– Brompheniramine ((±)-Brompheniramine) is a potent, orally active alkylamine class antihistamine and a selective antagonist of the histamine H1 receptor (Kd = 6.06 nM). It has applications in the research of allergic rhinitis and exhibits anticholinergic, antidepressant, and anesthetic properties. Brompheniramine blocks calcium channels, sodium channels, and hERG channels with IC50 values of 16.12 μM, 21.26 μM, and 0.90 μM, respectively [1] [2] [3] [4].