Mini-Science 2012 Q&A: “Just say know: what marijuana has taught us about pain control”
At the conclusion of each Mini-Science lecture, audience members submit their questions to the evening’s presenter, who answers as many as possible on the spot. Here are some of the best questions from Dr. Mark Ware’s May 2 talk, “Just say know: what marijuana has taught us about pain control.”
Q: What can you tell us about smoked cannabis for chronic neuropathic pain?
A: In a study, small amounts of cannabis were administered to patients with pain that they couldn’t be decreased in any other way. The cannabinoids improved sleep and mood while reducing pain when inhaled at 9.4% THC strength. This is a lower amount of THC than is usually taken during recreational use as a street drug. Patients cannot get comparable plasma levels with an oral THC, and smoking also has a more rapid onset of increased THC levels in the plasma.
Q: How can we validate that the desire for cannabis is ‘medical’?
A: People can be designated to grow the cannabis plant, however this type of designation is sometimes abused. Patients report that the pain is less bothersome after the use of cannabinoids. Cannabis is a powerful drug and has its adverse affects and precautions associated with it.
Q: Are these adverse affects and precautions the same for medical users as for recreational users?
A: Cannabis has the ability to unmask or worsen psychosis, and increase heart rate. It is not advised during pregnancy. Physicians should ask histories of legal issues or criminal charges in addition to use of other street drugs before authorizing patients to use it. Cannabis can be abused! This is clearly a risk factor in younger people, including adolescents. There may be other ways to use the endo-cannabinoid system without intaking cannabinoids (“natural ways”). E.g. Runners and cyclists have higher plasma levels of cannabinoids after exercise – this gives a feeling of well-being.
Q: Is it true that smoking marijuana can destroy brain cells?
A: No cannabinoids do not destroy brain cells, although they can change the way brain cells can connect to each other. This is important during fetal and childhood development. Having exposure to cannabinoids at the wrong time can rewire the brain. The brain is a plastic structure, and we don’t know enough to suggest cannabinoids cause cell death, but they may change the brain’s architecture. This hasn’t been studied for very long, but right now we know that controlled amounts can be used for a long time without harm.
Q: Would the pain return after the spike in blood levels of THC?
A: The cannabinoids very quickly leave plasma and get absorbed into the brain, which then results in pain relief. The clinical affect is after 20 minutes or 30 minutes and the pain relief lasts about 3-4 hours.
Q: Is cannabis a gateway drug for other drugs? How much marijuana is too much? When does it get you hooked?
A: I study the use of cannabis for therapeutic purposes. What I understand from my addiction colleagues, it’s clear that there is a cannabis dependence syndrome. The earlier that children use cannabis the more likely they are to have adverse affects including dependence and the use of other drugs. It is probably not the drug itself that leads to this but it may be the circumstances overall.
Q: Is the dosage of usage controlled when a patient is authorized to use medical marijuana?
A: The cannabis that is supplied by health Canada is approximately 12% THC. The amount that each person intakes is hard to standardize. Thus the amount getting into the patient varies. Patients that use it properly and find results usually find a dosage that works for them – some need only a little bit while other patients need a lot more.
Please visit the Mini-Science website for more information about the lecture series.