Antihistamine - Inhibitors of histamine release. These agents appear to stabilise the mast cells to prevent degranulation and mediator release. cromoglicate (cromolyn) nedocromil Antihistamine - H2-receptor antagonists. Main article: H2-receptor antagonist Clinically-relevant histamine H2-receptors are found principally in the parietal cells of the gastric mucosa. H2-receptor "antagonists" are also inve ...

See also:

Antihistamine, Antihistamine - Pharmacology, Antihistamine - Clinical use of antihistamines, Antihistamine - Indications, Antihistamine - Adverse drug reactions, Antihistamine - First-generation H1-receptor antagonists, Antihistamine - Ethylenediamines, Antihistamine - Ethanolamines, Antihistamine - Alkylamines, Antihistamine - Piperazines, Antihistamine - Tricyclics, Antihistamine - Common structural features of classical antihistamine, Antihistamine - Second-generation H1-receptor antagonists, Antihistamine - Systemic, Antihistamine - Topical, Antihistamine - Common structural features of non-sedating antihistamines, Antihistamine - Third-generation H1-receptor antagonists, Antihistamine - Systemic, Antihistamine - Other agents, Antihistamine - Inhibitors of histamine release, Antihistamine - H2-receptor antagonists, Antihistamine - H3- and H4-receptor antagonists, Antihistamine - Other agents with antihistaminergic activity

Read more here: » Antihistamine: Encyclopedia II - Antihistamine - Other agents

See also:

Antihistamine, Antihistamine - Pharmacology, Antihistamine - Clinical use of antihistamines, Antihistamine - Indications, Antihistamine - Adverse drug reactions, Antihistamine - First-generation H1-receptor antagonists, Antihistamine - Ethylenediamines, Antihistamine - Ethanolamines, Antihistamine - Alkylamines, Antihistamine - Piperazines, Antihistamine - Tricyclics, Antihistamine - Common structural features of classical antihistamine, Antihistamine - Second-generation H1-receptor antagonists, Antihistamine - Systemic, Antihistamine - Topical, Antihistamine - Common structural features of non-sedating antihistamines, Antihistamine - Third-generation H1-receptor antagonists, Antihistamine - Systemic, Antihistamine - Other agents, Antihistamine - Inhibitors of histamine release, Antihistamine - H2-receptor antagonists, Antihistamine - H3- and H4-receptor antagonists, Antihistamine - Other agents with antihistaminergic activity

Read more here: » Antihistamine: Encyclopedia II - Antihistamine - First-generation H₁-receptor antagonists

These are newer drugs that are much more selective for peripheral H1 receptors in preference to the central nervous system histaminergic and cholinergic receptors. This selectivity significantly reduces the occurrence of adverse drug reactions compared with first-generation agents, while still providing effective relief of allergic conditions. Antihistamine - Systemic. acrivastine astemizole cetirizine loratadine mizolastine terfenadine (withdrawn from ...

See also:

Antihistamine, Antihistamine - Pharmacology, Antihistamine - Clinical use of antihistamines, Antihistamine - Indications, Antihistamine - Adverse drug reactions, Antihistamine - First-generation H1-receptor antagonists, Antihistamine - Ethylenediamines, Antihistamine - Ethanolamines, Antihistamine - Alkylamines, Antihistamine - Piperazines, Antihistamine - Tricyclics, Antihistamine - Common structural features of classical antihistamine, Antihistamine - Second-generation H1-receptor antagonists, Antihistamine - Systemic, Antihistamine - Topical, Antihistamine - Common structural features of non-sedating antihistamines, Antihistamine - Third-generation H1-receptor antagonists, Antihistamine - Systemic, Antihistamine - Other agents, Antihistamine - Inhibitors of histamine release, Antihistamine - H2-receptor antagonists, Antihistamine - H3- and H4-receptor antagonists, Antihistamine - Other agents with antihistaminergic activity

Read more here: » Antihistamine: Encyclopedia II - Antihistamine - Second-generation H₁-receptor antagonists

