On February 8, 2016, Senator Elizabeth Warren wrote a well publicized letter to Dr. Thomas Friedan, the Director of the Centers for Disease Control and Prevention. In her letter she expressed her concern about the current epidemic of deaths by overdoses of opiate pain medications. Among her recommendations was taking steps to broaden our understanding of how marijuana might both help relieve pain as well as reduce the number of deaths by opioid overdose. She was quite correct in her effort.
As Senator Warren noted in her letter, there had been a 65% increase in deaths by overdose of opiates between 2012 and 2014 in her home state of Massachusetts. Those data are consistent with the epidemic of deaths by overdose that are occurring across our country. Indeed, the Centers for Disease Control has reported that since 2000, the rate of deaths from drug overdoses involving opioids has increased 200%. These numbers continue to grow. Thus, there is a pressing need to develop and utilize alternative methods to relieve pain and reduce the lethal misuse of opioid pain relievers.
There have long been indications that marijuana can be useful for the treatment of pain. For example, Sir William Osler, the father of modern medicine, recommended marijuana for the treatment of migraine in his 1892 textbook, The Principles and Practice of Medicine. However, after marijuana was made illegal in the United States in 1937, its use in medicine was discouraged and well controlled scientific evaluation of medical uses of marijuana virtually ceased.
In recent years there has been a resurgence in the study of marijuana, including its effects on pain. Opinions do differ on how effective marijuana is for pain and if we have reached the point where marijuana can be recommended or even prescribed for its treatment. Nonetheless, there is compelling evidence that marijuana relieves various types of pain.
A review of studies of the effects of marijuana on pain was published last year in the prestigious Journal of the American Medical Association. As have other recent reviews, it concluded that, " ... chronic pain, neuropathic pain, and spasticity associated with multiple sclerosis are the indications for medical marijuana supported by high-quality evidence."
In the context of the epidemic of deaths by opiate overdose, an important study was published in 2014 in The Archives of Internal Medicine. It was found that in states in which marijuana has been made legal for medical purposes, including the treatment of pain, the numbers of deaths by overdose of opioid pain medications have dropped dramatically. They saw 24.8% lower mean annual opioid overdose mortality rates compared with states without medical marijuana allowances.
Some have dismissed that study as being merely statistical, and that it did not reveal what happened to specific individuals nor suggest any mechanism by which the access to and use of marijuana could have generated such effects. However, a new study by Dr. Simon Haroutounian of the Washington University School of Medicine, supports and helps explain the results of that study. In this study, individuals with severe, treatment resistant pain were allowed to supplement their only partially effective opiate pain medications with marijuana. The results showed the expected, modest additional pain relief with the marijuana. However, perhaps the most significant result was that by the end of the study 44% of the subjects had, on their own, stopped using opiates altogether, and many of those that continued the pain medications had reduced their intake. This would explain how the numbers of deaths by overdose of opiates is so greatly reduced in states that allow medical marijuana use.
No medication is harmless or without risk of side effects. However, to the best of my knowledge there are no reports in the literature of lethal or life-threatening effects of marijuana. In fact, as a psychiatrist who regularly prescribes medications such as lithium, clozapine, tricyclic antidepressants, and monoamine oxidase inhibitors, all of which can have lethal effects if not managed properly, I find it ironic that the relatively minor side effects of marijuana have aroused such great concern among those opposed to greater utilization of marijuana. Thus, I wish to support Senator Warren's encouragement of the scientific community to pursue marijuana as treatment for pain and as a means to reduce the tragic increases in deaths by opiate overdose.