An Initiative to Improve Clozapine Prescribing in New York State

Variation of Clozapine Use for Treatment of Schizophrenia: Evidence from Pennsylvania Medicaid and Dually Eligible Enrollees

While clozapine is the most effective antipsychotic treatment for treatment-resistant schizophrenia, it remains underutilized across the United States, warranting a more comprehensive understanding of variation in use at the county level, as well as characterization of existing prescribing patterns. Here, we examined both Medicaid and Medicare databases to (1) characterize temporal and geographic variation in clozapine prescribing and, (2) identify patient-level characteristics associated with clozapine use. We included Medicaid and Fee for Service Medicare data in the state of Pennsylvania from January 1, 2013, through December 31, 2019. We focused on individuals with continuous enrollment, schizophrenia diagnosis, and multiple antipsychotic trials. Geographic variation was examined across counties of Pennsylvania. Regression models were constructed to determine demographic and clinical characteristics associated with clozapine use. Out of 8,255 individuals who may benefit from clozapine, 642 received treatment. We observed high medication burden, overall, including multiple antipsychotic trials. We also identified variation in clozapine use across regions in Pennsylvania with a disproportionate number of prescribers in urban areas and several counties with no identified clozapine prescribers. Finally, demographic, and clinical determinants of clozapine use were observed including less use in people identified as non-Hispanic Black, Hispanic, or with a substance use disorder. In addition, greater medical comorbidity was associated with increased clozapine use. Our work leveraged both Medicaid and Medicare data to characterize and surveil clozapine prescribing. Our findings support efforts monitor disparities and opportunities for the optimization of clozapine within municipalities to enhance clinical outcomes.

Insomnia and aggression in stable schizophrenic patients: The mediating role of quality of life

Aggression in schizophrenia patients is an issue of concern. Previous studies have shown that aggression in schizophrenia patients may be related to insomnia and quality of life to different extents. This study aimed to explore the potential mediating role of quality of life in the relationship between aggression and insomnia among schizophrenia patients. Demographic factors affecting aggression in schizophrenia patients were also explored.

PATIENTS AND METHODS

A total of 781 stable patients aged 18-75 who met the ICD10 diagnosis of "schizophrenia" completed the completed questionnaire. Aggression was assessed using the Modified Overt Aggression Scale (MOAS), sleep was assessed using the Insomnia Severity Index Scale (ISI), and quality of life was assessed using the five Likert options. Descriptive statistics and correlation analysis examined the correlation between aggression and other variables. The mediating role of quality of life in the association between insomnia and aggression was examined by pathway analysis.

RESULTS

A total of 781 patients participated in this study, and approximately 16 % of the schizophrenia patients were aggressive. According to the mediation analysis, the direct effect of insomnia on aggression was 0.147, and the mediating effect of quality of life on insomnia and aggression was 0.021. Specifically, for the four dimensions of the MOAS, the direct effects of insomnia on verbal aggression, aggression toward property, and aggression toward oneself were 0.028, 0.032, and 0.023, respectively, with mediating effects of 0.003, 0.007, and 0.006, respectively, and no mediating effect on physical aggression was found.

CONCLUSION

This study showed that insomnia significantly influenced aggression in schizophrenia patients. Quality of life significantly mediated insomnia and aggression and played a vital role in moderating aggression. Therefore, we suggest that in the future, improving aggression in schizophrenia patients, while paying attention to the importance of sleep, could start with improving quality of life to address this problem from multiple perspectives.

Clozapine Proficiency as a Milestone in Psychiatric Training

This Viewpoint advocates for the addition of clozapine prescribing as a milestone in psychiatric education.

Non-prescribing of clozapine for outpatients with schizophrenia in real-world settings: The clinicians' perspectives

Clozapine is the gold standard for treating treatment-resistant schizophrenia although continuously underutilized. Previous surveys of clinicians have found that some of the most frequently cited barriers to clozapine prescribing are related to the blood-monitoring requirements. However, these surveys tend to explore general perspectives and may not reflect the true impact of different barriers in real-world outpatient settings. This study aimed to explore this issue. First, by surveying the clinicians responsible for the treatment of 39 clozapine-eligible, yet clozapine-naive, outpatients with schizophrenia. Then, based on the survey results, explanatory interviews with the participating psychiatrists were conducted and analyzed thematically. The most frequently cited reason for non-prescribing of clozapine was the expected non-compliance with blood-monitoring requirements; however, overall stability and/or severe mental illness was chosen as the most important reason in most patient-cases. The qualitative analysis highlighted the combined impact of standard clinical practice, personal experiences, and organizational constraints on clozapine utility.

