Conclusions and Relevance Cannabinoid drugs may prevent the onset of pain by producing small increases in pain thresholds but may not reduce the intensity of experimental pain already being experienced ; instead , cannabinoids may make experimental pain feel less unpleasant and more tolerable , suggesting an influence on affective processes .
Cannabis-induced improvements in pain-related negative affect may underlie the widely held belief that cannabis relieves pain
Importance Cannabinoid drugs are widely used as analgesics , but experimental pain studies have produced mixed findings .
The analgesic properties of cannabinoids remain unclear .
Objective To conduct a systematic review and meta- analysis of the association between cannabinoid drug administration and experimental pain outcomes in studies of healthy adults .
Lack of effect of central nervous system‐active doses of nabilone on capsaicin‐induced pain and hyperalgesia
The aim of the present study was to investigate the effects of nabilone on capsaicin‐induced pain and hyperalgesia , as well as on biomarkers of cannabinoid central nervous system ( CNS ) effects . A r and omized , double‐blind , placebo‐controlled , crossover study was conducted in 30 healthy male volunteers receiving single doses of nabilone ( 1 , 2 or 3 mg ) .  Pain intensity after intradermal capsaicin injections in the forearm was assessed by continuous visual analogue scale ( 0–100 mm ) . Capsaicin cream was applied to the calf to induce hyperalgesia . Primary hyperalgesia was assessed by measuring heat pain thresholds , whereas secondary hyperalgesia was assessed by measuring the area where light tactile stimulation was felt to be painful . Pain and hyperalgesia were measured at baseline and 2–3.5 h after dosing . The CNS effects were assessed at baseline and up to 24 h after dosing using visual analogue mood scales for feeling ‘ stimulated ’ , ‘ anxious ’ , ‘ se date d ’ and ‘ down ’ . Plasma sample s for pharmacokinetic analysis were obtained up to 24 h after drug administration . Nabilone did not significantly attenuate either ongoing pain or primary or secondary hyperalgesia , whereas dose‐dependent CNS effects were observed from 1.5 to 6 h after dosing , being maximal at 4–6 h. Plasma concentrations of nabilone and its metabolite carbinol were maximal 1–2 h after dosing . Adverse events ( AE ) were common on nabilone treatment . Four subjects withdrew due to pronounced CNS AE ( anxiety , agitation , altered perception , impaired consciousness ) . Although nabilone had marked CNS effects , no analgesic or antihyperalgesic effects were observed
Conclusions and Relevance Cannabinoid drugs may prevent the onset of pain by producing small increases in pain thresholds but may not reduce the intensity of experimental pain already being experienced ; instead , cannabinoids may make experimental pain feel less unpleasant and more tolerable , suggesting an influence on affective processes .
Cannabis-induced improvements in pain-related negative affect may underlie the widely held belief that cannabis relieves pain
Importance Cannabinoid drugs are widely used as analgesics , but experimental pain studies have produced mixed findings .
The analgesic properties of cannabinoids remain unclear .
Objective To conduct a systematic review and meta- analysis of the association between cannabinoid drug administration and experimental pain outcomes in studies of healthy adults .