Therapeutic Drug Monitoring of Vancomycin: The Relationship Between Trough Plasma Concentration and Creatinine Clearance

Background: In this study which was conducted in Besat hospital (Hamadan, Iran), the therapeutic drugmonitoring (TDM) of vancomycin (VAN) was carried out based on the quantification of VAN trough inintensive care unit (ICU) patients.Methods: The study population was selected from ICU patients treated by intravenous VAN. To determineVAN trough, blood samples were taken from patients before the fourth dose. Then, trough concentrationswere determined by newly developed high-performance liquid chromatography (HPLC) and comparedwith the conventional method of immunoassay. Twenty patients were included based on the aim of thestudy.Results: The mean value of the trough for the studied patients was ۲۶.۳۱±۱۸.۰۵ μg/mL. For ۱۶ (۸۰%)patients, trough levels were found to be less than ۱۰ μg/mL. For ۱۲ (۶۰%) patients, creatinine clearancewas less than ۹۰ mL/min and more than ۱۲۰ mL/min. The mean value of creatinine clearance for thestudied patients was ۹۵.۴۹± ۲۵.۷۴ mL/min. Based on the results, there was a significant relationshipbetween VAN trough concentration and creatinine clearance (P=۰.۰۴۵).Conclusion: In general, the HPLC method is more sensitive than immunoassay for the determination ofVAN in plasma samples. However, VAN dosing based on creatinine clearance is not enough for achievingthe goal trough level but measuring the creatinine clearance and trough concentration are considered asvital aspects for the TDM of VAN.

Keywords:

Vancomycin , Therapeutic drug monitoring , Trough concentration , Creatinine clearance , Intensive care unit