While the medicinal use of cannabis (more commonly known as marijuana) remains controversial in many parts of the US, researchers are discovering more about the plant’s ability to help improve a variety of conditions.
Currently, 20 states and Washington, DC, have approved medical marijuana for patients with chronic or debilitating diseases that cause pain, nausea, vomiting, loss of appetite and other serious symptoms.*
What you need to know...
Medical marijuana is not the same as the prescription drug dronabinol (Marinol), which is derived from one of the plant’s active compounds, delta-9-tetrahydrocannabinol (THC). Marinol was approved by the FDA in 1985 for cancer patients whose nausea and vomiting did not respond to conventional treatments. In 1992, the drug was approved for loss of appetite due to AIDS wasting syndrome.
Though Marinol is widely available, it contains just one of marijuana’s estimated 70 compounds known as cannabinoids. For this reason, some researchers believe that it is important to investigate the medicinal use of marijuana because its many other cannabinoids may offer significant benefits beyond those conferred by THC alone.
However, marijuana has also been widely used as a recreational drug and remains illegal or "decriminalized" (regulated but not banned) in most parts of the world when used for this purpose.
Even now, when state laws permit the use of medical marijuana, federal law does not. Because of this, doctors can recommend marijuana only for medical conditions (such as cancer, chronic pain and glaucoma) for which medicinal use of the plant has been approved by state legislatures. In these cases, the physician generally writes a letter that allows patients to access medical marijuana from a dispensary.
The legal and political issues surrounding medical marijuana have prevented it from being studied in the same ways that other medications are researched in the US. However, the Institute of Medicine (IOM), an independent organization that provides unbiased scientific opinions to government agencies, did issue an important analysis on medical marijuana.
Landmark report: The IOM concluded in 1999 that chemical compounds in marijuana, particularly cannabinoids, appear to have therapeutic value in treating...
Appetite loss, nausea and pain. Cancer patients who undergo chemotherapy often experience nausea, pain, insomnia and/or depression. These symptoms can be treated separately with prescription drugs, but combining the drugs often results in drug-drug interactions. With marijuana, some patients get relief without this risk.
Nerve-related pain. Research published in the Journal of Pain found that patients who smoked marijuana had less nerve-related pain from spinal cord injuries or other conditions.
Neurological conditions. Some patients with multiple sclerosis who smoke marijuana report that they have less pain and fewer/less intense muscle spasms. Patients with seizure disorders may do better when they combine marijuana with antiseizure medications.
Glaucoma. Marijuana has been found to help reduce eye pressure caused by glaucoma and is approved for this purpose in several of the states that permit its use.
Marijuana is unlikely to cause serious side effects -- but, like any drug, it’s not appropriate for everyone. Marijuana may...
Lower blood pressure and increase heart rate. For this reason, it may not be appropriate for people with a history of heart problems.
Cause unwanted sedation. The use of marijuana might increase confusion in older adults with cognitive difficulties. Similarly, it shouldn’t be used when driving or operating machinery.
Many people wonder about the potential health risks of smoking marijuana, but there’s no evidence that the small amounts used for medicinal purposes are likely to increase the risk for lung cancer or serious respiratory diseases.
Best ways to use marijuana...
Choose your delivery method wisely. Some patients choose to eat marijuana -- in the form of brownies or other prepared foods -- rather than inhale it. However, there are some potential problems when marijuana is eaten.
Taken by mouth, marijuana takes two hours or longer to reach peak concentrations in the blood. Patients who don’t feel the effects right away tend to eat a little more -- and then discover that they’ve taken too much. Signs of taking too much include confusion, paranoia and dizziness. Caution: When eaten, the patient’s liver creates a metabolite that can accentuate the plant’s psychoactive effect.
Inhaled marijuana, on the other hand, reaches peak levels in the bloodstream within two to two-and-a-half minutes. Because the effects occur so quickly, patients can readily adjust the dose by inhaling more or less.
Consider using a "vaporizer." Some patients use devices that heat, but don’t actually burn, marijuana. Vapors go into a bag and can be extracted only through the mouthpiece. We’ve found in studies that fewer noxious gases are inhaled when marijuana is vaporized as opposed to smoked.
Be cautious with dosing. Go slowly. Because the potency varies by plant, marijuana can’t be standardized in the same ways that medications are standardized in a laboratory. In addition, a patient’s sensitivity to marijuana will partly depend on his/her genetic makeup. I recommend patient-titrated dosing -- try a small amount... see how you feel... then increase/decrease the dose as needed.
*Marijuana is approved for medicinal use in Alaska, Arizona, California, Colorado, Connecticut, Delaware, Hawaii, Illinois, Massachusetts, Maine, Michigan, Montana, Nevada, New Jersey,New Hampshire, New Mexico, Oregon, Rhode Island, Vermont, Washington and Washington, DC.
Source: Donald I. Abrams, MD, a professor of clinical medicine at the University of California, San Francisco, School of Medicine, chief of hematology and oncology at San Francisco General Hospital and president of the Society for Integrative Oncology. He has conducted clinical research on medical marijuana and other integrative approaches for treating cancer-related symptoms. He is the editor, with Andrew Weil, MD, of Integrative Oncology (Oxford University).