How do they work?
Antihistamines are inhibitors of histamine receptors. They do not affect its production, but two types of blocking specific receptors:
– The H1-receptor, responsible for allergic reactions. H1 blocking antihistamines provide symptomatic improvement in different types of allergic reactions: hay fever, allergic rhinitis …
– H2 receptors are involved in disorders of the stomach ulcer and duodenum, and in case of gastro esophageal reflux disease. In the treatment of allergic reactions, H2 blockers have only a limited value. However, they may be indicated in the treatment of certain atopic disease such as chronic urticaria.