A recent report by Buckley et al analyzed a previous study to determine the differences in second and third relapse rates in patients receiving long-acting injectable risperidone versus an oral second-generation antipsychotic medication.3 The original study, the Preventing Relapse Oral Antipsychotics Compared to Injectables Evaluating Efficacy (PROACTIVE) study, found comparable rates of relapse and time to first relapse in patients receiving LAI and oral antipsychotics. In the analysis by Buckley et al, second and third relapse rates were also found to be similar for patients taking injectable risperidone compared to oral antipsychotics. The authors did note, however, that low relapse rates were seen in all patients in this study due to the frequent physician contact and concluded that an increased level of care itself is an effective method for relapse prevention for these patients.
In another recent study, Subotnik et al analyzed the relapse rates in patients taking long-acting injectable risperidone versus oral risperidone over 12 months.4 Results found that 5% of patients receiving injectable risperidone had a psychotic exacerbation and/or relapse compared to 33% of patients taking oral risperidone (p < 0.001). In addition, the study found use of the long-acting injectable formulation led to significantly higher medication adherence rates compared to the oral formulation. Data obtained during the analysis found that 95% of patients in the injectable risperidone group had an excellent level of adherence compared to 33% in the oral risperidone group.
Several studies have also demonstrated the superior efficacy of long-acting injectable paliperidone palmitate compared to oral antipsychotic medications.1,5 In a study by Schreiner et al, the use of injectable paliperidone was found to not only reduce relapse rates in patients with schizophrenia, but also significantly lengthened the time to relapse versus oral antipsychotics.5 Data obtained showed that 14.8% of patients receiving long-acting injectable paliperidone met the criteria for relapse compared to 20.9% of patients receiving oral antipsychotics, which signifies a 29.4% relative risk reduction. In addition, the 85th percentile for time to relapse was 469 days for patients in the injectable paliperidone group versus 249 days for patients taking oral antipsychotics.