SB-334867 (free base)

SB-334867 free base (SB334867A free base) is an excellent, selective and blood–brain barrier permeable orexin-1 (OX1) receptor antagonist, shows selectivity over OX2 (pK_b=7.4), 100-fold over 5-HT_2B, 5-HT_2C with pK_i values of 5.4 and 5.3, respectively^[1]. SB-334867 reduces ethanol consumption and inhibits the acquisition of morphine-induced sensitization to locomotor activity in vivo^[2][3]. In Vitro: SB-334867 (100 pM– 10 μM) inhibits the orexin-A (10 nM) and orexin-B (100 nM)-induced calcium responses in a concentration-dependent manner, with apparent pK_b values of 7.27±0.04 and 7.23±0.03, but has no effect on the calcium response elicited by UTP (3 μM), which activates an endogenous purinergic receptor in CHO-OX1 and CHO-OX2 cells^[4].
In Vivo: SB-334867 (intraperitoneal injection; 20 mg/kg; 20 days) administers 15 min before morphine injection can significantly decrease the effect of the morphine challenge dose in mice in comparison with the sporadically morphine-treated group^[2].
SB-334867 (intraperitoneal injection; 3, 10 and 30 mg/kg) significantly reduces ethanol intake relative to vehicle and does not effect water consumption in female P rats^[3].
SB-334867 (intraperitoneal injection; 3, 10 and 30 mg/kg) reduces ethanol consumption at the 30 mg/kg dose, high dose suppresses sucrose intake relative to vehicle, and it results in lower blood ethanol concentrations (BECs) relative to both the 10 and 30 mg/kg doses^[3].