Safety and efficacy of long-acting injectable risperidone in patients with schizophrenia spectrum disorders: a 6-month open-label trial in Asian patients

Abstract

The study aimed to evaluate the efficacy of long-acting injectable risperidone (LAR) in Asian patients with schizophrenia spectrum disorders. Twenty-five patients enrolled in this 6-month open labelled study. They were switched from their current antipsychotic to LAR without a prior oral risperidone run-in phase. Efficacy was assessed by the positive and negative syndrome scale (PANSS) and clinical global impression (CGI) scales. Extra-pyramidal side effects (EPSE) was assessed using the Simpson Angus Scale (SAS), and weight and plasma levels of fasting blood glucose, lipids and prolactin were measured. Baseline and last visits differences were tested by paired t-test and Wilcoxon signed-rank test; ratings measured over time were analysed using repeated measures ANOVA. Participants' mean age was 30.3 (+/-6.6) years. Principal reason for switching to LAR was non-compliance (40.0%). Thirteen (52%) patients completed the trial. Over 6 months, there were significant reductions in total PANSS (p = 0.008) and CGI (p = 0.001) scores. There were significant increases in weight (p < 0.001), levels of plasma cholesterol and fasting glucose. LAR was effective in improving symptom severity within the first month of starting treatment. However, significant increases in weight and plasma levels of fasting glucose and cholesterol raise concern about metabolic side effects.