Fluphenazine levels during maintenance treatment of recent-onset schizophrenia: relation to side effects, psychosocial function and depression.

Rationale: The utility of fluphenazine levels during maintenance treatment of schizophrenia is still unclear.

Objectives: This study investigated the relationship between fluphenazine levels and a variety of clinical measures during maintenance treatment of schizophrenia.

Methods: Fluphenazine levels, side effects, depression and psychosocial outcome were measured at five time points over approximately 1 year in 59 recent onset schizophrenic patients treated with a maintenance dose of injectable fluphenazine decanoate. Negative symptoms were evaluated at the 1-year endpoint.

Results: Fluphenazine levels showed marked intraindividual variability even when measurements were restricted to the second 6 months of treatment, by which time steady state levels should have been achieved. No consistent relationship was found between fluphenazine levels and any of the outcome measures.

Conclusions: The results of this study suggest that fluphenazine plasma levels do not routinely add relevant clinical information beyond that of dose in evaluating potential side effects or negative consequences during maintenance treatment with the decanoate form of the medication.