Clozapine Prescribing Research Articles

P606. 20-Year Prevalence of Clozapine Prescribing in the Veterans Health Administration: Analysis of Electronic Health Records of 134,692 Veterans With Schizophrenia or Schizoaffective Disorder

Clozapine is the only medication approved for both treatment resistant schizophrenia and suicidal behavior in patients with schizophrenia or schizoaffective disorder. Of note, 16.3% of male veterans with schizophrenia die by suicide. However, despite its proven efficacy, clozapine has consistently been underutilized in the US. We therefore examined the extent of clozapine prescribing in the Veterans Health Administration (VHA), the largest integrated health care system in the US.

Concerns over the prescription of clozapine for people diagnosed with “borderline personality disorder” in private locked psychiatric units

PurposeThe use of long-term anti-psychotic medication for borderline personality disorder contravenes prescribing guidelines in the UK. There is evidence to suggest clozapine can be beneficial yet anecdotally it is prescribed almost exclusively in locked settings. A single study suggests a substantial proportion of psychiatrists disapprove of this practice. The purpose of this paper is to articulate concerns about the use of clozapine for “BPD” that are absent from current literature.Design/methodology/approachThis paper summarises the reflections and experiences of the authors lived experience, academic and clinical backgrounds.FindingsThe published literature is uniformly positive when describing the prescription of clozapine for those diagnosed with BPD; however, this in no way reflects the experience of the authors. There is no body of material reflecting a study showing that a substantial number of psychiatrists have issues with this practice.Research limitations/implicationsWhile it is a fact that there is a discrepancy between psychiatrists attitudes towards clozapine prescription for “BPD” and the published literature, the described concerns in this paper are based solely on the authors’ experiences and observations.Practical implicationsThose seeking literature to articulate concerns about the use of clozapine with this population will likely be disheartened by the paucity of published literature.Originality/valueTo the best of the authors’ knowledge, this paper is the first to raise substantial concerns about the use of clozapine for those diagnosed with “BPD” and the circumstances in which it is prescribed.

An evaluation of the prescribing of clozapine for treatment-resistant schizophrenia in one NHS Trust in England

Abstract Introduction As a merger of two trusts had occurred, and recent research on the impact of the delay of initiating clozapine (1), this study was initiated to investigate if NICE guidelines for the management of treatment-resistant schizophrenia (TR-SCZ) were followed. NICE recommends that clozapine is offered after a trial of two antipsychotics drugs of appropriate dose and duration. The risk of potentially fatal side effects and the need for regular blood monitoring can deter patients and prescribers in initiating clozapine at an earlier stage (1). Aim To evaluate the prescribing of clozapine in patients with TR-SCZ in a large NHS trust against NICE guidelines. Methods Due to a fixed project time scale of 3 months, the medical records of 20 patients with TR-SCZ were accessed in November 2019 in order to determine compliance with NICE guidelines. Inclusion criteria for the study included a diagnosis of TR-SCZ in patients over 18 but under 60 years-old and a first attempt of prescribing clozapine after 2017. The records were analysed to establish how many antipsychotics were prescribed before clozapine was initiated, the number of patients remaining on clozapine after nine months, and the reason for stopping (where appropriate). A collection tool was created in Excel and data was analysed using descriptive statistics. Results All 20 patients had tried at least two antipsychotics, with 75% (n=15) having tried more than two before the initiation of clozapine. The mode number of antipsychotics prescribed was three. At the point of data collection, 75% (n=15) of the patients remained on clozapine. Of the five patients no longer taking clozapine, three patients remained on it for more than nine months before it was stopped. Documented reasons for stopping included side effects (neutropenia (n=1) and tachycardia (n= 1)) and patient choice (n=3). Conclusion Clozapine is an effective treatment for TR-SCZ (1), (2). This is backed up by the majority of patients in this study remaining on the treatment after nine months. This study also agrees with previous research (1) indicating guidelines for prescribing clozapine are not followed. 75% of patients were prescribed more than the recommended two antipsychotics before clozapine was initiated. However, the patient notes did not indicate the reasons for using more than two other antipsychotics before trialling clozapine or impact of the delay of its initiation. It would therefore be prudent for future research to determine the reasons for and impact of prescribing clozapine after more than two other antipsychotics had been trialled. References (1) Shah P, Iwata Y, Plitman E, Brown EE, Caravaggio F, Kim J, Nakajima S, Hahn M, Remington G, Gerretsen P, Graff-Guerrero A. The impact of delay in clozapine initiation on treatment outcomes in patients with treatment-resistant schizophrenia: a systematic review. Psychiatry research. 2018 Oct 1;268:114-22. (2) National Institute for Health and Care Excellence. Psychosis and schizophrenia: treatment and management. (Clinical guideline 178.) c2014. [Updated 2021; cited 2021 Oct 14]. Available from: http://guidance.nice.org.uk/CG178

