Separate and combined effects of gabapentin and Δ9-THC in humans discriminating Δ9-THC

摘要

The aim of the present study was to examine a potential mechanism of action of gabapentin to manage cannabis-use disorders by determining the interoceptive effects of gabapentin in cannabis users discriminating Δ⁹-THC using a pharmacologically selective drug-discrimination procedure. Eight cannabis users learned to discriminate 30 mg oral Δ⁹-THC from placebo and then received gabapentin (600 and 1200 mg), Δ⁹-THC (5, 15 and 30 mg) and placebo, alone and in combination. Self-report, task performance and physiological measures were also collected. Δ⁹-THC served as a discriminative stimulus, produced positive subjective effects, elevated heart rate and impaired psychomotor performance. Both doses of gabapentin substituted for the Δ⁹-THC discriminative stimulus and engendered subjective and performance-impairing effects that overlapped with those of Δ⁹-THC when administered alone. When administered concurrently, gabapentin shifted the discriminative-stimulus effects of Δ⁹-THC leftward/upward, and combinations of Δ⁹-THC and gabapentin generally produced larger effects on cannabinoid-sensitive outcomes relative to Δ⁹-THC alone. These results suggest that one mechanism by which gabapentin might facilitate cannabis abstinence is by producing effects that overlap with those of cannabinoids.