Utility of duloxetine dose-related reference ranges calculated by AGNP consensus guidelines 2017

Updated AGNP Consensus Guidelines for Therapeutic Drug Monitoring in Neuropsychopharmacology 2017 list misleading dose-related concentration factors (DRC) for duloxetine. Therefore, calculated dose-related reference ranges of duloxetine were often too low. Future pharmacokinetic studies that strongly control for intrinsic and extrinsic confounding factors that may impact the pharmacokinetics of duloxetine were needed to receive reliable pharmacokinetic data. We propose for the next update two divided duloxetine DRC, for smokers and non-smokers. DRCmean should be approximately 75% higher, for about 0.47 in smokers and 0.75 in non-smokers. Currently, calculated dose-related reference ranges of duloxetine should be applied with caution in clinical practice.

Keywords: AGNP consensus guidelines, Dose-related reference range, Serum concentration, Therapeutic Drug Monitoring, Duloxetine.