Quantitative Determination of Citalopram and its Metabolite Desmethycitalopram in Plasma by High Performance Liquid Chromatography

Citalopram has by far the highest selectivity for serotonin reuptake and is used for the treatment of depression. Therapeutic drug monitoring is clinically important for psychiatrists in terms of therapy success. In this work a simplified, rapid, sensitive, selective and validated high performance liquid chromatographic method for the determination of racemic citalopram and its main metabolite desmethylcitalopram in human plasma using protriptyline as internal standard was developed. The compounds were extracted with solid phase extraction using C-18 extraction cartridges. Calibration curves were linear over a working range 10-150 ng ml-1 for citalopram and 5-75 ng ml-1 for desmethylcitalopram. High percentage recovery values were obtained from compounds. Precision data as well as accuracy were satisfactory. Therefore, the method can be used for therapeutic drug monitoring of desmethylcitalopram and citalopram in patients treated with citalopram.