Implications of the CATIE Trial on Treatment: Extrapyramidal Symptoms

Abstract

Development of extrapyramidal symptoms (EPS), particularly tardive dyskinesia (TD), has long been a troubling side effect for patients taking antipsychotics. Atypical antipsychotics have been hailed as an improvement over conventional antipsychotics, offering similar efficacy with more favorable EPS profiles. In the recent Clinical Antipsychotic Trials of Intervention Effectiveness (CATIE) study, which compared the conventional antipsychotic perphenazine with atypical antipsychotics olanzapine, quetiapine, risperidone, and ziprasidone in patients with schizophrenia, no significant differences in time to treatment discontinuation due to intolerability were observed between treatment groups. However, perphenazine was associated with a higher rate of patients experiencing EPS as well as a significantly higher rate of discontinuation due to EPS, despite the fact that patients with TD at baseline were excluded from the perphenazine group. Unfortunately, due to short treatment duration, the CATIE study did not have the assay sensitivity to detect differences in TD risk among any of the drugs. Thus, the atypical antipsychotics remain the first line of treatment for most patients, with specific drug selection based on benefit-risk profiles that best fit the individual patient's needs. Frequent monitoring, while noting a patient's subjective experience, remains the best strategy for choosing therapy to maximize symptom relief and minimize the impact of EPS and other side effects over the long- term. This article explores the reported results of the CATIE trial regarding EPS and emphasizes the differentiation of the atypicals from perphenazine on EPS and how these results should be incorporated into daily practice for the clinician.