Marijuana is also known as pot, grass and weed but its formal name is actually cannabis. It comes from the leaves and flowers of the plant Cannabis sativa. It is considered an illegal substance in the US and many countries and possession of marijuana is a crime punishable by law. The FDA classifies marijuana as Schedule I, substances which have a very high potential for abuse and have no proven medical use. Over the years several studies claim that some substances found in marijuana have medicinal use, especially in terminal diseases such as cancer and AIDS. This started a fierce debate over the pros and cons of the use of medical marijuana. To settle this debate, the Institute of Medicine published the famous 1999 IOM report entitled Marijuana and Medicine: Assessing the Science Base. The report was comprehensive but did not give a clear cut yes or no answer. The opposite camps of the medical marijuana issue often cite part of the report in their advocacy arguments. However, although the report clarified many things, it never settled the controversy once and for all.
Let’s look at the issues that support why medical marijuana should be legalized.
(1) Marijuana is a naturally occurring herb and has been used from South America to Asia as an herbal medicine for millennia. In this day and age when the all natural and organic are important health buzzwords, a naturally occurring herb like marijuana might be more appealing to and safer for consumers than synthetic drugs.
(2) Marijuana has strong therapeutic potential. Several studies, as summarized in the IOM report, have observed that cannabis can be used as analgesic, e.g. to treat pain. A few studies showed that THC, a marijuana component is effective in treating chronic pain experienced by cancer patients. However, studies on acute pain such as those experienced during surgery and trauma have inconclusive reports. A few studies, also summarized in the IOM report, have demonstrated that some marijuana components have antiemetic properties and are, therefore, effective against nausea and vomiting, which are common side effects of cancer chemotherapy and radiation therapy. Some researchers are convinced that cannabis has some therapeutic potential against neurological diseases such as multiple sclerosis. Specific compounds extracted from marijuana have strong therapeutic potential. Cannobidiol (CBD), a major component of marijuana, has been shown to have antipsychotic, anticancer and antioxidant properties. Other cannabinoids have been shown to prevent high intraocular pressure (IOP), a major risk factor for glaucoma. Drugs that contain active ingredients present in marijuana but have been synthetically produced in the laboratory have been approved by the US FDA. One example is Marinol, an antiemetic agent indicated for nausea and vomiting associated with cancer chemotherapy. Its active ingredient is dronabinol, a synthetic delta-9- tetrahydrocannabinol (THC).
(3) One of the major proponents of medical marijuana is the Marijuana Policy Project (MPP), a US-based organization. Many medical professional societies and organizations have expressed their support. As an example, The American College of Physicians, recommended a re-evaluation of the Schedule I classification of marijuana in their 2008 position paper. ACP also expresses its strong support for research into the therapeutic role of marijuana as well as exemption from federal criminal prosecution; civil liability; or professional sanctioning for physicians who prescribe or dispense medical marijuana in accordance with state law. Similarly, protection from criminal or civil penalties for patients who use medical marijuana as permitted under state laws.
(4) Medical marijuana is legally used in many developed countries The argument of if they can do it, why not us? is another strong point. Some countries, including Canada, Belgium, Austria, the Netherlands, the United Kingdom, Spain, Israel, and Finland have legalized the therapeutic use of marijuana under strict prescription control. Some states in the US are also allowing exemptions.
Now here are the arguments against medical marijuana.
(1) Lack of data on safety and efficacy. Drug regulation is based on safety first. The safety of marijuana and its components still has to first be established. Efficacy only comes second. Even if marijuana has some beneficial health effects, the benefits should outweigh the risks for it to be considered for medical use. Unless marijuana is proven to be better (safer and more effective) than drugs currently available in the market, its approval for medical use may be a long shot. According to the testimony of Robert J. Meyer of the Department of Health and Human Services having access to a drug or medical treatment, without knowing how to use it or even if it is effective, does not benefit anyone. Simply having access, without having safety, efficacy, and adequate use information does not help patients.
(2) Unknown chemical components. Medical marijuana can only be easily accessible and affordable in herbal form. Like other herbs, marijuana falls under the category of botanical products. Unpurified botanical products, however, face many problems including lot-to-lot consistency, dosage determination, potency, shelf-life, and toxicity. According to the IOM report if there is any future of marijuana as a medicine, it lies in its isolated components, the cannabinoids and their synthetic derivatives. To fully characterize the different components of marijuana would cost so much time and money that the costs of the medications that will come out of it would be too high. Currently, no pharmaceutical company seems interested in investing money to isolate more therapeutic components from marijuana beyond what is already available in the market.
(3) Potential for abuse. Marijuana or cannabis is addictive. It may not be as addictive as hard drugs such as cocaine; nevertheless it cannot be denied that there is a potential for substance abuse associated with marijuana. This has been demonstrated by a few studies as summarized in the IOM report.
(4) Lack of a safe delivery system. The most common form of delivery of marijuana is through smoking. Considering the current trends in anti-smoking legislations, this form of delivery will never be approved by health authorities. Reliable and safe delivery systems in the form of vaporizers, nebulizers, or inhalers are still at the testing stage.
(5) Symptom alleviation, not cure. Even if marijuana has therapeutic effects, it is only addressing the symptoms of certain diseases. It does not treat or cure these illnesses. Given that it is effective against these symptoms, there are already medications available which work just as well or even better, without the side effects and risk of abuse associated with marijuana.
The 1999 IOM report could not settle the debate about medical marijuana with scientific evidence available at that time. The report definitely discouraged the use of smoked marijuana but gave a nod towards marijuana use through a medical inhaler or vaporizer. In addition, the report also recommended the compassionate use of marijuana under strict medical supervision. Furthermore, it urged more funding in the research of the safety and efficacy of cannabinoids.
So what stands in the way of clarifying the questions brought up by the IOM report? The health authorities do not seem to be interested in having another review. There is limited data available and whatever is available is biased towards safety issues on the adverse effects of smoked marijuana. Data available on efficacy mainly come from studies on synthetic cannabinoids (e.g. THC). This disparity in data makes an objective risk-benefit assessment difficult.
Clinical studies on marijuana are few and difficult to conduct due to limited funding and strict regulations. Because of the complicated legalities involved, very few pharmaceutical companies are investing in cannabinoid research. In many cases, it is not clear how to define medical marijuana as advocated and opposed by many groups. Does it only refer to the use of the botanical product marijuana or does it include synthetic cannabinoid components (e.g. THC and derivatives) as well? Synthetic cannabinoids (e.g. Marinol) available in the market are extremely expensive, pushing people towards the more affordable cannabinoid in the form of marijuana. Of course, the issue is further clouded by conspiracy theories involving the pharmaceutical industry and drug regulators.
In conclusion, the future of medical marijuana and the settlement of the debate would depend on more comprehensive and comparable scientific research. An update of the IOM report anytime soon is well-needed.