Desmethylcitalopram is an active metabolite of the antidepressant drugs citalopram (racemic) and escitalopram (the S-enantiomer, which would be called desmethylescitalopram). Like citalopram and escitalopram, desmethylcitalopram functions as a selective serotonin reuptake inhibitor (SSRI), and is responsible for some of its parentâÂÂs therapeutic benefits.