Evaluation of two dose levels of loxapine succinate in chronic schizophrenia.

In a double-blind, placebo controlled design in chronic schizophrenic inpatients using 50 mg. and 100 mg. LOX, an attempt was made to replicate the findings of a previous study and to establish the dose-level and duration of treatment optimal for this kind of patient. Multiple regression analysis adjusting for dose, age, duration of illness, and baseline values indicated that 100 mg. LOX was an effective dose as previously shown. In contrast to the previous study, significant response effects were found by the 4th week. In addition, the dose was linearly related to response on nearly all the variables. The principal side effects were drowsiness and extrapyramidal signs.