The two main available strains of cannabis are cannabis sativa and cannabis indica. Cannabis sativa is associated with more psychotropic effects and cannabis indica causes more sedation. There is a third strain, cannabis ruderalis, which is less popular than the other two in our country.
MJ contains nearly 500 different actives and ~80 unique cannabinoids. THC (analgesic) as well as cannabidiol (CBD, anti-seizure for Dravet Syndrome) are the main cannabinoids responsible for most of MJ’s medicinal effects based on what we know today. The identification of the chemical structure for tetrahydrocannabinol (THC) took place in 1964. MJ strains often contain some amount of both THC and CBD making it difficult to accurately profile clinical outcomes and side effects.
By comparison, well-designed clinical research exists on the prescription product, dronabinol (Marinol, Schedule III, 100% THC) approved in 1986 for refractory chemotherapy-induced nausea and vomiting. Its indication for use expanded in 1992 to include treatment of weight loss/anorexia associated with AIDS wasting (J Clin Oncol 2006;24:3394).
The amount of THC in cannabis strains varies according to geographic origin and plant part being used (e.g. buds, stems, or seeds). As the quality of MJ products is not regulated, contaminants like fungus, bacteria, heavy metals from soil like aluminum and cadmium have been reported in some batches, as well as glass beads or sand added for weight to boost profits. Today’s MJ is more potent than it was in the 1970’s (%THC has risen from 5% to 30%).
Cannabis strains may interact with CNS depressants, protease inhibitors, sidenafil for erectile dysfunction, theophylline, antidepressants, anticholinergics, naltrexone, lithium, neuroleptic antipsychotics, and anesthetic agents, among many other medications. Cannabinoids are extensively metabolized by the liver via the CYP450 enzyme system. This is why it’s important to have a pharmacist involved in the care of patients using medical MJ to keep them safe from harm.
Continued in Part 3