Effectiveness of 2-year treatment with aripiprazole long-acting injectable and comparison with paliperidone palmitate

Background: The pragmatic management of psychotic disorders is more complex than that delivered in a controlled trial environment. Therefore, this study aims to evaluate the real-world effectiveness of aripiprazole long-acting injectable (ALAI) and compare it with another commonly used long-acting anti-psychotic, once-monthly paliperidone palmitate (PP1M). Methods: This naturalistic, independent 4-year mirror image study compared the mean number and length of hospital admissions 2 years before and 2 years after treatment initiation with ALAI. Retention rates, discontinuation reasons and level of adherence were also recorded. Furthermore, indirect comparisons were made between treatment outcomes on ALAI and PP1M. Results: A total of 109 eligible patients with a severe mental illness (65% with schizophrenia and 35% with other diagnosis) commenced on ALAI and 173 patients (69% with schizophrenia and 31% with other diagnoses) initiated on PP1M were included. Of these, 37% on ALAI and 34% on PP1M stopped treatment at 2 years; retention rates were most favourable for the schizophrenia group on PP1M. Patients were more likely to discontinue due to lack of effectiveness on ALAI and due to tolerability issues on PP1M. Those who continued for 2 years on ALAI ( n = 69), demonstrated an overall decrease of 84% in the mean number and 88% in the mean length of hospital admissions compared with the 2 years before initiation. Although patients on ALAI appeared to have a significantly higher bed occupancy the 2-year period before initiation than patients on PP1M, the reductions in hospitalizations were comparable across both cohorts after 2 years of treatment. Conclusions: The introduction of ALAI had a substantial impact on long-term clinical outcomes in this naturalistic cohort; more than half of patients continued treatment and had no admission during 2 years of follow up. There were no significant differences in hospitalisation rates between patients on ALAI and PP1M at 2 years.