RESUMO
BACKGROUND: Co-occurring methamphetamine (METH) use during methadone maintenance therapy (MMT) is a highly prevalent and progressive problem in Iran. There are no registered pharmacological treatments for treating METH use disorder. The present study investigates the potential efficacy of atomoxetine in the treatment of these patients. METHODS: In a double-blind, controlled clinical trial, 86 METH-dependents on MMT randomly received either atomoxetine (40 mg/d) or placebo. We measured the craving scores with visual analog scale (VAS) on a weekly basis, and evaluated depression, anxiety and stress with the Depression Anxiety Stress Scales (DASS) on a monthly basis. Measurements were made in each weekly visit with urinary METH drug test. RESULTS: Atomoxetine significantly reduced METH craving (P < 0.001). Negative METH urine test increased significantly in the drug group compared to the placebo group (P = 0.007). While initially the METH urine test was positive for all patients, 56% (25/45) in the atomoxetine group and 26% (11/41) in the placebo group had negative METH urine tests after 8 weeks. DASS were decreased in both groups with a greater reduction in the atomoxetine group [depression (P = 0.028), anxiety (P = 0.038), and stress (P = 0.031)]. Only mild side effects were observed. CONCLUSION: This study confirms the safety and clinical tolerance of atomoxetine, and its appropriate efficacy in suppressing METH craving and possible potential effects on its treatment.