How Do Nasal Decongestants Work


– Nasal decongestants: how do they work?

– Nasal decongestant medications 

– Contraindications and recommendations for the use of vasoconstrictor decongestants

Congestion is “an abnormal increase of blood in an organ or tissue.” We speak of passive congestion when it is caused by an obstacle hindering blood flow and active congestion due to local irritation of tissues.

The term decongestant refers mainly to certain medications used to treat congestion of the nasal mucosa caused by infection or allergy in colds, rhinitis, or sinusitis (active congestion).

These decongestants effectively and quickly treat uncomfortable symptoms due to nasal congestion, such as a blocked nose, runny nose, and difficulty breathing. 

Let’s see further below.

Nasal decongestants: how do they work?

In case of infectious rhinopharyngitis, allergic rhinitis (hay fever), or sinusitis, an inflammatory process and local irritation of the nasal mucous membrane trigger sneezing and hypersecretion of mucus responsible for the nasal discharge or obstruction. 

Decongestants reduce nasal congestion by inducing peripheral vasoconstriction in the skin and mucosa. 

Their active ingredients are vasoconstrictors derived from ephedrine (a potent natural vasoconstrictor) which stimulate certain alpha-1 and alpha-2 adrenaline receptors (sympathomimetic effect): 

– Activation of alpha-1 receptors reduces blood volume in the nasal mucosa, leading to a decrease in congestion. 

– Activation of alpha-2 receptors decreases blood flow in the capillaries and reduces the extracellular fluid associated with rhinorrhea (nasal discharge).

Their vasoconstrictive effect may also result in increased blood pressure and heart rate.

You may use other classes of medications in combination with decongestants to treat other cold symptoms:

– Analgesics (such as paracetamol) or anti-inflammatory drugs (such as ibuprofen) can be used to calm pain and lower fever.

– Antihistamines (such as pheniramine) act on inflammation and reduce runny nose, sneezing, itchy nose, tingling throat, and watery eyes.

– Thinners (such as acetylcysteine) clear the airways by thinning secretions.

– Antiseptics and antibiotics fight infection.

Decongestant nasal medications


Decongestant medications come in various oral forms (tablets, capsules, sachets) or topical use (nasal drops or sprays).

Oral decongestants

Oral decongestants are effective in stopping the main symptoms of a cold quickly.

They are most often based on pseudoephedrine (vasoconstrictor) associated with an analgesic (paracetamol, ibuprofen). Examples: Rhinadvil, Rhinureflex, Dolirhume, Actifed, Humex rhume…

They are generally delivered without prescription, and most of them are not reimbursed by social security.

Due to their sympathomimetic action (similar to adrenaline), their most frequent side effects are dryness of the mucous membranes, the nervous excitement that can lead to insomnia, constipation, and increased blood pressure.

Good to know: some cold medications contain “day” doses of a vasoconstrictor (which excites) and “night” doses of an antihistamine (which puts you to sleep) in the same box.

Nasal decongestants

Medications used by the nasal route contain:

– a vasoconstrictor alone: oxymetazoline (Pernazene®, Aturgyl®);

– a vasoconstrictor associated with other classes of drugs: oxymetazoline associated with prednisolone (anti-inflammatory corticoid): Deturgylone®; ephedrine associated with benzoic acid (antiseptic): Rhinamide®, or with sodium thiosulfate (antiinfective): Rhinosulfuryl®; naphazoline associated with prednisolone (anti-inflammatory corticoid): Derinox®; phenylephrine associated with benzalkonium chloride (antiseptic): Humoxal®; tuaminoheptane associated with benzalkonium chloride (antiseptic) and acetylcysteine (fluidifier): Rhinofluimucil®.

Their prolonged use (> 10 days) may lead to ineffectiveness of the product, resulting in the need to increase doses, rebound congestion (when treatment is stopped), or medicated rhinitis. Because of these effects, nasal decongestant solutions should be used for short-term treatment and require a doctor’s prescription.

Contraindications and recommendations for the use of vasoconstrictor decongestants

Vasoconstrictor decongestants (ephedrine, naphazoline, oxymetazoline, pseudoephedrine, phenylephrine, and tuaminoheptane) are contraindicated in children under 15 years of age and in cases of severe arterial hypertension, certain forms of glaucoma (increased eye pressure), urinary retention, cardiac disorders, or previous stroke.

They are not recommended during pregnancy or while breastfeeding.

It will help if you use them with caution in hyperthyroidism, diabetes, or nervous disorders.

They may interact with other drugs. Due to the occurrence of a few serious (even fatal) cases of cardiac (hypertensive crises, cardiac rhythm disorders including atrial fibrillations…) and neurological side effects, as well as ischemic colitis, it is recommended:

– to check the indications and contraindications before starting the treatment;

– to respect the recommended dosages;

– not to use two vasoconstrictors (oral and nasal) in the same treatment;

– to limit the duration of use to 5 days;

– to stop the treatment and consult a physician in case of significant adverse effects.

Hope this post has helped you get an idea about how do nasal decongestants work. Remember to share your views in the comments below.

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