Dosing strategies for switching from oral risperidone to paliperidone palmitate: Effects on clinical outcomes

Introduction: There are currently no guidelines for switching patients from oral risperidone to paliperidone palmitate (Invega Sustenna®). Furthermore, the paliperidone long-acting injectable (LAI) package insert does not recommend bridging with oral antipsychotics, which may result in inadequate serum concentrations in patients on ≥4 mg/d risperidone. Methods: This study evaluated the effects of suboptimal dosing and bridging in patients switched from oral risperidone to paliperidone LAI on hospitalization days, emergency department (ED)/mental health urgent care visits, and no-shows/cancellations to mental health appointments. Patients were categorized into optimal or suboptimal dosing based on their loading and maintenance paliperidone doses. Patients on risperidone ≥4 mg/d were categorized as bridged if they received risperidone for ≥7 days after the first paliperidone injection. Results: There were no significant differences in outcomes between optimally and suboptimally dosed patients. There were statistically significant reductions in hospitalization days in patients who were bridged compared with patients who were not bridged. There were statistically significant reductions in hospitalization days and ED/mental health urgent care visits after switching to paliperidone LAI. Discussion: The results of this study indicate that bridging patients who are on ≥4 mg/d risperidone, when converting to paliperidone LAI, is associated with reductions in hospitalization days. However, more research is required to determine the optimal dose and duration of the bridge. The results also indicate that switching patients from oral risperidone to paliperidone LAI, even if the dose is suboptimal, is associated with reductions in hospitalization days and ED/mental health urgent care visits.