Marinol

Fifteen mg of THC (Marinol®; Solvay Pharmaceuticals) was placed in opaque size 00 capsules with dextrose filler. Placebo capsules contained dextrose only. This dose of THC is within the range shown to affect memory encoding in prior work [3 (link),4 (link)].

Subjects consumed a low-fat snack approximately 20 minutes prior to drug administration. Doses of Δ⁹-THC were prepared by encapsulating commercially available capsules of Marinol® (Δ⁹-THC in sesame oil, Solvay Pharmaceuticals Inc., Marietta, GA) and a generic formulation of gabapentin (Ascend Laboratories, Montvale, NJ) in opaque green size 00 capsules. For reference, the acute recommended Δ⁹-THC dosing range in adults for appetite stimulation and the prevention of nausea and vomiting is 2.5 to 20 mg (Marinol® product information, 2006 ). The recommended starting therapeutic oral dose of gabapentin is 300–400 mg, administered three times a day, and titrated up to a clinically effective maintenance dose of 1800–3600 mg/day (Gabapentin product information, 2011 ). However, single-dose clinical research studies have administered 1200 mg, the maximum gabapentin dose administered in this study, on an acute basis without dose titration (e.g., Gordi et al., 2008 (link)). Gabapentin and Δ⁹-THC were administered concurrently, consistent with the onset of their peak concentrations following oral dosing (Gidal et al., 1998 (link); Lile et al., 2013 (link)). The use of oral Δ⁹-THC and gabapentin in this study was for investigational purposes.

Across their participation, subjects received placebo, 5, 15 and 30 mg of Δ⁹-THC, and 5 and 10 mg of diazepam, alone and in combination. Doses of Δ⁹-THC were prepared by encapsulating commercially available capsules of Marinol® (Δ⁹-THC in sesame oil, Solvay Pharmaceuticals, Marietta, GA) in three opaque green size 00 capsules. A generic formulation of diazepam was administered in one opaque blue/white size 0 capsule. Cornstarch was used to fill the remainder of all capsules. Placebo capsules contained only cornstarch. For reference, the acute recommended Δ⁹-THC dosing range in adults for appetite stimulation and the prevention of nausea and vomiting is 2.5 to 20 mg (Marinol® Product Information, 2006 ). The recommended acute oral dosage of diazepam for the treatment of anxiety is 2-10 mg (Valium® Product Information, 2013 ).