Risperidone and olanzapine versus another first generation antipsychotic in patients with schizophrenia inadequately responsive to first generation antipsychotics.

OBJECTIVE

This study compares the efficacy of risperidone and olanzapine to that of first-generation antipsychotics (FGAs) in patients with schizophrenia, who failed to show a response to initial trials of FGAs.

METHOD: This study was an 8-week treatment, randomized, rater-blind, active-control study with 3 treatment arms. 48 patients, who showed inadequate response to 1 FGA, were enrolled and randomized into risperidone, olanzapine, or FGA (haloperidol or trifluoperazine) groups. They were blindly assessed with the Positive and Negative Syndrome Scale (PANSS), the Clinical Global Impression Scale-Severity, and the Extrapyramidal Symptom Rating Scale (ESRS) at baseline and biweekly.

RESULTS

All 3 groups demonstrated a significant decrease in the PANSS total, positive, and general scores from baseline to endpoint (p-values range from 0.003 to 0.021). There were no significant differences among the 3 groups in score changes. The olanzapine group had significant score reductions than the risperidone and FGAs groups in terms of the ESRS subjective total score and did not experience a significant increase in the dose of anticholinergics. The FGA group demonstrated that extrapyramidal syndrome (EPS) worsened under an increased dosage of anti-EPS drugs. Olanzapine was associated with significant body weight gain (2.69 ± 4.0 kg, p=0.026), but there were no significant group differences on weight gain.

CONCLUSIONS

Haloperidol or trifluoperazine demonstrated similar efficacy as risperidone or olanzapine for patients with schizophrenia who had failed their first trial with a FGA. Related double-blind, fixed dose studies with a larger sample size are needed to confirm the results of our study.