Efficacy, tolerability, and safety of oral paliperidone extended release in the treatment of schizophrenia: a 24-week, open-label, prospective switch study in different settings in Taiwan

Purpose: Paliperidone extended release (ER) is an oral psychotropic treatment formulated to release paliperidone at a controlled, gradually ascending rate. We evaluated the efficacy and safety of switching to paliperidone ER in Taiwanese patients with schizophrenia who were unresponsive or intolerant to previous antipsychotic therapy. Patients and methods: This was a 24-week, open-label, single-arm, multicenter, Phase IV trial. Based on consulting psychiatrists' judgment, patients were deemed eligible for the switch to paliperidone ER; the switch was achieved by cross-tapering, using a recommended starting dose of 6 mg. Eligibility considerations included lack of efficacy, tolerability, and/or adherence to previous oral antipsychotic medication. Results: Of the 297 enrolled patients, 178 (59.5%) completed the study. The main reasons for discontinuation included insufficient efficacy (8.7%), patient decision (8.4%), and adverse events (AEs; 6.4%). Improvements in the: Positive and Negative Syndrome Scale total score and Clinical Global Impression-Severity score were observed only in patients treated at medical centers and not in those treated at psychiatric hospitals. The most common AEs were insomnia, headache, constipation, and extrapyramidal syndrome. One or more serious AEs were reported in 11 (3.7%) patients; none resulted in death. No significant changes in body weight, plasma glucose, or lipid levels were observed. Conclusion: Switching to paliperidone ER was effective and well tolerated for up to 24 weeks in patients with schizophrenia who were unresponsive or intolerant to previous antipsychotic therapy. The observed differences in treatment between psychiatric hospitals and medical centers with regard to dosage and titration of paliperidone ER warrant further investigation.