Investigation of MDR1 Gene Polymorphism and Losartan Plasma Concentration in Patients Undergoing Hypertensive Episodes While Under Losartan Treatment

20 ml of blood was collected from the enrolled patients. 10 ml of blood was stored in the tubes with ethylene diamine tetraacetic acid (EDTA) until Deoxyribonucleic acid (DNA) isolation was performed at -20 degrees and plasma level was identified. The remaining 10 ml was centrifuged at 3500 rpm for 10 min, and the plasma was separated. The resulting plasmas were stored in the eppendorf tubes at -20°C until the tandem mass spectrometry measurement. The blood samples in EDTA tubes were then transferred for DNA analysis. . To measure plasma losartan concentration, after the frozen plasma samples stored in the eppendorfs were thawed and brought to room temperature, plasma losartan and EXP3174 levels of the patients were calculated using tandem mass spectrometry