hydroxyethylpromethazine hydroxyethylpromethazine hydroxyethylpromethazine is an antihistamine with anticholinergic properties. it is structurally analogous to promethazine. hydroxyethylpromethazineclinical dataatc coder06ad05 (who) identifiers iupac name n-(2-hydroxyethyl)-n,n-dimethyl-1-(10h-phenothiazin-10-yl)propan-2-aminium cas number7647-63-4pubchem cid16406chemspider15559 yunii571559slajchemical and physical dataformulac19h25n2os+molar mass329.48 g·mol−13d model (jsmol)interactive image smiles occ(c)(c)c(c)cn1c3c(sc2c1cccc2)cccc3 inchi inchi=1s/c19h25n2os/c1-15(21(2,3)12-13-22)14-20-16-8-4-6-10-18(16)23-19-11-7-5-9-17(19)20/h4-11,15,22h,12-14h2,1-3h3/q+1 ykey:pdsvtrqobuiqbq-uhfffaoysa-n y (verify)