The Use of Long-Acting Injectable Antipsychotics in Schizophrenia

Schizophrenia is a mostly chronic mental disorder, and symptomatic relapse is frequently observed. It is often associated with social and/or occupational decline that can be difficult to reverse. Most patients with the illness need long-term pharmacological treatment, and antipsychotic drugs represent the mainstay of clinical care. Long-acting injectable antipsychotics (LAIs) are an important alternative to oral medication, particularly advantageous in the context of compliance management. Several new-generation antipsychotics (NGAs), including risperidone, olanzapine, paliperidone, and aripiprazole, have become available as long-acting formulations, and new evidence has been accumulating. To date, all of the NGA LAIs have demonstrated a statistically and clinically significant decrease of relapse rates over placebo. The results of clinical trials comparing NGA LAIs with oral antipsychotics (OAPs) are not consistent, as being influenced considerably by study design. Superiority of LAIs to OAPs in efficacy is most evident in mirror image and cohort studies. New-generation LAIs are comparable to their oral mother compounds regarding safety and tolerability if one disregards potential injection site complications. There is little evidence of efficacy differences between the available LAIs, but they have different characteristics in terms of pharmacodynamic and pharmacokinetic profiles, injection interval, cost, requirements for oral supplementation, as well as adverse events. Considering these differences is useful for selecting LAIs for the treatment of individual patients. There is increasing evidence suggesting the use of LAIs in special patient groups, such as first-episode or forensic schizophrenia patients. This article reviews data on the use of NGA LAIs in schizophrenia and discusses current issues from clinical and methodological perspectives.