Reduced clearance of venlafaxine in a combined treatment with quetiapine

Publication date: 13 July 2018 Source:Progress in Neuro-Psychopharmacology and Biological Psychiatry, Volume 85 Author(s): Michael Paulzen, Georgios Schoretsanitis, Christoph Hiemke, Gerhard Gründer, Ekkehard Haen, Marc Augustin Venlafaxine and the atypical antipsychotic quetiapine are often administered concomitantly. Both drugs share several metabolic hepatic pathways. However, pharmacokinetic interactions between venlafaxine and quetiapine have not been studied yet. A therapeutic drug monitoring database containing serum concentrations of venlafaxine (VEN) and its active metabolite O-desmethylvenlafaxine (ODVEN) was analyzed. Two groups of patients were compared: venlafaxine monotherapy V 0 (n = 153) and co-medication with quetiapine, V QUE (n = 71). Serum concentrations of VEN, ODVEN, and active moiety, AM (VEN + ODVEN), metabolite to parent compound ratio (ODVEN/VEN) and dose adjusted serum concentrations were compared using non-parametrical tests without information on CYP2D6 genotype. The two groups did not differ in terms of the daily dosage of venlafaxine, age, or sex. Median serum concentrations in the quetiapine group showed significantly, 15.8% and 29.3% higher values for AM and ODVEN (p = 0.002, Cohen's d = 0,41; p = 0.003, d = 0,44), respectively. Dose adjusted serum concentrations of active moiety and ODVEN revealed comparable differences (p = 0.038, d = 0,32; p = 0.015, d = 0,28) with significantly higher va...
Source: Progress in Neuro Psychopharmacology and Biological Psychiatry - Category: Psychiatry Source Type: research