Antipsychotic prescribing patterns in Australia: a retrospective analysis

BackgroundTo examine real-world patterns of antipsychotic use in patients with schizophrenia Australia.MethodsThis retrospective cohort analysis was conducted using the Australian Commonwealth Department of Human Services Pharmaceutical Benefits Scheme (PBS) 10% sample data. Included data were for patients aged 16-years or older who initiated treatment for the first time with a PBS-reimbursed antipsychotic medication for schizophrenia between July 2013 and September 2017. Patterns of treatment usage were summarised descriptively. Differences in prescribing patterns by age and prescribing year were reported. Treatment persistence was estimated using Kaplan-Meier methods, with differences explored using log-rank tests. Values of p < 0.05 were considered statistically significant.Results6,740 patients, representing 8,249 non-unique patients, received prescriptions for antipsychotic medications. Patients were aged 16 years to over 85 years (54.5% were < 55 years) and two-thirds of patients were male (61%). The majority of treatment episodes (62%, n = 5,139/8,249) were prescribed an atypical oral antipsychotic. Typical long-acting antipsychotic therapies (LATs) were prescribed 19% of the treatment episodes (n = 1,608/8,249. There was a small increase in prescribing of atypical LAT and typical LAT and a small decrease in atypical oral and clozapine prescribing over the study period. Treatment persistence was greatest in patients treated with clozapine, than in those treated with atypical LATs.ConclusionsWhile the majority of patients receive atypical antipsychotic medications, one in five continue to use older typical LAT therapies. Patient age and time on therapy may be associated with choice of therapy. Persistence to atypical LAT therapy is better than for other treatment modalities in this real-world cohort.

Association between previous and future antipsychotic adherence in patients initiating clozapine: real-world observational study.

Although recognised as the most effective antipsychotic for treatment-resistant schizophrenia, clozapine remains underused. One reason is the widespread concern about non-adherence to clozapine because of poor adherence before initiating clozapine. To determine if prior poor out-patient adherence to treatmentbefore initiating clozapine predisposes to poor out-patient adherence to clozapine or to any antipsychotics (including clozapine) after its initiation. This cohort study included 3228 patients with schizophrenia living in Quebec (Canada) initiating (with a 2-year clearance period) oral clozapine (index date) between 2009 and 2016. Using pharmacy data, out-patient adherence to treatment was measured by the medication possession ratio (MPR), over a 1-year period preceding and following the index date. Five groups of patients were formed based on their prior MPR level (independent variable). Two dependent variables were defined after clozapine initiation (good out-patient adherence to any antipsychotics and to clozapine only). Along with multiple logistic regressions, state sequence analysis was used as a visual representation of antipsychotic-use trajectories over time, before and after clozapine initiation. Although prior poor adherence to antipsychotics was associated with poor adherence after clozapine initiation, the absolute risk of subsequent poor adherence remained low, regardless of previous adherence level. Most patients adhered to their treatment after initiating clozapine (>68% to clozapine and >84% to any antipsychotics). Despite the fact that poor adherence prior to initiating clozapine is widely recognised by clinicians as a barrier for the prescription of clozapine, the current study supports the initiation of clozapine in all eligible patients.

Antipsychotic polypharmacy and clozapine prescribing patterns: evolution and correlates before and after a psychiatric hospitalisation

