Clozapine-associated elevation of plasma cholinesterase

Objective The goal of this study was to identify adverse effects of the atypical neuroleptic clozapine on liver function and lipid metabolism. Methods Data which included serum levels of clozapine and its hepatic metabolite N-desmethyl clozapine were collected from medical records of patients treated with clozapine and controls. Results We identified a clozapine-associated marked elevation of plasma cholinesterase (ChE) with unchanged levels of AST, ALT or g-GT. ChE was correlated to the serum level of clozapine and even closer to N-desmethyl clozapine. For the total patient group we observed significant correlations of ChE with the body-mass index and body weight. However, clozapine-treated patients and controls did not differ with regard to body-mass index, triglycerides, and cholesterol. Conclusion We report for the first time a clozapine-associated and dose-dependent elevation of plasma ChE, which may be related to clozapine-associated effects on hepatic lipid metabolism or ChE enzyme induction.