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

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.

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.

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.

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.