Ask the Doctors

Dear Doctor: I try not to use opioids for my chronic back pain, but I'm finding myself turning to them more often. Could marijuana help?

Dear Reader: Pain is one of most difficult aspects of medicine to understand. No one can actually feel the pain of another person, but we can see the suffering that it causes. As doctors, we try to alleviate pain in a number of ways.

Opiates -- starting with opium, which is derived from the poppy plant -- have been used for pain relief for more than 3,000 years. The opiates morphine and codeine, also from the poppy plant, were isolated and made available in the early 1800s. Since that time, multiple synthetic opiates such as hydrocodone and oxycodone have been widely used for pain. These drugs attach to opiate receptors in both the brain and spinal cord.

One problem with opiates is that they relieve pain in the short term, but will not control it in the long term. Thus to relieve chronic pain, a person has to perpetually use the medication -- creating one of the addictive aspects of the drugs. The other problem with opiates is that people become tolerant of the medications, meaning that with consistent use, a person needs more medication to relieve the same amount of pain.

For these reasons, opium and its progeny have been abused worldwide. The United States is facing an epidemic of opiate abuse, with prescription opiate medication leading to a rapid increase in lethal drug overdoses. In 2014, more than 18,000 people died from overdosing on prescription opiates, according to the federal Centers for Disease Control and Prevention.

Marijuana has been used also for more than 3,000 years. It works through the endocannabinoid system of the body, which has receptors in the brain and spinal cord as well as the immune system. The receptors in the brain and spinal cord can decrease muscle spasms and pain, while those receptors in the immune system can decrease inflammation and pain.

A 2015 study published in the Journal of the American Medical Association (JAMA) looked at 14 different clinical trials of marijuana use by multiple sclerosis patients and found relief from chronic pain, nerve pain, and pain and muscle spasm. Another study published in 2015 in JAMA looked at 28 different studies with 2,454 patients and found a 30 percent reduction of pain with cannabis-related products compared with placebo.

Opiates can relieve pain in the short term, such as after surgery or an acute injury. But due to their addictive potential and lack of long-term benefit, opiates are not a good choice for long-term pain relief.

Marijuana is not without its own potential risks and side effects. These include short-term memory loss, poor motor coordination, paranoid thoughts and, for some, psychosis. Long-term use can also create the potential for addiction, but not to the degree of opiate medications. Also, overdosing on marijuana doesn't lead to death, as it can with opiates.

My suggestion in regard to chronic back pain is to try other methods of pain control over opioids. These include physical therapy, yoga and stretching. If these don't work, marijuana is an option, but beware of its side effects -- and try to minimize its use.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095.)

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