SLC6A4 and Coma: In contrast, vortioxetine, a serotonin modulator and stimulator, was least associated with somnolence and potently inhibits the serotonin transporter (SERT) with a Ki = 1.6 nM, however weakly binds to the 5-HT2C receptor with a Ki = 180 nM and the NET with a Ki = 113 nM (D’Agostino, English & Rey, 2015; Di & Kerns, 2015; Roth et al., 2000).