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30 April 2021

Postcode lottery access to schizophrenia drug puts patients at risk

Two in three treatment-resistant schizophrenia patients could be missing out.

Pot of prescription drugs knocked over with tablets spilling out

Researchers at King’s College London’s Institute of Psychiatry, Psychology & Neuroscience and South London & Maudsley NHS Foundation Trust have shown that overall, only a third of eligible patients are being prescribed Clozapine, an antipsychotic drug known to reduce suicidal behaviour in patients with treatment-resistant schizophrenia. The study, published in Acta Psychiatrica Scandinavica also showed that there is substantial variation in clozapine prescribing across different regions of England and the rate of clozapine per population is lower in England than other parts of the UK.

Clozapine is the only licensed treatment available for treatment resistant schizophrenia. Despite this, it remains grossly underused relative to the number of people diagnosed with this condition. This is the first study to look at the extent of underuse and the degree of regional variation in prescribing in the United Kingdom.

Patients need to be confident that they can get a consistent level of care, regardless of where they live. That’s why it is crucial that clinicians take on board the findings from this study when making decisions about whether to prescribe clozapine for their treatment-resistant schizophrenia.

Prof Sukhi Shergill, Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, Kings College London

It is estimated that a third of patients with schizophrenia are treatment resistant. The estimated prevalence of schizophrenia across all ages in the UK is 0.7% (NICE). Based on the 2018 adult population, there are 377,000 people living with schizophrenia in the UK. From this figure, the projected number of patients with treatment resistant schizophrenia is 125,000. These results show that less than a third of potentially eligible patients currently receive clozapine in the UK and there is a three-fold variation in the rates of clozapine prescribing across England.

The team compared the overall clozapine prescribing rate in the UK with other European countries.  Given that clozapine use has increased over the decade, the UK figures from 2019 is still substantially lower than countries like Finland, Netherlands and Iceland, but may be higher than countries like Italy, France and Spain.

Some of the barriers to appropriate prescribing by clinicians include prescribers’ knowledge, views, attitudes and experience which constituted a major factor in the variation and underuse of clozapine.

Surveys of prescribers have consistently demonstrated a lack of confidence or expertise in clozapine prescribing, negative perceptions, insufficient knowledge about its adverse effects and their management, as key limiting factors in limiting prescribing, and consequently, increased preference for less evidence based prescribing of other antipsychotics in high dose and combinations.

There is clear regional inequity in access to the most effective treatment in schizophrenia in England. Strategies to increase clozapine use, by overcoming both real and perceived barriers, are urgently necessary to reduce treatment inequity for patients with treatment-resistant schizophrenia.

Corresponding author Mr Eromona Whiskey, Pharmacy Department, South London & Maudsley NHS Foundation Trust

An evaluation of the variation and underuse of clozapine in the United Kingdom ( Eromona Whiskey, Alex Barnard, Ebenezer Oloyede, Olubanke Dzahini, David M. Taylor, Sukhwinder S. Shergill was published in Acta Psychiatrica Scandinavica

For further information please contact Patrick O’Brien, Senior Media Officer at the Institute of Psychiatry, Psychology & Neuroscience, King's College London

In this story

Sukhwinder Shergill

Professor of Psychiatry & Systems Neuroscience