Effectiveness of switching from long-acting injectable fluphenazine or haloperidol decanoate to long-acting...

This multisite randomized trial addressed risks and benefits of staying on long-acting injectable haloperidol or fluphenazine versus switching to long-acting injectable risperidone microspheres.

From December 2004 through March 2008, adult outpatients with a Structured Clinical Interview for DSM-IV Axis I Disorders-Patient Edition diagnosis of schizophrenia or schizoaffective disorder who were taking haloperidol decanoate (n = 40) or fluphenazine decanoate (n = 22) were randomly assigned to stay on current long-acting injectable medication or switch to risperidone microspheres and followed for 6 months under study protocol and an additional 6 months naturalistic follow-up. Kaplan-Meier and Cox regression analyses were used to examine the primary outcome (time to treatment discontinuation), and random regression models were used to examine secondary outcomes.

Groups did not differ significantly in time to treatment discontinuation through 6 months of protocol-driven treatment. When the 6-month naturalistic follow-up period was included, time to treatment discontinuation was significantly shorter for individuals assigned to switch than for individuals assigned to stay (10% of stayers discontinued versus 31% of switchers; P = .01). Groups did not differ with respect to psychopathology, hospitalizations, sexual side effects, new-onset tardive dyskinesia, or new-onset extrapyramidal symptoms. However, those randomized to switch to long-acting injectable risperidone microspheres had greater increases in body mass (increase of 1.0 body mass index [BMI] versus decrease of -0.3 BMI; P = .00) and prolactin (maximum increase to 23.4 ng/mL versus decrease to 15.2 ng/mL, P = .01) compared to those randomized to stay.

Switching from haloperidol decanoate or fluphenazine decanoate to risperidone microspheres resulted in more frequent treatment discontinuation as well as significant weight gain and increases in prolactin.

ClinicalTrials.gov identifier: NCT00044655.