Health, Australia (Commonwealth Union) – A recent research collaboration between the University of Queensland and experts from the University of Adelaide has yielded significant insights into the usage of the antipsychotic drug clozapine. The study suggests that individuals utilizing clozapine may not require regular blood monitoring beyond the initial two years of treatment.
Researchers of the study point out that Clozapine is commonly prescribed for individuals with treatment-resistant schizophrenia, particularly when other antipsychotic medications have proven ineffective or led to severe side effects. An inherent challenge with clozapine usage is its potential impact on the production of neutrophils, a type of white blood cell crucial for immune function. This interference can leave individuals vulnerable to infections, particularly in the initial stages of drug administration.
Traditionally, individuals prescribed clozapine undergo a stringent monitoring regimen, including weekly blood tests for the first 18 weeks and subsequent monthly tests for the duration of their medication usage. However, this new study, drawing on historical data from 26,630 clozapine users in Australia and New Zealand, challenges the necessity of prolonged and frequent monitoring.
The research identified 313 individuals within the cohort who had to discontinue clozapine due to significantly low neutrophil levels. Notably, the majority of these instances occurred within the initial 18 weeks of commencing the medication. After analyzing the data, the researchers observed a notable decline in the occurrence of severely low neutrophil levels after individuals had been on clozapine for two years.
Dr. Korinne Northwood, from UQ’s Faculty of Medicine, highlighted the key findings, indicating that, they found that once people had taken clozapine for 2 years, the rate of someone experiencing seriously low neutrophils was just 0.001 per cent per week.
Professor Dan Siskind, also from UQ’s Faculty of Medicine, emphasized the positive impact of clozapine on reducing hospitalizations and mortality rates among the one-third of individuals with schizophrenia who are resistant to conventional treatments. These findings could potentially revolutionize the approach to clozapine treatment, improving accessibility and outcomes for patients grappling with treatment-resistant schizophrenia.
“Clozapine is a necessary, lifesaving medication for many people, but the weekly and then monthly blood testing which is currently mandated presents a burden to consumers,” he said.
According to Professor Siskind, there is a global trend of under-prescribing clozapine, potentially influenced by clinicians’ apprehension about associated risks and the lifelong monitoring burden imposed on patients.
The expectation is that this research could serve as a catalyst for a shift in medical practices, making clozapine more readily available to those who could benefit from it and enhancing the quality of life for individuals undergoing this treatment, Professor Siskind emphasized.
The collaborative effort between the University of Adelaide, the University of Queensland, and pharmaceutical company Viatris was instrumental in formulating the analysis protocol and gaining access to extensive datasets. Associate Professor Scott Clark, heading the University of Adelaide’s Discipline of Psychiatry, highlighted the uniqueness of the study’s dataset on an international scale.
Describing it as one of the most extensive longitudinal analyses of neutropenia in clozapine treatment, Associate Professor Clark underscored the significance of the research which can contribute to a better understanding of the drug’s long-term effects and guiding future medical practices.
“The analysis plan is novel in that we were able to separate the low- and high-risk cases of neutropenia to identify that high risk was negligible after two years. This is critical for determining safety.”
Associate Professor Clark expresses the intention to delve deeper into the dataset to explore additional risks linked to the use of clozapine.
His upcoming focus involves examining the timing and rates of clozapine-associated myocarditis, building on insights from three recent papers that indicate an elevated risk in South Australia.
