Objectives: Venlafaxine is metabolized by CYP2D6 to O-desmethylvenlafaxine (ODV) and by CYP3A4 to N-desmethylvenlafaxine (NDV). CYP2C19 is also involved in the formation of ODV. The PPIs omeprazole and pantoprazole inhibit CYP2C19 to a different extent. Aim of this study was to investigate the potential effects of both PPIs on serum levels of VEN and ODV. Methods: From a therapeutic drug monito...