Effects of clozapine/norclozapine level on metabolic side-effects, cognitive functions and functionality in patients wit schizophrenia

Objective: The aim of this study was to evaluate the relationship between clozapine/ norclozapine ratio and quality of life, cogntive functions, metabolic parameters and to determine the predictors of quality of life in treatment-resistant schizophrenia patients using clozapine. Material and Method: Thirty schizophrenic patients using clozapine and 30 healty controls were included in our study to compare metabolic parameters. Schizophrenia patients were first evaluated with semi-structured sociodemographic form and then PANSS, FROGS, SMMT, WCST, TMT, RAVLT tests were applied. Venous blood was taken from both the patient and control groups to evaluate metabolic parameters. The obtained data were was statistically analyzed by SPSS 22 programme. Results: No correlation was found between clozapine/norclozapine ratio and BMI, metabolic parameters, leptin and ghrelin levels of schiophrenia patients (p 0.05). A correlation was found between the clozapine/norclozapine ratio and the patients' quality of life, which was evaluted with FROGS both in the social domain and between the total FROGS scores ( p0.05) When the patients were evaluated in terms of neurocognitive function, a positive correlation (r: 0.524; p0.03), between TMT A; a negative correlation (r: -0.411; p0.024) between RAVLT total 5 and a negative corelation (r:-0.423, p0.005) was found. In the Multiple Linear Regression Analysis performed for the total FROGS score, it was determined that the PANSS total score, WCST total perseverative error number and RAVLT Proximal Memory Score were predictors of FROGS total score. Conclusion: In our study, we found that clozapine/norclozapine ratios are associated with quality of life, psychomotor speed, attention and memory functions of schizophrenia patients using clozapine. We also found that disease severity and cognitive functions predict quality of life in patients witg schizophrenia. Keywords: Clozapine, Norclozapine, Schizophrenia, Neurocognitive Functions, Quality of Life