A review of compliance, depot intramuscular antipsychotics and the new long-acting injectable atypical antipsychotic risperidone in schizophrenia.

Background: Several oral atypical antipsychotics are available for schizophrenia management. Besides positive and negative symptom control, they may improve cognition. Due to their limited availability as oral agents only, benefits are limited by noncompliance.

Methods: Using Medline and PsycINFO databases, literature was reviewed to address: (1) factors underlying medication noncompliance; (2) available evidence on efficacy of depot intramuscular (IM) typical antipsychotics; and (3) current knowledge of long-acting atypicals.

Results: Noncompliance remains high due to illness-, treatment-, and clinician-related factors. Compared to oral typicals, atypicals may improve compliance, even though noncompliance remains high. Depot IM typicals are efficacious (reduced relapses and rehospitalizations), but extrapyramidal symptoms are problematic. Available data on long-acting atypical risperidone suggest that it is safe and efficacious.

Conclusion: Development of long-acting injectable atypical agents is warranted since noncompliance remains high. Future long-acting IM atypical trials should include outpatient functioning, and preferably be of longer duration to address cost-effectiveness.