Trial of maintenance neuroleptic dose reduction in schizophrenic outpatients: two-year outcome

Abstract

Background: An open trial was undertaken to assess the feasibility of reducing maintenance doses in a public clinical setting and to identify eventual predictors of outcome after dose reduction in schizophrenia.

Method: Forty-one remitted and chronically psychotic schizophrenic outpatients were assigned, on the basis of their previously clinically determined maintenance dosages, to one of two reduced fluphenazine decanoate regimens: 35 mg/4 wk (19 patients) or 10 mg/4 wk (22 patients). Subsequently, patients were assessed, for a 2-year period, by means of the Brief Psychiatric Rating Scale, the Scale for the Assessment of Positive Symptoms, the Scale for the Assessment of Negative Symptoms, the Simpson-Angus Scale, and the Abnormal Involuntary Movement Scale.

Results: Chronically psychotic patients, who represented 74% of the high-dose group and only 14% of the low-dose group, had a significantly higher cumulative relapse rate (81%) than remitted patients (38%). For most remitted patients a dose of 10 mg of fluphenazine decanoate, injected every 4 weeks, was satisfactory. Both remitted and chronically psychotic patients displayed reductions in the severity of neuroleptic side effects.

Conclusion: Maintenance dose reductions may be beneficial for many schizophrenic outpatients. Chronically psychotic and remitted patients maintained on lowered dosages differ significantly in the stability of their course of illness.