Comparative effectiveness and safety of antipsychotic drugs in patients with schizophrenia initiating or reinitiating treatment: A Real-World Observational Study

Safety outcomes of antipsychotics classes in drug-naïve patients with first-episode schizophrenia: A nationwide cohort study in South Korea

INTRODUCTION

Given the similar efficacies across antipsychotic medications for schizophrenia, understanding their safety profiles, particularly concerning receptor-binding differences, is crucial for optimal drug selection, especially for patients with first episode schizophrenia. We aimed to compare the safety outcomes of second-generation antipsychotics.

METHODS

We conducted a retrospective cohort study with new user active comparator design using a nationwide claims database in South Korea. Participants were drug-naïve adult patients with first-episode schizophrenia. Three representative drugs with different pharmacologic profiles were compared: risperidone, olanzapine, and aripiprazole. Propensity scores were used to match the study groups, and the Cox proportional hazard model was used to calculate hazard ratios. Sensitivity analyses were performed in various epidemiological settings. Seventeen safety outcomes, including neuropsychiatric, cardiometabolic and gastrointestinal events, were assessed, with upper-respiratory-tract infection as a negative control outcome.

RESULTS

A total of 1044, 2078, and 3634 participants were matched for olanzapine vs. risperidone, olanzapine vs. aripiprazole, and risperidone vs. aripiprazole comparisons, respectively. For parkinsonism, there was a significant difference in outcomes between the risperidone and aripiprazole groups (HR 1.80 [95% CI 1.13-2.91]), with consistent sensitivity analysis results. There were no significant differences in other neuropsychiatry outcomes or in the risk of cardiometabolic and gastrointestinal outcomes between any of the comparative group pairs.

CONCLUSIONS

The risk of drug-induced parkinsonism was significantly higher with risperidone than with aripiprazole. Although olanzapine is known for its metabolic risk, there were no significant differences in risk between the other pairs.

Short communication: Prevalence of long-acting injectable antipsychotic use in Canadian early intervention services for psychosis

The use of long-acting injectable (LAI) antipsychotic drugs for psychotic disorders in Canada has been historically low compared to other jurisdictions despite advantages of LAIs in improving medication adherence and preventing relapse. In response, treatment recommendations were developed in 2013 by the Canadian Consortium for Early Intervention in Psychosis and other Canadian provincial expert groups. The impact of these guidelines needed to be assessed. To document practices in LAI use in early intervention services (EIS) for psychosis, Canadian EIS were surveyed in 2016 (n = 18) and 2020 (n = 12). Trends and descriptive information were examined using repeated cross-sectional survey data. Eight EIS responded to surveys at both time points allowing for longitudinal comparisons. Outcomes of interest included i) LAI use frequency, ii) timing of LAI starts, and iii) factors influencing LAI use. Cross-sectional analysis identified a significant increase in overall LAI usage (24.7% in 2016; 35.1% in 2020). Longitudinal analysis indicated that patients in the second program year saw the greatest increase in LAI use between 2016 and 2020 (25.6% vs. 36.1%), especially among patients under community treatment orders (65.5% vs. 81.5%). Results support increases in LAI use over time, accessibility, awareness, and increasing comfortability among Canadian clinicians.

Real-life effectiveness of transitioning from paliperidone palmitate 1-monthly to paliperidone palmitate 3-monthly long-acting injectable formulation

BACKGROUND

Non-adherence to antipsychotics in schizophrenia is associated with an increased risk of psychotic relapse and hospitalization, a risk that is reduced with the use of long-acting injectable (LAI) antipsychotics. Randomized clinical trials (RCTs) have demonstrated the efficacy of paliperidone palmitate 3-monthly (PP3M) for psychotic relapse prevention in schizophrenia, but it remains poorly documented among individuals treated in real-life settings who can benefit the most out of LAIs.

OBJECTIVES

The objective of this study was to evaluate the effectiveness of PP3M in relapse prevention among patients with schizophrenia.

METHODS

This is a multicentre retrospective study conducted in four outpatients' clinics across Canada. All consecutive patients with a main diagnosis of schizophrenia who initiated PP3M between June 2016 and March 2020 were included. The primary outcome was psychotic relapse, defined using broad and clinically relevant criteria.

RESULTS

Among 178 consecutive patients who were switched to PP3M, the 12-month relapse rate was 18.5% and the relapse-free survival probability was 0.788 (95% confidence interval [CI] = 0.725-0.856). Comorbid diagnoses of personality disorders and substance use disorders were associated with hazard rates (HRs) of 3.6 (95% CI = 1.8-7.3, p < 0.001) and 3.1 (95% CI = 1.6-6.2), respectively. Increased psychopathology severity was associated with an increased likelihood of relapse, while having a job or being in school was protective.

CONCLUSION

These findings reinforce the necessity of conducting research in patients with comorbid psychiatric disorders who are typically underrepresented in RCTs, yet overrepresented in real-life settings, in order to better inform and guide clinical practice.