title: Concomitant use of selective serotonin reuptake inhibitors with other cytochrome P450 2D6 or 3A4 metabolized medications: how often does it really happen?
abstract: This study retrospectively examines the one-month concomitant use of cytochrome P450 2D6 or 3A4 metabolized medications in 544,309 patients who were also receiving selective serotonin reuptake inhibitors (SSRIs). Overall, 25.53% of SSRI patients experienced concomitant use with at least one of the 33 studied CYP 2D6 or 3A4 metabolized medications. Certain drugs and drug classes were more likely to be used concurrently among SSRI patients (e.g., benzodiazepines, tricyclic antidepressants, calcium channel blockers). Similarly, of the SSRI patients experiencing concomitant use, this concurrent use was twice as likely with cytochrome P450 medications metabolized by the 3A4 isoenzyme as with those metabolized by the 2D6 isoenzyme. Finally, the vast majority (80.9%) of SSRI patients experiencing concomitant use did so with one CYP 2D6 or 3A4 metabolized medication. In sum, concomitant use generally was not extensive and did not appear to be differential among the fluoxetine, paroxetine, or sertraline patient comparison groups.
authors.affiliation: Outcomes Research, PCS Health Systems, Inc., Scottsdale, Arizona 85260, USA.
authors.forename: K J
authors.initials: KJ
authors.lastname: Gregor
authors.forename: K
authors.initials: K
authors.lastname: Way
authors.forename: C H
authors.initials: CH
authors.lastname: Young
authors.forename: S P
authors.initials: SP
authors.lastname: James
mesh_terms: D015057:1-Naphthylamine / Q000031:analogs & derivatives / Q000494:pharmacology; D019389:Cytochrome P-450 CYP2D6 / Q000502:physiology; D065690:Cytochrome P-450 CYP2D6 Inhibitors; D051544:Cytochrome P-450 CYP3A; D065607:Cytochrome P-450 Enzyme Inhibitors; D003577:Cytochrome P-450 Enzyme System / Q000502:physiology; D003866:Depressive Disorder / Q000201:enzymology*; D004347:Drug Interactions; D004359:Drug Therapy, Combination; D005473:Fluoxetine / Q000494:pharmacology; D006801:Humans; D008099:Liver / Q000187:drug effects* / Q000201:enzymology; D008657:Metabolic Clearance Rate / Q000187:drug effects* / Q000502:physiology; D006899:Mixed Function Oxygenases / Q000037:antagonists & inhibitors* / Q000502:physiology; D017374:Paroxetine / Q000494:pharmacology; D011619:Psychotropic Drugs / Q000493:pharmacokinetics; D012189:Retrospective Studies; D012307:Risk Factors; D017367:Selective Serotonin Reuptake Inhibitors / Q000494:pharmacology*; D020280:Sertraline
chemical_list: D015057:1-Naphthylamine; D019389:Cytochrome P-450 CYP2D6; D065690:Cytochrome P-450 CYP2D6 Inhibitors; D051544:Cytochrome P-450 CYP3A; D065607:Cytochrome P-450 Enzyme Inhibitors; D003577:Cytochrome P-450 Enzyme System; D005473:Fluoxetine; D006899:Mixed Function Oxygenases; D017374:Paroxetine; D011619:Psychotropic Drugs; D017367:Selective Serotonin Reuptake Inhibitors; D020280:Sertraline; C104464:CYP3A protein, human