Decongestants for Allergies & Asthma


Also called: Naphazoline, Pseudoephedrine

Reviewed By:
Marc J. Sicklick, M.D., FAAAAI, FACAAI


A decongestant is a type of drug that relieves symptoms associated with nasal swelling, congestion and mucus secretion. These symptoms include runny nose, coughing, sneezing, red, teary eyes, stuffiness within the ears and even snoring. Decongestants are often used to treat symptoms associated with allergic rhinitis (hay fever), non-allergic rhinitis (cold and flu), allergic conjunctivitis and sinusitis.

Most decongestants are available over-the-counter (OTC). Several different brands are available, most using the ingredients pseudoephedrine or naphazoline. They are available in tablets, capsules, liquid, eye drops and nasal sprays. The nasal spray is often the preferred form, because it can deliver the medication to the specific problem area for quicker relief of symptoms with fewer side effects.

Because of interactions with some other medications (e.g., beta blockers, MAO inhibitors), individuals taking other drugs should consult their physicians before using a decongestant. The risk of increased blood pressure may also prevent individuals with some medical conditions (e.g., heart disease, high blood pressure, glaucoma) from using decongestants.

Rebound congestion (also known as rhinitis medicamentosa) can occur if a decongestant nasal spray is used for longer or more frequently than is directed. This condition produces symptoms of congestion very similar to the ones being treated. Individuals should not use decongestant nasal sprays for longer than three to five days.

Many parts of the United States have begun to pass laws aimed at keeping OTC medications that contain ephedrine and pseudoephedrine behind the counter – rather than on store shelves – due to widespread abuse of these drugs. In some areas it may now be necessary to ask a store clerk or pharmacist for assistance when purchasing these medications. Some stores may also require the customer to be 18 years of age or older and limit the amount of medication that can be bought at one time.

About decongestants

Decongestants are a type of drug capable of relieving many of the symptoms associated with allergies and colds (e.g., sneezing, coughing, runny nose). They work by reducing the amount of congestion in the nose and sinuses. The two main types of decongestants are pseudoephedrine and naphazoline.

Many allergy symptoms are the result of swollen tissue in the lining of the nose and sinuses and the cellular secretion of fluids into those spaces. These swellings and fluid secretions lead to symptoms such as sneezing, runny nose, red eyes and coughing. The buildup of fluids in the sinuses can cause further pressure and pain.

Decongestants treat the symptoms associated with allergic rhinitis (hay fever), non-allergic rhinitis (colds and flu), sinusitis and allergic conjunctivitis. They do not treat the underlying cause of the symptoms.

Decongestants work by helping to drain the nasal passages. The medication constricts small blood vessels, which reduces secretions into the nose and sinuses. This has the effect of reducing swollen nasal tissue, which opens up the breathing passageways. They also allow the tissue in the inner eyelid to shrink, which reduces eye irritation.

Types and differences of decongestants

There are several different types of decongestants available in several forms, including:

  • Eye drops
  • Tablet
  • Capsule
  • Liquid
  • Nasal spray

Most nasal spray decongestants work very quickly (in about 10 minutes) and can help to reduce nasal congestion for up to 12 hours. Nasal sprays also affect only the areas of the nose and sinuses, limiting the number and severity of side effects (which may include a stinging or burning sensation within the nose or nosebleeds).

Oral decongestants (tablets, capsules or liquids) begin to work in about 30 minutes and some can reduce nasal congestion for up to 24 hours. Oral forms of the medication cause blood vessels to constrict throughout the body, which can help reduce effectiveness and are more likely to cause adverse side effects (such as increased blood pressure or difficulty urinating).

Some medications combine decongestants and antihistamines, which delivers a two-pronged approach to relieving allergy symptoms. In addition to reducing nasal congestion, sneezing and other allergy symptoms, these combinations also block the histamines that the immune system uses to produce allergy symptoms.

Most decongestants are available over-the-counter (OTC) and though there are several brands available, all contain similar medicine that works in the same manner. 

Decongestants in common use include: 

Generic NameBrand Name(s)
with triprolidine
Actifed (decongestant
plus antihistamine)
with fexofenadine
Allegra-D (decongestant
plus antihistamine)
with loratadine
Claritin-D (decongestant
plus antihistamine)
with guaifenesin
Mucinex-D Extended Release (decongestant
plus expectorant)
with cetirizine
Zyrtec-D (decongestant
plus antihistamine)
naphazolineAllerest, Clear Eyes, Naphcon

It is very important not to exceed the dose of any medication, including OTC drugs. Follow all directions on the package and contact a physician if there are any questions about the medication or its effects. Depending on local laws, OTC medications with ephedrine and pseudoephedrine may be kept behind the counter – rather than on store shelves – because of widespread abuse of these drugs. It may be necessary to ask a store clerk or pharmacist for assistance when purchasing these medications. Some stores may also require the customer to be 18 years of age or older.

