In 1995, the president of the American Pain Society called for pain to be added as a fifth vital sign to be evaluated and managed by physicians. This was due to the fact that 20% of adults were experiencing chronic pain and the use of prescription opioids had doubled. As a result, Americans began consuming 80% of the global opioid supply.
President Trump declared the opioid crisis a “public health emergency” in October 2017. By then, the United States had seen nearly 50,000 opioid overdose deaths, with 60% of them due to illicit synthetic opioids such as fentanyl or tramadol. This crisis has continued to escalate, with more than 80,000 opioid overdose deaths in the past year, 90% of which were due to highly potent synthetic forms.
Given the severity of the opioid crisis, many have turned to cannabis as a potential solution. Early population studies found that states that legalized medical cannabis saw a reduction in opioid overdose deaths. However, this effect was short-lived and studies have failed to find consistent results on cannabis co-use with prescription opioids.
Animal studies have consistently found that THC, a cannabinoid found in cannabis, reduces the need for opioids. THC stimulates CB1 receptors in the endocannabinoid system, which are found in the same pain-processing brain areas as opioid receptors and may contribute to pain reduction. CB1 receptors also interact with opioid receptors to boost their pain-relieving effect. Additionally, CB2 receptors, another cannabinoid target, can stimulate the release of the body’s own opioids which activate pain-relieving opioid receptors.
The inconsistency between these studies and population studies may be due to the placebo effect, where people can boost their opioid levels without drugs and dampen pain simply because they think they’re receiving an active pain medication. Additionally, THC tolerance may reduce the ability of CB1 and opioid receptors to work together to reduce pain.
CBD, another cannabinoid found in cannabis, is emerging as a potential strategy to help those trying to overcome from opioid use disorder. Studies have found that CBD reduces cues that trigger opioid cravings, and dampens the increased stress response that accompanies cravings.
Overall, the evidence on whether cannabis can replace or reduce the need for opioids in pain management is inconsistent. Co-use of cannabis and opioids may be associated with worsened mental health, and may be worse for those over 65 years old. However, co-use of cannabis does not increase opioid use.
Given the current evidence, more research is needed to determine whether cannabis can be a viable alternative to opioids in pain management.