Clozapine use – has practice changed?

Abstract

Background: One-third of individuals with schizophrenia have treatment-resistant illness. Of these, up to 60% will respond to clozapine treatment. Aims: This study retrospectively examined clozapine prescribing patterns against National Institute for Health and Care Excellence (NICE) guidelines as treatment-resistant illness emerged in a first-episode psychosis cohort. Methods: A total of 339 individuals with a first-episode psychosis were included in the study. Clozapine prescribing patterns were compared against the NICE guidelines and the impact of clozapine use on one index of service utilisation (hospitalisation) was assessed. Results: A total of 32 individuals (9.4%) from the cohort were prescribed clozapine. The mean time to clozapine trial was 2.1 years (SD 1.95; range 0.17–6.25). The mean number of adequate trials of antipsychotic prior to starting clozapine was 2.74 (SD 1.13; range 1–5). Following clozapine initiation, mean hospital admissions per year reduced from 2.3 to 0.3 ( p=0.00). Mean hospital days pre- and post-clozapine also reduced (147 vs. 53; p=0.00). In total, 18 patients discontinued clozapine use during follow-up – 5 temporarily and 13 permanently. Conclusions: Patients are being prescribed clozapine earlier than previously demonstrated, though delays are still evident, and many patients discontinue treatment. More work needs to be undertaken to understand and address factors which lead to its discontinuation.

What is the extent of research assessing patients’ and clinicians’ perspectives on clozapine treatment? – a comprehensive scoping review

“…No other published studies within the identified underprioritized areas were found. Instead, eight additional studies on general clinician perspectives on clozapine treatment [203][204][205][206][207][208][209][210] , three additional studies on clozapinepatients' (and their clinicians') attitudes towards their ongoing treatment 40 211 212 , and three additional studies on case-note derived reasons for clozapine cessation or withholding [213][214][215] appeared, ratifying the repetitive behavior of current research and the importance of disseminating these results in order to direct future research towards more meaningful and less well-described areas.…”

Pharmacogenomics of Clozapine-induced agranulocytosis: a systematic review and meta-analysis

“…At present, clozapine remains the standard treatment of choice for TRS recommended by international guidelines due to its superior efficacy compared to other existing antipsychotics [3][4][5][6][7]. Despite the abundance of robust evidence supporting the effectiveness of clozapine in improving outcomes for TRS patients, clozapine is underutilized due to concerns about tolerability and monitoring [8], and its initiation is commonly delayed for several years in many countries worldwide, including in the USA and Canada [9][10][11]. Studies have even suggested that the utilization of clozapine earlier in treatment, rather than waiting for multiple drug failures and subsequent severe TRS, results in better response [12][13][14].…”

Prescription patterns in patients with schizophrenia who discontinued long‐acting injectable antipsychotics: A chart‐review

“…In conclusion, the real-world data indicate that patients who discontinued LAI antipsychotics eventually needed to resume LAI antipsychotics or receive antipsychotic polypharmacy, which indicates that earlier use of clozapine may be useful. 6…”