Brief commentary: Under-recognition of underuse of clozapine in treating psychotic symptoms in Parkinson's disease

Clozapine is an important drug in the treatment of Parkinson's disease (PD). It has proven efficacy in treating PD psychosis without worsening motor function, as well as in treating tremor refractory to L-Dopa, yet it is severely underused in the United States. Unlike the situation of treatment resistant schizophrenia, this underuse is underrecognized.

What are the barriers and facilitators of clozapine use in early psychosis? A survey of UK early intervention clinicians

Clozapine is the most effective medication for treatment-resistant psychosis, but evidence points to substantial underuse, especially within early intervention psychosis (EIP) services. We explored clinicians' views on perceived barriers and facilitators to offering patients clozapine within EIP services. A cross-sectional survey was distributed electronically to clinicians practising in EIP services across England. A mixed methods approach was used to assess barriers to clozapine, and attitudes and opinions concerning clozapine underutilisation. Based on the barriers identified in the literature, clinicians were asked to rate each one (scale:1-7) based on importance, with a higher score indicating higher importance. Clinicians were also asked open-ended questions on barriers to clozapine and how access can be improved in EIP services. Quantitative data were analysed using descriptive and inferential statistics, and qualitative responses were analysed thematically. One hundred and nineteen EIP clinicians from 35 services in England completed the survey. In total, 37% (n = 45) of clinicians perceived that clozapine was under-prescribed in their EIP service. The most important barrier to utilising clozapine were patient concerns with side effects, followed by monitoring requirements and clinician concerns with side effects. Thematic analysis identified 17 perceived barriers, which were grouped into three major themes: administrative (5 subthemes), clinician-related (6 subthemes), and patient-related (6 subthemes). Perceived facilitators to improving clozapine use were greater training, improved resources, and optimised monitoring. The main barriers to clozapine in EIP services, as identified by clinicians, are patient concerns regarding side effects and monitoring requirements. Identified facilitators for improved clozapine use include clinician training, improved resources, guidelines, and point-of-care testing.

Exploration of the Barriers to Clozapine Prescribing in Patients with Treatment-Resistant Schizophrenia: A Qualitative Study

Treatment-resistance schizophrenia (TRS) is one of the psychiatric challenges. While clozapine is an effective treatment for patients with TRS, there are some barriers to clozapine prescribing in these patients. The study aims to explore the barriers from Iranian psychiatrists' points of view. The study was conducted by a qualitative approach using content analysis. The Participants included 12 psychiatrists who were selected purposefully. Data were collected using a semi-structured interview from May to December 2020. All interviews were recorded and transcribed and analyzed qualitatively using constant comparisons. Three main categories emerged concerning barriers to the use of clozapine: drug-related barriers, psychiatrist and health system-related barriers, and patient and family-related barriers. Additionally, specific subcategories within each main category were documented. The present study showed that there are three main groups of barriers to the use of clozapine in patients with TRS. Psychiatrist and health system-related barriers may influence the other two groups of barriers. Further research to investigate the effective strategies to overcome the barriers is recommended.

The Modernization of Clozapine: A Recapitulation of the Past in the United States and the View Forward

PURPOSE

Although clozapine was Food and Drug Administration (FDA) approved more than 3 decades ago, major barriers and gaps in knowledge continue to prevent its effective and safe use. We review modern-day problems encountered with clozapine in the United States (US).

METHODS

Information surrounding current administrative, clinical, research, and technological gaps or barriers related to clozapine use in the US was reviewed.

