Sunday, December 16, 2007


The rhetoric surrounding marijuana, or cannabis sativa, as medicine ranges from calling it everything from "the killer weed" to "the miracle drug." Each side in the debate pulls snippets from scientific studies to confirm or rebut their point of view.  One need only review information provided by groups like the National Organization for Reform of Marijuana Laws or the White House policy room to see this effect. 

The most comprehensive look at the issue to date is Marijuana and Medicine: Assessing the Science Base, conducted by the U.S.  Institute of Medicine and published in 1999.  With minimal research being conducted in the U.S.  on marijuana as medicine, in 2000, the California Legislature created the University of California's Center for Medicinal Cannabis Research in San Diego.  The center was tasked to assess the use of cannabis as an alternative for treating specific medical conditions. 

Research is now being conducted in institutions around the world, trying to unlock the potential medical benefits of compounds called cannabinoids found in cannabis sativa.  A summary of research published in 2007 is at the end of the article. 

One of the spurs to this increased interest was the discovery in the 1990s of special receptors in different areas of the brain, which respond to cannabinoids.  This led to the identification of a substances created naturally by the body that resemble THC the main active ingredient in marijuana. 

Most people smoke marijuana to get "high." This high provides a "sense of well-being or euphoria and increased talkativeness and laughter alternating with periods of introspective dreaminess followed by lethargy and sleepiness.  A characteristic feature of a marijuana 'high' is a distortion in the sense of time associated with deficits in short-term memory and learning.  A marijuana smoker typically has a sense of enhanced physical and emotional sensitivity, including a feeling of greater interpersonal closeness.  The most obvious behavioral abnormality displayed by someone under the influence of marijuana is difficulty in carrying on an intelligible conversation, perhaps because of an inability to remember what was just said even a few words earlier," according to the 1999 IOM study. 

"Although marijuana smoke delivers THC and other cannabinoids to the body, it also delivers harmful substances, including most of those found in tobacco smoke.  In addition, plants contain a variable mixture of biologically active compounds and cannot be expected to provide a precisely defined drug effect.  For those reasons, there is little future in smoked marijuana as a medically approved medication," concluded the IOM study. 

The study further concluded that for some patients, such as the terminally ill, if marijuana would possibly benefit the patient, the long-term risk was "not of great concern." 

For other patients, the study advised that physicians could consider marijuana for a narrow range of short term health issues such as AIDs wasting diseases, severe nausea and vomiting associated with cancer and its treatment and relief of neuropathic pain.  While the study concluded marijuana had the potential in some patients to relieve the symptoms, the study also suggested stringent guidelines for physicians recommending marijuana to their patients. 

The prescription guidelines were established to relieve symptoms considered debilitating such as intractable pain or vomiting.  The key points were for marijuana to be tried after all approved medications had failed to provide relief; the prescription be for less than six months; a follow up program be implemented to assess effectiveness; and the recommendation be supported by an oversight review board within the hospital or clinic. 

For chronic debilitating conditions such as pain or AIDS wasting, the IOM study recognized that the issues of long-term medical use of marijuana was more complex.  Patients who had exhausted the other available medical options could not be reasonably expected to wait until some time in the unknown future for someone to isolate and synthesize the precise cannabinoid drug cocktail that provided the best benefit or to develop a "nonsmoked rapid-onset cannabinoid drug delivery system." 

Since the IOM study, a number of vaporizers, which claim to provide the user with the benefit of marijuana without the hazard of the smoke, have been developed.  A recent pilot study tested one such device on 18 healthy volunteers and concluded it had the potential to provide the benefit of marijuana without the toxic smoke. 

The psychoactive effects of marijuana make it difficult for users to function in society while on a marijuana high.  Those desiring to operate a vehicle or machinery, conduct a conversation, get to work on time, stay awake or learn new things may find it difficult to conduct routine business while high on marijuana.  These side effects were found particularly hard for patients not already familiar with marijuana use. 

Other physiological effects from marijuana use such as increased heart rate and its effects on blood pressure make it a concern for older patients already suffering from heart disease, potentially leading to heart attacks or other cardiovascular event. 

Medical Treatments 

A review of the literature shows that very few rigorous studies have been conducted on the use of marijuana to treat disease.  While cannabinoid receptor locations in the brain offer some insight into which diseases may be helped by drugs developed from marijuana, most studies have involved few participants and were not conducted following traditionally recognized methods for evaluating treatments.  Despite this, some synthetic derivatives from marijuana are now available and are being prescribed to patients for specific ailments. 

A large part of the medical research community has recommended increased research into how marijuana compounds can be harnessed to reduce suffering while minimizing any negative effects. 

Despite recognizing the substantial potential for future benefit, the IOM study believed that only a small group of patients would actually benefit from using marijuana.  The study observed that for most symptoms marijuana was being considered to treat there were other more effective treatment options, which most patients responded to. 

