Long-acting injectable risperidone in partially adherent and nonadherent patients with schizophrenia

Mário Rodrigues Louzã¹, Helio Elkis¹, Sandra Ruschel², Irismar Reis de Oliveira³, Rodrigo Affonseca Bressan⁴, Paulo Belmonte-de-Abreu⁵, Hamilton Grabowski⁶, José Carlos Appolinário^7
1Universidade de São Paulo, São Paulo; ²Hospital Mário Kroeff, Rio de Janeiro; ³Universidade Federal da Bahia, Salvador; ⁴Universidade Federal de São Paulo, São Paulo; ⁵Universidade Federal do Rio Grande do Sul, Porto Alegre; ⁶Hospital Bom Retiro, Curitiba; ⁷Janssen-Cilag Farmaceutica Ltda, São Paulo, Brazil

Background: Long-acting injectable antipsychotics may improve medication adherence, thereby improving overall treatment effectiveness. This study aimed to evaluate the effectiveness, safety, and tolerability of risperidone long-acting injection in schizophrenic patients switched from oral antipsychotic medication.
Methods: In a 12-month, multicenter, open-label, noncomparative study, symptomatically stable patients on oral antipsychotic medication with poor treatment adherence during the previous 12 months received intramuscular injections of risperidone long-acting injection (25 mg starting dose) every 2 weeks. The primary endpoint was the change in Positive and Negative Syndrome Scale (PANSS) total score.
Results: Of the 60 patients who were screened, 53 received at least one injection (safety population), and 51 provided at least one postbaseline assessment. Mean PANSS total scores improved significantly throughout the study and at endpoint. Significant improvements were also observed in Clinical Global Impression of Severity, Personal and Social Performance, and Drug Attitude Inventory scales. Risperidone long-acting injection was safe and well-tolerated. Severity of movement disorders on the Extrapyramidal Symptom Rating Scale was reduced significantly. The most frequently reported adverse events were insomnia (22.6%), increased prolactin (17.0%), and weight gain (13.2%).
Conclusion: Risperidone long-acting injection was associated with significant symptomatic improvements in stable patients with schizophrenia following a switch from previous antipsychotic medications.

Keywords: patient compliance, adherence, risperidone, delayed-action preparations, schizophrenia