Psychopharmacology of Atypical Antipsychotics and Clinical Outcomes in Elderly Patients

The differential effects of receptor blockade on the clinical efficacy and safety of atypical antipsychotics are reviewed. Studies of both clozapine and risperidone in geriatric patients have been published. Clozapine appears to have a greater side effect burden than risperidone. No studies of olanzapine or quetiapine in the elderly have been published. In a recent double-blind study, 625 patients with Alzheimer’s disease, vascular dementia, or mixed dementia were randomly assigned to receive risperidone (0.5, 1, or 2 mg/day) or placebo for 12 weeks. Risperidone was found to be significantly more effective than placebo in reducing psychotic symptoms and the severity and frequency of aggressiveness. The optimal dose of risperidone in terms of both efficacy and safety was 1 mg/day. In an open-label trial, 103 elderly patients with a diagnosis of schizophrenia or schizoaffective disorder received risperidone for 12 weeks. The mean risperidone dose was 2.4 mg/day. Clinical improvement (20% reduction in Positive and Negative Syndrome Scale [PANSS] total scores) was seen in 50%; the severity of positive and negative symptoms (PANSS positive and negative scores) was significantly improved, and the frequency of extrapyramidal symptoms was significantly reduced. It is concluded that risperidone is efficacious and safe in the treatment of elderly patients with dementia or psychoses.