Medical Marijuana: The Myths and Realities

MARCH 18, 2015
Yvette C. Terrie, BSPharm, RPh
How Is Medical Marijuana Administered?
If your doctor thinks you are a candidate for the use of medical marijuana, he or she will determine the appropriate dosage and frequency. Medical marijuana is available in many forms and can be smoked, vaporized, taken orally in pill or liquid extract form, brewed into a tea, or added to certain foods.

According to the National Institute on Drug Abuse, research is focusing on the 2 main chemicals in marijuana: delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD).4 These chemicals are found in different ratios in the marijuana plant.4 THC is thought to stimulate appetite and decrease nausea but may also reduce pain and inflammation.4 As a result of research on the active chemicals in marijuana, the FDA has approved 2 medications that are synthetic forms of THC, including Marinol (dronabinol) and Cesamet (nabilone), for treating nausea and vomiting related to chemotherapy in patients who have failed to respond to traditional antiemetic treatments.13,14 Marinol is also indicated for the treatment of significant weight loss in patients with HIV/AIDS.4,14 Both of these agents are available by prescription only, in capsule form.4

Research has shown that CBD is a nonpsychoactive cannabinoid that may be beneficial in decreasing pain and inflammation, controlling epileptic seizures, and possibly even treating psychoses and addictions.4 Moreover, an investigational drug that contains cannabidiol (Epidiolex; not yet approved by the FDA) is being studied for treatment of the childhood epilepsy conditions Dravet’s syndrome and Lennox–Gastaut syndrome.15,16 Another drug, Sativex, a combination of THC and CBD that is administered by oral spray, is being investigated in clinical trials for its role in treating pain in patients with advanced cancer and for treating spasticity in those with multiple sclerosis.15,16

Are There Adverse Effects to Using Medical Marijuana?
The effect of marijuana on an individual’s ability to function is not the drug’s only side effect.10 Although the long-term effects of marijuana are not fully understood, results of some studies show that longterm use may be associated with cardiovascular and respiratory problems.16-19 Study results show that marijuana contains hundreds of compounds that may damage the lungs—an estimated 50% to 70% more cancer-causing chemicals than are in tobacco products—and the American Lung Association reports that marijuana smoke releases 33 cancer-causing chemicals.19,20

Research has also shown that regular and frequent use of marijuana, particularly in high doses, can cause problems with short-term memory and concentration.10,17 According to the National Cancer Institute and the National Institutes of Health, possible adverse effects of marijuana may include dizziness, increased heart rate, low blood pressure, problems with short-term memory, decreased attention span, hallucinations, depression, issues with problem-solving skills, impairment of motor and cognitive skills, and insomnia.8 Some individuals may also experience dry mouth, red eyes, anxiety, low blood glucose levels, and drowsiness.8

Debate continues regarding the use of marijuana for treating and managing certain medical conditions, and more research is clearly needed. Individuals interested in the medical use of marijuana should discuss this issue with their primary health care provider, understand the potential for adverse effects, and clearly understand and weigh the risks versus the benefits. Just as with any other medication, you need to be informed about its proper use, side effects, and potential interactions with other medications. The most important thing you can do is have an open dialogue with your primary health care provider to learn the facts about the use of medical marijuana in your state and the available treatment options.

For more information on state medical marijuana laws, visit the National Conference of State Legislatures website at or call your state’s Department of Health and Human Services to learn more about the laws regarding medical marijuana where you live.

Ms. Terrie is a clinical pharmacist and medical writer based in Haymarket, Virginia.


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