Chronically administered risperidone did not change the number of hepatocytes in rats: a stereological and...

Risperidone, an antipsychotic agent, has been used in the therapy of patients with acute and chronic schizophrenia. The strategy in the choice of antipsychotic agent should take into account the hepatic tolerance. The aim of the present study was to analyse whether or not the chronic administration of risperidone has a toxic effect on rat livers. Rats were divided into three groups. Low dose (n = 5) and high dose (n = 5) groups that were given 0.5 and 1 mg/kg intraperitoneal doses of risperidone daily for 6 weeks, respectively. The control group received distilled water as a vehicle. At the end of the experiment, the rats were killed, and livers were dissected out immediately and transferred into the fixation solution. Both conventional light and transmission electron microscopic tissue preparation procedures were applied to liver tissues and they were evaluated using stereological and histopathological methods; in this respect, this is the first study using stereological methods for searching the effects of risperidone on liver. There were no significant differences about the total hepatocyte number and their numerical density of rat liver between groups (P > 0.05). Stereological results were also confirmed by the histopathological findings that come from both structural and ultrastructural levels examination. The results of the current study indicate that neither low nor high doses of risperidone resulted in damage to the rat livers at cellular level. In conclusion, we did not find any evidence for hepatotoxicity of risperidone rats. Larger-scale, prospective studies are needed in order to confirm these findings.