Search results
Results From The WOW.Com Content Network
H 1 antagonists, also called H 1 blockers, are a class of medications that block the action of histamine at the H 1 receptor, helping to relieve allergic reactions.Agents where the main therapeutic effect is mediated by negative modulation of histamine receptors are termed antihistamines; other agents may have antihistaminergic action but are not true antihistamines.
It is classified as a second-generation antihistamine because it is less able to pass the blood–brain barrier and cause sedation, compared to first-generation antihistamines. [12] [13] It was patented in 1979 and came into medical use in 1996. [14] It is on the World Health Organization's List of Essential Medicines. [15]
H2: Products approved for food-adjacent use. No food contact allowed. Machinery parts that do not touch food. H3: Soluble oils for rust prevention. Hooks and trolleys in food processing plants. HX-1: Additives for H1 lubricants (incidental contact). Enhancing properties of H1 lubricants. HX-2: Additives for H2 lubricants (no contact).
H 1-antihistamines work by binding to histamine H 1 receptors in mast cells, smooth muscle, and endothelium in the body as well as in the tuberomammillary nucleus in the brain. Antihistamines that target the histamine H 1-receptor are used to treat allergic reactions in the nose (e.g., itching, runny nose, and
Cimetidine was the prototypical histamine H 2 receptor antagonist from which later drugs were developed. Cimetidine was the culmination of a project at Smith, Kline & French (SK&F; now GlaxoSmithKline) by James W. Black, C. Robin Ganellin, and others to develop a histamine receptor antagonist that would suppress stomach acid secretion.
Diphenhydramine, sold under the brand name Benadryl among others, is an antihistamine and sedative. It is a first-generation H 1-antihistamine and it works by blocking certain effects of histamine, which produces its antihistamine and sedative effects. [11] [2] Diphenhydramine is also a potent anticholinergic. [12]
Clemastine, also known as meclastin, is a first-generation H1 histamine antagonist (antihistamine) with anticholinergic properties (drying) and sedative side effects. [1] Like all first-generation antihistamines, it is sedating. [2] [3] Patented in 1960, it came into medical use in 1967. [4]
Hydroxyzine, sold under the brand names Atarax and Vistaril among others, is an antihistamine medication. [8] It is used in the treatment of itchiness, anxiety, insomnia, and nausea (including that due to motion sickness). [8] It is used either by mouth or injection into a muscle. [8] Hydroxyzine works by blocking the effects of histamine. [9]