[Safety and efficacy of olanzapine versus perphenazine in patients with schizophrenia: results of multicenter, 18-week, double-blind clinical trial].

Aim: The primary objective of the study was to evaluate the severity of extrapyramidal symptoms during treatment with olanzapine (10-20 mg) versus perphenazine (8-40 mg) using the Simpson Angus Scale (SAS). The secondary objective was to assess the safety profile and clinical efficacy of the investigated drugs.

Material And Method: A total of 95 patients with schizophrenia who met the criteria for DSM-IV were randomized to a double-blind, 18 week prospective comparative trail conducted in Poland. The tolerance of treatment was assessed with the use of scales: BAS, SAS and UKU. The efficacy of treatment was evaluated with BPRS, PANSS and CGOI scales.

Results: For olanzapine patients, the severity of extrapyramidal symptoms improved after 3 first weeks of treatment, and significantly decreased from the baseline to endpoint. Perphenazine patients showed an increase of extrapyramidal symptoms. The difference of the SAS scores change was statistically significant between olanzapine and perphenazine groups. Akathisia symptoms decreased significantly in the olanzapine group during the treatment period, whereas symptoms of akathisia increased in the perphenazine group. Statistically significant differences of mean change of BAS total score from baseline to endpoint were noted between treatment groups Treatment--emergent adverse events occurred more frequently in patients receiving perphenazine (46%), than in patients receiving olanzapine (17%). The proportion of patients complying with improvement criteria for CGI scale score was statistically greater in the olanzapine group (72.7%) than in the perphenazine group (47.9%). Results of this study showed that the tolerance profile in patients taking olanzapine is superior to perphenazine.

Conclusions: Olanzapine was better tolerated than perphenazine. After olanzapine treatment more subjects fulfilled the criterion of improvement and schizophrenic symptoms were less severe than in patients treated with perphenazine.