title: P-glycoprotein interactions of nefazodone and trazodone in cell culture.
abstract: This study investigated the effects of nefazodone (NFZ) and trazodone (TZD) on P-glycoprotein (P-gp) activity and expression in cell culture. NFZ and TZD showed no differential transport between the basolateral to apical and apical to basolateral direction across Caco-2 cell monolayers. Transport in either direction was not affected by verapamil. NFZ was a potent inhibitor (IC50 = 4.7 microM) of rhodamine123 (Rh123) B to A transport across Caco-2 cell monolayers, while TZD had minimal effect. Following 72-hour exposure of LS180V cells to NFZ and TZD (10 microM), a twofold increase in immunoreactive P-gp was observed. Rh123 accumulation into these cells was reduced to 65% and 74% of control by NFZ and TZD (10 microM), respectively. It was concluded that differential rates of transport of NFZ and TZD in Caco-2 cells were not evident. However, NFZ is an inhibitor of P-gp activity at clinically relevant in vivo concentrations and may have the potential to increase bioavailability of coadministered compounds that are substrates for transport. Concentrations of NFZ and TZD achieved in the intestine after chronic oral dosing may induce P-gp expression and reduce absorption of coadministered drugs.
authors.affiliation: Department of Pharmacology and Experimental Therapeutics, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA.
authors.forename: E
authors.initials: E
authors.lastname: Störmer
authors.forename: L L
authors.initials: LL
authors.lastname: von Moltke
authors.forename: M D
authors.initials: MD
authors.lastname: Perloff
authors.forename: D J
authors.initials: DJ
authors.lastname: Greenblatt
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000378:metabolism*; D018687:Antidepressive Agents, Second-Generation / Q000494:pharmacology*; D001692:Biological Transport / Q000187:drug effects; D018938:Caco-2 Cells; D002121:Calcium Channel Blockers / Q000494:pharmacology; D002851:Chromatography, High Pressure Liquid; D004347:Drug Interactions; D006801:Humans; D010879:Piperazines; D014196:Trazodone / Q000494:pharmacology*; D014230:Triazoles / Q000494:pharmacology*; D014700:Verapamil / Q000494:pharmacology
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D018687:Antidepressive Agents, Second-Generation; D002121:Calcium Channel Blockers; D010879:Piperazines; D014230:Triazoles; C051752:nefazodone; D014700:Verapamil; D014196:Trazodone