MRK-898, an orally active modulator of the GABA(A) receptor, selectively interacts with the α1, α2, α3, and α5 subunits, displaying K i values of 1.2 nM, 1.0 nM, 0.73 nM, and 0.50 nM, respectively. It is noteworthy that the α1-containing receptors of GABA(A) are classified as "sedative," whereas receptors containing α2 and/or α3 are designated as "anxiolytic" subtype(s) [1].

α3 GABA(A) receptor:0.73 nM (Ki), α1 GABA(A) receptor:1.2 nM (Ki), α2 GABA(A) receptor:1.0 nM (Ki)