This pilot study examined the efficacy of the N-type calcium channel blocker gabapentin to improve outcomes during a brief detoxification protocol with buprenorphine. Treatment-seeking opioid-dependent individuals were enrolled in a 5-week, double-blind, placebo-controlled trial examining the effects of gabapentin during a 10-day outpatient detoxification from buprenorphine. Participants were inducted onto buprenorphine sublingual tablets during Week 1, were randomized and inducted onto gabapentin or placebo during Week 2, underwent a 10-day buprenorphine taper during Weeks 3 and 4, and then were tapered off gabapentin/placebo during Week 5. Assessments included thrice-weekly opioid withdrawal scales, vitals, and urine drug screens. Twenty-four individuals (13 male; 17 Caucasian, 3 African American, 4 Latino; mean age 29.7 years) participated in the detoxification portion of the study (gabapentin, n = 11; placebo, n = 13). Baseline characteristics did not differ significantly between groups. Self-reported and observer-rated opioid withdrawal ratings were relatively low and did not differ between groups during the buprenorphine taper. Urine results showed a Drug × Time interaction, such that the probability of opioid-positive urines significantly decreased over time in the gabapentin versus placebo groups during Weeks 3 and 4 (OR = 0.73, p = .004). These results suggest that gabapentin reduces opioid use during a 10-day buprenorphine detoxification procedure.

Methamphetamine has become a major public health issue globally, particularly in the United States. Despite this, no effective pharmacotherapy for methamphetamine abuse has been developed to date. This 6-week, open-label pilot clinical trial examined the safety and tolerability of modafinil up to 400 mg/d in 8 methamphetamine-dependent individuals. Subjects were inducted onto modafinil at 400 mg/d for more than 3 days and remained on 400 mg/d for 4.5 weeks. Participants received weekly blister packs and underwent weekly individual cognitive behavioral therapy. Adjunctive contingency management procedures were used to enhance retention. Vital signs and supervised urine samples were obtained thrice weekly, and self-reported drug use and Hamilton anxiety and depression ratings were completed once weekly. Eight subjects (50% female, 100% white, aged 35-52 years) were enrolled. Four completed the 6-week study, 3 completed a portion, and 1 withdrew consent before completing intake. Results showed that systolic blood pressure (t = 1.09, P = 0.28), diastolic blood pressure, (t = 1.18, P = 0.24), and heart rate (t = 1.55, P = 0.13) did not change over time. Scores on the modafinil side effects checklist (t = −2.63, P = 0.01), Hamilton anxiety scale (t = −2.50, P = 0.018), and Hamilton depression scale (t = −3.25, P = 0.003) all decreased over time. The proportion of urine positive for amphetamines did not change over time (t = −0.52, P = 0.61), whereas self-reported methamphetamine use did (t = −2.86, P < 0.005). These results suggest that modafinil at 400 mg/d is safe and tolerable for methamphetamine-dependent individuals.

Despite the therapeutic use and abuse potential of γ-hydroxybutyrate (GHB or Xyrem), relatively few studies have examined the behavioral effects of GHB in humans under controlled laboratory conditions. Thus, this eight-session study examined in 10 nonsubstance-abusing volunteers the behavioral effects of GHB at each of the following doses: 0, 0.32, 0.56, 0.75, 1.0, 1.8, 2.4, 3.2 g/70 kg, orally. Order of dose testing was random, except that the first two participants received active doses in ascending order and 2.4 g/70 kg was always tested before 3.2 g/70 kg. Before drug administration and at several postdrug time points, self-report, observer report, physiological, and psychomotor performance measures were obtained. Analyses based on area under the curve showed that GHB produced dose-related increases in subjective ratings of sedative-like, stimulant-like, positive mood, and dissociative effects, but no changes in psychomotor performance measures or blood pressure. Analyses based on peak effects generally showed dose-related increases in ratings indicating sedative-like, dissociative, and drug liking, although some measures showed U-shaped dose-related changes. These initial findings suggest that GHB at doses of 0.32–3.2 g/70 kg produces dissociative, sedating and some stimulant-like effects in humans without a history of sedative abuse.