The Effect of Age, Sex, Smoking and Co-Medication on Serum Levels of Venlafaxine and O-Desmethylvenlafaxine under Naturalistic Conditions

Venlafaxine (VEN) is a modern antidepressant which exerts both serotonin and norepinephrine reuptake inhibition. In this study we examined the influence of age, sex, smoking, and co-medication on serum levels of VEN and its metabolite O-desmethylvenlafaxine (ODVEN) in patients treated with VEN under naturalistic conditions.We retrospectively evaluated 478 TDM analyses of VEN requested in the Pychiatric University Hospitals of Mainz, Regensburg, and Würzburg. The determination of serum levels was performed by virtually identical chromatographic methods in the TDM laboratories of the participating hospitals.Serum levels varied widely on each dose level. Women had about 30% higher dose-correct…