Interaction of the cannabinoid and opioid systems in the modulation of nociception

“Cannabinoids and opioids produce antinociceptive synergy. Cannabinoids such as Δ-9-tetrahydrocannabinol (THC) release endogenous opioids and endocannabinoids such as anandamide (AEA) also alter endogenous opioid tone. Opioids and cannabinoids bind distinct receptors that co-localize in areas of the brain involved with the processing of pain signals. Therefore, it is logical to look at interactions of these two systems in the modulation of both acute and chronic pain. This review summarizes the data indicating that with cannabinoid/opioid therapy one may be able to produce long-term antinociceptive effects at doses devoid of substantial side effects, while preventing the neuronal biochemical changes that accompany tolerance. The clinical utility of modulators of the endocannabinoid system as a potential mimic for THC-like drugs in analgesia and tolerance-sparing effects of opioids is a critical future direction also addressed in the review.” https://www.tandfonline.com/doi/abs/10.1080/09540260902782794]]>

Pharmacotherapeutic considerations for use of cannabinoids to relieve pain in patients with malignant diseases.

  “The aim of this review was to assess the efficacy of cannabis preparations for relieving pain in patients with malignant diseases, through a systematic review of randomized controlled trials (RCTs), which were predominantly double-blind trials that compared cannabis preparation to a placebo.

RESULTS:

Fifteen of the 18 trials demonstrated a significant analgesic effect of cannabinoids as compared to placebo. The most commonly reported adverse effects were generally well tolerated, mild to moderate. The main side effects were drowsiness, nausea, vomiting and dry mouth. There is evidence that cannabinoids are safe and modestly effective in neuropathic pain and also for relieving pain in patients with malignant diseases. The proportion of “responders” (patients who at the end of 2 weeks of treatment reported ≥30% reduction in pain intensity on a scale of 0-10, which is considered to be clinically important) was 43% in comparison with placebo (21%).

CONCLUSION:

The target dose for relieving pain in patients with malignant diseases is most likely about 10 actuations per day, which is about 27 mg tetrahydrocannabinol (THC) and 25 mg cannabidiol (CBD), and the highest approved recommended dose is 12 actuations per day (32 mg THC/30 mg CBD). Further large studies of cannabinoids in homogeneous populations are required.” https://www.ncbi.nlm.nih.gov/pubmed/29719417 https://www.dovepress.com/pharmacotherapeutic-considerations-for-use-of-cannabinoids-to-relieve–peer-reviewed-article-JPR
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