Background:Antipsychotic polypharmacy (APP) prescribing and clozapine underuse are considered inappropriate prescribing in schizophrenia. Psychiatric hospitalisations may be suitable occasions to re-evaluate patient pharmacotherapy and to switch to monotherapy.Objectives:To explore the evolution of APP and other psychotropic prescribing patterns during psychiatric hospitalisations, to detect characteristics associated with APP on admission and at discharge, and to examine clozapine prescribing patterns.Design:We performed a retrospective observational study based on electronic health records.Methods:Data on adult inpatients diagnosed with schizophrenia spectrum disorders were collected retrospectively from 6 Belgian hospitals in 2020-2021.Results:Of the 516 patients included, APP prescribing increased significantly from 47.9% on hospital admission to 59.1% at discharge. On admission and at discharge, APP was associated with prior clozapine use (ORadmission = 2.53, CI = 1.1–5.84, ORdischarge = 11.01, CI = 4.45–27.28), treatment with a first-generation antipsychotic (ORadmission = 26.79, CI = 13.08–54.86, ORdischarge = 25.2, CI = 12.2–52.04), increased antipsychotic exposure (ORadmission = 8.93, CI = 5.13–15.56, ORdischarge = 19.89, CI = 10–39.54), and a greater number of hypno-sedatives (ORadmission = 1.88, CI = 1.23–2.88, ORdischarge = 4.18, CI = 2.53–6.91). APP was negatively associated with involuntary admission (ORadmission = 0.31, CI = 0.14–0.7, ORdischarge = 0.3, CI = 0.13–0.68). When using an alternative definition of monotherapy (i.e. including patients with an add-on low-dose antipsychotic for sleep disorders), alcohol use disorder (ORadmission = 0.26, CI = 0.13–0.54) and higher age (ORdischarge = 0.53, CI = 0.29–0.95) were negatively associated with APP, and living in a residential facility (ORdischarge = 2.39 CI = 1.21–4.71) and a higher daily dosage of benzodiazepines during the stay (ORdischarge = 1.32 CI = 1.03–1.69) increased the odds of being discharged on APP. On admission, 9.3% of patients were being treated with clozapine. Although 28.1% of patients were eligible for clozapine treatment, only 11% of patients were discharged with a clozapine prescription. For 7 of the 10 patients with a new clozapine prescription, it was directly prescribed in combination with another antipsychotic, without a prior trial of clozapine monotherapy.Conclusion:Suboptimal prescriptions of antipsychotics in patients with schizophrenia persist after psychiatric hospitalisations and are associated with identifiable characteristics.

Clozapine prescription trends in Brazil in the last decade.

Clozapine is a second-generation antipsychotic indicated for treatment-resistant schizophrenia. Studies in several countries have shown a low rate of clozapine use despite the fact that approximately 30% of schizophrenia cases are treatment-resistant. In Brazil, few studies have addressed the frequency and variety of antipsychotic use in individuals diagnosed with schizophrenia (ICD F20). The objective of this study was to measure the rates of clozapine use in this population in the last decade using Brazilian Ministry of Health data. Prescriptions made between 2010 and 2020 in all 26 states and the Federal District registered at the Outpatient Information System Database from the Brazilian Health System (SIASUS) were evaluated. A total of 25,143,524 prescriptions were recorded in this period, with clozapine representing 8.86% of all antipsychotics. The most frequently prescribed antipsychotic for patients with schizophrenia was olanzapine (35.8%), followed by quetiapine (27.5%). From 2010 to 2020, the rate of clozapine prescriptions in Brazil increased from 7.2% to 10.9%. Despite a slight increase in prescriptions in the last decade, clozapine is still underutilized in Brazil.

COVID‐19 and clozapine use in an early intervention for psychosis service

Clozapine prescribing in treatment‐refractory schizophrenia is underutilised, including in early intervention for psychosis services. COVID‐19 has brought various challenges to the utilisation of clozapine, particularly in the context of initiation and monitoring. There is a need for clear national guidance in this regard.

APA Joins in Negotiations Over New Problematic Clozapine REMS

APA Joins in Negotiations Over New Problematic Clozapine REMS

List of essential psychotherapeutic medicines 2019 of India: When science was left behind.

List of essential psychotherapeutic medicines 2019 of India: When science was left behind.

Association between the examination rate of treatment-resistant schizophrenia and the clozapine prescription rate in a nationwide dissemination and implementation study.

