Trends in the prescription of clozapine in a psychiatric hospital: a 5-year observational study

Abstract

Introduction Clozapine is a well-recognized effective treatment for some patients with treatment-resistant schizophrenia (TRS). Although it has potential benefits and approximately 30% of patients have a clinical indication for clozapine use, prescription rates are low. Objective To evaluate clozapine prescription trends over a 5-year period in a tertiary psychiatric hospital. Methods In this observational study, data prospectively collected by the Medical and Statistical File Service (Serviço de Arquivo Médico e Estatístico) and the Pharmacy Division of Instituto de Psiquiatria de Santa Catarina between January 2010 and December 2014 were summarized and analyzed by investigators blinded to data collection. The number of 100 mg clozapine pills dispensed by the Pharmacy Division to the inpatient units was the outcome and considered a proxy measure of clozapine prescriptions. The number of occupied inpatient unit beds and the number of patients admitted with F20-F29 (ICD-10) diagnoses during the study period were considered to be possible confounders. Results A multiple linear regression model showed that time in months was independently associated with an increase in the number of clozapine pills dispensed by the Pharmacy Division (β coefficient = 15.82; 95% confidence interval 10.88-20.75). Conclusion Clozapine prescriptions were found to have increased during the 5-year period studied, a trend that is opposite to reports from several other countries.

Safety of antipsychotics for the treatment of schizophrenia: a focus on the adverse effects of clozapine

“…However, regardless of the evidence, clozapine is still underprescribed or utilized too late and this may be due to, but not limited to, blood monitoring because it is often tedious for the patients, 129 and the psychiatrists' fear of severe adverse effects. 232,233 Some psychiatrists do not prescribe clozapine when required as they are anxious about its management and perceive a lack of knowledge and a negative attitude toward this drug. 234,235 Such discomfort with clozapine is a major cause of concern that the patients will pay in terms of a lack of a therapeutic possibility and, therefore, efforts should be made to overcome this.…”

“…However, regardless of the evidence, clozapine is still underprescribed or utilized too late and this may be due to, but not limited to, blood monitoring because it is often tedious for the patients, 129 and the psychiatrists’ fear of severe adverse effects. 232,233…”

Focus on Clozapine Withdrawal- and Misuse-Related Cases as Reported to the European Medicines Agency (EMA) Pharmacovigilance Database

“…Clozapine ADRs of interest showed a peak in 2008, but an overall increase was observed between 2010 and 2018. One could argue that this upward trend may have been associated with a range of factors, including the increasing rates of worldwide availability of clozapine due to an overwhelming evidence of its effectiveness [2,[49][50][51] and/or a major awareness of the relevant and significant impact of pharmacovigilance processes and issues, resulting in a rise of spontaneous reporting practices related to safety monitoring of medicinal products in general [52].…”