A within-subject, double-blind, placebo-controlled randomized evaluation of the combined effects of cannabidiol and hydromorphone in a human laboratory pain model

Preclinical and epidemiological evidence supports that cannabinoids may have opioid-sparing properties and could be one strategy to decrease opioid use and associated harms like overdose and extramedical use. The objective of this within subjects, double-blind, double-dummy, randomized human laboratory trial was to examine whether cannabidiol (CBD) increases opioid analgesic effects and whether there are corresponding increases in other opioid mediated effects. Healthy participants (N = 31) attended 5 outpatient sessions where they received the following drug conditions: (1) placebo + placebo, (2) 4 mg hydromorphone + placebo, (3) 4 mg hydromorphone + 50 mg CBD, (4) 4 mg hydromorphone + 100 mg CBD, and (5) 4 mg hydromorphone + 200 mg CBD. Before and at multiple time points after drug administration, participants completed (1) quantitative sensory testing, which induced and assessed acute and chronic laboratory models of pain; (2) standard assessments, which queried acute subjective drug effects; and (3) tasks, which assessed psychomotor performance. When combined with a dose of hydromorphone that did not reliably produce analgesic effects on its own, CBD increased the analgesic effects for some laboratory acute pain outcomes but none of the laboratory chronic pain outcomes. At the highest dose of CBD (200 mg), there were concurrent increases in self-report Bad Effects and adverse effects that were not observed at lower doses of CBD (50 mg). Cannabidiol mitigated psychomotor impairment observed with hydromorphone alone. These findings suggest that lower doses of CBD (50 mg) may have utility for enhancing acute analgesic properties of opioids without having corresponding increases in bad effects.