Relative Safety and Efficacy of Two Doses of Tandospirone Citrate for Generalized Anxiety Disorder: A Multicenter Randomized Controlled Trial

PURPOSE: To determine the relative safety and efficacy of different doses of tandospirone in treating generalized anxiety disorder (GAD). PATIENTS AND METHODS: This parallel randomized controlled trial enrolled patients with GAD from eight centers in China. The patients were randomly assigned to 60 mg/day or 30 mg/day tandospirone groups. The primary endpoint was the overall response rate after receiving 6-week treatment. The secondary endpoints included significant response rate, clinical recovery rate, change in the Hamilton Anxiety Scale (HAMA) total score, HAMA subscale score, Hamilton Depression Scale-17 (HAMD-17), Clinical Global Impression-Severity Scale (CGI-S) score, and Impression-Improvement scale (CGI-I) score. RESULTS: No significant difference was found in the overall response rate between the two groups (65.7% vs 58.4%, p = 0.213). A higher significant response rate and change in the HAMA total score were found in the 60 mg/day group. The reduction in the CGI-S score and percentage of patients with a CGI-I score of ≤2 were higher in 60 mg/day group. The reduction in HAMA somatic anxiety factor, cardiovascular symptom factor, gastrointestinal symptom factor, and HAMD-17 score were more significant in the 60 mg/day group. The incidence of total adverse events was higher in the 60 mg/day group than in the 30 mg/day group. No significant difference was found in the proportion of withdrawal due to adverse events. CONCLUSION: Both 60 mg/day and 30 mg/day tandospirone show good efficacy in treating patients with GAD. High doses of tandospirone may have advantages in relieving the somatic symptoms but also present disadvantages due to their high level. TRIAL REGISTRATION: The trial registration no. was NCT01614041.