成人大片

Clozapine is used to treat schizophrenia when other antipsychotic medicines either have not worked or have caused severe side effects, and these findings could improve access to the drug and outcomes for patients.

鈥淕enerally prescribed for treatment-resistant schizophrenia, clozapine can interfere with the production of neutrophils, a kind of white blood cell, leaving people dangerously vulnerable to infection in the first month or so after starting the drug,鈥� said Dr Korinne Northwood, from UQ鈥檚 Faculty of Medicine.

People taking clozapine are currently required to have weekly blood tests for the first 18 weeks, then monthly tests for as long as they are on the medication.

In this study, which analysed historical data from 26,630 people taking clozapine across Australia and New Zealand, researchers found 313 in the cohort who had to stop taking the antipsychotic because of seriously low neutrophil levels.

The overwhelming majority of those incidences were seen within the first 18 weeks of a patient taking the drug.

鈥淲e 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,鈥� Dr Northwood said.

Professor Dan Siskind, from UQ鈥檚 Faculty of Medicine explained that the drug effectively reduced hospitalisations and mortality for the third of people with schizophrenia who are treatment resistant.

鈥淐lozapine 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,鈥� he said.

Professor Siskind says clozapine is under-prescribed globally, possibly due in part to fear among clinicians of the risks and the burden of lifelong monitoring on patients.

鈥淲e hope this study will provide the basis for a change in practice, making clozapine more accessible to those who need it and improving the lives of people on the drug,鈥� he said.

The 成人大片 worked closely with UQ and in partnership with pharmaceutical company Viatris to develop the analysis protocol and secure access to large scale data.

Associate Professor Scott Clark, head of the 成人大片鈥檚 Discipline of Psychiatry, described the study鈥檚 dataset as internationally unique.

鈥淚t represents one of the largest longitudinal analyses of neutropenia in clozapine treatment,鈥� he said.

鈥淭he 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.鈥�

Associate Professor Clark hopes to dig further into the dataset to assess other risks associated with clozapine use.

鈥淲e will focus next on the timing and rates of clozapine-associated myocarditis based on three of our own recent papers suggesting risk is elevated in South Australia,鈥� he said.

鈥淒ue to the sensitivity of current monitoring protocols the rates of serious myocarditis may also be over reported, but recent evidence also suggests personalised titration may reduce risk.鈥�

The research, which also involved the Queensland Centre for Mental Health Research, is published in .