Medical marijuana is contraindicated in adolescents and patients with unstable ischemic heart disease or a personal or family history of psychosis: All of the clinical trials have screened for and excluded patients with a history of psychosis, either personally or in a first-degree relative. So there is no evidence supporting its safe use in such individuals.
A growing number of case reports suggest recreational cannabis use in young adolescents can trigger a latent psychotic episode in selected susceptible individuals. This is a major concern.
Cannabis is a powerful peripheral vasodilator. "The way to remember that is the red eyes of Bob Marley," Dr. Ware suggested. Peripheral vasodilation results in an increased heart rate, which could trigger an MI in a patient with unstable ischemic heart disease.
Always ask about legal issues: A surprisingly large number of patients inquiring about medical marijuana are under investigation for a crime and are seeking a stay-out-of-jail card. They won’t mention it if they’re not asked.
Consider the prescription alternatives to medical pot: Nabilone and Marinol (dronabinol, which is tetrahydrocannabinol), are approved for prescription use in the United States. The beneficial effects last longer than with smoked cannabis, and there is no uncertainty about the concentration, source, or possible contaminants.
Keep an eye out for improved technology: Smoking is a dirty delivery system for marijuana. While it’s not nearly as harmful to the lungs as smoking tobacco, as Dr. Tashkin recently concluded, cannabis smoke nevertheless does contain carcinogens and toxins. Vaporization devices are now commercially available as an alternative: a smokeless marijuana delivery system. This approach has recently been shown effective in a randomized, double-blind, placebo-controlled, crossover clinical trial conducted in patients with neuropathic pain (J. Pain 2013;14:136-48).
Dr. Ware has received lecture fees from the Canadian Consortium for the Investigation of the Cannabinoids and a research grant and honoraria from Valeant for conducting a randomized trial of nabilone in fibromyalgia patients.
bjancin@frontlinemedcom.com