Tolerability and efficacy of paliperidone ER compared to olanzapine in the treatment of schizophrenia: A randomized, double–blind, multicentric trial

BACKGROUND: Paliperidone is an active metabolite of risperidone and actss through a combination of central dopamine Type 2 (D2) and serotonin Type 2 (5HT2A) receptor antagonism. AIM: The present randomized, double-blind, multicentric trial was designed to determine the safety and efficacy of paliperidone extended release (ER) compared to olanzapine in the treatment of acute schizophrenia. MATERIALS AND METHODS: A total of 214 patients with diagnosis of schizophrenia were randomized to paliperidone ER (n=109) and olanzapine (n=106) treatment groups. Totally 206 patients were evaluated for efficacy parameters using Positive and negative syndrome scale (PANSS) score and Clinical Global Impression-severity of illness (CGI-S) and Clinical Global Impression-improvement of illness (CGI-I) scales. Safety was assessed by treatment-emergent adverse events and movement disorders. RESULTS: All patients showed significant reduction in PANSS scores at the end of treatment. However, the results were comparable and there was no significant difference at the end of the trial between paliperidone ER group and olanzapine group. Both the treatment groups showed decrease in the severity of illness and improvement in symptomatology. The most common adverse events reported in paliperidone ER versus olanzapine group were Extra Pyramidal Syndrome (EPS) (13.7% vs. 15.6%), headache (12.7% vs. 8.9%), increased appetite (8.8% vs. 10.0%) and drowsiness (4.9% vs. 303%). There was no clinically relevant difference in change from baseline to the end of the trial in abnormal involuntary movement scale (AIMS) and barnes akathisia rating scale (BARS) total scores between both the groups. CONCLUSION: Paliperidone ER is effective in controlling schizophrenic symptoms as well as exhibits comparable tolerability profile. Thus, paliperidone ER has the potential to be a useful new treatment option for patients with schizophrenia.