NEW YORK (Reuters Health) – Monthly intramuscular injection of a depot formulation of aripiprazole delays the time to impending relapse in stabilized adults with schizophrenia, and has a favorable safety profile similar to oral aripiprazole, according to a study reported in the May issue of the Journal of Clinical Psychiatry.
“Long-acting injectable antipsychotics offer an alternative to oral treatment and relieve patients from the daily need to take medication,” comment Dr. John M. Kane, at the Zucker Hillside Hospital in Glen Oaks, New York, and colleagues.
The researchers first treated 710 schizophrenia patients with daily oral aripiprazole for up to 12 weeks. The 576 participants who met stabilization criteria were then transitioned to aripiprazole-IM-depot injection every 4 weeks.
After a further 12 weeks, 403 of these patients were randomly assigned to double-blind treatment with continued aripiprazole-IM-depot or placebo injections monthly. The primary endpoint was time to exacerbation of psychotic symptoms signaling impending relapse.
Addressing the ethics of a placebo group in the trial, the authors write: “The Independent Data Monitoring Committee could discontinue the study for ethical reasons, most notably continued exposure to placebo if efficacy was established at the preplanned first interim analysis (64 events).”
In fact, the trial was terminated early for this reason. At the interim analysis, relapse rates were 9.6% in the aripiprazole-depot group compared with 36.8% in the placebo group (hazard ratio 4.72), a significant difference.
During the double-blind phase, adverse events that occurred in 5% or more aripiprazole-depot subjects and more frequently than with placebo were insomnia, headache and tremor. Rates of discontinuation due to treatment-emergent adverse events in the two groups were 7.1% and 13.4%.
Summing up, Dr. Kane and colleagues conclude: “Aripiprazole-IM-depot significantly delayed time to impending relapse compared with placebo and appears to be a well-tolerated maintenance treatment option for schizophrenia.”