title: Desvenlafaxine and venlafaxine exert minimal in vitro inhibition of human cytochrome P450 and P-glycoprotein activities.
abstract: OBJECTIVE
  Identification of potential pharmacokinetic drug-drug interactions is an important step in clinical drug development.We assessed and compared the drug-drug interaction potential of desvenlafaxine and venlafaxine, based on their inhibitory potency on human cytochrome P450 (CYP) and P-glycoprotein (P-gp) activities in vitro.
  
  
  METHODS
  Reversible inhibition of CYP1A2, CYP2A6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, and CYP3A4, and mechanism-based inhibition of CYP2C9, CYP2C19, CYP2D6, and CYP3A activity by desvenlafaxine and venlafaxine were determined in human liver microsomes.Whether these drugs were substrates for efflux or inhibitors of P-gp were determined in Caco-2 monolayers.
  
  
  RESULTS
  Desvenlafaxine and venlafaxine showed little or no reversible inhibition of various CYP enzymes (concentration that inhibits 50% [IC50] or inhibition constant [Ki] ~ or >100 muM). In addition, neither drug acted as a mechanism-based inhibitor of CYP2C9, CYP2C19, CYP2D6, or CYP3A as they did not reduce the IC50 value for any of these enzymes in the presence of preincubations with or without a nicotinamide adenine dinucleotide phosphate-regenerating system. Desvenlafaxine and venlafaxine showed little inhibition of P-gp activity (IC50 values >250 muM) and did not act as substrates (efflux ratios <2) for efflux in Caco-2 monolayers.
  
  
  CONCLUSIONS
  Considering in vitro and available clinical data, desvenlafaxine and venlafaxine appear to have low potential for pharmacokinetic drug-drug interactions via inhibiting the metabolic clearance of concomitant drugs that are substrates of various CYP enzymes, in particular CYP2D6. In addition, these data suggest that desvenlafaxine and venlafaxine exhibit little potential for pharmacokinetic interactions with concomitant drugs that are substrates or inhibitors of P-gp.
authors.affiliation: Incyte Corp, Wilmington, DE, USA.
authors.forename: Aram
authors.initials: A
authors.lastname: Oganesian
authors.forename: Adam D
authors.initials: AD
authors.lastname: Shilling
authors.forename: Ruth
authors.initials: R
authors.lastname: Young-Sciame
authors.forename: Judy
authors.initials: J
authors.lastname: Tran
authors.forename: Adiba
authors.initials: A
authors.lastname: Watanyar
authors.forename: Farooq
authors.initials: F
authors.lastname: Azam
authors.forename: John
authors.initials: J
authors.lastname: Kao
authors.forename: Louis
authors.initials: L
authors.lastname: Leung
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000187:drug effects* / Q000378:metabolism; D000928:Antidepressive Agents / Q000008:administration & dosage / Q000494:pharmacology; D018938:Caco-2 Cells; D003511:Cyclohexanols / Q000008:administration & dosage / Q000494:pharmacology*; D019389:Cytochrome P-450 CYP2D6 / Q000187:drug effects / Q000378:metabolism; D003577:Cytochrome P-450 Enzyme System / Q000187:drug effects* / Q000378:metabolism; D000069468:Desvenlafaxine Succinate; D004347:Drug Interactions; D006801:Humans; D066298:In Vitro Techniques; D020128:Inhibitory Concentration 50; D008862:Microsomes, Liver / Q000187:drug effects / Q000201:enzymology; D000069470:Venlafaxine Hydrochloride
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000928:Antidepressive Agents; D003511:Cyclohexanols; D000069470:Venlafaxine Hydrochloride; D003577:Cytochrome P-450 Enzyme System; D019389:Cytochrome P-450 CYP2D6; D000069468:Desvenlafaxine Succinate