Azepexole dihydrochloride (B-HT 933), a potent and selective alpha 2-adrenoceptor agonist, exhibits affinity for α2A-, α2B-, and α2C-adrenoceptor subtypes with pKis of 8.3, 7.6, and 7.5, respectively [1]. It elicits a concentration-dependent inhibition of peristaltic contractions, evidenced by an IC50 of 78.72 nM.

In normoglycemic rats, Azepexole dihydrochloride dose-dependently inhibits sympathetically-induced vasopressor responses at 1 and 3 μg/kg.min (i.v.), with no further inhibition observed at doses of 10 and 30 μg/kg.min. Conversely, in diabetic rats, 1 and 3 μg/kg.min doses of Azepexole dihydrochloride do not alter electrically-induced vasopressor responses, whereas all frequencies of stimulation are significantly reduced by 10 μg/kg.min B-HT 933 dihydrochloride. At a dose of 30 μg/kg.min, Azepexole dihydrochloride similarly achieves supramaximal inhibition of these responses.