Sandra A. Fryhofer, MD
Clinical Associate Professor of Medicine, Emory University School of Medicine, Atlanta, Georgia; Past President, American College of Physicians, Philadelphia, Pennsylvania

You may well wonder what marijuana has to do with staying well. After all, the new report by the American Medical Association’s (AMA) Council on Science and Public Health says that “marijuana is the most common illicit drug used by the nation’s youth and young adults.”^[1] Some people get hooked on it. If marijuana becomes more readily available for medical use, will increased nonmedical use follow? As a primary care physician and as the mother of 2 college students, this concerns me. In fact, I had a very negative view of physician organizations even talking about medical marijuana until recently, when I read this new report.

History of Medical Marijuana

Marijuana is a botanical derived from the Cannabis sativa plant. It is probably one of the oldest psychotropic drugs known to man, with origins in central Asia. Marijuana contains more than 400 chemical compounds, including more than 60 cannabinoids. The main psychoactive cannabinoid is believed to be tetrahydrocannabinol (THC).

The pharmacologic properties of marijuana were first described by Irish physician William O’Shaughnessy in 1839. The drug was touted for its anti- inflammatory, antispasmodic, anti-asthmatic, anticonvulsant, and sedative properties. Almost incredibly, given its current reputation, marijuana was once listed in the United States Pharmacopeia.^[2] The Marihuana Tax Act of 1937 marked the beginning of federal restrictions. Medical users were taxed a dollar an ounce. Recreational users were hit with a tax of $100 per ounce.

Marijuana was removed from the United States Pharmacopeia in 1942, but it was still available legally for medicinal use until 1970.^[2] That’s when the Controlled Substances Act was passed, classifying marijuana , along with heroin and LSD as a schedule I drug — the most restrictive category. .

The Endocannabinoid System

Since then, an explosion of research has unlocked the mysteries of the endocannabinoid system, which helps explain marijuana’s myriad effects. From modulating neurotransmitters to regulating immune system cells and organs, the endocannabinoid system can affect appetite regulation, energy metabolism, obesity, pain and inflammation, gastrointestinal motility, and central nervous system disorders.

Debate Over Marijuana’s Classification As a Schedule I Controlled Substance

The Controlled Substances Act of 1970 classified marijuana as a schedule I drug: a controlled substance with a “high potential for abuse” and “no currently accepted medical use.”^[3] But is that characterization really accurate?

Two previous AMA council reports, in 1997 and 2001, concluded that sufficient evidence existed to support further research on the potential use of marijuana in treating medical illness.^[1] For example, marijuana has been used to treat cachexia, neuropathy, or chronic pain in patients with HIV; intractable nausea and vomiting in patients on chemotherapy; and neuropathic pain and spasticity in patients with spinal cord injury.

In 1999, the Institute of Medicine recognized the medical potential of synthetic and plant-derived cannabinoids and recommended further research.^[4] Other physician organizations like the American College of Physicians (ACP) agreed. In their 2008 policy statement, the ACP, like the AMA, supports “rigorous scientific evaluation of the potential therapeutic benefits of medical marijuana.”^[5] Why is consideration of reclassification important?

Reclassification would make it easier to conduct research. Reclassification would remove the red tape of a Drug Enforcement Administration (DEA) schedule I license requirement. The AMA council report states: “The future of cannabinoid-based medicine lies in development of botanical drug substances … but that cannot happen without bona fide research. Reclassification of current marijuana scheduling could expedite that process.”^[1] Both the AMA and the ACP urge federal review of marijuana’s schedule 1 classification.

Some marijuana derivatives are already available. Dronabinol (Marinol® is 100% pure synthetic THC, marijuana’s most psychoactively potent ingredient, and is classified as schedule III. It is approved by the US Food and Drug Administration (FDA) for treating recalcitrant chemotherapy-induced nausea and vomiting, and as an appetite stimulant for patients with HIV. Nabilone (Cesamet™, classified as schedule II is an FDA-approved synthetic analogue approved to treat chemotherapy-induced nausea and vomiting. Both are oral preparations, which have some potential disadvantages, including slow absorption and slow onset of action. In addition, some patients are too sick to take these medications.

