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  1. Department of Psychosis, Institute of Mental Health, Singapore
  2. Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
  3. Corresponding author: Shushan Zheng, MBBS, Institute of Mental Health, Buangkok Green Medical Park, 10 Buangkok View, Singapore 539747 ([email protected]).
  4. Department of Psychosis, Institute of Mental Health, Singapore
  5. Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
  6. Department of Psychiatry, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR
  7. The State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong SAR
  1. Meltzer HY. Treatment-resistant schizophrenia—the role of clozapine. Curr Med Res Opin. 1997;14(1):1–20. PubMed CrossRef
  2. Agid O, Arenovich T, Sajeev G, et al. An algorithm-based approach to first-episode schizophrenia: response rates over 3 prospective antipsychotic trials with a retrospective data analysis. J Clin Psychiatry. 2011;72(11):1439–1444. PubMed CrossRef
  3. Lehman AF, Lieberman JA, Dixon LB, et al; American Psychiatric Association; Steering Committee on Practice Guidelines. Practice Guideline for the Treatment of Patients With Schizophrenia, Second Edition. Am J Psychiatry. 2004;161(suppl):1–56. PubMed
  4. Siskind D, Orr S, Sinha S, et al. Rates of treatment-resistant schizophrenia from first-episode cohorts: systematic review and meta-analysis. Br J Psychiatry. 2022;220(3):115–120. PubMed
  5. Chan SKW, Chan HYV, Honer WG, et al. Predictors of treatment-resistant and clozapine-resistant schizophrenia: a 12-year follow-up study of first-episode schizophrenia-spectrum disorders. Schizophr Bull. 2021;47(2):485–494. PubMed CrossRef
  6. Warnez S, Alessi-Severini S. Clozapine: a review of clinical practice guidelines and prescribing trends. BMC Psychiatry. 2014;14(1):102. PubMed CrossRef
  7. Vos T, Haby MM, Magnus A, et al. Assessing cost-effectiveness in mental health: helping policy-makers prioritize and plan health services. Aust N Z J Psychiatry. 2005;39(8):701–712. PubMed CrossRef
  8. Kirwan P, O’Connor L, Sharma K, et al. The impact of switching to clozapine on psychiatric hospital admissions: a mirror-image study. Ir J Psychol Med. 2019;36(4):259–263. PubMed CrossRef
  9. Siskind D, Reddel T, MacCabe JH, et al. The impact of clozapine initiation and cessation on psychiatric hospital admissions and bed days: a mirror image cohort study. Psychopharmacology (Berl). 2019;236(6):1931–1935. PubMed CrossRef
  10. Masuda T, Misawa F, Takase M, et al. Association with hospitalization and all-cause discontinuation among patients with schizophrenia on clozapine vs other oral second-generation antipsychotics: a systematic review and meta-analysis of cohort studies. JAMA Psychiatry. 2019;76(10):1052–1062. PubMed CrossRef
  11. Tang C, Subramaniam M, Ng BT, et al. Clozapine use in first-episode psychosis: The Singapore Early Psychosis Intervention Programme (EPIP) perspective. J Clin Psychiatry. 2016;77(11):e1447–e1453. PubMed CrossRef
  12. Howes OD, Vergunst F, Gee S, et al. Adherence to treatment guidelines in clinical practice: study of antipsychotic treatment prior to clozapine initiation. Br J Psychiatry. 2012;201(6):481–485. PubMed CrossRef
  13. Alessi-Severini S, Le Dorze J-A, Nguyen D, et al. Clozapine prescribing in a Canadian outpatient population. PLoS One. 2013;8(12):e83539. PubMed CrossRef
  14. Shah P, Iwata Y, Brown EE, et al. Clozapine response trajectories and predictors of non-response in treatment-resistant schizophrenia: a chart review study. Eur Arch Psychiatry Clin Neurosci. 2020;270(1):11–22. PubMed CrossRef
  15. Gee S, Vergunst F, Howes O, et al. Practitioner attitudes to clozapine initiation. Acta Psychiatr Scand. 2014;130(1):16–24. PubMed CrossRef
  16. Daod E, Krivoy A, Shoval G, et al. Psychiatrists’ attitude towards the use of clozapine in the treatment of refractory schizophrenia: a nationwide survey. Psychiatry Res. 2019;275:155–161. PubMed CrossRef
  17. Grover S, Balachander S, Chakarabarti S, et al. Prescription practices and attitude of psychiatrists towards clozapine: a survey of psychiatrists from India. Asian J Psychiatr. 2015;18:57–65. PubMed CrossRef
