(HealthDay News) – Dronabinol (Δ9 tetrahydrocannabinol [THC]), a pharmaceutical formulation of the psychoactive component of marijuana, produces a longer duration of pain relief than smoked marijuana, according to a small study published online April 22 in Neuropsychopharmacology.
Ziva D. Cooper, PhD, from the College of Physicians and Surgeons at Columbia University in New York City, and colleagues randomized 15 healthy male and 15 healthy female daily marijuana smokers to either marijuana (0%, 1.98%, or 3.56% THC) or dronabinol (0, 10, or 20mg). The Cold-Pressor Test was used to assess pain response while participants immersed their left hand in cold water (4 degrees Celsius). The time to report pain (pain sensitivity) and withdraw the hand from the water (pain tolerance) was also recorded. Other measurements included subjective pain and drug effect ratings as well as cardiovascular effects.
The researchers found that, compared to placebo, marijuana and dronabinol decreased pain sensitivity (3.56%; 20mg), increased pain tolerance (1.98%; 20mg), and decreased subjective ratings of pain intensity (1.98% and 3.56%; 20mg). There was no difference between marijuana and dronabinol with regard to the magnitude of peak change in pain sensitivity and tolerance, although dronabinol produced analgesia that was of a longer duration. Relative to placebo, abuse-related subjective ratings were greater with marijuana (1.98% and 3.56%) than with dronabinol (20mg).
“These data indicate that under controlled conditions, marijuana and dronabinol decreased pain, with dronabinol producing longer-lasting decreases in pain sensitivity and lower ratings of abuse-related subjective effects than marijuana,” the authors write.