BackgroundThe decision to initiate clozapine treatment should be made on an individual basis and may be closely related to the early detection of treatment‐resistant schizophrenia (TRS), although there is evidence that the early use of clozapine results in a better response to treatment. Therefore, we investigated the relationship between the examination rate of TRS and the prescription rate of clozapine.MethodsAfter attending a 1‐day educational program on schizophrenia based on the "Guidelines for the Pharmacological Treatment of Schizophrenia," we asked the participating facilities to submit records of whether or not TRS was evaluated for each patient. We calculated the clozapine prescription rate from the schizophrenic patients prescribed clozapine and all of the schizophrenic patients. Forty‐nine facilities in 2017 were included in the study.ResultsThere were dichotomous distributions in the examination rate of TRS and a non‐normal distribution in the prescription rate of clozapine. There was a significant correlation between the prescription rate of clozapine and the examination rate of TRS (r s = 0.531, P = 1.032 × 10−4). A significant difference was found in the prescription rate of clozapine between the three groups of facilities according to the examination rate of TRS.ConclusionAs a preliminary problem for the use of clozapine, in Japan, the examination rate of TRS varies, and there are many facilities that typically do not consider the possibility of TRS; this trend leads to a low rate of clozapine use. Clearly, further clinician training is needed for the early detection and appropriate management of TRS that includes an explanation of TRS and how to introduce clozapine therapy to patients and their families.

Clozapine prescribing barriers in the management of treatment-resistant schizophrenia: A systematic review.

Treatment-resistant schizophrenia is prevalent and difficult to manage, as patients fail multiple antipsychotic trials before being considered as treatment-resistant. Currently clozapine is the only Food and Drug Administration-approved pharmacotherapy for treatment-resistant schizophrenia but remains under-prescribed. The purpose of this study is to investigate recent literature on clozapine in order to identify barriers to prescribing clozapine and categorize the recommended solutions. We conducted a systematic review following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Using free text and the medical subject headings, we searched MEDLINE/PubMed electronic bibliographic database from 2017 until 2020. Eligible studies included peer-reviewed English language articles with multiple methodologies aiming to identify clozapine barriers in treatment-resistant schizophrenia. We used search terms combining clozapine AND treatment OR treatment-resistant schizophrenia AND barriers AND prescribing OR prescription OR prescriber. We merged search results in a citation manager software, removed duplicates, and screened the remaining articles based on the study eligibility criteria. We retrieved 123 studies, however, only 10 articles exclusively met the study inclusion criteria for full text review. These studies represented 20 countries; 6 were exclusively conducted in the US. The top barriers delineated by the studies include: providers' lack of knowledge and training (n = 7), concern about side effects (n = 8), and poor adherence (n = 7). All studies described more than 1 barrier. Other barriers included prescriber-perceived barriers (n = 4), administrative barriers (n = 5), and other healthcare systems-related barriers (n = 3). Top recommendations to overcome clozapine prescription barriers included improving prescriber clozapine education/training, utilizing interdisciplinary teams and providing integrated care via clozapine clinics, and simplifying blood test monitoring. Clozapine remains under-prescribed for patients with treatment-resistant schizophrenia due to multiple barriers related to the individual prescriber, system of care, and technology. It is recommended that by improving prescriber knowledge and training, use of integrated care, and use of technology that can enable continuous, real-time blood test monitoring, these barriers may be overcome.

Clozapine in the Treatment of Schizophrenic Psychosis: Patient Characteristics and Antipsychotic Combinations in One Cohort at a Psychiatric Care Hospital

In many studies, clozapine has been reported to have superior effectiveness compared to other antipsychotics. So far there is little systematic data on the practice of clozapine prescription and characteristics of patients treated. Retrospective evaluation of all 392 treatment courses of inpatients with schizophrenic psychoses during one year. Detailed analysis of the patients treated with clozapine including the dosages and additional psychotropic medication. Patients treated with clozapine showed a higher disease severity than patients without clozapine. They received more frequently pharmacological combination therapies, which in some cases significantly contradicted the current guideline recommendations. The results underline the pronounced disease severity of patients receiving clozapine treatment and substantiate evidence from the literature on the limited implementation of guidelines in prescribing practice. The study carried out serves as a pilot survey of a multicenter research project on the practice of prescribing clozapine in psychiatric hospitals in different German regions.

Audit of therapeutic drug monitoring of ‘clozapine plasma levels’