Smoking as a delivery system works more quickly at providing relief. Several studies conducted in the 1970s and 1980s using FDA-approved protocols found that smoked cannabis was just as effective — and in some cases even more effective — than oral THC.^[6] Granted, smoking anything is not good for you. In certain situations, however, such as for compassionate use, for comfort at end of life, or as a last resort to relieve symptoms, the long-term effects of smoking don’t matter.

Safeguarding doctors and patients from prosecution. Reclassification would also keep doctors who are simply trying to do the right thing out of jail. Thirteen states already have passed laws or referenda making marijuana available for medical use: Alaska, California, Colorado, Hawaii, Maine, Michigan, Montana, Nevada, New Mexico, Oregon, Rhode Island, Vermont, and Washington.^[6] But those are state, not federal, laws.

During the Bush administration, doctors and patients were caught between a rock and a hard place. Federal agents would raid medical marijuana distributors for violating federal statutes, even though what they were doing was in compliance with state laws. On October 19, 2009, the Obama administration announced an attitude quite different from its predecessor’s approach. The New York Times reported a memorandum giving federal prosecutors more wiggle room when marijuana is used for medicinal purposes. The justice department said: “It will not be a priority to use federal resources to prosecute patients with serious illnesses or their caregivers who are complying with state laws on medical marijuana.” However, Attorney General Eric H. Holder Jr. went on to say there would be no tolerance for “drug traffickers who hide behind claims of compliance with state law to mask activities that are clearly illegal.”^[7]

Additional Concerns About Marijuana

Marijuana has as many adverse effects as it has nicknames. Marijuana is known by numerous names, including Mary Jane, pot, grass, weed, and bambalacha. It can trigger severe adverse reactions, including acute anxiety, panic, confusion, dysphoria, paranoia, delusions, and hallucinations. It also can cause acute cardiovascular effects, such as increased heart rate and drops in blood pressure.

Marijuana use impairs short-term memory, attention, motor skills, reaction time, and the organization and integration of complex information. In the long term, smoking marijuana may lead to lung damage and chronic bronchitis.

Will facilitating medical use encourage nonmedical use? One criticism of medical marijuana laws is that they might increase nonmedical use. This is a valid concern, and one I worry about. Two facts in particular in the AMA council report drive home this point:

• Marijuana is the most common illicit drug used by the nation’s youth and young adults; and
  
• Of those who use cannabis, 4%-9% fulfill diagnostic criteria for substance dependence

The AMA report continues, “even if marijuana is prone to nonmedical use, that does not obviate its potential for medical product development. In fact, many “legal” pharmaceutical products that are used for pain relief, palliation, and sleep induction have more serious acute toxicities than marijuana, including death.”^[1]

Philosophically, I agree that further research and easier access for medical use are good things if marijuana can help alleviate patient suffering. As a primary care physician and a mother, however, I worry that becoming too lax with restrictions might make it easier to obtain for nonmedical use. The AMA report also reminds us that “whether or not cannabis is a gateway drug to other substance misuse is controversial.” That’s what makes this issue hit close to my home and my office.

I’m interested in hearing your take on medical marijuana. Please post your comments on the message board. I also invite you to look for Medicine Matters video blog series, which is addressing medical marijuana.

References

1. American Medical Association Council on Science and Public Health. Report 3. Use of Cannabis for Medical Purposes. November 2009. Available at: www.ama-assn.org/ama1/pub/upload/mm/443/csaph-report3-i09.pdf Accessed January 7, 2010.
   
2. MacDonald J. Medical marijuana: informational resources for family physicians. Am Fam Physician. 2009;80:779-783. Abstract
   
3. US Food and Drug Administration. Inter-agency advisory regarding claims that smoked marijuana is a medicine. April 20, 2006. Available at: www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/2006/ucm108643. Assessed January 7, 2010.
   
4. Joy JE, Watson S Jr, Benson JA Jr, eds. Marijuana and Medicine. Assessing the Science Base. Washington, DC: National Academy Press; 1999.
   
5. American College of Physicians. Supporting research into the therapeutic role of marijuana. Position paper 2008. Available at: www.acponline.org/advocacy/where_we_stand/other_issues/medmarijuana.pdf. Accessed January 7, 2010.
   
6. Kalant H. Medicinal use of cannabis: history and current status. Pain Res Manag. 2001;6:80-91. Abstract
   
7. Stout D. US won’t prosecute in states that allow medical marijuana. The New York Times. October 20, 2009:A1.