Alterations in oxidative stress markers and its correlation with clinical findings in schizophrenic patients consuming perphenazine, clozapine and risperidone

Background and objective: Today, the role of oxidative stress in development of schizophrenia has gained attention. Also, some atypical antipsychotic agents showed antioxidant properties. Therefore, in this study, we evaluated the level of oxidative stress parameters between patients treated with perphenazine, clozapine and risperidone and their relationship with schizophrenia symptoms' severity.

Materials and methods: This was a descriptive study on 100 patients with chronic schizophrenia. Patient selection was done based on the DSM-IV-TR criteria for at least 3 months regular use of clozapine or risperidone or perphenazine and a minimum period of 2 years of schizophrenia. Ten ml of patient's blood samples were used to assess serum levels of glutathione (GSH), protein carbonyl, lipid peroxidation (LPO), superoxide dismutase (SOD) and Ferric Reducing Ability of Plasma (FRAP). Also, the severity of symptoms was assessed with the positive and negative syndrome scale (PANSS scale). P-values of less than 0.05 were considered significant.

Results: The results showed a significant difference between clozapine and risperidone with perphenazine in all subscales of PANSS. Also, there was a positive correlation between MDA and PANSS all subscales in risperidone and perphenazine groups and a negative correlation between MDA and PANSS in all subscales in the clozapine group. Serum level of GSH and negative symptoms in patients receiving clozapine showed a negative correlation. The results also represented that clozapine significantly increased SOD levels in comparison to perphenazine and risperidone and reduced LPO in comparison to perphenazine and risperidone, While the protein carbonyl level did not show a significant difference between three groups (p-value = 0.8).

Conclusion: This study showed that clozapine, as an atypical antipsychotic agent, has significant antioxidant effects compared to risperidone and perphenazine. Especially, it increased SOD and GSH levels and reduced LPO in patients with schizophrenia. Therefore, clozapine's antioxidant effect may be contributive to improving negative symptoms of schizophrenic patients.