AimsTo re audit the monitoring of Plasma Clozapine levels in Rehabilitation setting in CNTW Trust as per Trust Guidelines PGN on “Safe prescribing of Clozapine”.Objectives:To determine if1. The reason for a clozapine plasma level request is recorded.2. Results are recorded correctly.3. Appropriate action is taken and recorded when results are significant.BackgroundClozapine plasma level monitoring is useful when assessing adherence, adjusting the dose, monitoring the effects of changes in smoking habit, investigating clozapine side effects and when toxicity is suspected.An initial audit was carried out within the Trust in 2015 and the following recommendations were made:Check and record clozapine plasma levelAt baseline (a level should be taken once the patient has been on the target dose for at least a week)Annually.When clinically relevant to optimise therapy.An entry must be made in the patient's progress notes recording the reason of requesting the test.On receipt of results, the paper copy must be scanned &amp; an entry made in progress notes.The clinician should comment on the significance of the results and propose an action plan.We re-audited compliance with the guidance in Rehabilitation (inpatients and community) by reviewing patient notes for a 2 year period of 2017–2018.MethodThe audit work involved a review of 31 case records of patients prescribed Clozapine whose last plasma level was taken between 2017–2018. Patient's details were identified from a randomly generated list by the Trust pharmacy.Result&lt;50% compliance was seen with baseline, annual monitoring, reason for recording and proposed action plan by clinician.&gt;50% compliance was seen with scanned results and levels checked when clinically relevant.No significant improvement from the previous audit except improvement in compliance with documentation of levels.ConclusionDissemination of Clozapine Key cards within teams.

Gender disparities in clozapine prescription in a cohort of treatment-resistant schizophrenia in the South London and Maudsley case register

BackgroundGender disparities in treatment are apparent across many areas of healthcare. There has been little research into whether clozapine prescription, the first-line treatment for treatment-resistant schizophrenia (TRS), is affected by patient gender. MethodsThis retrospective cohort study identified 2244 patients with TRS within the South London and Maudsley NHS Trust, by using a bespoke method validated against a gold-standard, manually coded, dataset of TRS cases. The outcome and exposures were identified from the free-text using natural language processing applications (including machine learning and rules-based approaches) and from information entered in structured fields. Multivariable logistic regression was carried out to calculate the odds ratios for clozapine prescription according to patients' gender, and adjusting for numerous potential confounders including sociodemographic, clinical (e.g., psychiatric comorbidities and substance use), neutropenia, functional factors (e.g., problems with occupation), and clinical monitoring. ResultsClozapine was prescribed to 77% of the women and 85% of the men with TRS. Women had reduced odds of being prescribed clozapine as compared to men after adjusting for all factors included in the present study (adjusted OR: 0.66; 95% CI 0.44–0.97; p = 0.037). ConclusionWomen with TRS are less likely to be prescribed clozapine than men with TRS, even when considering the effects of multiple clinical and functional factors. This finding suggests there could be gender bias in clozapine prescription, which carries ramifications for the relatively poorer care of women with TRS regarding many outcomes such as increased hospitalisation, mortality, and poorer quality of life.

Clozapine prescribing during follow-up of a first-episode psychosis cohort

IntroductionOf those with schizophrenia, one third develop treatment-resistant illness. Nearly 60% of these benefit from clozapine- the only antipsychotic medication licensed in this group.ObjectivesAs treatment-resistant illness developed in the follow-up of a first-episode psychosis (FEP) cohort, clozapine was prescribed. This study retrospectively compared the clozapine prescribing patterns, within this cohort, to National Institute for Health and Care Excellence (NICE) guidelines. In addition, impact on hospitalisation, physical health monitoring and augmentation strategies employed following clozapine initiation were examined. Factors delaying initiation of clozapine treatment or contributing to its discontinuation were also explored.MethodsThe study included 339 individuals resident within an Irish community mental health team catchment area, referred with FEP from 1 January 2005 to 31 August 2016. Data were extracted from electronic medical records.ResultsWithin the cohort, clozapine was prescribed to 32 individuals (9.4%). The mean number of adequate trials of antipsychotic prior to starting clozapine was 2.74 (SD 1.13; range 1–5). The mean time to clozapine trial was 2.1 years (SD 1.95; range 0.17–6.25). Following initiation of clozapine, mean hospital admissions per year fell from 2.3 to 0.3 (p=0.00). Mean inpatient days pre- and post-clozapine also decreased (147 vs. 53; p=0.00). In all, 18 patients ceased use of clozapine, 5 temporarily and 13 permanently.ConclusionsPatients are being prescribed clozapine earlier than previously demonstrated. However, delayed treatment remains common, and many patients discontinue clozapine. Further research is necessary to describe and address factors which contribute to its discontinuation.DisclosureNo significant relationships.

