it may, Abrams, who has been studying medical marijuana for 14 years, says the research is "difficult, payoffs are few and far between, and there is a lot of frustration and angst" and he doesn't expect that to change. Still, he vows to press on because "marijuana can do amazing things. If you have a have a drug that increases appetite, decreases pain, decreases depression and nausea, and makes people who are in the late stages of cancer happy, why is that bad?" he said.
Aminah Jatoi, M.D., an associate professor of oncology at the Mayo Clinic in Rochester, Minn., agrees that studying marijuana "is very, very hard. It is a unique substance, and getting a placebo to compare it to is difficult. But even with those limitations, I think it is very important to look for therapies that can help our patients."
In a 2002 study in the Journal of Clinical Oncology, Jatoi compared dronabinol, an FDA-approved synthetic cannabis derivative, with megestrol, an accepted treatment for cancer-associated anorexia. She found that dronabinol had no advantage over megestrol. She said it may be because the cannabis derivative contains just one of the hundreds of chemicals that work synergistically in the natural plant. She rarely recommends dronabinol to stimulate the appetite.
"We need more research to treat symptoms of cancer patients, such as pain, wasting, and nausea," Jatoi said. "It is important to look at all avenues, not just to put up roadblocks and say we are not going to examine this product or that. We need real information."
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