RESUMO
OBJECTIVE: Patients with substance use disorders (SUD) under methadone maintenance therapy (MMT) are susceptible to a number of complications (psychological and metabolic disorders). Evidence studies have shown the roles of the glutamatergic system in addiction. N-Acetylcysteine (NAC) enhances extracellular glutamate, and is effective in the treatment of neuropsychiatric disorders. We assessed oral NAC as an add-on to MMT medication for the treatment of SUD. METHODS: In the current randomized, double-blind, placebo-controlled clinical trial, outpatients with SUD under MMT who were 18-60 years old received 2400 mg/day NAC (n = 30) or placebo (n = 30) for 12 weeks. Psychological status and metabolic biomarkers were assessed at baseline and the end of the trial. RESULTS: Compared with the placebo group, NAC treatment resulted in a significant improvement in depression score (ß -2.36; 95% CI, -3.97, -0.76; p = .005), and anxiety score (ß -1.82; 95% CI, -3.19, -0.44; p = .01). Furthermore, NAC treatment resulted in a significant elevation in total antioxidant capacity levels (ß 72.28 mmol/L; 95% CI, 11.36, 133.19; p = .02), total glutathione (GSH) levels (ß 81.84 µmol/L; 95% CI, 15.40, 148.28; p = .01), and a significant reduction in high-sensitivity C-reactive protein levels (ß -0.89 mg/L; 95% CI, -1.50, -0.28; p = .005), and homeostasis model of assessment-insulin resistance (ß -0.33; 95% CI, -0.65, -0.009; p = .04), compared with the placebo group. CONCLUSION: In the current study, improvement in depression and anxiety symptoms as well as some metabolic profiles with NAC treatment for 12 weeks in outpatients with SUD under MMT was detected.