The chemical Promethazine has a known molecular formula of C17-H20-N2-S. Synonyms may include: A-91033, 4-27-00-01253 (Beilstein Handbook Reference), 3277 RP, Aprobit, Atosil, Avomine, BRN 0088554, CCRIS 7056, Dimapp, Dimethylamino-isopropyl-phenthiazin [German], N-Dimethylamino-2-methylethyl thiodiphenylamine, (2-Dimethylamino-2-methyl)ethyl-N-dibenzoparathiazine (ChemID). Promethazine has been assigned a MeSH pharmacological action of: Histamine H1 Antagonist.