Discovered in 1933 by Jeff Forneau and Daniel Bovent, Piperoxan was the first antihistamine available to humans. As a result, the two scientists received the Nobel Prize in 1957. An antihistamine is formally known as a drug that eliminates the effects as mediated by the natural chemical histamine. The body releases histamine to act as a receptor during allergic reactions. Therefore, an antihistamine is an agent that therapeutically affects the body by mediating a negative modulation of the histamine receptors. Once in the body, antihistamine competes with histamine for binding receptor sites. Therefore, antihistamine is unable to remove histamines if already bound to a receptor site. If the antihistamine binds to the receptor first, the histamine will not be able to overtake the site.
Causes of Allergies
Allergies that cause the release of histamine in the body can be caused by a number of different factors. However, all allergies are a hypersensitivity reaction of an antibody on mast cells in tissues as well as basophils in the blood. When an allergen is encountered in the body, it binds directly to the antibody which activates the mast cells resulting in the release of histamines. These histamines cause inflammatory responses which range from runny nose and sneezing to anaphylactic shock. Furthermore, allergies are hereditary in most cases. If both parents have allergies, their offspring has a 70 percent chance of also being inflicted.
Types of Antihistamines
There are two types of antihistamine, sedating and non-drowsy. Typically, patients take the sedating antihistamine before going to bed to help alleviate symptoms during the night so they are able to have regular sleep. Sedating versions of the drug enter the brain thus causing the drowsy feeling. The most commonly used sedating antihistamine is promethazine, hydroxyzine and alimemazine. Non-drowsy antihistamine is taken during the day so the patient can continue with their daily functions. This version of the drug does not enter the brain and therefore is does not result in drowsiness. The most widely-used non-drowsy antihistamine is cetirizine and loratadine.
Summary of Non Drowsy Antihistamines
Against popular belief, non-drowsy antihistamine is not suitable for everyone as they have a variety of side-effects that can result in worst conditions like glaucoma, retention of urine, obstruction of the gut and an enlarged prostate. Additionally, for those with kidney or liver disease, a lower dose is usually in order. Therefore, non-drowsy antihistamine should always be administered with caution. Furthermore, if not totally essential it should not be administered, especially in pregnant women unless prescribed by a doctor. Also, non-drowsy antihistamine can be used in children of specific ages. For instance, hydroxyzine should not be used on children under six months of age while promethazine and alimemazine are not recommended for children under two years old. As always, when seeing a doctor for any allergic problems, it is important to reveal any other medicines being administered including herbal and over-the-counter medications. Non-drowsy antihistamine is a powerful and effective treatment for allergic reactions but should always be ingested according to the doctor's orders and directions on the package.