An International Adult Guideline for Making Clozapine Titration Safer by Using Ancestry-Based Personalized Dosing Titrations, C-Reactive Protein and Serum Clozapine Levels: Korean Translation and Its Clinical Application Cases

Abstract

Objectives: During the initial clozapine titration, it is crucial to monitor for inflammatory reactions to ensure safe and effective administration. Clozapine metabolism varies by ancestry, particularly among Asians, warranting lower dosage. Recently, Dr. De Leon introduced guidelines based on ancestral differences. We aimed to provide a Korean translation, focusing on illustrating the necessity through clinical cases.Methods: The Korean translation of the guidelines, approved by Dr. De Leon, involved two psychiatrists who reviewed and revised each other’s work. An additional board-certified psychiatrist conducted an independent review. We examined two clinical cases from our institution’s database, where clozapine titration faced challenges due to fever and pneumonia, assessing guideline applicability.Results: The guidelines recommend a target clozapine dose of 175-300 mg/day for Asians with average metabolism and a slower titration rate compared to other ancestries. In both cases, CRP elevation was detected either before or simultaneously with the onset of fever, with a concentration-to-dose ratio ranging from 3.06 to 6.97.Conclusion: The initial clozapine titration process should consider metabolic differences by ancestry and monitor for inflammation. Further research is needed to optimize the titration process for Koreans, considering metabolic rates, usage patterns, and side effects.