Characteristics of people on long-acting injectable antipsychotics in Australia: Data from the 2010 National Survey of High Impact Psychosis

Abstract

Objective: This study investigates (1) the proportion of people with psychosis who are on long-acting injectable antipsychotics; (2) the difference in the demographic, clinical, substance use and adverse drug reaction profiles of people taking long-acting injectables compared to oral antipsychotics; and (3) the differences in the same profiles of those on first-generation antipsychotic versus second-generation antipsychotic long-acting injectables. Methods: Data were collected as part of the Survey of High Impact Psychosis. For this study, participants with diagnoses of schizophrenia or schizoaffective disorder who were on any antipsychotic medication were included (N\u2009=\u20091049). Results: Nearly a third (31.5%) of people with psychosis were on long-acting injectables, of whom 49.7% were on first-generation antipsychotic long-acting injectables and 47.9% were on second-generation antipsychotic long-acting injectables. This contrasts with oral antipsychotics where there was a higher utilisation of second-generation antipsychotics (86.3%). Of note, compared to those on the oral formulation, people on long-acting injectables were almost four times more likely to be under a community treatment order. Furthermore, people on long-acting injectables were more likely to have a longer duration of illness, reduced degree of insight, increased cognitive impairment as well as poor personal and social functioning. They also reported more adverse drug reactions. Compared to those on first-generation antipsychotic long-acting injectables, people on SGA long-acting injectables were younger and had had a shorter duration of illness. They were also more likely to experience dizziness and increased weight, but less likely to experience muscle stiffness or tenseness. Conclusion: Long-acting injectable use in Australia is associated with higher rates of community treatment order use, as well as poorer insight, personal and social performance, and greater cognitive impairment. While long-acting injectables may have the potential to improve the prognosis of people with psychosis, a better understanding of the choices behind the utilisation of long-acting injectable treatment in Australia is urgently needed.