title: The pharmacology of citalopram enantiomers: the antagonism by R-citalopram on the effect of S-citalopram.
abstract: Recent results on the in vivo and in vitro pharmacology of escitalopram are summarised. The exact molecular mechanism by which R-citalopram inhibits the effect of S-citalopram on the serotonin transporter remains to be elucidated. Preliminary evidence indicates an effect of R-citalopram on the association of escitalopram with the high affinity primary site, and on its dissociation from the serotonin transporter, via an allosteric mechanism. Escitalopram can be considered as an allosteric serotonin reuptake inhibitor. This serotonin dual action in binding to two sites on the serotonin transporter (both the primary site and the allosteric site) is hypothesised to be responsible for a longer binding to, and therefore greater inhibition of the serotonin transporter by escitalopram.
authors.affiliation: H. Lundbeck A/S, Neuropharmacological Research, Ottiliavej 9, DK-2500 Valby, Copenhagen, Denmark. cs@lundbeck.com
authors.forename: Connie
authors.initials: C
authors.lastname: Sánchez
mesh_terms: D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D015283:Citalopram / Q000737:chemistry / Q000494:pharmacology*; D006801:Humans; D008954:Models, Biological; D044263:Receptors, Serotonin, 5-HT1 / Q000502:physiology; D012701:Serotonin / Q000378:metabolism*; D050486:Serotonin Plasma Membrane Transport Proteins / Q000502:physiology*; D017367:Selective Serotonin Reuptake Inhibitors / Q000737:chemistry / Q000494:pharmacology; D013237:Stereoisomerism
chemical_list: D015283:Citalopram; D044263:Receptors, Serotonin, 5-HT1; D012701:Serotonin; D050486:Serotonin Plasma Membrane Transport Proteins; D017367:Selective Serotonin Reuptake Inhibitors