H1 antagonist

H1 antagonists, also called H1 blockers, are a class of medications that block the action of histamine at the H1 receptor, helping to relieve allergic reactions. Agents where the main therapeutic effect is mediated by negative modulation of histamine receptors are termed antihistamines; other agents may have antihistaminergic action but are not true antihistamines.[citation needed]

In common use, the term "antihistamine" refers only to H1-antihistamines. Virtually all H1-antihistamines function as inverse agonists at the histamine H1-receptor, as opposed to neutral antagonists, as was previously believed.[1][2][3]

  1. ^ Leurs R, Church MK, Taglialatela M (April 2002). "H1-antihistamines: inverse agonism, anti-inflammatory actions and cardiac effects". Clinical and Experimental Allergy. 32 (4): 489–98. doi:10.1046/j.0954-7894.2002.01314.x. PMID 11972592. S2CID 11849647.
  2. ^ Cite error: The named reference :1 was invoked but never defined (see the help page).
  3. ^ Khilnani G, Khilnani AK (September 2011). "Inverse agonism and its therapeutic significance". Indian Journal of Pharmacology. 43 (5): 492–501. doi:10.4103/0253-7613.84947. PMC 3195115. PMID 22021988.