The effects of concurrent oral paliperidone or risperidone use with paliperidone long-acting injection.

Introduction: Dosing recommendations for paliperidone long-acting injectable antipsychotic (LAIA) do not include oral antipsychotic (OAP) overlap; however, OAPs are often given concurrently despite limited evidence describing both the risks and benefits of this practice.

Methods: A retrospective chart review was conducted in patients initiated on paliperidone palmitate (PP) during a psychiatric hospitalization to compare patients who received OAP overlap versus those who did not. The primary outcome is the proportion of patients who receive prescription claims for benztropine, a medication commonly prescribed for extrapyramidal symptoms, at the time of LAIA discontinuation and 6 months postdischarge. Secondary outcomes include prescription claims for beta blockers and diphenhydramine, number of psychiatric emergency visits and hospitalizations, length of stay of the index hospitalization, frequency of LAIA discontinuation and the time to LAIA discontinuation.

Results: There is a significant difference in the proportion of benztropine prescription claims in the OAP overlap group versus the no-overlap group at the time of LAIA discontinuation (30% vs 0%,  = .046) but not at 6 months postdischarge. There are also significant differences in the number of psychiatric emergency visits (0.7 vs 0.1,  = .02) and psychiatric hospitalizations (0.6 vs 0.1,  = .029) at the time of LAIA discontinuation. No other differences are observed in defined secondary outcomes.

Discussion: Patients who receive OAP overlap while receiving PP receive more benztropine and have more psychiatric emergency visits and hospitalizations than those treated without OAP. Larger studies with better control for confounding variables are needed to confirm these results.