Histamine antagonist

A histamine antagonist is a medicine used to reduce or block the effects of histamine. This endogenous chemical mediator is particularly released in allergic reactions. It is also involved in regulating consciousness, awareness – a factor that is very important here – and in gastric secretion. Histamine antagonists are used in the management of allergy for their antihistaminergic properties.

How do the histamine antagonists work?

Histamine antagonists are histamine receptor inhibitors. Therefore, they do not affect its production but block two categories of specific receptors.

• Firstly, H1 receptors responsible for allergic reactions. H1 histamine antagonists produce symptomatic improvement in different types of allergic reactionshttp://www.futura-sciences.com/fr/doc/t/medecine-1/d/allergie-decryptage-allergies_942/c3/221/p1/: hay fever, allergic rhinitis… .
• Secondly, H2 receptors are involved in stomach and duodenal ulcer problems and in gastro-oesophageal reflux. H2 histamine antagonists only have limited use in the management of allergic reactions. On the other hand, they may be used to treat some atopic diseases such as chronic urticaria.

Source: Merck Manual – 4^th Edition