Efficacy of loxapine in the treatment of paranoid schizophrenia.

A combined analysis of data from 11 controlled studies of loxapine versus either chlorpromazine or trifluoperazine in acute schizophrenia (5 studies) and chronic schizophrenia (6 studies) showed statistically significant superiority of loxapine on several items and factors of standardized psychiatric rating scales. Upon review of these findings, it was observed that the rating scale symptoms for which loxapine appeared superior to the reference compounds could, in the main, be considered a broad paranoid "cluster". The data were then reanalyzed to detect possible differences in efficacy of loxapine versus the reference compounds in those patients with a clinical diagnosis of schizophrenia, paranoid type and in those patients of any diagnostic subtype other than paranoid. Results of these analyses demonstrated clear superiority of loxapine in paranoid schizophrenic patients; nonparanoid patients responded at least equally as well to loxapine as to the reference compounds. Findings could not be attributed to inadequate dosages of the references compounds or inequality of treatment groups at baseline.