Anti-Histamines are medicines that relieve or prevent the symptoms of Hay
Fever and other kinds of allergy.
An allergy is a condition in which the body becomes unusually sensitive to
some substance, such as pollen, mold spores, dust particles, certain foods,
or medicines. These substances, known as Allergens, cause no unusual
reactions in most people. But in people who are sensitive to them, exposure
to Allergens causes the immune system to overreact. The main reaction is the
release of a chemical called Histamine from specialized cells in the body
tissues. Histamine causes such familiar and annoying allergy symptoms as
sneezing, itching, runny nose, and watery eyes.
As their name suggests, Anti-histamines block the effects of Histamine,
reducing allergy symptoms. When used for this purpose, they work best when
taken before symptoms are too severe. Anti-histamine creams and ointments
may be used to temporarily relieve itching. Some Anti-histamines are also
used to treat motion sickness, nausea, dizziness, and vomiting. And because
some cause drowsiness, they may be used as sleep aids.
Some Anti-histamine products are available only with a physician's
prescription. Others can be bought without a prescription. These drugs come
in many forms, including tablets, capsules, liquids, injections and
suppositories. Some common Anti-histamines are Astemizole (Hismanal),
Brompheniramine (Dimetane, Dimetapp), Chlorpheniramine (Deconamine),
Clemastine (Tavist), Diphenhydramine (Benadryl), Doxylamine (an ingredient
in sleep aids such as Unisom and Vicks NyQuil), Loratadine (Claritin), and