Patients using medical marijuana to control chronic pain reported a 64 percent reduction in their use of opioid medications, a recent University of Michigan study found. The 185 patients from a medical marijuana dispensary in Ann Arbor also said they had fewer side effects from their medications and a 45 percent improvement in quality of life since using cannabis to manage pain.
The study’s senior author, Daniel Clauw, M.D., a rheumatologist at the University of Michigan and a researcher on the potential medical uses of cannabis, explained at a recent symposium of the American College of Rheumatology that the chemical compounds in marijuana known as cannabinoids have two separate effects. In the brain, they bind to receptors that decrease pain, and in the peripheral tissues, they have anti-inflammatory properties. Consequently, cannabis might have a two-pronged effect.
There is no evidence yet that cannabinoids can help treat rheumatoid arthritis, osteoarthritis, or lupus, Clauw said, but studies are ongoing and may yet prove their value for these rheumatic conditions. In general, he said, the best evidence for the effectiveness of cannabinoids is for pain that has its origin in the central nervous system; consequently, there is evidence that cannabis can be helpful in treating fibromyalgia.
The method by which cannabis is administered makes a difference, he added. For chronic pain, cannabis usually works much better if it is not smoked but is taken orally. Smoking causes the level of the active ingredients to rise quickly, which can lead to getting high. A more practical way to ingest cannabis is to drink a tea made from it or to eat foods that have cannabis baked into them.
Clauw explained that all drugs have side effects and cannabis is like any other drug. However, when cannabis is used for pain and taken orally, the side effects are much fewer than when it is smoked. He also said the risks of taking opioids are much higher. To date, about half the states, as well as the District of Columbia, Guam, and Puerto Rico, have passed laws permitting the medical use of cannabis.