medical marijuana 
By: Leslie Bohner, PharmD candidate
Drug Topics

I am a fourth-year student. During a consultation at a community pharmacy rotation, I asked a patient what additional medications he was taking. Most often, the answer is "calcium" or "vitamins." When the patient answered "medical marijuana," I was surprised and a bit perplexed, as was my preceptor, about how to counsel a patient using marijuana.

Under the federal Controlled Substances Act, marijuana is classified as Schedule I, a definition that gives it a high potential for abuse, with no current safe or medical use.

Meanwhile, in the state of California, as in 13 other states, patients have legal access to medical marijuana upon physician recommendation for the following approved indications: AIDS (anorexia), arthritis, cachexia, cancer, chronic pain, glaucoma, migraine headaches, muscle spasms, seizures, severe nausea, or any disabling, persistent medical symptom that if not alleviated would cause harm to the patient's safety or health.

Certain cannabinoids in marijuana activate 2 specific receptors considered to provide medical benefits. CB1 sites are located mainly in the central nervous system (affecting pleasure, thought concentration, sensory and time perception, and coordinated movement) and CB2 sites are located in peripheral tissues and immune cells (affecting immunosuppressive, anti-inflammatory, and anti-nociceptive effects).

Marinol is the only FDA-approved synthetic cannabinoid (CB1) used for chemotherapy-induced nausea and vomiting; it is argued that Marinol does not produce effects similar to those produced when its natural counterpart is smoked.

When medical marijuana enters the picture, within the pharmacy practice a simple consult becomes a legally and medically complex argument with no clear answer.

A simple Google search produces vast amounts of information based on anecdotal and recreational sources that can be misleading to the public. A search of databases such as PubMed, IOM, and NIMH led me to believe that the research data were mostly related to toxicology and mental health. Most of the information I found was not the randomized and blinded data upon which we base our pharmaceutical recommendations. However, as I researched this topic further, I did find the following general information, which may be helpful to our practice of pharmacy.

Click here to read possible drug-drug interactions and other side effects.