Clinical Trial: Low Dose of Synthetic THC Augments Analgesic Efficacy of Opioids

Baltimore, MD: The co-administration of low doses (2.5mgs) of dronabinol (FDA-approved synthetic THC) augments the pain-relieving properties of opioids compared to placebo, according to clinical trial data published in the journal Neuropsychopharmacology.

A team of researchers affiliated with Johns Hopkins University’s School of Medicine assessed the co-administration of dronabinol and hydromorphone (a/k/a Dilaudid) on measurements of sensory-induced pain in a cohort of 29 healthy adults. Subjects received varying doses (2.5mg, 5mg, or 10mg) of either dronabinol or placebo in addition to 4mg of hydromorphone. 

Investigators reported that the co-administration of 2.5mgs of dronabinol augmented the pain-relieving effects of hydromorphone whereas doses of 10mg of dronabinol was associated with increased perceptions of pain among some subjects.

Authors concluded: “These data suggest that dronabinol may enhance the analgesic effects of a low dose of hydromorphone, indicative of possible opioid-sparing effects, but that this effect only occurs within a narrow dose range beyond which hyperalgesia, increased risk for AEs [adverse events], and abuse liability are more likely to occur.”

A pair of prior clinical trials have previously documented that the co-administration of cannabis augments the analgesic effects of opioids, even when administered at subclinical doses. Dozens of longitudinal studies of various patient populations show that subjects typically reduce or altogether eliminate their use of opioids following the initiation of medical cannabis therapy.

Full text of the study, “Within-subject, double-blinded, randomized, and placebo-controlled evaluation of the combined effects of the cannabinoid dronabinol and the opioid hydromorphone in a human laboratory model,” appears in Neuropsychopharmacology. Additional information regarding the relationship between cannabis and prescription pain relievers is available from the NORML fact sheet, “Relationship Between Marijuana and Opioids.”