MRK-898 is an orally active GABA(A) receptor modulator. MRK-898 binds to α1, α2, α3 or α5 subunit of GABA(A) receptor with Ki values of 1.2 nM, 1.0 nM, 0.73 nM, and 0.50 nM, respectively. However, α1-containing GABA(A) receptors are identified as the "sedative" and α2- and/or α3-containing receptors as the "anxiolytic" subtype(s)[1].
[1]. Atack JR. GABAA receptor subtype-selective modulators. I. α2/α3-selective agonists as non-sedating anxiolytics. Curr Top Med Chem. 2011;11(9):1176-202.