Several pharmaceutical drugs based on cannabis, in purified and standardized form, have been made available for medical use. However, the use of herbal cannabis in medicine remains highly controversial, in part because of the lack of standardization among products to ensure safe and consistent dosing and in part because of disagreement over legalization. In the United States, for example, while the cultivation, possession, and consumption of cannabis is illegal, some states have enacted laws that legalize the use of herbal medical cannabis specifically. Examples of products that have been approved by the U.S. Food and Drug Administration include cannabidiol (CBD), an active ingredient in cannabis, and certain synthetic cannabis-like drugs, namely dronabinol and nabilone. While the use of herbal medical cannabis is permitted in some European countries, it is illegal in the United Kingdom. The latter does, however, permit the prescription of a cannabis-based drug known as nabiximols (Sativex).
Despite the legal issues, researchers and drug companies continued to investigate and develop herbal cannabis products. For instance, a standardized cannabis product known as CanniMed was developed for medical use in Canada under Health Canada’s Medical Marihuana Access Regulations (MMAR), which were enacted in 2001. The cannabis plants cultivated for CanniMed are grown under carefully controlled conditions, and the drug is standardized to contain approximately 12.5 percent THC. A similar approach has been taken in the Netherlands, where several herbal cannabis products are available, including Bedrocan (19 percent THC) and Bedrobinol (12 percent THC).
Herbal cannabis products in medicine
Medical cannabis, also called medical marijuana, herbal drug derived from plants of the genus Cannabis that is used as part of the treatment for a specific symptom or disease. Although the term cannabis refers specifically to the plant genus, it is also used interchangeably with marijuana, which describes the crude drug isolated from the plants’ leaves and flowers.
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A major safety concern associated with medical cannabis is the possibility of medical use encouraging or transitioning into recreational use, which is associated with side effects that range from acute to chronic. Acute effects include intoxication, impaired cognition and motor function, elevated heart rate, anxiety, and psychosis in predisposed individuals. Chronic effects include bronchitis (from smoked cannabis), psychological cannabis dependency, loss of motivation, and cognitive deficits. By and large these effects seem to disappear on abstinence.
The most common use for medical marijuana in the United States is for pain control. While marijuana isn’t strong enough for severe pain (for example, post-surgical pain or a broken bone), it is quite effective for the chronic pain that plagues millions of Americans, especially as they age. Part of its allure is that it is clearly safer than opiates (it is impossible to overdose on and far less addictive) and it can take the place of NSAIDs such as Advil or Aleve, if people can’t take them due to problems with their kidneys or ulcers or GERD.
My advice for patients is to be entirely open and honest with your physicians and to have high expectations of them. Tell them that you consider this to be part of your care and that you expect them to be educated about it, and to be able to at least point you in the direction of the information you need.
Marijuana without the high
Marijuana is also used to manage nausea and weight loss and can be used to treat glaucoma. A highly promising area of research is its use for PTSD in veterans who are returning from combat zones. Many veterans and their therapists report drastic improvement and clamor for more studies, and for a loosening of governmental restrictions on its study. Medical marijuana is also reported to help patients suffering from pain and wasting syndrome associated with HIV, as well as irritable bowel syndrome and Crohn’s disease.
This is not intended to be an inclusive list, but rather to give a brief survey of the types of conditions for which medical marijuana can provide relief. As with all remedies, claims of effectiveness should be critically evaluated and treated with caution.
There are few subjects that can stir up stronger emotions among doctors, scientists, researchers, policy makers, and the public than medical marijuana. Is it safe? Should it be legal? Decriminalized? Has its effectiveness been proven? What conditions is it useful for? Is it addictive? How do we keep it out of the hands of teenagers? Is it really the “wonder drug” that people claim it is? Is medical marijuana just a ploy to legalize marijuana in general?
The potential medicinal properties of marijuana and its components have been the subject of research and heated debate for decades. THC itself has proven medical benefits in particular formulations. The U.S. Food and Drug Administration (FDA) has approved THC-based medications, dronabinol (Marinol ® ) and nabilone (Cesamet ® ), prescribed in pill form for the treatment of nausea in patients undergoing cancer chemotherapy and to stimulate appetite in patients with wasting syndrome due to AIDS.
The FDA also approved a CBD-based liquid medication called Epidiolex ® for the treatment of two forms of severe childhood epilepsy, Dravet syndrome and Lennox-Gastaut syndrome. It’s being delivered to patients in a reliable dosage form and through a reproducible route of delivery to ensure that patients derive the anticipated benefits. CBD does not have the rewarding properties of THC.
Medical Marijuana Laws and Prescription Opioid Use Outcomes
An additional concern with “medical marijuana” is that little is known about the long-term impact of its use by people with health- and/or age-related vulnerabilities—such as older adults or people with cancer, AIDS, cardiovascular disease, multiple sclerosis, or other neurodegenerative diseases. Further research will be needed to determine whether people whose health has been compromised by disease or its treatment (e.g., chemotherapy) are at greater risk for adverse health outcomes from marijuana use.
Researchers generally consider medications like these, which use purified chemicals derived from or based on those in the marijuana plant, to be more promising therapeutically than use of the whole marijuana plant or its crude extracts. Development of drugs from botanicals such as the marijuana plant poses numerous challenges. Botanicals may contain hundreds of unknown, active chemicals, and it can be difficult to develop a product with accurate and consistent doses of these chemicals. Use of marijuana as medicine also poses other problems such as the adverse health effects of smoking and THC-induced cognitive impairment. Nevertheless, a growing number of states have legalized dispensing of marijuana or its extracts to people with a range of medical conditions.
A 2019 analysis, also funded by NIDA, re-examined this relationship using data through 2017. Similar to the findings reported previously, this research team found that opioid overdose mortality rates between 1999-2010 in states allowing medical marijuana use were 21% lower than expected. When the analysis was extended through 2017, however, they found that the trend reversed, such that states with medical cannabis laws experienced an overdose death rate 22.7% higher than expected. 79 The investigators uncovered no evidence that either broader cannabis laws (those allowing recreational use) or more restrictive laws (those only permitting the use of marijuana with low tetrahydrocannabinol concentrations) were associated with changes in opioid overdose mortality rates.