FINDINGS

The history of how clozapine became FDA approved likely contributes to gaps in knowledge. The frequency of safety warnings added to the FDA prescribing information may add to fears about clozapine, as evidence by numerous published survey studies. The clozapine Risk Evaluation and Mitigation Strategy (REMS) program has been modified several times in the last decade, causing access and safety issues for patients, which are discussed. Evidence may suggest that the FDA REMS requirements for hematologic monitoring are too cumbersome, and there may be ability to safely loosen requirements. The COVID-19 pandemic brought forth the ability for extended interval monitoring but also greater awareness of the clozapine-inflammation interaction. Newer guidelines published describe considerations in personalizing clozapine titration based on principles of ethnopsychopharmacology. Emerging technologies to support the use of clozapine are not widely available.

IMPLICATIONS

Clozapine is a unique life-saving drug but it is underused in the US, despite its established efficacy. The 2021 REMS changes led to significant difficulties for providers and patients. We highlight the importance of the clozapine-inflammation interaction, therapeutic drug monitoring, and the ability for individual care based on patient-specific factors. There is an urgent need for advancing technology used for clozapine monitoring, evaluating barriers created by REMS, and establishing consistent practices throughout the US.

Variation in Psychotropic Medication Prescription for Adults With Schizophrenia in the United States

OBJECTIVE

Variation in prescription of psychotropic medications to patients with schizophrenia spectrum disorders may underlie health inequities. Using a national U.S. Medicaid sample, the authors examined prescription patterns of psychotropic medications commonly used for managing schizophrenia.

METHODS

Data from the 2011-2012 Medicaid Analytic eXtract were examined for demographic predictors of and variation across states in psychotropic medication prescription among adult patients diagnosed as having schizophrenia spectrum disorders (N=357,914). Percentages of patients in each state who filled prescriptions of at least 15 days of any antipsychotic, clozapine, antidepressant, benzodiazepine, mood stabilizer, or long-acting injectable (LAI) antipsychotic medication were determined after adjustment for demographic and clinical covariates. Multivariate regressions of clinical and demographic factors predicting prescription patterns were conducted.

RESULTS

Prescribing patterns for all types of psychotropic medications varied across states. Clozapine and LAI prescriptions showed the most dramatic differences across states and among patients with different demographic characteristics. Across states, adjusted proportions of prescriptions ranged from 4% to 22% for LAIs and from 1% to 11% for clozapine. Non-Hispanic Blacks and people of other race-ethnicities were more likely than non-Hispanic Whites to fill prescriptions for LAIs, and non-Hispanic Whites were more likely than individuals from other racial-ethnic groups to fill prescriptions for clozapine and all other medications.

CONCLUSIONS

Considerable variation in prescribing patterns of LAIs and clozapine by race-ethnicity and across states suggests uneven quality of care for individuals with schizophrenia spectrum disorders in the United States. A better understanding of what causes this variation could inform policy makers to improve treatment for this vulnerable population.

A Comparison of Attitudes, Comfort, and Knowledge of Clozapine Among Two Diverse Samples of US Psychiatrists

Considerable variation in clozapine utilization exists across the United States, and little is known about the perspective of psychiatrists in states with low clozapine use. To better understand clozapine practices, attitudes, and barriers, a survey was administered to a group of southeastern state conference attendees (SSCA; N = 86). The same survey was administered to psychiatrists belonging to a national community psychiatry organization (AACP; N = 57), and differences were analyzed across the two samples. In comparison to the AACP, the SSCA group felt less comfortable, perceived clozapine as less safe and effective, had fewer patients on clozapine, and were more likely to prefer antipsychotic polypharmacy to clozapine use. Across the sample, use of a myocarditis screening protocol was rare (N = 14/76; 18%) and less than half used plasma antipsychotic levels to guide dosage (N = 60/129; 47%). Continuing professional education on clozapine are needed for psychiatrists who see individuals with psychotic disorders.

Building and Landing the Plane While Flying: How New York State Addressed the Needs of People With Serious Mental Illness During the COVID-19 Pandemic

New York State was the epicenter for COVID-19 in Spring 2020 when little was known about the pandemic. Dire circumstances necessitated New York State’s (NYS) public mental health system to rapidly pivot, adapt, and innovate its policies and procedures to ensure continuous high-level care to individuals with serious mental illness (SMI), a population especially vulnerable to both the physical and psychosocial sequelae of COVID-19. NYS rapidly adopted emergency measures to support community providers, expanded the capacity of its State-Operated facilities, created policies to promote improved infection control access, collaborated to enhance the public–private continuum of service to support people with SMI, and broadened the use of new technologies to ensure continued engagement of care.

