Cannabis as an Opioid Weaning Adjuvant in Chronic Low Back Pain Patients: A Case Series
Several survey studies have suggested that patients may be using cannabis as an alternative to opioid analgesics1,2 but a seemingly opposing study did not show any benefit in use of cannabis to wean addiction patients from opioids.3 The use of cannabis as a weaning adjuvant in opioid-dependent chronic low back pain patients without history of addiction has not been described. We report 5 cases of patients with chronic low back pain that used medical cannabis to successfully decrease opioid use and improve pain control and functional status. All subjects provided consent.
The cases to be described in detail include 5 female patients between the ages of 63 and 80 with chronic opioid use (20-60 OME daily) for low back pain for greater than 3 years. With use of 100% CBD oil none of the patients noted a decrease in opioid use, pain score or functional status. However, by using medical cannabis with a combined ratio of THC:CBD they each reduced their opioid use by 50-100% within one month. No withdrawal side effects were noted but psychotropic side effects were more common with higher ratios of THC:CBD. The 1:1 ratio caused the most mental alteration and 1:20 was reported to produce no mental clouding but preserved analgesia. Patients described 3-5 hours of analgesic benefit with use of medical cannabis.
Medical cannabis has been associated with a reduction in pain experienced by chronic pain patients when used in combination with opioids.4 We describe a case series of 5 patients in whom cannabis was used to successfully wean opioid dose. Cannabis consists of many known clinically active compounds, the most commonly investigated of which are cannabidiol (CBD) and delta-9-tetrahydrocannabinol (THC). THC, which is a partial agonist upon the cannabidiol 1 receptor (CB1), is more likely the clinically active component in pain reduction. Conversely, CBD is an inverse agonist of the CB1 receptor and likely functions as a modulating agent, attenuating the psychotropic side effects of cannabis. Interestingly, neither of the clinically active compounds are responsible for the characteristic odor of cannabis, which is caused by another botanical component of the plant: terpenes.
Our case series of 5 patients comprises the first group of cannabis naïve chronic low back pain patients that have markedly reduced opioid use with medical cannabis. A recent finding that the cannabinoid 2 receptor agonist may partially attenuate opioid tolerance5 could be an explanation for the findings of our case series. Additionally, existing opioid tolerance seems to increase tolerance to a cannabinoid agonist5 which could explain the ability of our patients to tolerate cannabis as all patients in this series were opioid tolerant. This case series demonstrates that future directions of cannabis research should focus upon ratio-finding studies in addition to dose-finding investigations.
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