Vortioxetine-d 8 (Lu AA 21004-d 8 ) hydrobromide is the deuterated form of Vortioxetine. Vortioxetine (Lu AA 21004) is an antagonist of 5-HT 3A and 5-HT 7 receptors ( K i : 3.7 nM, 19 nM) and an inhibitor of 5-hydroxytryptamine transporter ( SERT ) ( K i : 1.6 nM), as well as a 5-HT 1A agonist and a partial 5-HT 1B agonist ( K i : 15 nM, 33 nM).