Histamine trifluoromethyl toluidide
Histamine trifluoromethyl toluidide (HTFMT) is a mixed H1/H2 histamine agonist which is significantly more potent than histamine itself. It also produces additional actions which appear to be independent of histamine receptors. References 

Histamine agonists
Imidazoles
Trifluoromethyl compounds