Abstract
INTRODUCTION: Amphetamine-type stimulants (ATSs) are related to significant harm worldwide, with limited effective pharmacological treatments for ATS use disorder (ATSUD). Modafinil has been explored as a potential treatment for ATSUD. This systematic review and meta-analysis (PROSPERO ID: CRD42023388487) aimed to evaluate the efficacy and safety of modafinil for the treatment of ATSUD. METHODS: A comprehensive search of major indexing sources and trial registries, from inception to search date, was conducted on February 15, 2023, and updated on October 31, 2023. Eligible studies were randomized placebo-controlled trials (RCTs) of modafinil in individuals meeting the criteria for the Diagnostic and Statistical Manual of Mental Disorders, fourth and fifth editions, diagnoses of ATSUD. Eligible studies were assessed for risk of bias, using the Cochrane Risk of Bias tool. The primary outcome included the effect of modafinil on ATS use. Secondary outcomes included retention in treatment, ATS craving, treatment discontinuation due to adverse events (AEs), and serious AEs. Subgroup analysis by modafinil dose was conducted where appropriate. Risk ratio (RR) or Peto's odds ratio (OR) was calculated for the meta-analysis of dichotomous variables and standardized mean difference (SMD) was calculated for the random-effect meta-analysis of continuous variables. RESULTS: Five RCTs (N = 451 participants) were included. Modafinil did not significantly impact ATS use (RR = 0.99; 95% CI, 0.97 to 1.02; p = 0.655), retention in treatment (RR = 1.02; 95% CI, 0.91 to 1.14; p = 0.799), ATS craving (SMD = -0.36; 95% CI, -1.19 to 0.47; p = 0.398), or treatment discontinuation due to AEs (Peto's OR = 0.48; 95% CI, 0.20 to 1.14; p = 0.100). These results were consistent across subgroup analyses. More episodes of serious AEs were reported in the modafinil group than in the placebo group, at higher doses (Peto's OR = 4.80; 95% CI, 1.18 to 19.56, p = 0.029). CONCLUSION: There is currently no evidence suggesting that modafinil has a statistically significant effect on efficacy outcomes in populations with ATSUD. Continued research into effective treatments and harm reduction strategies for ATSUD is essential.