Definition A decongestant, or nasal decongestant, is a type of pharmaceutical drug that is used to relieve nasal congestion in the upper respiratory tract. The active ingredient in most decongestants is either pseudoephedrine or phenylephrine (the latter of which has disputed effectiveness). Intranasal corticosteroids can also be used as decongestants and antihistamines can be used to alleviate runny nose, nasal itch, and sneezing. [1]
Topical decongestants on topical application as dilute solution (0.05–0.1%) produce local vasoconstriction.
Regular use of decongestants for long periods should be avoided because mucosal ciliary function is impaired: atrophic rhinitis and anosmia (loss of the sense of smell) can occur due to persistent vasoconstriction.
Decongestants can be absorbed from the nose via an inhaler and produce systemic effects, mainly central nervous system stimulation and rise in blood pressure. These drugs should be used cautiously in hypertensives and in those receiving monoamine oxidase inhibitors (MAOIs), as they can cause hypertensive crisis.
Expectorants such as guaifenesin are a related type of drug which help to clear mucus.
Decongestants are used to treat nasal congestion, for instance in allergies, infections like the common cold, influenza, and sinus infection, and nasal polyps. Decongestants are also used to reduce redness in the treatment of simple conjunctivitis.
A 2016 Cochrane review found insufficient evidence to support the use of intranasal corticosteroids in the relief of common cold symptoms; [2] however, the review was based on three trials and the quality of the evidence was regarded as very low. [2]
The vast majority of decongestants act via enhancing norepinephrine (noradrenaline) and epinephrine (adrenaline) or adrenergic activity by stimulating the α1-adrenergic receptor since they mediate vasoconstriction and constricting nasal vasculature causes decongestion of nasal mucosa. This induces vasoconstriction of the blood vessels in the nose, throat, and paranasal sinuses, which results in reduced inflammation (swelling) and mucus formation in these areas.
Decongestant nasal sprays and eye drops often contain oxymetazoline and are used for topical decongestion. Pseudoephedrine acts indirectly on the adrenergic receptor system, whereas phenylephrine and oxymetazoline are direct agonists. The effects are not limited to the nose, and these medicines may cause hypertension (high blood pressure) through vasoconstriction; it is for this reason that people with hypertension are advised to avoid them. Most decongestants, however, are not pronounced stimulants, due to lack of response from the other adrenoreceptors. Besides hypertension, common side-effects include sleeplessness, anxiety, dizziness, excitability, and nervousness.
Topical nasal or ophthalmic decongestants quickly develop tachyphylaxis (a rapid decrease in the response to a drug after repeated doses over a short period of time). Long-term use is not recommended since these agents lose effectiveness after a few days.
Pseudoephedrine (PSE) is a sympathomimetic drug of the phenethylamine and amphetamine chemical classes. It may be used as a nasal/sinus decongestant, as a stimulant, or as a wakefulness-promoting agent in higher doses.
Vasoconstriction is the narrowing of the blood vessels resulting from contraction of the muscular wall of the vessels, in particular the large arteries and small arterioles. The process is the opposite of vasodilation, the widening of blood vessels. The process is particularly important in controlling hemorrhage and reducing acute blood loss. When blood vessels constrict, the flow of blood is restricted or decreased, thus retaining body heat or increasing vascular resistance. This makes the skin turn paler because less blood reaches the surface, reducing the radiation of heat. On a larger level, vasoconstriction is one mechanism by which the body regulates and maintains mean arterial pressure.
H1 antagonists, also called H1 blockers, are a class of medications that block the action of histamine at the H1 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.
Allergic rhinitis, of which the seasonal type is called hay fever, is a type of inflammation in the nose that occurs when the immune system overreacts to allergens in the air. Signs and symptoms include a runny or stuffy nose, sneezing, red, itchy, and watery eyes, and swelling around the eyes. The fluid from the nose is usually clear. Symptom onset is often within minutes following allergen exposure, and can affect sleep and the ability to work or study. Some people may develop symptoms only during specific times of the year, often as a result of pollen exposure. Many people with allergic rhinitis also have asthma, allergic conjunctivitis, or atopic dermatitis.
Topical decongestants are decongestants applied directly to the nasal cavity. Their effectiveness by themselves in the common cold appears to have a small benefit in adults.
ATC code R01Nasal preparations is a therapeutic subgroup of the Anatomical Therapeutic Chemical Classification System, a system of alphanumeric codes developed by the World Health Organization (WHO) for the classification of drugs and other medical products. Subgroup R01 is part of the anatomical group R Respiratory system.
Sympathomimetic drugs are stimulant compounds which mimic the effects of endogenous agonists of the sympathetic nervous system. Examples of sympathomimetic effects include increases in heart rate, force of cardiac contraction, and blood pressure. The primary endogenous agonists of the sympathetic nervous system are the catecholamines, which function as both neurotransmitters and hormones. Sympathomimetic drugs are used to treat cardiac arrest and low blood pressure, or even delay premature labor, among other things.