  18. Farooq S, Choudry A, Cohen D, et al. Barriers to using clozapine in treatment-resistant schizophrenia: systematic review. BJPsych Bull. 2019;43(1):8–16. PubMed CrossRef
  19. Cheung EFC, Lam LCW, Hung SF. Mental health in Hong Kong: transition from hospital-based service to personalised care. Int Psychiatry. 2010;7(3):62–64. PubMed CrossRef
  20. Nielsen J, Dahm M, Lublin H, et al. Psychiatrists’ attitude towards and knowledge of clozapine treatment. J Psychopharmacol. 2010;24(7):965–971. PubMed CrossRef
  21. Leung JG, Cusimano J, Gannon JM, et al. Addressing clozapine under-prescribing and barriers to initiation: a psychiatrist, advanced practice provider, and trainee survey. Int Clin Psychopharmacol. 2019;34(5):247–256. PubMed CrossRef
  22. Stahl SM. Clozapine: is now the time for more clinicians to adopt this orphan? CNS Spectr. 2014;19(4):279–281. PubMed CrossRef
  23. Singh B, Hughes AJ, Roerig JL. Comfort level and barriers to the appropriate use of clozapine: a preliminary survey of us psychiatric residents. Acad Psychiatry. 2020;44(1):53–58. PubMed CrossRef
  24. Verdoux H, Quiles C, Bachmann CJ, et al. Prescriber and institutional barriers and facilitators of clozapine use: a systematic review. Schizophr Res. 2018;201:10–19. PubMed CrossRef
  25. Kalaria SN, Kelly DL. Development of point-of-care testing devices to improve clozapine prescribing habits and patient outcomes. Neuropsychiatr Dis Treat. 2019;15:2365–2370. PubMed CrossRef
  26. Netherlands Clozapine Collaboration Group. Guideline for the Use of Clozapine [English version]. 2013. https://www.clozapinepluswerkgroep.nl/wp-content/uploads/2013/07/Guideline-for-the-use-of-Clozapine-2013.pdf
  27. Schulte P. Risk of clozapine-associated agranulocytosis and mandatory white blood cell monitoring. Ann Pharmacother. 2006;40(4):683–688. PubMed CrossRef
  28. Gee S, Gaughran F, MacCabe J, et al. Management of clozapine treatment during the COVID-19 pandemic. Ther Adv Psychopharmacol. 2020;10:2045125320928167. PubMed CrossRef
  29. Zhang M, Owen RR, Pope SK, et al. Cost-effectiveness of clozapine monitoring after the first 6 months. Arch Gen Psychiatry. 1996;53(10):954–958. PubMed CrossRef
  30. Siskind D, Honer WG, Clark S, et al. Consensus statement on the use of clozapine during the COVID-19 pandemic. J Psychiatry Neurosci. 2020;45(3):222–223. PubMed CrossRef
  31. Chan SKW, So HC, Hui CLM, et al. 10-year outcome study of an early intervention program for psychosis compared with standard care service. Psychol Med. 2015;45(6):1181–1193. PubMed CrossRef
  32. Ho CSH, Ho RCM, Mahendran R. The evolving mental health landscape in Singapore. Adv Psychiatr Treat. 2014;20(4):293–294. CrossRef
  33. Hui C, Wong G, Lam Y, et al. Patient-clinician communication and needs identification for outpatients with schizophrenia in Hong Kong: role of the 2-COM Instrument. Hong Kong J Psychiatry. 2008;18(2):69–75.
  34. Kelly DL, Freudenreich O, Sayer MA, et al. Addressing barriers to clozapine underutilization: a national effort. Psychiatr Serv. 2018;69(2):224–227. PubMed CrossRef
  35. Tang JY, Wong GH, Hui CL, et al. Early intervention for psychosis in Hong Kong—the EASY programme. Early Interv Psychiatry. 2010;4(3):214–219. PubMed CrossRef
  36. Thien K, O’Donoghue B. Delays and barriers to the commencement of clozapine in eligible people with a psychotic disorder: a literature review. Early Interv Psychiatry. 2019;13(1):18–23. PubMed CrossRef
  37. Maryan S, Harms M, McAllister E, et al. Comparison of clozapine monitoring and adverse event management in a psychiatrist-only and a clinical pharmacist-psychiatrist collaborative clinic. Ment Health Clin. 2019;9(2):70–75. PubMed CrossRef
  38. Kelly DL, Love RC. Psychiatric pharmacist’s role in overcoming barriers to clozapine use and improving management. Ment Health Clin. 2019;9(2):64–69. PubMed CrossRef
  39. Chan CY, Chua BY, Subramaniam M, et al. Clinicians’ perceptions of pharmacogenomics use in psychiatry. Pharmacogenomics. 2017;18(6):531–538. PubMed CrossRef
  40. Hui CLM, Wong AKH, Leung WWT, et al. Psychiatrists’ opinion towards medication discontinuation in remitted first-episode psychosis: a multi-site study of the Asian Network for Early Psychosis. Early Interv Psychiatry. 2019;13(6):1329–1337. PubMed CrossRef