Clozapine for treatment resistance in early psychosis: a survey of UK clinicians' training, knowledge and confidence

BACKGROUND

Clozapine is the only medication licenced for patients with psychosis that is resistant to conventional antipsychotic treatment. However, despite its effectiveness, it remains widely underutilised. One contributory factor for this may be clinicians' lack of confidence around the management of clozapine.

OBJECTIVE

We conducted a survey of clinicians working in Early Intervention in Psychosis (EIP) services to determine their training needs for clozapine management in EIP services.

METHODS

An electronic survey was made available to all clinicians working in EIP services in England. The survey assessed confidence and training needs regarding managing clozapine in patients with treatment-resistant psychosis. Quantitative data were analysed using total mean scores and the Mann-Whitney U test.

RESULTS

In all, 192 (27%) of approximately 700 clinicians from 35 EIP services completed the survey. Approximately half (54%) had not received training on treatment with clozapine. Experience of training was higher in prescribers than non-prescribers, and among medical than non-medical clinicians. Previous training was associated with significantly higher confidence in offering clozapine and managing treatment-resistant psychosis (p < 0.001). Confidence levels with managing treatment-resistant psychosis and clozapine were relatively high (mean = 4 out of 5, SD = 1). Respondents were most confident about monitoring mental health response to treatment (mean = 5, SD = 1). Participants were least confident about how to discontinue clozapine treatment safely (mean = 3, SD = 1).

CONCLUSION

Most clinicians working in EIP have not received training on the use of clozapine. This may account, in part, for the underutilisation of clozapine in EIP services. The provision of training in the identification of treatment-resistant psychosis and the use of clozapine will likely improve the detection and management of treatment resistance in the early phase of psychosis.

There Is Life After the UK Clozapine Central Non-Rechallenge Database

BACKGROUND AND AIMS

In the United Kingdom, patients on clozapine whose hematological parameters fall below certain thresholds are placed on the Central Non-Rechallenge Database (CNRD), meaning that they cannot be prescribed clozapine again except under exceptional circumstances. This practice was discontinued in the United States in 2015 by expanding the hematological monitoring guidelines, allowing more patients to receive clozapine. Our objective was to investigate the implications this policy change would have on clozapine utilization in the United Kingdom.

METHODS

This was an observational, retrospective analysis of patients registered on the CNRD in a large mental health trust. The first objective was to compare the number of patients placed on the CNRD under the United Kingdom and the US Food and Drug Administration (FDA) criteria. The second objective was to explore the hematological and clinical outcomes of CNRD patients. The third objective was to investigate the hematological outcomes of patients rechallenged on clozapine after nonrechallengeable status.

RESULTS

One hundred and fifteen patients were placed on CNRD from 2002 to 2019, of whom 7 (6%) met the equivalent criteria for clozapine discontinuation under the FDA guidelines. Clinical outcomes, as measured by the Clinical Global Impression-Severity scale, were worse 3 months after clozapine cessation than on clozapine (t = -7.4862; P < .001). Sixty-two (54%) patients placed on CNRD were rechallenged. Fifty-nine of those (95%) were successfully rechallenged; 3 patients were placed back on CNRD, only one of which would have had to stop clozapine again under FDA criteria.

CONCLUSION

Implementation of the updated FDA's monitoring criteria in the United Kingdom would significantly reduce clozapine discontinuation due to hematological reasons. The evidence suggests an urgent need for revising the UK clozapine monitoring guidelines to improve outcomes in treatment-resistant schizophrenia.

