1. ¹Department of Psychiatry, National Institute of Neurology and Neurosurgery Manuel Velasco Suarez, Mexico City, Mexico
2. ²Clinical Research Division, National Institute of Psychiatry Ramón de la Fuente, Mexico City, Mexico
3. ³Child Psychiatric Hospital JN Navarro, Mexico City, Mexico
4. ⁴Carracci Medical Group, Mexico City, Mexico
5. ⁵Psychiatric Hospital Fray Bernardino Alvarez, Mexico City, Mexico
6. ⁶Department of Genomic Medicine, Mexico City University, Mexico City, Mexico
7. ⁷Schizophrenia Program and the Department of Psychiatry, University of Toronto, Toronto, ON, Canada

Correspondence: Dr R Apiquian, Department of Psychiatry, National Institute of Neurology and Neurosurgery Manuel Velasco Suarez, Av. Insurgentes Sur 3877, Mexico City, 14296 Mexico. Tel: 5255 56115822; Fax: 5255 56150067; E-mail: rogelioapiquian@yahoo.com.mx

Received 3 March 2005; Revised 3 May 2005; Accepted 4 May 2005; Published online 8 June 2005.

Abstract

Amoxapine is marketed as an antidepressant. However, its invitro profile, receptor occupancy and preclinical effects are very similar to atypical antipsychotics. Amoxapine has also shown efficacy as an atypical antipsychotic in open trials. The objective of this study was to compare the antipsychotic and side effect profile of amoxapine and risperidone in a randomised assignment, standardized dosing, double-blind trial of acutely psychotic patients with schizophrenia. A total of 48 schizophrenic patients were enrolled and randomized in a double-blind 6-week trial to receive either risperidone (up to 5 mg/day) or amoxapine (up to 250 mg/day). Positive, negative, affective symptoms and motor side effects were measured using standardized weekly assessments. Prolactin levels were also determined at baseline and at the end of the study. A total of 39 patients (amoxapine, n=22; risperidone, n=21) completed the trial. Both pharmacological treatments, amoxapine 228.0 mg/day (SD=34.6) and risperidone 4.5 mg/day (SD=0.7), showed equivalent improvement in positive, negative, and depressive symptoms. Amoxapine was associated with less EPS and less prolactin elevation than risperidone. These data support previous reports about the efficacy of amoxapine as an atypical antipsychotic. Since amoxapine is off-patent, it may be a valuable low-cost alternative to new atypical antipsychotics, particularly in low-income countries where the majority of the patients are still treated with typical antipsychotics.