Vortioxetine-d8 (Lu AA 21004-d8) hydrobromide is the deuterated form of Vortioxetine. Vortioxetine (Lu AA 21004) is an antagonist of 5-HT3A and 5-HT7 receptors (Ki: 3.7 nM, 19 nM) and an inhibitor of 5-hydroxytryptamine transporter (SERT) (Ki: 1.6 nM), as well as a 5-HT1A agonist and a partial 5-HT1B agonist (Ki: 15 nM, 33 nM)[1].