An antihistamine is a drug which serves to reduce or eliminate effects mediated by histamine, an endogenous chemical mediator released during allergic reactions, through action at the histamine receptor. Only 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. In common use, the term antihistamine refers only to H1-receptor antagonists, also known as HIncluding:

Antihistamine - Pharmacology Antihistamine - Clinical use of antihistamines
Antihistamine - Indications Antihistamine - Adverse drug reactions
Antihistamine - First-generation H1-receptor antagonists
Antihistamine - Ethylenediamines Antihistamine - Ethanolamines Antihistamine - Alkylamines Antihistamine - Piperazines Antihistamine - Tricyclics Antihistamine - Common structural features of classical antihistamine
Antihistamine - Second-generation H1-receptor antagonists
Antihistamine - Systemic Antihistamine - Topical Antihistamine - Common structural features of non-sedating antihistamines
Antihistamine - Third-generation H1-receptor antagonists
Antihistamine - Systemic
Antihistamine - Other agents
Antihistamine - Inhibitors of histamine release Antihistamine - H2-receptor antagonists Antihistamine - H3- and H4-receptor antagonists Antihistamine - Other agents with antihistaminergic activity

Read more here: » Antihistamine: Encyclopedia - Antihistamine

Brompheniramine Brompheniramine is an antihistaminergic medication of the propylamine class. It is commonly available over the counter and is indicated for the treatment of the symptoms of the common cold and allergic rhinitis, such as runny nose, itchy eyes, watery eyes, and sneezing. It is a first-generation antihistamine. Brompheniramine works by acting as an antagonist of the H1 histamine receptors. It also functions as a moderately effective anticholingeric agent, likely an antimuscarinic agent similar ...

Read more here: » Brompheniramine: Encyclopedia - Brompheniramine

Promethazine (sold as Phenergan and Promethegan) is a first-generation H1 receptor antagonist (antihistamine) and anti-nausea medication available by prescription in the United States, and over-the-counter in the United Kingdom, Switzerland, Australia, South Africa, New Zealand and many other countries. Promethazine belongs to the phenothiazine class of drugs. It can be prescrib ...

See also:

Promethazine, Promethazine - General Remarks and Pharmacology, Promethazine - Indications, Promethazine - Contraindications, Promethazine - Side Effects, Promethazine - Interactions, Promethazine - Dosage, Promethazine - Laboratory Examinations

Read more here: » Promethazine: Encyclopedia II - Promethazine - General Remarks and Pharmacology

Small hypodermic syringes are used to inject commercial allergen extracts. Injections are normally given into the loose tissue over the back of the upper arm, half way between the shoulder and elbow. Injections are given under the skin ("subcutaneous"). This is the least painful place to inject allergen, as there are few nerve endings in the skin. When given correctly, the injections should be slightly uncomfortable. They are not normally painful and are usually well tolerated by adults and teenagers. Some doctors may advise you to take an antihistamine a few hours before each injection to reduce the likelihood of l ...

See also:

Hyposensitization, Hyposensitization - Clinical Experience and Research, Hyposensitization - Benefits from Immunotherapy, Hyposensitization - Mechanism of Therapeutic Action, Hyposensitization - Indications for Immunotherapy, Hyposensitization - Age Considerations, Hyposensitization - Procedure, Hyposensitization - Side Effects and Adverse Reactions

Read more here: » Hyposensitization: Encyclopedia II - Hyposensitization - Procedure

Cimetidine was the prototypical histamine H2-receptor antagonist from which the later members of the class were developed. Cimetidine was the culmination of a project at Smith, Kline & French (SK&F; now GlaxoSmithKline) to develop a histamine receptor antagonist to suppress stomach acid secretion. At the time (1964) it was known that histamine was able to stimulate the secretion of stomach acid, but also that traditional antihistamines had no effect on acid production. In the process, the SK&F scient ...

