Antihistamine : What are Antihistamines?

By | May 23, 2011

Discussing the history of the antihistamine, its creation and origins, must begin with the histamine. What happens is that histamine is released when someone has a genetically induced allergic reaction. Henry Dale and Patrick Laidlaw discovered histamine in 1910.

An antihistamine combats the allergy-producing histamines. Allergens release large amounts of histamines – distributed on the cellular level – that cause inflammatory responses such as runny noses and eyes, nausea and sleep disorders and even stomach ulcers.

Allergies and Antihistamines

Allergies tend to be inherited. One parent with allergies makes it about 50-50 for the child inheriting the reaction. Both parents give a child a 70 percent chance of developing allergies, according to the American Academy of Asthma, Allergies and Immunology. About 50 million Americans suffer allergies costing $18 billion a year, researchers say.

Development of the Antihistamine

Jeff Forneau synthesized the first antihistamine. Daniel Bovant, assisted by Anne-Marie Staub, studied the chemical process behind the antihistamine, later marketed as Piperoxan, in 1933 while testing pigs for immune responses. A Swiss-Italian pharmacologist who lived from 1907-1992, Bovant led the group synthesizing the first antihistamines in 1937. He won the 1957 Nobel Prize in Physiology or Medicine for work developing antihistamines.

Antihistamine Treatment History

Antihistamines were first used successfully to treat people in 1942. Bernard Halpern introduced the first product, antergan. It was revised in 1944, and then introduced in the United States in 1946 as diphenhydramine and tripellinamine. Antihistamines became all the rage by 1950 as the first classes of antihistamines were introduced, including ethylenediamine, ethanolamines, alkylamines, piperazine, tricyclics.

Types of Antihistamine Treatments

Ethylenediamines were the first group of antihistamines to be clinically effective. Those led to ethanolamines, which led to Benedryl, an over-the-counter medication causing sleepiness, but considered very effective. Benedryl was used in nonprescription anti-allergy formulations such as Tylenol PM. The serotonin inhibiting properties also led to the development of antidepressants such as Prozac. Ethanolamines also were used in popular Hay fever medications marketed to children due to its mild taste. A molecular variation also was the basis for Nyquil.

Alkylamines were developed with fewer drowsiness factors. Available over the counter, they were used to treat the common cold, addressing symptoms like sneezing, runny noses and watery eyes. They are the antihistamine component in Visine-A. Piperazine was an antihistamine developed to act on parts of the brain that treat nausea and vomiting, vertigo and motion sickness. Tricyclics were antihistamines developed as antidepressants but are now used mainly for morning sickness, anti-nausea and sedation.

Second Generation Antihistamine Drugs

The second generation of antihistamine was non-sedating, providing fewer side effects. They also varied greatly as to structure and effects. These antihistamines were introduced beginning in 1981. Ranitidine, marketed as Zantac, was introduced that year, becoming the most-prescribed drug by the end of the decade. The third generation of antihistamine was developed in the 1990s with even more efficacy and fewer side effects, including far less drowsiness. This generation of drugs was being developed for potential treatment of Alzheimer’s disease. Future research will continue to focus on better effects and fewer side effects, according to analysts.