For cancer patients undergoing chemotherapy, the study found the public was not aware of the major strides made in medicine to treat nausea and side effects.  While cannabinoid substances were only effective in 24 percent of the cases, a combination of currently available drugs is considered nearly 100 percent effective if started before chemotherapy begins.  Because pills are less effective once a patient starts vomiting, an inhaled fast acting drug, such as the THC from marijuana could provide some benefit. 

For HIV patients, while marijuana may provide some relief from wasting diseases it has also been linked to suppressing the immune system.  For unknown reasons the relative 12-year risk of death from marijuana smokers with HIV is nearly twice that of those not using it.  Many HIV patients are effectively taking synthetic derivatives of marijuana for wasting diseases. 

In a 2003, 23 percent of HIV patients in a public health study in San Mateo used marijuana.  Of those users, only 17 percent met the strict definition of medical marijuana use for the relief of nausea, anorexia or pain.  Some used a synthetic to treat AIDS wasting and smoked marijuana recreationally. 

Marijuana is no longer believed by most to be an effective treatment for glaucoma.  While it does temporarily reduce the pressure within the eye, it acts for a short period of time and reduces the blood flow to the optic nerve, potentially damaging it.  Other treatments are now considered significantly more effective in managing glaucoma. 

For multiple sclerosis, the studies have not shown marijuana to be particularly effective in managing the pain, spasticity or the disease.  Studies have had mixed results, although the cannabinoid receptors are particularly abundant in areas of the brain controlling movement so further study is being conducted. 

2007 Research Developments 

Some new studies show the importance of being able to deliver predictable and repeatable dosages of THC to patients and clearly established that more is not always better. 

A study of 15 healthy volunteers found that medium doses of marijuana relieved some neuropathic pain in healthy volunteers while higher doses actually made the pain worse.  Neuropathic pain is associated with cancer, AIDS, diabetes, etc.  Low doses had no effect.  Report published in October 2007 

While low doses of THC seem to alleviate depression, higher doses makes the depression worse, concluded McGill University researchers in a report published in October 2007. 

These studies show the value of being able to control and adjust the amount of THC delivered to a patient to get the desirable outcome. 

Other Developments 

Foot pain associated with HIV ( neuropathic ) shows some relief from smoking marijuana over a placebo according to a study in February 2007. 

Smoking one joint causes the same lung damage as three to five tobacco cigarettes according to an August 2007 Danish study. 

A cannabinoid called CDB in marijuana has shown early promise in laboratory tests for treating metastatic forms of breast cancer.  Very small quantities of CDB are present naturally in marijuana.  Published in November 2007. 

THC may help the virus causing Kaposi's sarcoma both infect healthy cells and then multiply according to a study conducted by Harvard Medical School researchers and published in August 2007.  Kaposi's sarcoma is a cancer affecting those with depressed immune systems such as HIV and transplant patients. 

A team of Swedish researchers has identified how the brains of unborn babies are damaged by mothers smoking marijuana, published in May 2007. 

Harvard researchers have shown in lab and mice studies that certain THC treated lung cancer cells grew at half the rate of untreated cells, published in April 2007. 

Research done in Cardiff University in Wales, suggests that marijuana use could increase the risk of developing psychotic illness later in life by 40 percent, published in August 2007. 

THC may help reduce the symptoms of allergic skin disease according to study on mice by an international group of researchers published in August 2007. 

GW Pharmaceuticals in Britain has been conducting tests for eight years on Sativex, a prescription drug derived from cannabis to relieve symptoms of neuropathic dysfunction and pain.  The drug is being reviewed in Canada for market approval. 


EDITOR'S NOTE - Information on the medical effects of marijuana was gleaned from research published in a variety of scientific journals.  The basis of much of the article came from the Institute of Medicine Marijuana and Medicine study published in 1999, which was requested by White House Office of National Drug Control Policy in 1997.  While the study is much referenced by medical marijuana support groups, it is less quoted in White House drug policy.  The IOM is one of four US National Academies and is a not-for-profit and non-governmental agency established as an independent think tank to advise the nation on matters concerning health and medicine.  It remains the most comprehensive treatise available on the issue.  The Canadian Senate authored a similar study in 2002 that mirrored much of the IOM findings.  Many of these findings were also supported by several sponsored reports from the UC Center for Medical Cannabis Research and the Medical Board of California marijuana policy.  An effort was made to focus this article on the science associated with marijuana's medical value and not explore other medical marijuana issues.  

Author: Linda Williams, TWN Staff Writer
Photo: A residential pot grow in the Ukiah area. [Mendocino County 
Sheriff's Department photo]
Referenced: The Institute of Medicine report
Referenced: The Canadian Senate report
Cited: University of California's Center for Medicinal Cannabis 
Bookmark: (Marijuana - Medicinal)

No comments: