Gaboxadol hydrobromide is a GABA agonist. It is an inhibitor of GABA uptake systems. Gaboxadol can also be a non-opioid analgesic and a novel type of hypnotic.
AR-A 2 is a selective 5-HT1B receptor antagonist, with a high affinity to guinea pig cortex 5HT1B 1D and recombinant guinea pig 5-HT1B receptors (Ki: 0.24 and 0.47 nM) and with 10-fold lower affinity to guinea pig 5-HT1D receptor (Ki: 5 nM).