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By Robert G. Bell

Robert BellThere are several cannabis derived pharmaceuticals, including dronadinaol, nabilone, and nabiximols (not available in the USA). Dronabinol and nabilone were approved in 1985 for the treatment of chemotherapy-induced nausea and vomiting in patients who have failed to respond adequately to conventional antiemetic therapy and for the treatment of anorexia associated with weight loss in patients with AIDS (dronabinol). Nabiximols is a cannabis-derived liquid extract oromucosal spray formulated from two strains of Cannabis sativa. Nabiximols is approved in Canada, New Zealand, and eight European countries for the symptomatic relief of spasticity in adults with multiple sclerosis who have not responded adequately to other therapy and who demonstrate meaningful improvement during an initial trial of therapy, the symptomatic relief of neuropathic pain in patients with multiple sclerosis, and intractable cancer pain. It is currently being evaluated in several clinical trials in the United States.

The Mayo Clinic’s Drugs and Supplements listing for marijuana evaluated the many uses of marijuana and the scientific evidence associated with the claims. The evaluation states that there is “good scientific evidence for marijuana’s use” in the treatment of chronic pain and multiple sclerosis. “Unclear scientific evidence for marijuana’s use” included ALS, appetite stimulant (which dronabinol and nabilone were approved for), atopic dermatitis, chemotherapy side effects, brain injuries, dementia, eating disorders, epilepsy, glaucoma, Huntington’s disease, neuromuscular/rheumatoid arthritis, quality of life (“high” life), schizophrenia, sleep disorders, and Tourette syndrome. There are many uses of marijuana that range from the cure-all magic elixir to the devil’s brew, and these are based on tradition, lore, and some scientific theory. But most, if not all, lack evidence and remain unproven.

Now, the “should nots” of marijuana use. Perhaps the biggest—the adverse effects of cannabis use on mental health—are greater during development, particularly during adolescence, than in adulthood.

Marijuana should not be used by:

  • persons under the age of 18;
  • persons hypersensitive to any cannabinoids or smoke (smoking anything is not recommended in patients with respiratory insufficiency such as asthma or chronic obstructive pulmonary disease);
  • patients with severe cardio-pulmonary disease (occasional hypotension, possible hypertension, syncope, or tachycardia);
  • patients with severe liver or renal disease;
  • patients with a personal history of psychiatric disorders (especially schizophrenia), or a family history of schizophrenia.

Marijuana should be used with caution in patients:

  • with a history of substance abuse, including alcohol abuse, and may be more prone to abuse with cannabis; and
  • who are receiving concomitant therapy with sedative-hypnotics or other psychoactive drugs due to the potential of additive or synergistic CNS depressant or psychoactive effects.

Cannabis typically exacerbates the CNS depressant effects of alcohol and increases the incidence of adverse effects.

Cannabis is not recommended for:

  • women of childbearing age not on a reliable contraceptive, as well as those planning pregnancy, those who are pregnant, or women who are breastfeeding.

There are some interesting cannabis uses that have potential for real medicinal benefit, but there is also the real possibility for abuse. The mixed message to children and the public is having medicinal use of marijuana in many states but recreational use in others. We need less confusion: education and abuse prevention is the real conclusion.

Robert G. Bell, Ph.D., is president and owner of Drug and Biotechnology Development LLC, a consultancy to the pharmaceutical industry and academia for biological, drug, and device development.