Phenotypic Assessment of Drug Metabolic Pathways and P-Glycoprotein in Patients Treated With Antidepressants in an Ambulatory Setting

Drug-metabolizing enzymes (DMEs), such as cytochrome P450 (CYP) enzymes, and transporters have emerged as major determinants of variability in drug metabolism and response. This study investigated the association between CYP and P-glycoprotein activities and plasma antidepressant concentration in an outpatient clinical setting. Secondary outcomes were antidepressant efficacy and tolerance. We also describe phenotypes in patients treated with antidepressants and evaluate the tolerance of a minimally invasive phenotyping approach.