Medical Marijuana – A Viable Option for the Treatment of RA?
For thousands of years and across many cultures, marijuana, or cannabis, was touted as possessing medicinal properties.1 And its use for both medicinal and recreational purposes is gaining in popularity in recent times. Some activists are advocating its use for rheumatoid arthritis.2
My desire is that RA patients will carefully consider all treatments for their disease. The topic must be raised in public forums and from scientific perspectives. I realize that this article will likely bring about a slate of responses, both for and against. Such is a nature of controversial topics and I hope for a reasoned conversation on this site’s discussion forums.
Where is medical marijuana legal?
There are currently 20 states in which medical marijuana is legal. Another 13 states have pending legislation. Some of the laws were approved legislatively and others were voter-approved initiatives.3 Washington and Colorado voters also recently approved recreational uses of marijuana.
Some states restrict the use of medical marijuana to a predetermined list of conditions. For example, Washington State approved marijuana for “terminal or debilitating medical conditions” including but not limited to:4
Nausea, vomiting, cachexia associated with cancer, HIV-positive status, AIDS, hepatitis C, anorexia, and their treatments, severe muscle spasms associated with multiple sclerosis, epilepsy, and other seizure and spasticity disorders, acute or chronic glaucoma, Crohn's disease; and some forms of intractable pain.
Rheumatoid arthritis or other forms of arthritis are not directly included in this language or in most state laws except in California. However, most state laws include vague language that could include almost any chronic disease. For example, the Washington State law adds, “Any other medical condition duly approved by the Washington state medical quality assurance commission in consultation with the board of osteopathic medicine and surgery as directed in this chapter.5 Most state laws require that the use of medical marijuana be under the direct supervision of a licensed physician.
In spite of state laws on medical and recreational use of cannabis, the United States federal government continues to maintain that it is illegal to possess, use, and sell marijuana and it is defined as a schedule I substance under the Controlled Substance Act.6 The Food and Drug Agency (FDA) of the United States has not approved it for medical use although they state that it could be approved should research support it.7
Chemicals in cannabis
There are many chemicals found in the cannabis plant. The chemicals commonly attributed to the medical and psychoactive properties are called cannabinoids with the most common called tetrahydrocannabinol or THC. When ingested, these chemicals attach to receptors in the brain that are involved with “pleasure, memory, thinking, concentration, movement, coordination, and sensory and time perception.” (National Institute on Drug Abuse8)
How is marijuana ingested?
There are multiple ways to ingest marijuana including smoking, vaporizers, eating, and topical lotions.9 In addition to these methods of delivery, there are also pharmaceuticals pills or sprays that include the active ingredients of cannabis. These include Sativex, Marinol (dronabinol) and Cesamet (nabilone) along with several others.10 Smoking has long been associated with RA risk and severity.11 Like with tobacco, smoking marijuana also produces cancer-causing chemicals.12 If cannabis is to be used, ingesting it in ways other than by smoking would be wise.
Research on medical marijuana for RA
The bulk of research studies on the overall use of medicinal marijuana for a variety of ailments produced mixed results.13 There have been few double blind studies, the gold standard for experiments and government approval for drugs, published in peer-reviewed journals. One consistent finding in these studies is that the use of cannabis may help relieve pain. There have been few research studies on the use of marijuana for the treatment of rheumatoid arthritis. In one small study published in 2006, the researchers used a cannabis-based medicine called Sativex. The researchers found that the RA patients who received the drug displayed less pain and higher quality of sleep. But there was no impact on morning stiffness.14 An argument for the use of cannabis to treat nausea that originates from other RA treatments like methotrexate could be made. Nausea is a classic and problematic side effect of methotrexate that causes many patients to stop taking this disease modifier (DMARD).15 There are not, however, any controlled studies on this specific use of marijuana.
In spite of the scarcity of solid scientific evidence supporting marijuana or cannabis-based medicines for arthritis, some groups strongly advocate its use. For example, the group Americans for Safe Access published an extensive treatise on the subject.16 The numerous footnotes included in this article did not include citations so the sources supporting their arguments could not be checked. An article by the National Organization for the Reform of Marijuana Laws (NORML) also advocates for the use of cannabis for rheumatoid arthritis.17 But the references provided fail to build a strong case although they did include the 2006 study mentioned above. It could be argued that the push for medical marijuana by advocacy groups is simply a ploy to legitimize recreational use. It is true that teen use of marijuana is significantly higher in states with medical approval than in states without it.18 It is common street knowledge that just about anyone can walk into a medical marijuana store and walk out with a supply.
Research-based principles for rheumatologists
An article was recently published in the Rheumatology Network, a publication for practicing rheumatologists, regarding the use of medical marijuana for RA. The physician authors articulated eight research-based principles that rheumatologists should recognize about medical marijuana and RA. Patients should also carefully consider these principles. The eight principles are as follows:
- There are hundreds of chemicals in marijuana and their full impact is unknown.
- Cannabinoid receptors are found throughout the body and involve complex processes.
- The immunosuppressive and anti-inflammatory actions of the cannabinoid system are not well understood.
- Solid evidence for its use for pain relief is lacking. Not a single published randomized controlled trial has examined the dosing, efficacy, or side effect profile of herbal cannabis in patients with rheumatic diseases.
- The groundswell of advocacy driving the use of medicinal herbal cannabis is contrary to medical opinion.
- Smoking cannabis cannot be recommended.
- Contrary to common belief, herbal cannabis is not an innocuous substance, either for short- or long-term use, and its effects undermine the primary goals for treatment of rheumatic pain, namely reduction of symptoms and maintenance of function.
- There are no grounds on which to recommend herbal cannabis use for rheumatic disease and numerous other pain-management options can be explored.19
More evidence is needed
While there could be some evidence and reasoning for the use of cannabis for treating pain and nausea, there appears to be a lack of research to strongly support its use for treating RA. There certainly is no evidence to support its use to treat autoimmune disease processes and in fact, it may actually interfere with these processes especially if ingested via smoking.
Continued research is needed before wholesale support of the medical community is likely. There is increasing approval by states while the federal government continues to resist. Advocacy groups continue to exert much pressure for its approval and use. There are numerous voices on all sides of the issue and RA patients and doctors must make informed decisions. Debates regarding the use of medical marijuana are not likely to fade anytime soon.
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