Efficacy and safety of long-acting risperidone in elderly patients with schizophrenia and schizoaffective disorder

Background. Elderly patients are often an underserved population in terms of optimizing treatment outcomes. Long-acting risperidone, the first long-acting injectable atypical antipsychotic, can improve outcomes through continuous medication delivery. Objective. To assess the efficacy and safety of long-acting injectable risperidone in elderly patients with psychotic disorders. Methods. This is a subanalysis of 57 patients aged ≥ 65 years enrolled in an open-label study of long-acting risperidone that included 725 symptomatically stable patients with schizophrenia or schizoaffective disorder. Patients were assigned to receive 25, 50, or 75 mg of long-acting risperidone every 2 weeks for up to 50 weeks. Results. Fifty-seven elderly patients (mean ± SE age, 70.9 ± 0.7 years) were enrolled. Mean Positive and Negative Syndrome Scale (PANSS) total scores improved significantly throughout the study and at endpoint (p < 0.001). The PANSS factor scores (positive symptoms, negative symptoms, disorganized thoughts, uncontrolled hostility/excitement, and anxiety/depression) also significantly improved (p < 0.01). Clinical improvement (≥ 20% reduction in PANSS total scores) was achieved by 49% of these stable patients, and 55% improved on the Clinical Global Impressions scale. Severity of movement disorders (Extrapyramidal Symptom Rating Scale scores) was reduced significantly. Adverse events reported in >10% of patients were insomnia (14%), constipation (12%), and bronchitis (12%). Conclusions. Long-acting risperidone was associated with significant symptom improvements in stable elderly patients with schizophrenia or schizoaffective disorder. Treatment was well tolerated.