Nasal sprays are used to deliver medications locally in the nasal cavities or systemically. They are used locally for conditions such as nasal congestion and allergic rhinitis. In some situations, the nasal delivery route is preferred for systemic therapy because it provides an agreeable alternative to injection or pills. Substances can be assimilated extremely quickly and directly through the nose. Many pharmaceutical drugs exist as nasal sprays for systemic administration. Other applications include hormone replacement therapy, treatment of Alzheimer's disease and Parkinson's disease. Nasal sprays are seen as a more efficient way of transporting drugs with potential use in crossing the blood–brain barrier.
Phenylephrine is a medication used as a decongestant for uncomplicated nasal congestion, used to dilate the pupil, used to increase blood pressure, and used to relieve hemorrhoids. It can be taken by mouth, as a nasal spray, given by injection into a vein or muscle, or applied to the skin.
Oxymetazoline, sold under the brand name Afrin among others, is a topical decongestant and vasoconstrictor medication. It is available over-the-counter as a nasal spray to treat nasal congestion and nosebleeds, as eyedrops to treat eye redness due to minor irritation, and as a prescription topical cream to treat persistent facial redness due to rosacea in adults. Its effects begin within minutes and last for up to six hours. Intranasal use for longer than three days may cause congestion to recur or worsen, resulting in physical dependence.
Fluticasone propionate, sold under the brand names Flovent and Flonase among others, is a steroid medication. When inhaled it is used for the long term management of asthma and COPD. In the nose it is used for hay fever and nasal polyps. It can also be used for mouth ulcers. It works by decreasing inflammation.
Rhinitis medicamentosa is a condition of rebound nasal congestion suspected to be brought on by extended use of topical decongestants and certain oral medications that constrict blood vessels in the lining of the nose, although evidence has been contradictory.
Actifed is a registered trademark for a combination antihistamine and nasal decongestant medication used for cold and allergy symptoms. Actifed was developed in 1958 by Burroughs Wellcome & Company, later Haleon.
Levomethamphetamine is the levorotatory (L-enantiomer) form of methamphetamine. Levomethamphetamine is a sympathomimetic vasoconstrictor that is the active ingredient in some over-the-counter (OTC) nasal decongestant inhalers in the United States.
Azelastine, sold under the brand name Optivar among others, is a H1 receptor-blocking medication primarily used as a nasal spray to treat allergic rhinitis (hay fever) and as eye drops for allergic conjunctivitis. Other uses may include asthma and skin rashes for which it is taken by mouth. Onset of effects is within minutes when used in the eyes and within an hour when used in the nose. Effects last for up to 12 hours.
Mometasone, also known as mometasone y 3 s, is a steroid medication used to treat certain skin conditions, hay fever, and asthma. Specifically it is used to prevent rather than treat asthma attacks. It can be applied to the skin, inhaled, or used in the nose. Mometasone furoate, not mometasone, is used in medical products.
Fluticasone furoate, sold under the brand name Flonase Sensimist among others, is a corticosteroid for the treatment of non-allergic and allergic rhinitis administered by a nasal spray. It is also available as an inhaled corticosteroid to help prevent and control symptoms of asthma. It is derived from cortisol. Unlike fluticasone propionate, which is only approved for children four years and older, fluticasone furoate is approved in children as young as two years of age when used for allergies.
A norepinephrine releasing agent (NRA), also known as an adrenergic releasing agent, is a catecholaminergic type of drug that induces the release of norepinephrine (noradrenaline) and epinephrine (adrenaline) from the pre-synaptic neuron into the synapse. This in turn leads to increased extracellular concentrations of norepinephrine and epinephrine therefore an increase in adrenergic neurotransmission.
Pseudoephedrine/loratadine (trade names Claritin-D, Clarinase, Clarinase Repetabs, Lorinase, Rhinos SR, Allerclear-D) is an orally administered combination drug used for the treatment of allergic rhinitis and the common cold. This drug can be bought "over the counter" in some countries (United States, Hong Kong), but it is restricted to prescription in others (Czech Republic, Israel).
Nonallergic rhinitis is rhinitis—inflammation of the inner part of the nose—not caused by an allergy. Nonallergic rhinitis displays symptoms including chronic sneezing or having a congested, drippy nose, without an identified allergic reaction. Other common terms for nonallergic rhinitis are vasomotor rhinitis and perennial rhinitis. The prevalence of nonallergic rhinitis in otolaryngology is 40%. Allergic rhinitis is more common than nonallergic rhinitis; however, both conditions have similar presentation, manifestation and treatment. Nasal itching and paroxysmal sneezing are usually associated with nonallergic rhinitis rather than allergic rhinitis.