Considerations of HLA, Renal Failure, Valproic Acid Use, and Current Treatment Guidelines in Clozapine-Induced Agranulocytosis

Clozapine, the choice atypical antipsychotic for refractory schizophrenia, schizoaffective disorder, and bipolar disorder, has been shown to reduce positive and negative symptoms of schizophrenia. Clozapine, though beneficial in reducing the need for hospitalization, rehabilitation, and health care costs, is known as a drug of last resort due to its potential adverse event of clozapine-induced agranulocytosis, which holds a case fatality rate between 4.2 and 16%. Herein, we describe a female patient with longstanding schizoaffective disorder and chronic kidney disease who suffered from clozapine-induced agranulocytosis after failing two other atypical antipsychotics. Retrospective considerations of this case and management highlight risk factors such as HLA status, renal failure, and concurrent valproic acid use which presently do not have official screening, guidelines, or restrictions in place when prescribing clozapine. Additionally, there are no specific clozapine-induced agranulocytosis management recommendations such as G-CSF/filgrastim dose, timing of bone marrow aspirate and biopsy, and use of concomitant valproate. We propose that further comprehensive official screening, monitoring, and guidelines in the prescribing of clozapine, and further guidelines in the treatment of clozapine induced agranulocytosis, could increase the cost-effectiveness of clozapine treatment, and decrease the incidence, and morbidity of this feared adverse event.

A Legal Right to Clozapine Therapy for Incarcerated Individuals With Treatment-Resistant Schizophrenia.

People with serious mental illnesses increasingly are being treated in jails and prisons, and during incarceration are afforded a constitutional right to medical care. This right pertains to both general medical and mental illnesses and both acute and chronic conditions. However, incarcerated patients with treatment-resistant schizophrenia (TRS) often are not offered clozapine, the only medication for this debilitating illness approved by the U.S. Food and Drug Administration. In this column, the authors argue that incarcerated individuals with TRS have a statutory and constitutional right to treatment with clozapine.

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

Clozapine is the only licensed treatment for treatment refractory schizophrenia. Despite this, it remains grossly underused relative to the prevalence of refractory schizophrenia. The extent of underuse and the degree of regional variation in prescribing in the United Kingdom is unknown. It is also unclear, how the UK compares with other European countries in rates of clozapine prescribing. We obtained data relating to all clozapine prescribing in the UK from the relevant clozapine registries. We examined regional variation in clozapine use across England, corrected for the known prevalence of severe mental illness (SMI). We also compared the UK rate of clozapine use per 100,000 population to that described in other European countries. There is substantial variation in clozapine prescribing across different regions of England and only about a third of potentially eligible patients were prescribed the drug in the UK. Clozapine prescribing rate in the UK was lower than in several European countries. There is clear regional inequity in access to the most effective treatment in refractory schizophrenia in England. Strategies to increase clozapine use, by overcoming both real and perceived barriers, are urgently necessary to reduce treatment inequity for patients with refractory schizophrenia.

Psychotropic drug prescription patterns and their predictors among older adult patients with schizophrenia in a tertiary-referral psychiatric hospital

Objective: Medical treatments for patients with refractory schizophrenia can be roughly divided into three strategies – clozapine administration, adjuvant use of mood stabilizers, and antipsychotic polypharmacy. Few studies exist on older adult patients with schizophrenia. In this study, we intended to assess the prevalence of clozapine administration, adjuvant use of mood stabilizers, and antipsychotic polypharmacy, and to find their predictors in those patients with schizophrenia. Methods: In this cross-sectional study, we collected information of patients' sociodemographic and clinical details. Their psychotic symptoms were evaluated using a clinical interview with a positive and negative syndrome scale (PANSS). Results: We enrolled 240 study participants, with 74 patients (30.8%) receiving clozapine, 40 patients (16.7%) receiving adjuvant use of mood stabilizers, and 42 patients (17.5%) receiving antipsychotic polypharmacy. Younger age (p < 0.05), higher PANSS general symptoms subscales (p < 0.001), and higher dosage of antipsychotics (p < 0.01) were significantly related to patients with clozapine administration. As to patients with adjuvant therapy with mood stabilizers, only younger age (p < 0.01) and male gender (p < 0.05) showed significant association. Finally, patients receiving antipsychotic polypharmacy were significantly related to lower body mass index (BMI) (p < 0.05), higher PANSS positive symptoms subscale (p < 0.05), and higher dosage of antipsychotics (p < 0.001). Conclusions: Our findings showed that patients with clozapine prescription were 30.8% in prevalence which is higher than other studies in Asia. The prevalence of adjuvant mood stabilizers and antipsychotic polypharmacy were 16.7% and 17.5%, respectively. Those two findings are lower than those in other studies in Asia.