An evaluation of the variation and underuse of clozapine in the United Kingdom

Abstract

Despite its unique effectiveness in treating refractory schizophrenia, substantial evidence indicates gross underuse of clozapine. 1,2 Aligned with the underuse is a demonstrable international variation in use of the drug. 3 Widespread geographical variation in usage has been reported in the United States, 4 Canada, 5 Middle East, 6 Europe 7 and the United Kingdom. 8 The factors responsible for the underuse of clozapine are numerous, varied and often interconnected; these can be separated into four key domains relating to the drug itself, the prescribers, the patients and associated infrastructure and regulatory processes. Clozapine causes neutropenia in about (3%) 9 of patients and the more severe agranulocytosis in (0.4%) 10 in treated patients. Haematological monitoring is therefore

Maintenance Therapy of Psychosis Spectrum Disorders in a Real-World Setting: Antipsychotics Prescription Patterns and Long-Term Benzodiazepine Use

“…97.5%, respectively) ( 39 ). On the contrary, the utilization of clozapine in the present sample was higher in comparison to the U.S. ( 40 ) or the UK ( 41 ) suggesting low levels of “clozaphobia” ( 42 ) in the Western Balkans. Clozapine is not an expensive drug, blood monitoring is fully covered by the national health insurance and dispensing requirements for it are less restrictive in comparison to the western countries, which might have impact on its prescribing and wider usage.…”

Clozapine-induced gastrointestinal hypomotility: presenting features and outcomes, UK pharmacovigilance reports, 1992–2017

“…11 In the UK in November 2019 there were 37 301 patients under treatment with clozapine. 21 In 2017 there were 61 ADR reports of potentially harmful CIGH with a case-fatality rate of 20% (Table 1). Taking the 2019 figure of patients prescribed clozapine this gives an incidence of potentially dangerous CIGH of 1.6 per 1000 suggesting incomplete reporting of non-fatal cases.…”

Benign ethnic neutropenia: an analysis of prevalence, timing and identification accuracy in two large inner-city NHS hospitals

“…For example, SLaM hosts several specialist services, including the National Psychosis Service, a tertiary referral service with a special interest in clozapine rechallenge for whom this is deemed to be safe, often in close liaison with other medical specialities such as haematology [27]. Recent geographical data has demonstrated a substantial variation in clozapine prescription rates in the UK, with suggestions for a national training programme for clinicians and the implementation of a 'Hub and Spoke' model to improve clozapine management practices [28][29][30][31].. While tentative, our data suggests that this variability in practice may also be present with the identification of BEN in those receiving clozapine treatment.…”

“…Nevertheless, this estimate is likely to be confounded by other differentials such as BEN [19]. In the second half of the twentieth century, neutropenia was defined as an ANC value less than 1500/μL in individuals after the age of one [28], statistically determined as two standard deviations below the population mean at the time [27]. However, this classification system was originally developed in a largely Caucasian population and has consequently been recognised to preclude those with haematological variants such as BEN [27,37].…”