An expert review of clozapine in Latin American countries: Use, monitoring, and pharmacovigilance

Abstract

There is growing interest in clozapine clinical use, monitoring, and research, particularly adverse drug reactions (ADRs) other than agranulocytosis. In this study we focused on clozapine pharmacovigilance. Hence, we contacted clinicians and researchers in Latin America and requested information about local psychiatric services, clozapine availability, clinical use, and ADR monitoring with the VigiBase system. Only two countries have the minimum recommended number of psychiatric beds (15 per 100,000 residents): Uruguay (N = 34.9) and Argentina (N = 17). Bolivia is the only country where clozapine is unavailable. Nine out of twenty countries (45 %) reported ADRs to VigiBase. Argentina, Brazil, Chile, Colombia, and Mexico published national guidelines for schizophrenia treatment. Chile is the sole country with clozapine clinics with drug serum monitoring. Ethnicity-related drug titration in not described in package inserts in any country. We examined in detail the 9 most frequent and important clozapine ADRs in the worldwide database (pneumonia, sudden death, cardiac arrest, agranulocytosis, myocarditis, constipation, arrhythmia, seizure, and syncope). These 9 ADRs led to 294 reports with fatal outcomes in Argentina (N = 3), Brazil (N = 3), Chile (N = 2), and Peru (N = 1). Agranulocytosis was reported from 7 countries: constipation or seizures from 8 countries. Only two countries reported pneumonia and one country reported myocarditis. The number of clozapine reports in VigiBase has no relationship to the country's population. All Latin American countries underreport clozapine associated ADRs. Latin American governments, along with clinicians, researchers, and educators, should optimize clozapine use and monitoring for the benefit of people with severe mental and some neurological disorders.

Keywords: Adverse effects; Antipsychotic agents; Clozapine; Hospitals; Pharmacovigilance; Risk assessment.