Patterns of clozapine prescribing in a mental health service in New Zealand

Medicines Management Research Group, School of Pharmacy, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand.
International Journal of Clinical Pharmacy (Impact Factor: 0.92). 08/2010; 32(4):503-11. DOI: 10.1007/s11096-010-9398-5
Source: PubMed


To describe clozapine prescribing in a mental health service in Auckland, New Zealand and compare it with national and international treatment guidelines.
A large public mental health service for adults in Auckland, New Zealand.
A retrospective cross-sectional study of all adult outpatients and stable inpatients being treated with clozapine on 31st March 2007 in one mental health service in Auckland, New Zealand. Data on patient characteristics, diagnosis, duration of illness, number of hospitalisations, legal status relating to their treatment, living situation, marital status and occupational activity were recorded from case notes. Data collected on clozapine included date of initiation, dose and duration of treatment. Prior antipsychotic use and information on all other psychotropic drugs prescribed was also collected. Data were entered into a custom-designed Microsoft Access database and analysed using SPSSv15.0.
Clozapine prescribing patterns and concordance with best practice recommendations for clozapine use.
402 adult mental health outpatients and stable inpatients were eligible for inclusion. The mean daily dose of clozapine was 383 (SD 166) mg. For those first presenting after universal government funding, the mean time between presentation and initiation of clozapine, was 2.8 (SD 1.9) years, compared to 5.7 (SD 3.3) years prior to funding. Of those presenting after universal government funding, approximately two-thirds (69.0%) had < or = 2 trials with other antipsychotics prior to commencing clozapine; of whom the majority (62.0%) received only second-generation antipsychotics (SGA). Both the number of antipsychotic agents trialled and the time to clozapine initiation has fallen since government subsidy was introduced in 1999. Based on a analysis of annualised hospitalization rates, it appears that shortening the delay to receiving clozapine leads to fewer hospitalisations in this treatment-resistant population, although this did not achieve statistical significance in our study.
Contemporary management of patients with treatment resistant schizophrenia in New Zealand is broadly in line with national and international best practice guidelines. There is some evidence, based on hospitalisation rates, to support the assertion that shorter delays in accessing clozapine leads to better outcomes. This needs further evaluation using measures of clinical outcome including objective measures of functioning.

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Available from: Jeff Harrison, Nov 14, 2014
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    • "Similar to our findings, a recent study by Nielsen et al. (2012) reported that less frequent psychiatric hospitalizations and fewer antipsychotic trials before clozapine initiation were associated with greater clozapine response. Harrison et al. (2010) also reported that shortening the delay to receiving clozapine lead to fewer hospitalizations in treatment-resistant patients. We also found that there is a relationship between longer delay to starting clozapine and higher maximum doses of clozapine . "
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    ABSTRACT: The aim of this retrospective chart-review study was to investigate the relationship between delayed commencement of clozapine and the level of response in treatment-resistant schizophrenia (TRS). We included 162 patients with schizophrenia who used clozapine. The mean delay until starting clozapine after fulfillment of the TRS criteria was 29 months. The delay was shorter in those who gained benefit from clozapine (P=0.04), those who were treated in a specialized psychosis outpatient unit (P=0.01), and in men (P=0.009), and it correlated with age (P<0.001). The delay in starting clozapine and the maximum clozapine dose were independent contributors toward the response to clozapine in the logistic regression analysis. Moreover, of those who gained considerable benefit from clozapine, the patients were younger (P=0.01), the duration of illness before clozapine treatment was shorter (P=0.001), and the numbers of adequate antipsychotic trials before the use of clozapine were fewer (P=0.05). Our findings suggest that efforts aimed at reducing the delay for starting clozapine may increase the effectiveness of clozapine in TRS.
    International clinical psychopharmacology 07/2015; 30(5). DOI:10.1097/YIC.0000000000000086 · 2.46 Impact Factor
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    • "Several studies have reported that male patients are more likely than female patients to experience refractory schizophrenia and have chronic onset. Moreover, the duration of hospitalization was longer in male patients, and their main clinical features were prominent positive and negative symptoms accompanied by comprehensive social dysfunction.21,25,26) The survey results indicated that Chinese physicians in 2006 were more likely to use clozapine as a second-line treatment for refractory schizophrenia than as a first-line treatment. "
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    ABSTRACT: Clozapine is one of the most commonly used antipsychotic drugs in China. To date, few studies have investigated the patterns the prescription of clozapine nationwide. The present study examined these patterns in China in 2006 and identified the demographic and clinical characteristics associated with the use of clozapine. Using a standardized protocol and data collection procedure, we surveyed 5,898 patients with schizophrenia in 10 provinces with differing levels of economic development. Overall, clozapine had been prescribed for 31.9% (n=1,883) of the patients; however we found considerable variation among the 10 provinces. The frequency of clozapine use was highest in Sichuan (39.3%) and lowest in Beijing (17.3%). The mean daily dose of clozapine was 210.36±128.72 mg/day, and 25.1% of the patients were treated with clozapine in combination with other antipsychotics. Compared with the group not receiving clozapine, clozapine-user had been treated for longer durations and had experienced a greater number of relapses and hospitalizations. Furthermore, those in the clozapine-user had lower family incomes, were less able to seek psychiatric services, and more likely to be male and have a positive family history of schizophrenia. A multiple logistic regression analysis revealed that age, sex, professional help-seeking behaviors, duration of illness, economic status, educational level, and clinical manifestations were associated with the use of clozapine. Clozapine use is common in China. However, use of the antipsychotic varies among provinces, and demographic and clinical factors play important roles in the prescription of clozapine.
    Clinical Psychopharmacology and Neuroscience 08/2012; 10(2):99-104. DOI:10.9758/cpn.2012.10.2.99
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    ABSTRACT: BACKGROUND: Clozapine is the only antipsychotic drug licensed for treatment-resistant schizophrenia but its use is often delayed. Since previous studies, national guidelines on the use of clozapine and other antipsychotics have been disseminated to clinicians. AIMS: To determine the theoretical delay to clozapine initiation and to quantify the prior use of antipsychotic polypharmacy and high-dose antipsychotic treatment. METHOD: Clinico-demographic data were extracted from the treatment records of all patients commencing clozapine in our centre between 2006 and 2010. RESULTS: Complete records were available for 149 patients. The mean theoretical delay in initiating clozapine was 47.7 months (s.d. = 49.7). Before commencing clozapine, antipsychotic polypharmacy and high-dose treatment was evident in 36.2 and 34.2% of patients respectively. Theoretical delay was related to illness duration (β = 0.7, P<0.001) but did not differ by gender or ethnicity. CONCLUSIONS: Substantial delays to clozapine initiation remain and antipsychotic polypharmacy and high doses are commonly used prior to clozapine, despite treatment guidelines.
    The British journal of psychiatry: the journal of mental science 09/2012; 201:481-485. DOI:10.1192/bjp.bp.111.105833 · 7.99 Impact Factor
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