The atypical antipsychotics quetiapine, risperidone and ziprasidone do not increase insulin release in vitro.

OBJECTIVE: In the light of the recent finding that the atypical antipsychotics clozapine and olanzapine have a stimulatory effect on basal insulin release in vitro, the influence on insulin release of three other atypical agents; quetiapine, risperidone and ziprasidone, was examined.

METHODS: The effect of each atypical antipsychotic in a concentration of 10(-6) M was investigated on both basal and glucose-stimulated insulin release from isolated rat pancreatic islets.

RESULTS: No difference in effect on insulin release was found for any of the three atypical antipsychotic substances compared to controls without antipsychotics, either in basal or in glucose-stimulated insulin release.

CONCLUSION: This study demonstrates that the main compounds of quetiapine, risperidone and ziprasidone do not increase insulin release from isolated pancreatic islets, which stands in clear contrast to what has been found previously for clozapine and olanzapine. Thus, atypical antipsychotics seem to differ in their effect on insulin release in vitro.