N-Acetylcysteine Not Effective for Treating Cannabis Use Disorder in Adults – CTN-0053 Outcomes

  • Cannabis use disorder (CUD) is a prevalent and impairing condition, impacting an estimated 1 in 11 adult users of cannabis, and established psychosocial treatments convey limited efficacy.
  • In light of recent findings supporting the efficacy of N-acetylcysteine (NAC) for CUD in adolescents, the objective of this trial, NIDA Clinical Trials Network protocol CTN-0053, was to evaluate its efficacy in adults.
  • In a 12-week double-blind randomized placebo-controlled trial, treatment-seeking adults ages 18-50 with CUD (N=302), enrolled across six NIDA Clinical Trials Network-affiliated clinical sites, were randomized in a 1:1 ratio to a 12-week course of NAC 1200 mg (n=153) or placebo (n=149) twice daily.

    All participants received contingency management (CM) and medical management. The primary efficacy measure was the odds of negative urine cannabinoid tests during treatment, compared between NAC and placebo participants.

    Results found that the NAC and placebo groups did not differ significantly in cannabis abstinence. Overall, 22.3% of urine cannabinoid tests in the NAC group were negative, compared with 22.4% in the placebo group. Many participants were medication non-adherent; however, exploratory analysis within the medication-adherent subgroups revealed no significant differential abstinence outcomes by treatment group.

    Conclusions: In contrast with significant prior findings in adolescents, there is no evidence that NAC 1200mg twice daily plus CM is differentially efficacious for CUD in adults when compared to placebo plus CM. This discrepant finding between adolescents and adults with CUD may have been influenced by differences in development, cannabis use profiles, responses to embedded behavioral treatment, medication adherence, and other factors. In light of these findings, a replication trial of NAC in adolescents with CUD is indicated.

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    Funding for this Addiction Science Made Easy project is provided by the Addiction Technology Transfer Center National Office, under the cooperative agreement from the Center for Substance Abuse Treatment of SAMHSA.

    Articles were written based on the following published research:

    Gray KM, et al. A Randomized Placebo-Controlled Trial of N-acetylcysteine for Cannabis Use Disorder in Adults. Drug and Alcohol Dependence 2017 (in press).

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