Efficacy and safety of V1a receptor antagonists in autism spectrum disorder: A meta-analysis

This meta-analysis has evaluated the efficacy and safety of V_1a receptor antagonists in ASD compared to placebo. The reviewers extracted data from four relevant clinical trials after a literature search on databases and clinical trial registries. Quality assessment was done using the risk of bias assessment tool, and the random-effects model was used to estimate effect size. Subgroup analysis, meta-regression and sensitivity analysis were done. PRISMA guidelines were followed in the selection, analysis and reporting of findings. V_1a receptor antagonists did not reduce Vineland II Adaptive behaviour composite score significantly (SMD: 0.14; 95% CI: −0.06–0.35; p = 0.16; PI: −0.44–0.73), communication domain subscale score and socialization domain subscale score. The change in daily living skills domain subscale score was significant and favourable for V_1a receptor antagonists (SMD: 0.15; 95% CI: 0.03–0.26; p = 0.01). The subgroup analysis revealed a significant improvement in Vineland II Adaptive behaviour composite score with doses <10 mg (SMD: 0.45; 95% CI: 0.11–0.78; p = 0.009). Meta-regression does not show a significant association between SMD of ASD symptom score reduction with the duration and dose of V_1a receptor antagonist therapy. Treatment-emergent adverse effects were not serious and dose dependent. Low doses (<10 mg) of V_1a receptor antagonist may be effective in reducing the core symptoms of ASD compared to placebo; however, future active-controlled clinical trials are necessary to generate conclusive evidence.