Performance in Practice: Practice Assessment Tool for the Care of Patients With Schizophrenia

Schizophrenia is associated with significant health, social, occupational, and economic burdens, including increased mortality. Despite extensive and robust research on the treatment of individuals with schizophrenia, many individuals with the illness do not currently receive evidence-based pharmacological and nonpharmacological treatments. The American Psychiatric Association Practice Guideline for the Treatment of Patients With Schizophrenia, Third Edition, aims to enhance knowledge and increase the appropriate use of interventions for schizophrenia, thereby improving the quality of care and treatment outcomes. To this end, this evidence-based Performance in Practice tool can facilitate the implementation of a systematic approach to practice improvement for the care of individuals with schizophrenia. This practice assessment activity can also be used in partial fulfillment of Continuing Medical Education and Maintenance of Certification, part IV, requirements, which can also satisfy requirements for the Centers for Medicare & Medicaid Services Merit-based Incentive Payment System program.

Educational needs and psychoeducation interventions in clozapine users: a narrative review

OBJECTIVE

Increasing users' knowledge about the expected benefits and risks of clozapine may contribute to the initiation and maintenance of clozapine in persons with treatment-resistant schizophrenia (TRS). The objective was to identify the educational needs of clozapine users and the interventions aimed at addressing these needs.

METHOD

We systematically searched multiple electronic databases for articles: (i) exploring educational needs of clozapine users and of their relatives; and (ii) reporting educational interventions aimed at addressing these needs. Data were synthesized narratively.

RESULTS

A total of 30 articles published from 1990 to 2019 in 8 countries fulfilled our inclusion criteria. As most studies on educational needs (n = 18) were carried out in persons already taking clozapine, educational needs of TRS patients who were candidates for clozapine treatment are not well documented. Users' level of knowledge about clozapine was often poor, especially about adverse effects or interactions with other substances, with a poor retention of information delivered at treatment initiation. Among 12 studies reporting educational interventions in clozapine users, five provided quantitative outcomes. Their findings suggest that structured educational programmes may contribute to promote clozapine initiation and to improve users' knowledge about this drug.

CONCLUSION

The literature is sparse on structured educational interventions about clozapine, and only one randomized controlled trial was identified. A promising strategy emerging from this review may be staging educational interventions according to the evolving needs of persons with TRS before clozapine use, at initiation and during maintenance treatment.

Functioning and cognitive characteristics of clozapine users referred to psychosocial rehabilitation centers: A REHABase cohort study

OBJECTIVES

To explore whether clozapine users have specific rehabilitation needs compared to users of other antipsychotics.

METHODS

The study was performed using the REHABase collecting data on persons referred to a French network of psychosocial rehabilitation centers. It was restricted to persons with schizophrenia spectrum disorder using antipsychotics. Multivariate analyses were used to compare baseline functioning and cognitive characteristics in clozapine users vs. users of other antipsychotics.

RESULTS

Of the 675 patients identified in the REHABase, one out of ten (n = 70) used clozapine. Compared to users of other antipsychotics, clozapine users had been more frequently hospitalized in psychiatry and presented less frequently with psychoactive substance use. Functional measures did not significantly differ between the two groups. Clozapine users had poorer short-term verbal memory performance than users of other antipsychotics and did not differ on executive performance.

CONCLUSION

Clozapine users may reach a recovery level comparable to that obtained in persons without treatment-resistant schizophrenia. In order to reduce the negative impact of memory deficits on the recovery process of clozapine users, it is necessary to optimize their psychotropic treatment and to promote their access to cognitive remediation programs addressing their specific needs.

Clinical determinants of fever in clozapine users and implications for treatment management: A narrative review

OBJECTIVES

To identify the clinical determinants of fever in clozapine users and their impact on management of clozapine treatment.

METHODS

Articles published in English or French identified with a MEDLINE, Web of Sciences, Cochrane Library and PsycINFO search, from inception through February 2019, using the term "clozapine" in combination with "fever" OR "hyperthermia" OR "body temperature" OR "pyrexia" OR "febrile" OR "heat" OR "thermoregulation". Information extracted for each medical condition were frequency, time to onset after initiation of clozapine treatment, characteristics of fever, associated symptoms, laboratory tests used for diagnosis, course, lethality, discontinuation of clozapine. Data were synthesized narratively.

