what is antihistamine
Antihistamines are drugs that block the action of histamine (a compound released in allergic inflammatory reactions) at the H1 receptor sites, responsible for immediate hypersensitivity reactions such as sneezing and itching.
Antihistamines are a type of medicine often used to treat a number of allergic health conditions. Although antihistamines can't cure these conditions, they often provide relief from symptoms. For example, antihistamines may be used to treat: hay fever.