Amisulpride Switching in Schizophrenic Patients Who Showed Suboptimal Effect and/or Tolerability to Current Antipsychotics in a Naturalistic Setting: An Explorative Study

Objective Despite numerous atypical antipsychotics (AAP) available, many patients with schizophrenia still experience lack of efficacy and persistent side-effects. Switching from one AAP to another with a different side-effect profile has become a common clinical strategy. We aimed to investigate effect of switching to amisulpride in patients who showed suboptimal effect and /or tolerability to current antipsychotics treatment. Methods This was a 6-week, prospective, multicenter, open-label, flexible-dose study in patients with schizophrenia. Switching to amisulpride was achieved using cross-titration within 7 days (day 1: 300 mg on day 1 then flexibly dosed 400-800 mg/day). The primary end-point measure was proportion of patients achieving improvement in clinical benefit at week 6 based on Clinical Global Impressions-Clinical Benefit (CGI-CB). Secondary endpoints included change in scores in CGI-CB, CGI-Severity (CGI-S), Subjective Satisfaction Scores (SSS), Brief Psychiatric Rating Scale (BPRS), and Simpson and Angus Rating Scale. Results Among 37 patients switched to amisulpride, 76% completed study and 56.8% had clinical benefit measure by CGI-CB. CGI-CB and CGI-S scores showed significant improvement at week 6 compared to baseline (mean changes of CGI-CB and CGI-S scores: -1.7+1.0, p<0.0001 and -0.6±0.0, p=0.001, respectively). SSS scores also improved significantly (mean change: 2.1±2.6, p<0.0001). Mean weight of patients significantly lowered compared to baseline (mean change: -1.2±2.0, p<0.0001). Conclusion Patients with schizophrenia who showed suboptimal efficacy or tolerability with their current antipsychotics and thereby switched to amisulpride resulted in clinical benefit in terms of both improved efficacy and tolerability. The small sample size limits generalizability of the study results.