In the first post concerning opioid use and cannabis use, we investigated cannabis use within opioid addiction recovery programs. We found that current evidence is indicating that cannabis use does not interfere with addiction treatment or increase likelihood of opioid abuse despite a higher percentage of opioid abusers also being cannabis users. In the second article on this topic, we’ll deal with patients that are not abusing opioids but being prescribed them as treatment for chronic pain or other illness and ask how cannabis use may be used to decrease or eliminate the prescription.

As was the case with those in opioid addiction recovery programs, many of the patients currently being prescribed opioids for chronic or acute pain are already cannabis users. One meta-study considered over 45 studies with data on both prescribed opioid use and urine tests that confirmed cannabis use and found almost across the board that the rate of cannabis users in this population was around 20%. As expected, this percentage is higher in states with medical cannabis exceptions than in states where cannabis is completely illegal. However, even in data from conservative states such as Tennessee, West Virginia, Kentucky, etc., usage was measured at around 10%. Average rates hover between these two figures and illustrate that there is a significant link between cannabis use and opioid prescription.

While correlation does not imply causation, it is possible that many of these users are self-medicating for pain, whether intentionally or unintentionally. In fact, in one informal review, doctors described three specific patient situations (work injury, AIDS symptoms, and genetic degenerative disorder) in which patients were able to reduce or completely halt use of opioids for chronic pain treatment. The doctors in this study go on to argue that this treatment model should be expanded and cannabis rescheduled by the FDA. While the study is anecdotal, this hypothesis is backed by the current medical consensus that cannabis plays a role in pain management in a variety of conditions, from those caused by neurological issues, nerve damage, inflammation, etc. This pain relief will be covered in another post, but the most critical point here is that cannabinoids have been proven effective against thermal, mechanical, and chemical pain in countless studies. This of course, gives cannabis great potential in replacing traditional painkillers.

Since opioids are the most commonly prescribed painkillers, though, why would someone use cannabis to reduce pain and therefore reduce necessary opioid intake? Opioids are cost-effective, well-researched, effective at treating many types of pain, and available in many forms of administration. Unfortunately, opioid use results in many unfortunate side-effects. Minor side effects include nausea and constipation, in contrast with cannabis, which relieves nausea and aids intestinal movement. However, more critically, opioid use, even prescribed, can lead to death. This occurs when the regimen needed to provide relief from pain exceeds the amount the body is capable of processing and results in overdose. Although doctors are generally careful to monitor appropriate levels, the number of prescription opioid deaths from 1999 to 2006 nearly doubled and use of prescription opioids quadrupled during the same time period.

Opioid related morbidity is especially noticeable in palliative care, where patients are being treated for what are thought to be terminal illnesses. Due to declining conditions in patient’s health, doctors often become more lax in prescribing opioids, reasoning that like hospice care, patients should be as comfortable as possible for the remainder of their lives. Unfortunately, many palliative patients still have years ahead or may go on to recover after all. What then happens is that many patients die of opioid overdose before their time or for no reason at all, which underscores the danger in relying solely on opioid medications for pain. As a result, one group has argued in the American Journal of Hospice and Palliative Medicine that cannabis makes a good substitute or partial replacement for opioids. Their argument is based on not only cannabis’ effectiveness against pain but also its inability to cause toxicity or overdose in patients, making it very safe.

The suggestion of using cannabis to replace or reduce opioid prescription is supported by a recent CNN article, which cites that states with cannabis legalized for managing chronic pain have 25% fewer deaths from prescription painkiller overdoses each year. Again, correlation does not mean causation, and the study authors note that it is impossible to say for sure that medical cannabis use alone is directly responsible for 25% fewer deaths or the corresponding decrease in opioid use. However, the Johns Hopkins Bloomberg School of Public Health felt confident enough about the data to state that they believe cannabis is allowing safer treatment of chronic pain and that “medical cannabis laws might provide unexpected benefits to public health.”

Sadly, most of the specific mechanisms of cannabis pain relief are still obscured, which is why doctors are understandably hesitant to prescribe it. After cannabis was made a Schedule 1 drug (prohibited in all cases) by the FDA in the 1970’s, cannabis research became much harder, and opioid research continued unaffected. However, we do know that almost 40% of medical cannabis patients are using cannabis for pain relief, which offers statistical evidence that patients have a real or perceived effect of pain relief. What is needed now is a rigorous study comparing various pain treatment schedules involving different ratios of cannabis and opioids. Such a study could pave the way for FDA reclassification of cannabis or at least standardized synthetic analogues that would allow wide-spread access to the treatments currently only available to patients residing in states with medical cannabis.

Gregory T. Carter, Aaron M. Flanagan, Mitchell Earleywine, et al. (2011) Cannabis in Palliative Medicine: Improving Care and Reducing Opiod-Related Morbidity, American Journal of Hospice and Palliative Medicine 28(5):297-303.

Gary M. Reisfield, Ajay Wasan, and Robert Jamison (2009) The Prevalence and Significance of Cannabis Use in Patients Prescribed Chronic Opioid Therapy: A Review of the Extant Literature, Pain Medicine, 10(8): 1435-1441.

Mary Lynch and Alexander Clark (2003) Cannabis Reduces Opiod Dose in the Treatment of Chronic Non-Cancer Pain, doi: 10.1016/S0885-3924(03)00142-8.

Young, Saundra. “Medical Marijuana Laws May Reduce Painkiller Overdoses.” CNN. Cable News Network, Web. 25 Aug. 2014.