Treatment of Patients with Recently Exacerbated Schizophrenia with Paliperidone Palmitate: A Pilot Study of Efficacy and Tolerability

Background: Paliperidone palmitate is a long-acting, second-generation antipsychotic (SGA) indicated for the treatment of acute exacerbations and maintenance treatment of adults with schizophrenia. This study addressed the response to paliperidone palmitate in Latin American patients with acute symptoms and recently diagnosed schizophrenia. Objective: Explore the efficacy and tolerability of paliperidone palmitate administered once a month for 4 months in patients with acute phase and recent diagnosis (within 1-6 years) of schizophrenia in 3 Latin American countries. Methods: This was a non-randomized, open-label, multicenter study with paliperidone palmitate injected intramuscularly in the deltoid muscle at an initial loading dose of 150 mg eq. (234 mg) on day 1 and 100 mg eq. (156 mg) on day 8 (+/- 4 days). The recommended maintenance dose was 75 mg eq. (117 mg) from day 36 to day 92. Efficacy was evaluated with PANSS and CGI-S. The last observation carried forward (LOCF) was used for efficacy analysis for imputation of missing data; no adjustments were made for multiplicity. Adverse events were evaluated during treatment. Results: The patient retention rate was 84.0% (144 patients received study drug; 121 finished the study). The percentage of patients with a reduction of at least 30% in PANSS total score compared to baseline gradually increased during the study, and at the end, 78.4% of patients showed response. The PANSS total score and CGI-S scores decreased significantly from baseline to LOCF endpoint (P <0.0001 for both); significant reduction in PANSS total score was observed at day 8 and persisted to the end of the study. Most common adverse events were muscle rigidity (11.8%), akathisia (11.1%), injection-site pain (7.6%), weight gain (7.6%), and insomnia (7.6%). Conclusion: Paliperidone palmitate was efficacious in Latin American patients studied with an acute exacerbation and recent diagnosis of schizophrenia, and no new safety signals were identified.