ATC Group: R01A Decongestants and other nasal preparations for topical use

Antazoline is an antagonist of histamine H1 receptors. It selectively bind to but does not activate histamine H1 receptors, thereby blocking the actions of endogenous histamine, which subsequently leads to temporary relief of the negative symptoms brought on by histamine.

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.

Beclometasone is a pro-drug with weak glucocorticoid receptor binding affinity. It is extensively hydrolysed via esterase enzymes to the active metabolite beclometasone-17-monopropionate (B-17-MP), which has potent topical anti-inflammatory activity.

Betamethasone is a glucocorticoid which is about eight to ten times as active as prednisolone on a weight-for-weight basis. Betamethasone has anti-inflammatory, antipruritic, and vasoconstrictive properties.

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.

Ciclesonide exhibits low binding affinity to the glucocorticoid-receptor. Once orally inhaled, ciclesonide is enzymatically converted in the lungs to the principal metabolite (C21-des-methylpropionyl-ciclesonide) which has a pronounced anti-inflammatory activity and is thus considered as the active metabolite.

Sodium cromoglicate (Cromoglicic acid) inhibits the activation of many of the cell types involved in the development and progression of asthma. Thus, sodium cromoglicate inhibits the release of inflammatory mediators including cytokines from mast cells and reduces the chemotactic activity of eosinophils and neutrophils.

Dexamethasone is a synthetic glucocorticoid; it combines high anti-inflammatory effects with low mineralocorticoid activity. It has an approximately 7 times greater anti-inflammatory potency than prednisolone, another commonly prescribed corticosteroid. At high doses it reduces the immune response.

Ephedrine is a sympathomimetic amine acting directly on the alpha and beta receptors and indirectly by increasing the release of noradrenaline by the sympathetic nerve endings. As with any sympathomimetic agent, ephedrine stimulates the central nervous system, the cardiovascular system, the respiratory system, and the sphincters of the digestive and urinary systems.

Epinephrine is a direct acting sympathomimetic agent, which exerts effects on both α and β adrenoceptors. It has more pronounced effects on β than on α adrenoceptors, although α effects prevail at high doses. The effects of adrenaline include increased rate and force of cardiac contraction, cutaneous vasoconstriction and broncho-dilatation.

Flunisolide is a glucocorticoid and it is several hundred times more potent than the cortisol standard. The principal mechanism of action of flunisolide is to activate glucocorticoid receptors, meaning it has an anti-inflammatory action. It is used for the treatment of allergic rhinitis.

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.

Ipratropium is a quaternary ammonium compound with anticholinergic (parasympatholytic) properties. Ipratropium appears to inhibit vagally mediated reflexes by antagonising the action of acetylcholine, the transmitter agent released from the vagus nerve. Anticholinergics prevent the increase in intracellular concentration of Ca++, which is caused by interaction of acetylcholine with the muscarinic receptor on bronchial smooth muscle. Ca++ release is mediated by the second messenger system consisting of IP3 (inositol triphosphate) and DAG (diacylglycerol).

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

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.

Mupirocin is a novel antibiotic produced through fermentation by Pseudomonas fluorescens. Mupirocin inhibits isoleucyl transfer-RNA synthetase, thereby arresting bacterial protein synthesis. Mupirocin has bacteriostatic properties at minimum inhibitory concentrations and bactericidal properties at the higher concentrations reached when applied locally.

Naphazoline is a sympathomimetic amine with pronounced alpha adrenergic activity and as a consequence has vasoconstrictor activity.

Nedocromil is a non-steroidal agent, which has anti-inflammatory properties when administered topically in the lung. In the treatment of bronchial asthma, nedocromil sodium reduces bronchospasm, cough and bronchial hyperreactivity and improves objective measurements of lung function.

Olopatadine is a potent selective antiallergic/antihistaminic agent that exerts its effects through multiple distinct mechanisms of action.

Oximetazoline is an imidazoline derivative. It exhibits sympathomimetic activity and specifically stimulates the α-adrenergic receptors of the sympathetic system. When administered topically to the nose it causes vasoconstriction of the expansed arterioles of the mucosal nose and a concurrent reduction in blood flow. It also reduces the hypersecretion of the nasal mucosa, ultimately contributing to the decongestion of the nasal mucosa.

Phenylephrine is a sympathomimetic agent with mainly direct effects on adrenergic receptors. It has predominantly alpha adrenergic activity and is without stimulating effects on the central nervous system. The sympathomimetic effect of phenylephrine produces vasoconstriction which in turn relieves nasal congestion.

Prednisolone is a glucocorticoid which has anti-inflammatory activity. Naturally occurring glucocorticoids (hydrocortisone and cortisone), which also have salt-retaining properties, are used as replacement therapy in adrenocortical deficiency states. Their synthetic analogs are primarily used for their potent anti-inflammatory effects in disorders of many organ systems.

Tetryzoline is an alpha adrenergic receptor agonist, which is used in form of nasal solution or spray for decongestion of nasal and nasopharyngeal mucosa.

Tixocortol is a 21-thiol derivative of hydrocortisone classified as a class A corticosteroid. It is a synthetic steroid with topical anti-inflammatory properties without the systemic glucocorticoid and mineralocorticoid activities and toxicity.

Tramazoline is an α-sympathomimetic agent with local action, which mainly causes vasoconstriction and therefore immediately reduces mucosal edema.

Triamcinolone acetonide is a more potent derivative of triamcinolone and is approximately 8 times more potent than prednisone. Although the precise mechanism of corticosteroid anti-allergic action is unknown, corticosteroids are very effective in the treatment of allergic diseases in man. Also, local injections are thought to have an anti-inflammatory effect.

Xylometazoline acts directly on α-adrenoreceptors but does not act on β-receptors. When used topically as a nasal decongestant, xylometazoline acts rapidly and provides long-lasting relief. Onset of action is within minutes, the decongestant effect being prolonged and lasting for up to 10 hours.