ICD-10 Specific code J30.1: Allergic rhinitis due to pollen

Azelastine, a phthalazinone derivative is classified as a potent long-acting anti-allergic compound with selective H₁ antagonist properties. An additional anti-inflammatory effect could be detected after topical ocular administration. Data from in vivo (pre-clinical) and in vitro studies show that azelastine inhibits the synthesis or release of the chemical mediators known to be involved in early and late stage allergic reactions e.g. leukotriene, histamine, PAF and serotonin.

Budesonide is a glucocorticosteroid with a high local anti-inflammatory effect. At doses clinically equivalent to systemically acting glucocorticosteroids, budesonide gives significantly less HPA axis suppression and has a lower impact on inflammatory markers.

Cetirizine, a human metabolite of hydroxyzine, is a potent and selective antagonist of peripheral H₁-receptors. In vitro receptor binding studies have shown no measurable affinity for other than Η₁-receptors.

Chlorphenamine is a potent antihistamine (H₁-antagonist). Antihistamines diminish or abolish the actions of histamine in the body by competitive reversible blockade of histamine H₁-receptor sites on tissues. Chlorphenamine also has anticholinergic activity.

Cyproheptadine is a first generation antihistamine which also has anticholinergic and antiserotonergic activities that is used to treat allergic conditions including seasonal rhinitis, conjunctivitis, dermatitits and urticaria.

Desloratadine is a non-sedating, long-acting histamine antagonist with selective peripheral H₁-receptor antagonist activity. After oral administration, desloratadine selectively blocks peripheral histamine Η₁-receptors because the substance is excluded from entry to the central nervous system.

Dexchlorpheniramine, the d-isomer of the racemic compound chlorpheniramine, is two times more active than chlorpheniramine. Dexchlorpheniramine does not prevent the release of histamine, but rather, competes with free histamine for binding at the H₁-receptor sites, and competitively antagonizes the effects of histamine on H₁-receptors in the GI tract, uterus, large blood vessels, and bronchial muscle. Blockade of H₁-receptors also suppresses the formation of oedema, flare, and pruritus that result from histaminic activity. Since dexchlorpheniramine binds to central and peripheral H₁-receptors, sedative effects are likely to occur. Dexchlorpheniramine has high antihistaminic activity, moderate anticholinergic effects and minimal sedative effects.

Dimetindene is an antihistaminic of the alkylamine group. Its action is the result of the capture of histamine Η₁ subunits. It has mild anticholinergic and sedative action.

Ebastine has been shown to produce a rapid and long-lasting inhibition of histamine-induced effect and to have a strong affinity towards H₁-receptors.

Fexofenadine is a non-sedating H₁ antihistamine. Fexofenadine is a pharmacologically active metabolite of terfenadine.

Fluticasone has anti-inflammatory and vasoconstrictive features. Fluticasone given by inhalation at recommended doses has a potent glucocorticoid anti-inflammatory action within the lungs, resulting in a reduction of both symptoms and exacerbations of asthma, with a lower incidence and severity of adverse effects than those observed when corticosteroids are administered systemically.

Fluticasone furoate is a synthetic trifluorinated corticosteroid that possesses a very high affinity for the glucocorticoid receptor and has a potent anti-inflammatory action.

Ketotifen is a histamine H₁-receptor antagonist. In vivo animal studies and in vitro studies suggest the additional activities of mast cell stabilisation and inhibition of infiltration, activation and degranulation of eosinophils.

Levocabastine is a potent, fast-acting and highly selective histamine H1-antagonist with a sustained duration of action.

Levocetirizine, the ® enantiomer of cetirizine, is a potent and selective antagonist of peripheral H₁-receptors. Pharmacodynamic studies in healthy volunteers demonstrate that, at half the dose, levocetirizine has comparable activity to cetirizine, both in the skin and in the nose.

Loratadine is a tricyclic antihistamine with selective, peripheral H₁-receptor activity. Loratadine has no clinically significant sedative or anticholinergic properties in the majority of the population and when used at the recommended dosage.

Mequitazine is a phenothiazine derivative with the actions and uses of antihistamines. Antihistamines diminish or abolish the main actions of histamine in the body by competitive, reversible blaockade of histamine receptor site on tissues; they do not inactivate histamine or prevent its synthesis or release. Antihistamines are used for palliative treatment of allergic reactions.

Methylprednisolone is a synthetic glucocorticoid and a methyl derivative of prednisolone. Methylprednisolone is a potent anti-inflammatory agent with the capacity to profoundly inhibit the immune system.

Mizolastine possesses antihistamine and antiallergic properties due to a specific and selective antagonism of peripheral histamine H₁ receptors.

Mometasone is a topical glucocorticoid with local anti-inflammatory properties. It is likely that much of the mechanism for the effects of mometasone lies in its ability to inhibit the release of mediators of the inflammatory cascade.

Promethazine is a potent, long acting, antihistamine with additional anti-emetic central sedative and anti-cholinergic properties.

Rupatadine is a second-generation antihistamine, long-acting histamine antagonist, with selective peripheral H1-receptor antagonist activity. Some of the metabolites (desloratadine and its hydroxylated metabolites) retain an antihistaminic activity and may partially contribute to the overall efficacy of the drug.