Therapeutic drug monitoring of quetiapine regarding plasma level concentration and dependence from daily dosage

In the treatment of schizophrenic psychosis, modern atypical antipsychotic agents have increasingly been used in recent years. We want to report our management of the atypical antipsychotic Quetiapine, a 5HT2/D2 antagonist with affinity for H1 and alpha 1 receptors, in a clinical context in a German State Hospital. Results in measuring the plasma level concentrations of Quetiapine (N=220) will be presented which were found in therapeutic drug monitoring (TDM) of this antipsychotic agent. Various clinical parameters like antipsychotic and antidepressive comedication, daily dosage of Quetiapine and the psychopathological clinical status of the patient were investigated in detail since January 2001. Plasma level concentrations of Quetiapine were examined depending on sex, height, weight, diagnosis, side effects, comedication and age of the patients. Special interest in this investigation was focussed on the reasons and clinical indications for carrying out a therapeutic drug monitoring. Main indication was the control of compliance. The study has been focused on observed various side effects of Quetiapine associated with medication dosage and interactions with psychotropic comedication.