Amisulpride, a benzamide derivative belongs to a second generation of antipsychotics. It is characterized by higher affi nity for dopaminergic receptors D2/D3 in the limbic rather than in the striatal regions. Amisulpride at low doses antagonize presynaptic D2 and D3 receptors, resulting in enhanced dopamine transmission; however at high doses block postsynaptic receptors, resulting in reduced dopamine transmission.
Clinical effectiveness of amisulpride: antipsychotic effects at high dosages (400-800 mg/d) and reducing of negative symptoms at low dosages (50-300 mg/d) is a consequence of preferential affinity for D2/D3 receptors at low doses and blocking of postsynaptic receptors at high doses. Amisulpride has preferential affi nity for limbic and hippocampal structures and low affi nity for striatal structures which may account for its low potential to induce extrapyramidal adverse effects.
Clinical trials with patients in acute phase of schizophrenia revealed that amisulpride was at least as effective in the control of positive symptoms as haloperidol, flupentixol, ziprasidone, olanzapine and risperidone, and more effective than haloperidol in the control of negative symptoms. Amisulpride signifi cantly reduced persistent negative symptoms in long term treated patients. In the long-term treatment, amisulpride appeared to be more effective and better tolerated than haloperidol and similarly effective as risperidone and olanzapina. Quality of life and social functioning were improved signifi cantly more with amisulpride than other antipsychotics.
All clinical trials showed good tolerability profile of amisulpride and its low influence on extrapyramidal system, weight gain and metabolism of glucose and lipids.
Amisulpride is associated with slight weight gain, and does not seem to be associated with diabetogenic effects.
Influence of amisulpride on the prolactine level is dose related.
Amisulpride is an effective and well tolerated first line atypical antipsychotic used in patients with acute schizophrenia as well as in the long-term maintenance therapy.