Giving the gold standard the cold shoulder
: Delay to clozapine use in treatment-resistant schizophrenia

    Student thesis: Doctoral ThesisDoctor of Philosophy


    Clozapine is the only antipsychotic that has been repeatedly shown to be effective in treatment-resistant schizophrenia. Despite this, it is underused. This thesis investigates prescribing patterns of clozapine in a large NHS Trust in South East London. Retrospective clinical note review found a mean theoretical delay to clozapine prescription of 3.93 years. The length of delay to clozapine use was not affected by age, ethnicity or diagnosis. In a survey of clinical staff, the majority were familiar with clozapine prescribing guidelines and how to prescribe the drug, and felt that barriers to prescribing were predominantly patient concerns about tolerability or compliance with blood testing. Almost half of patients surveyed had never heard of clozapine. A narrow majority (57%) of patients said that blood testing would not stop them taking clozapine, with less than half being concerned about side effects. Being admitted to hospital for clozapine initiation was a barrier to treatment for patients. I found that taking clozapine reduces the number of days spent as an inpatient per year. The length of delay to starting clozapine had no effect on the eventual clinical benefit, as measured by inpatient admissions, although younger patients did derive more benefit. The majority of patients in my cohort remained compliant with clozapine for the duration of the study. Those that discontinued were more likely to be male, but no other factors affected the likelihood of stopping clozapine. Patients that discontinued clozapine gained less benefit in clinical outcomes that those that continued taking it. My research shows that clozapine should be introduced as early as possible in the treatment pathway. Not only do younger people benefit more in terms of reductions in time spent in psychiatric institutions, but for all patients clinical and economic savings continue to accrue over time. Strategies that may enable earlier introduction of clozapine should focus on reducing blood testing requirements or making blood testing a less unattractive prospective to patients. Making patients more familiar with clozapine earlier in their illness may help to reduce the fear of side effects, which if they occur must be treated swiftly and robustly. Dedicated and accessible day hospital beds for clozapine initiation may be helpful for some. Every effort should be made to allow patients to remain compliant with clozapine – male patients may especially require support.
    Date of Award2019
    Original languageEnglish
    Awarding Institution
    • King's College London
    SupervisorDavid Taylor (Supervisor) & Sukhi Shergill (Supervisor)

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