A Randomized Controlled Trial of Long-Acting Injectable Risperidone vs Continuation on Oral Atypical Antipsychotics for First-Episode Schizophrenia Patients: Initial Adherence Outcome

Objective: Nonadherence for first-episode schizophrenia is a major unsolved challenge. The long-acting injectable route is an appealing strategy, but there are concerns about acceptability. We report on acceptance and initial adherence outcomes with risperidone long-acting injection (RLAI) in first-episode schizophrenia patients.

Method: We conducted a prospective randomized controlled trial in which we enrolled patients defined
by appropriate Structured Clinical Interview for DSM-IV diagnosis and ≤‘ ‰16 weeks of lifetime antipsychotic exposure. Participants were randomly assigned (2:1 ratio) to a recommendation of changing to RLAI versus continuing on oral therapy (ORAL). Nonadherence behavior was defined as a medication gap ≥‘ ‰14 days. Adherence attitudes were determined by the Rating of Medication Influences (ROMI) scale. A priori analysis defined treatment groups as intent-to-treat (ITT) and as-actually-treated (AAT) for the first 12 weeks after initial randomization. Participants were enrolled from December 2004 to March 2007.

Results: Of 46 eligible patients, 37 were randomly
assigned, 11 to ORAL and 26 to RLAI. Nineteen of 26 patients (73%) accepted the RLAI recommendation. There were no differences in adherence behavior at 12 weeks based on initial randomization (Kaplan-Meier survival for ITT: 76% [95% CI, 35%-90%] adherent for RLAI vs 72% [95% CI, 55%-89%] for ORAL; log-rank P‘ ‰=‘ ‰.78), but patients accepting RLAI were significantly more likely to be adherent than patients staying on ORAL (AAT: 89% [95% CI, 64%-97%] adherent for RLAI vs 59% [95% CI, 32%-78%] for ORAL; log-rank P‘ ‰=‘ ‰.035). There were no ROMI attitude differences between either treatment group comparison at 12 weeks.

Conclusions: Most first-episode patients taking
oral antipsychotics will accept a recommendation of
RLAI therapy. On the basis of initial randomization status, an RLAI recommendation did not affect adherence behavior at 12 weeks. However, acceptance of RLAI was associated with significantly better adherence. Regardless of whether RLAI is recommended or accepted, there is
no adverse impact on subsequent medication attitudes
at 12 weeks. These results support the feasibility and
acceptability of introducing RLAI as a treatment
option for first-episode schizophrenia patients.

Trial Registration: clinicaltrials.gov Identifier: NCT00220714

Submitted: April 14, 2009; accepted July 14, 2009.

Corresponding author: Peter J. Weiden, MD, Center for Cognitive Medicine, Department of Psychiatry, University of Illinois, 912 S Wood St, MC 913, Chicago, IL 60612 (pweiden@psych.uic.edu).