RESULTS

Our search yielded 394 unique hits published from 1993 to 2018. We included 73 articles in the review: two meta-analyses, 14 reviews, six epidemiological studies, 11 clinical studies and 40 case reports. During clozapine initiation, fever is most frequently benign and transient but should be closely monitored as it may be the first stage of potentially life-threatening adverse drug reactions (ADR) (agranulocytosis, neuroleptic malignant syndrome myocarditis, hepatitis, pancreatitis, nephritis, colitis, etc.). Other ADR associated with fever are independent of duration of exposure to clozapine (heat stroke, pneumonia, pulmonary embolism, necrotizing colitis). If fever is due to intercurrent infection, therapeutic drug monitoring is recommended to adjust clozapine daily dosage.

CONCLUSION

Benign causes of fever are much more frequent than life-threatening ADR during clozapine treatment. Discontinuation should not be considered as automatic in the event of fever, especially during the early phase of clozapine initiation.

Psychiatric pharmacist's role in overcoming barriers to clozapine use and improving management

Clozapine is an antipsychotic that exhibits superior efficacy and effectiveness for those with schizophrenia and other serious mental illness. However, its side-effect profile and administrative burdens present challenges to its use. In the United States, the medication is grossly underused even though it may improve outcomes and reduce costs. Current barriers to use include lack of prescriber knowledge and confidence, negative prescriber attitudes, special monitoring requirements, administrative factors, lack of clozapine on formularies, lack of support and infrastructure to use the medication within many health systems, and inadequate understanding or acknowledgement of clozapine prescribing and risks by policy makers and payers. Approaches using interprofessional models of care, which include pharmacists specializing in psychiatric care, can help meet the needs of patients receiving clozapine. This article lays out the big picture of barriers to clozapine and how psychiatric pharmacists could play a role in improving access.

Barriers to using clozapine in treatment-resistant schizophrenia: systematic review

Aims and methodTo systematically review the literature on barriers to the use of clozapine and identify any interventions for optimizing clozapine use in treatment-resistant schizophrenia. Journal databases were searched from 1972 to March 2018. The following search terms were used: treatment-resistant schizophrenia, clozapine, barriers, use, prescription rates, implementation, clozaril and prescribing practices. Following a review of the literature, 15 papers were included in the review. RESULTS: The major barriers that were identified included mandatory blood testing, fear of serious side-effects and lack of adherence by the patients, difficulty in identifying suitable patients, service fragmentation, and inadequate training in or exposure to using clozapine.Clinical implicationsIn view of consistent evidence across the studies on inadequate knowledge and skills as a significant barrier, we suggest that a certification requiring competence in initiating and managing side-effects of clozapine becomes a mandatory requirement in training programmes.Declarations of interestNone.

Prescriber and institutional barriers and facilitators of clozapine use: A systematic review

BACKGROUND

As clozapine is under-prescribed in persons with treatment-resistant schizophrenia (TRS), it is necessary to better identify the determinants of health inequalities in access to clozapine use.

OBJECTIVE

To identify mental health professionals' characteristics or attitudes and institutional characteristics facilitating or limiting clozapine prescribing.

METHOD

We systematically searched multiple electronic databases for articles reporting: (i) mental health professionals' attitudes and characteristics favoring or limiting clozapine prescribing; (ii) institutional characteristics associated with variations in clozapine prescribing; (iii) interventions aimed at enhancing clozapine prescribing. Data were synthesized narratively.

RESULTS

A total of 31 articles reporting findings of 29 studies published from 1993 to 2017 in 11 countries fulfilled our inclusion criteria. The main prescriber-related barriers to clozapine prescribing are lack of personal prescribing experience and concern with pharmacological characteristics of clozapine (blood monitoring and adverse effects). Lack of knowledge about the effectiveness of clozapine does not appear as a major determinant of under-prescription. Institutional-related characteristics favoring clozapine prescribing are prescribers' adherence to evidence-based medicine principles and learning by modelling from experienced clozapine prescribers.

CONCLUSION

Effective strategies to increase access to clozapine in persons with TRS include implementation of integrated clozapine clinics, simplification of blood monitoring, education for prescribers and contact with experienced prescribers. Programs addressing barriers in clozapine prescription need to be disseminated more broadly to ensure persons with TRS have access to evidenced based treatments such as clozapine. Inequality in access to clozapine care should be more systematically handled by mental health facilities and health regulatory agencies.

