Second-generation long-acting injectable antipsychotics in schizophrenia: patient functioning and quality of life

Long-acting injectable antipsychotics (LAIs) were developed to make treatment easier, improve adherence, and/or signal the clinician when nonadherence occurs. Second-generation antipsychotic LAIs (SGA-LAIs) combine the advantages of SGA with a long-acting formulation. The purpose of this review is to evaluate the available literature concerning the impact of SGA-LAIs on patient functioning and quality of life (QOL). Although several studies regarding schizophrenia patients' functioning and QOL have been performed, the quantity of available data still varies greatly depending on the SGA-LAI under investigation. After reviewing the literature, it seems that SGA-LAIs are effective in ameliorating patient functioning and/or QOL of patients with schizophrenia, as compared with placebo. However, while methodological design controversy exists regarding the superiority of risperidone LAI versus oral antipsychotics, the significant amount of evidence in recently published research demonstrates the beneficial influence of risperidone LAI on patient functioning and QOL in stable patients and no benefit over oral treatment in unstable patients. However, the status of the research on SGA-LAIs is lacking in several aspects that may help physicians in choosing the correct drug therapy. Meaningful differences have been observed between SGA-LAIs in the onset of their clinical efficacy and in the relationships between symptoms and functioning scores. Moreover, head-to-head studies comparing the effects of SGA-LAIs on classical measures of psychopathology and functioning are available mainly on risperidone LAI, while those comparing olanzapine LAI with other SGA-LAIs are still lacking. Lastly, some data on their use, especially in first-episode or recent-onset schizophrenia and in refractory or treatment-resistant schizophrenia, is available.