See also:

H₂-receptor antagonist, H₂-receptor antagonist - History and development, H₂-receptor antagonist - Pharmacology, H₂-receptor antagonist - Clinical use of H2-antagonists, H₂-receptor antagonist - Indications, H₂-receptor antagonist - Adverse drug reactions, H₂-receptor antagonist - Drug interactions, H₂-receptor antagonist - Examples

Read more here: » H₂-receptor antagonist: Encyclopedia II - H₂-receptor antagonist - History and development

In allergic reactions an allergen (a type of antigen) interacts with and cross-links surface IgE antibodies on mast cells and basophils. Once the mast cell-antibody-antigen complex is formed, a complex series of events occurs that eventually leads to cell-degranulation and the release of histamine (and other chemical mediators) from the mast cell or basophil. Once released, histamine can react with local or widespread tissues through histamine receptors. Histamine, acting on H1-receptors, produces pruritis, vasodilatation, hypotension, flushing, headache, tachycardia, bronchoconstriction, increases vascular permeabili ...

See also:

Antihistamine, Antihistamine - Pharmacology, Antihistamine - Clinical use of antihistamines, Antihistamine - Indications, Antihistamine - Adverse drug reactions, Antihistamine - First-generation H1-receptor antagonists, Antihistamine - Ethylenediamines, Antihistamine - Ethanolamines, Antihistamine - Alkylamines, Antihistamine - Piperazines, Antihistamine - Tricyclics, Antihistamine - Common structural features of classical antihistamine, Antihistamine - Second-generation H1-receptor antagonists, Antihistamine - Systemic, Antihistamine - Topical, Antihistamine - Common structural features of non-sedating antihistamines, Antihistamine - Third-generation H1-receptor antagonists, Antihistamine - Systemic, Antihistamine - Other agents, Antihistamine - Inhibitors of histamine release, Antihistamine - H2-receptor antagonists, Antihistamine - H3- and H4-receptor antagonists, Antihistamine - Other agents with antihistaminergic activity

Read more here: » Antihistamine: Encyclopedia II - Antihistamine - Pharmacology

Antihistamine - Indications. H1-antihistamines are clinically used in the treatment of histamine-mediated allergic conditions. Specifically, these indications may include: (Rossi, 2004) allergic rhinitis allergic conjunctivitis allergic dermatological conditions (contact dermatitis) urticaria angioedema pruritus (atopic dermatitis, insect bites) anaphylactic or anaphylactoid reactions - adjunct only nausea and vomiting (first-generation H1-antihistamines)

These are the active enantiomer (levocetirizine, desloratadine) or metabolite (fexofenadine) derivatives of second-generation drugs intended to have increased efficacy with fewer adverse drug reactions. Indeed, fexofenadine is associated with a decreased risk of cardiac arrhythmia compared to terfenadine. However, there is little evidence for any advantage of levocetirizine or desloratadine, compared to cetirizine or loratadine respectively. Antihistamine - SystemicSee also:

Antihistamine, Antihistamine - Pharmacology, Antihistamine - Clinical use of antihistamines, Antihistamine - Indications, Antihistamine - Adverse drug reactions, Antihistamine - First-generation H1-receptor antagonists, Antihistamine - Ethylenediamines, Antihistamine - Ethanolamines, Antihistamine - Alkylamines, Antihistamine - Piperazines, Antihistamine - Tricyclics, Antihistamine - Common structural features of classical antihistamine, Antihistamine - Second-generation H1-receptor antagonists, Antihistamine - Systemic, Antihistamine - Topical, Antihistamine - Common structural features of non-sedating antihistamines, Antihistamine - Third-generation H1-receptor antagonists, Antihistamine - Systemic, Antihistamine - Other agents, Antihistamine - Inhibitors of histamine release, Antihistamine - H2-receptor antagonists, Antihistamine - H3- and H4-receptor antagonists, Antihistamine - Other agents with antihistaminergic activity

Read more here: » Antihistamine: Encyclopedia II - Antihistamine - Third-generation H₁-receptor antagonists