Is There Any Clinically Relevant Cannabinoid-Induced Analgesia?

Cannabis sativa is one of the oldest crops cultivated for the production of fibers and for medical and recreational purposes. Since the detection of specific cannabinoid receptors and their physiological ligands, the understanding of the cannabinoid signalling system has increased, leading to a recent resurgence of interest in its medicinal properties. In animal studies, cannabinoids exerted significant analgesic and antihyperalgesic effects, suggesting the usefulness of cannabinoids in pain conditions. However, in human experimental or clinical trials, no convincing reduction of acute pain was observed. In contrast, in chronic pain and (painful) spasticity, an increasing number of randomized, double-blind, placebo-controlled studies have shown some efficacy of cannabinoids. Besides pain, cannabinoids consistently improved mood, sleep and coping. Although cannabinoids are not first-line analgesics, they may be useful adjuvants for some special groups of patients.