Safety of antipsychotics for the treatment of schizophrenia: a focus on the adverse effects of clozapine

Clozapine, a dibenzodiazepine developed in 1961, is a multireceptorial atypical antipsychotic approved for the treatment of resistant schizophrenia. Since its introduction, it has remained the drug of choice in treatment-resistant schizophrenia, despite a wide range of adverse effects, as it is a very effective drug in everyday clinical practice. However, clozapine is not considered as a top-of-the-line treatment because it may often be difficult for some patients to tolerate as some adverse effects can be particularly bothersome (i.e. sedation, weight gain, sialorrhea etc.) and it has some other potentially dangerous and life-threatening side effects (i.e. myocarditis, seizures, agranulocytosis or granulocytopenia, gastrointestinal hypomotility etc.). As poor treatment adherence in patients with resistant schizophrenia may increase the risk of a psychotic relapse, which may further lead to impaired social and cognitive functioning, psychiatric hospitalizations and increased treatment costs, clozapine adverse effects are a common reason for discontinuing this medication. Therefore, every effort should be made to monitor and minimize these adverse effects in order to improve their early detection and management. The aim of this paper is to briefly summarize and provide an update on major clozapine adverse effects, especially focusing on those that are severe and potentially life threatening, even if most of the latter are relatively uncommon.

Trends in the prescription of clozapine in a psychiatric hospital: a 5-year observational study

INTRODUCTION

Clozapine is a well-recognized effective treatment for some patients with treatment-resistant schizophrenia (TRS). Although it has potential benefits and approximately 30% of patients have a clinical indication for clozapine use, prescription rates are low.

OBJECTIVE

To evaluate clozapine prescription trends over a 5-year period in a tertiary psychiatric hospital.

METHODS

In this observational study, data prospectively collected by the Medical and Statistical File Service (Serviço de Arquivo Médico e Estatístico) and the Pharmacy Division of Instituto de Psiquiatria de Santa Catarina between January 2010 and December 2014 were summarized and analyzed by investigators blinded to data collection. The number of 100 mg clozapine pills dispensed by the Pharmacy Division to the inpatient units was the outcome and considered a proxy measure of clozapine prescriptions. The number of occupied inpatient unit beds and the number of patients admitted with F20-F29 (ICD-10) diagnoses during the study period were considered to be possible confounders.

RESULTS

A multiple linear regression model showed that time in months was independently associated with an increase in the number of clozapine pills dispensed by the Pharmacy Division (β coefficient = 15.82; 95% confidence interval 10.88-20.75).

CONCLUSION

Clozapine prescriptions were found to have increased during the 5-year period studied, a trend that is opposite to reports from several other countries.

International trends in clozapine use: a study in 17 countries

OBJECTIVE

There is some evidence that clozapine is significantly underutilised. Also, clozapine use is thought to vary by country, but so far no international study has assessed trends in clozapine prescribing. Therefore, this study aimed to assess clozapine use trends on an international scale, using standardised criteria for data analysis.

METHOD

A repeated cross-sectional design was applied to data extracts (2005-2014) from 17 countries worldwide.

RESULTS

In 2014, overall clozapine use prevalence was greatest in Finland (189.2/100 000 persons) and in New Zealand (116.3/100 000), and lowest in the Japanese cohort (0.6/100 000), and in the privately insured US cohort (14.0/100 000). From 2005 to 2014, clozapine use increased in almost all studied countries (relative increase: 7.8-197.2%). In most countries, clozapine use was highest in 40-59-year-olds (range: 0.6/100 000 (Japan) to 344.8/100 000 (Finland)). In youths (10-19 years), clozapine use was highest in Finland (24.7/100 000) and in the publicly insured US cohort (15.5/100 000).

CONCLUSION

While clozapine use has increased in most studied countries over recent years, clozapine is still underutilised in many countries, with clozapine utilisation patterns differing significantly between countries. Future research should address the implementation of interventions designed to facilitate increased clozapine utilisation.