The worldâs largest wine glass has been unveiled in Lebanon, blowing Portugalâs previous 1998 record out of the water. Guinness World Records rep Elizabeth Smith hands over the certificate to the brains behind the worldâs largest wine glass (EPA)
An antihistamine is a type of pharmaceutical drug that opposes the activity of histamine receptors in the body.Antihistamines are subclassified according to the histamine receptor that they act upon: the two largest classes of antihistamines are H1-antihistamines and H2-antihistamines.n H3-antihistamine is a classification of drugs used to inhibit the action of histamine at the H3 receptor. H 3 receptors are primarily found in the brain and are inhibitory autoreceptors located on histaminergic nerve terminals, which modulate the release of histamine.
When an antihistamine is administered, it prevents histamine from reaching the receptors on cells at the site of the irritation, thereby preventing the allergic reaction from taking place. Some classes are designed to block receptors throughout the body.