| Research Article: | Comparison of the Effectiveness and Safety of Clozapine Between Once-Daily and Divided Dosing Regimen in Patients With Treatment-Resistant Schizophrenia |
| Author: | Thanompong Sathienluckana, Thaksin Jansing, Supakan Srisuriyakamon, Aunchalee thonkhunthod, Parsiri Sangsuwanto, Pholphat Losatiankij and Suttha Supanya |
| Email: | thanompong.sat@siam.edu ; thaksin.jan@siam.edu |
| Department|Faculty: | Faculty of Pharmacy, Siam University, Bangkok 10160 |
| Published: | Annals of Pharmacotherapy. 2023 Sep 24;10600280231201708. doi: 10.1177/10600280231201708. |
Citation
Sathienluckana T, Jansing T, Srisuriyakamon S, Thonkhunthod A, Sangsuwanto S, Losatiankij P and Supanya S. (2023). Comparison of the effectiveness and safety of clozapine between once-daily and divided dosing regimen in patients with treatment-resistant schizophrenia. Annals of Pharmacotherapy, 10600280231201708, doi: 10.1177/10600280231201708
ABSTRACT
Background: Clozapine is the most effective antipsychotic with respect to the incidence of discontinuation and is indicated for treatment-resistant schizophrenia. Although the recommendation for clozapine administration is divided dosing, oncedaily dosing of clozapine is commonly prescribed in many countries. However, there is currently no clinical data comparing all-cause discontinuation between the 2 methods of administration of clozapine. Objectives: To compare the all-cause discontinuation and safety of clozapine administration between once-daily and divided dosing regimens. Methods: This was a retrospective cohort study. Participants were patients with treatment-resistant schizophrenia who had received 300 to 600 mg/day of clozapine for at least 3 months. Data were collected from outpatient medical records at Somdet Chaopraya Institute of Psychiatry. Eligible patients were classified into 2 groups: once-daily dosing and divided dosing. The primary outcome was the all-cause discontinuation rate between groups. The duration of the study was 2 years. Results: One hundred eighteen patients were included and analyzed in this study (once-daily dosing group: n = 58; divided dosing group: n = 60). There was no significant difference in all-cause discontinuation between the 2 groups (odds ratio 1.03; 95% confidence interval: [0.28, 3.79]: P = 1.00), or adverse events between groups. Conclusion and Relevance: In patients with treatment-resistant schizophrenia, there were no significant differences in effectiveness or safety between once-daily and divided dosing of clozapine. Further prospective studies with larger sample sizes are required to confirm these findings.
Keywords: clozapine, treatment-resistant schizophrenia, once-daily dosing, divided dosing.
Comparison of the Effectiveness and Safety of Clozapine Between Once-Daily and Divided Dosing Regimen in Patients With Treatment-Resistant Schizophrenia
Faculty of Pharmacy, Siam University, Bangkok, Thailand