1. Nonselective (H1+H2+H3) agonists:
Histamine
Betahistine
2.Selective H1 agonists:
2-Methylhistamine
2-Pyridyl ethylamine
2-Thiazolyl ethylamine
3. Selective H2 agonists:
4-Methylhistamine
Dimaprit
Impromidine
4. Selective H3 agonists
(R) α-Methylhistamine
Imetit
HISTAMINERGIC AGONISTS