Comparative Outcomes of Clozapine Therapy in Early versus Late Initiators in Patients with Treatment-Resistant Schizophrenia
DOI:
https://doi.org/10.51253/pafmj.v75i6.12071Keywords:
Clozapine Initiation, Initiators, Schizophrenia, Treatment Resistant Schizophrenia.Abstract
Objective: To compare the outcomes of clozapine treatment in early initiators vs late initiators in patients with treatment-resistant schizophrenia
Study Design: Quasi-experimental study
Place and Duration of Study: Departments of Psychiatry Combined Military Hospital Peshawar and Combined Military Hospital Nowshera, Pakistan, from Jan 2023 to Mar 2024.
Methodology: The study included 103 patients with treatment-resistant schizophrenia, diagnosed by going over the past history and record, naive to clozapine, categorized into early (Group-A) and late (Group-B) initiators based on whether they started treatment within or after four years of diagnosis. Data was collected using a semi-structured questionnaire and Positive and Negative Syndrome Scale (PANSS) scores, with treatment efficacy evaluated via changes in these scores after three months using an independent t-test.
Results: Out of 103 patients 78(75.7%) were male and 25(24.3%) were female. The mean age of the participants was 31.49±9.06 years. Comparison of post-treatment PANSS scores between the two groups indicated a significant difference (p<0.001), suggesting that the timing of clozapine initiation impacts treatment outcomes.
Conclusion: Starting clozapine earlier in the course of illness is associated with improvement in symptoms
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References
1. Nucifora FC, Woznica E, Lee BJ, Cascella N, Sawa A. Treatment resistant schizophrenia: Clinical, biological, and therapeutic perspectives. Neurobiol Dis 2019; 131(1): 104257.
https://doi.org/10.1016/j.nbd.2018.08.016
2. 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(2): 18–23. https://doi.org/10.1111/eip.12683
3. Hatano M, Kamei H, Takeuchi I, Gomi K, Sakakibara T, Hotta S, et al. Long-term outcomes of delayed clozapine initiation in treatment-resistant schizophrenia: a multicenter retrospective cohort study. BMC Psychiatry 2023; 23(1): 1–7.
https://doi.org/10.1186/s12888-023-05176-y
4. Correll CU, Brevig T, Brain C. Patient characteristics, burden and pharmacotherapy of treatment-resistant schizophrenia: results from a survey of 204 US psychiatrists. BMC Psychiatry 2019; 19(1): 362. https://doi:10.1186/s12888-019-2318-x
5. Masuda T, Misawa F, Takase M, Kane JM, Correll CU. Association With Hospitalization and All-Cause Discontinuation Among Patients With Schizophrenia on Clozapine vs Other Oral Second-Generation Antipsychotics. JAMA Psychiatry 2019; 76(2): 1052.
https://doi.org/10.1001/jamapsychiatry.2019.1702
6. Okhuijsen-Pfeifer C, Sterk AY, Horn IM, Terstappen J, Kahn RS, Luykx JJ. Demographic and clinical features as predictors of clozapine response in patients with schizophrenia spectrum disorders: A systematic review and meta-analysis. Neurosci Biobehav Rev 2020; 111: 246–252.
https://doi.org/10.1016/j.neubiorev.2020.01.017
7. Jakobsen MI, Schaug JP, Nielsen J, Simonsen E. Antipsychotic prescribing practices for outpatients with schizophrenia and reasons for non-clozapine treatment - Data from a Danish quality assessment audit. Nord J Psychiatry 2023; 77(5): 481–490.
https://doi.org/10.1080/08039488.2022.2160878
8. Lally J, Gaughran F. Treatment resistant schizophrenia - review and a call to action. Ir J Psychol Med 2019; 36(4): 279-291.
https://doi.org/10.1017/ipm.2018.47
9. Üçok A, Çikrikçili U, Karabulut S, Salaj A, Öztürk M, Tabak Ö, et al. Delayed initiation of clozapine may be related to poor response in treatment-resistant schizophrenia. Int Clin Psychopharmacol 2015; 30(5): 290–295.
https://doi.org/10.1097/YIC.0000000000000086
10. Yoshimura B, Yada Y, So R, Takaki M, Yamada N. The critical treatment window of clozapine in treatment-resistant schizophrenia: Secondary analysis of an observational study. Psychiatry Res 2017; 250: 65–70.
https://doi.org/10.1016/j.psychres.2017.01.064
11. Köhler-Forsberg O, Horsdal HT, Legge SE, MacCabe JH, Gasse C. Predictors of Nonhospitalization and Functional Response in Clozapine Treatment. J Clin Psychopharmacol 2017; 37(2): 148–154. https://doi.org/10.1097/JCP.0000000000000649
12. Farooq S, Choudry A, Cohen D, Naeem F, Ayub M. Barriers to using clozapine in treatment-resistant schizophrenia: systematic review. BJ Psych Bull 2019; 43: 8–16.
https://doi.org/10.1192/bjb.2018.67
13. Jones R, MacCabe JH, Price MJ, Liu X, Upthegrove R. Effect of age on the relative efficacy of clozapine in schizophrenia. Acta Psychiatr Scand 2020; 142(2): 109–120.
https://doi.org/10.1111/acps.13156
Warnez S, Alessi-Severini S. Clozapine: a review of clinical practice guidelines and prescribing trends. BMC Psychiatry 2014; 14(1): 102. https://doi.org/10.1186/1471-244X-14-102
14. Matsuzaki H, Hatano M, Iwata M, Saito T, Yamada S. Effectiveness of Clozapine on Employment Outcomes in Treatment-Resistant Schizophrenia: A Retrospective Bidirectional Mirror-Image Study. Neuropsychiatr Dis Treat 2023;19: 615–622.
https://doi.org/10.2147/NDT.S402945
15. Taylor DM, Young C, Paton C. Prior antipsychotic prescribing in patients currently receiving clozapine: a case note review. J Clin Psychiatry 2003; 64(1): 30–34. https://doi.org/10.4088/jcp.v64n0107
16. Wheeler AJ, Feetam CL, Harrison J. Pathway to Clozapine Use: A Comparison Between a Patient Cohort from New Zealand and a Cohort from the United Kingdom. Clin Drug Investig 2014; 34(3): 203–211.
https://doi.org/10.1007/s40261-013-0166-x
17. Iruretagoyena B, Castañeda CP, Mena C, Diaz C, Nachar R, Ramirez-Mahaluf JP, et al. Predictors of clozapine discontinuation at 2years in treatment-resistant schizophrenia. Schizophr Res 2021; 235: 102–108.
https://doi.org/10.1016/j.schres.2021.07.024
18. Trinczek E, Heinzel-Gutenbrunner M, Haberhausen M, Bachmann CJ. Time to Initiation of Clozapine Treatment in Children and Adolescents with Early-Onset Schizophrenia. Pharmacopsychiatry 2016; 49(6): 254–259. https://doi.org/10.1055/s-0042-116947
19. Jones R, Upthegrove R, Price MJ, Pritchard M, Chandan JS, Legge S, et al. Duration of prior psychotic illness and clozapine response: a retrospective observational study using electronic health records. Ther Adv Psychopharmacol 2022;12: 20451253221103353.
https://doi:10.1177/20451253221103353
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