Nabilone decreases marijuana withdrawal and a laboratory measure of marijuana relapse.
Few individuals seeking treatment for marijuana use achieve sustained abstinence. The cannabinoid receptor agonist, Δ(9)-tetrahydrocannabinol (THC dronabinol), decreases marijuana withdrawal symptoms, yet does not decrease marijuana use in the laboratory or clinic. Dronabinol has poor bioavailability, which may contribute to its poor efficacy. The FDA-approved synthetic analog of THC, nabilone, has higher bioavailability and clearer dose-linearity than dronabinol. This study tested whether nabilone administration would decrease marijuana withdrawal symptoms and a laboratory measure of marijuana relapse relative to placebo. Daily, nontreatment-seeking marijuana smokers (8 men and 3 women), who reported smoking 8.3±3.1 marijuana cigarettesday completed this within-subject study comprising three, 8-day inpatient phases each phase tested a different nabilone dose (0, 6, 8 mgday, administered in counter-balanced order on days 2-8). On the first inpatient day, participants took placebo capsules and smoked active marijuana (5.6% THC) at six timepoints. For the next 3 days, they had the opportunity to self-administer placebo marijuana (0.0% THC withdrawal), followed by 4 days in which active marijuana was available for self-administration (5.6% THC relapse). Both nabilone dose conditions decreased marijuana relapse and reversed withdrawal-related irritability and disruptions in sleep and food intake (p<0.05). Nabilone (8 mgday) modestly worsened psychomotor task performance. Neither dose condition increased ratings of capsule liking or desire to take the capsules relative to placebo. Thus, nabilone maintenance produced a robust attenuation of marijuana withdrawal symptoms and a laboratory measure of relapse even with once per day dosing. These data support testing of nabilone for patients seeking marijuana treatment.