Specific mechanism of action of amisulpride in the treatment of schizophrenia and correlation with clinical response and tolerability

The treatment of schizophrenia has advanced because the therapeutic efficacy, tolerability, and safety profiles of atypical antipsychotics seem to be superior to those of classical neuroleptics. Amisulpride is an atypical antipsychotic drug with a unique receptor pharmacology, which is dose-dependent. As could be predicted from the pharmacologic profile of a pure D2/D3 receptor blocker, amisulpride is an atypical antipsychotic agent, effective for positive and negative symptoms, which can bring about additional improvement in the social functioning and quality of life of patients with schizophrenia. Amisulpride has one of the lowest potentials for weight gain of all the antipsychotic agents, and is clearly associated with lower use of anti-parkinsonian medication and with fewer dropouts due to adverse events than conventional antipsychotics. Amisulpride is well tolerated in terms of anxiety and insomnia. Amisulpride has a pronounced prolactin-elevating effect which appears to be independent of dosage and duration of administration. Hyperprolactinemia rapidly reverses after amisulpride discontinuation. Amisulpride benefits patients with negative symptoms, and is the only antipsychotic to demonstrate efficacy in patients with predominantly negative symptoms. Amisulpride maintains its efficacy when used for medium-/long-term treatment, as demonstrated in studies of up to 12 months. Amisulpride has the best evidence as an effective adjunct to clozapine treatment. In conclusion, amisulpride is an antipsychotic agent with proven efficacy and good tolerability.