Conditions treated with decongestants

Decongestants are prescribed to relieve symptoms associated with a variety of conditions, including:

  • Allergic rhinitis (hay fever). Inflammation of the mucous membrane that lines the nose due to an allergic reaction. Decongestants treat the runny nose and congestion that are among the most common symptoms of allergic rhinitis.
  • Non-allergic rhinitis. Inflammation of the mucous membrane that lines the nose. Though caused by viruses rather than contact with allergens, this condition has many of the same symptoms associated with allergic rhinitis.

  • Allergic conjunctivitis. Inflammation of the tissues inside the lining of the eyelid can often be reduced with the use of decongestants (usually administered through eye drops).
  • Sinusitis. Inflammation of the lining of the sinus cavity in the face. It often leads to nasal congestion and a runny nose. Decongestants help reduce swelling of the mucous membrane in the nose and decrease mucus production.
  • Snoring. The nasal passageway often becomes obstructed with mucus during sleep, causing snoring to occur. Decongestants can help open up the nasal passageway and temporarily reduce snoring.

  • Bacterial infection. Decongestants may be prescribed to patients with bacterial infections, such as ear infections (bacterial infection of the middle ear and eardrum). Though these conditions require antibiotics to fight infection, symptoms can sometimes be treated with a decongestant before the antibiotics take full effect. Decongestants work as an adjunct, removing the favorable environment for the infection.

  • Viral infections (e.g., cold, flu). Decongestants may be used in combination with analgesics (pain relievers) or cough suppressants to help relieve symptoms such as a stuffy nose and cough.

Conditions of concern with decongestants

Decongestants can cause dangerous interactions with some medications and potentially complicate some health conditions. Patients should not take decongestants (even over-the-counter versions) unless they have consulted their physician. Patients should be particularly careful if they have been diagnosed with or are being treated for any of the following conditions:

  • Asthma. Condition in which the airways become blocked or narrowed leading to breathing difficulties. Decongestants are never recommended for asthma treatment and can actually trigger an asthma attack in some individuals.
  • Allergies to decongestants or other ephedrine-based products, as well as any other allergies (including other medications, food, pollen, dyes, etc.).

  • Heart disease. Refers to many types of diseases or conditions of the heart, which usually result from an inadequate flow of blood to the heart muscle. The elevated blood pressure that sometimes results from decongestants can complicate this condition.

  • Arrhythmias (abnormal heart rhythms). Decongestants can exacerbate this condition.

  • Hypertension (high blood pressure). Because decongestants can lead to elevated blood pressure, hypertensive individuals should avoid the drugs when possible.

  • Diabetes mellitus. Condition in which the body cannot adequately process glucose (blood sugar) for energy. Decongestants can cause an elevated blood glucose level, further complicating the condition.

  • Enlarged prostate. Condition whereby the prostate grows large enough to press on the urethra and interfere with urination. Decongestants can cause individuals with this condition to have trouble urinating.

  • Glaucoma. A group of diseases that affect the optic nerve, which connects the eye to the brain. The condition causes elevated pressure inside the eye. Decongestants can raise blood pressure, worsening this condition.

  • Raynaud syndrome. A type of peripheral vascular disease in which spasms in the small arteries in the hands and feet cause a restriction in the flow of blood to the fingers and toes. As a result, the fingers and toes turn whitish, then cold, and eventually blue.

  • Thyroid problems. Problems caused when the thyroid gland is producing too much (hyperthyroidism) or too little (hypothyroidism) of the hormones used to regulate the body’s metabolism. The use of decongestants can exacerbate these conditions.

  • Kidney disease. The use of decongestants can increase the chance of side effects. Patients with kidney disease may require a different dose.

Potential side effects of decongestants

Several types of side effects are common with decongestant use. These are usually not a cause for concern. However, if these side effects worsen or become problematic, patients should contact a physician. These side effects include:

  • Elevated blood pressure
  • Dizziness and drowsiness
  • Dry or irritated nose and nosebleeds
  • Headache
  • Loss of appetite
  • Sleep disturbance
  • Nervousness
  • Restlessness
  • Excitability

More serious side effects are occasionally experienced with decongestants. Patients experiencing these side effects should immediately inform their physician:

  • Palpitations (an awareness of a strong, fast, irregular, abnormal or “galloping” heartbeat)
  • Hallucinations
  • Weakness
  • Tremors (shaking or trembling)
  • Seizures
  • Very high blood pressure

In addition, some people may be at increased risk of stroke (an event in which blood flow to the brain is restricted) when taking oral decongestants. Some decongestants may contain phenylpropanolamine, a substance that constricts blood vessels and also acts as a stimulant. This substance has been linked to an increased risk of hemorrhagic stroke in certain patients.

It is extremely important not to exceed the dosage of any OTC or prescription decongestant. One of the most commonly experienced side effects results from the overuse of decongestant nasal sprays. Rebound congestion (rhinitis medicamentosa) occurs when a decongestant nasal spray is used for too long (usually longer than three to five days). The condition is characterized by nasal swelling and congestion, which can make the condition difficult to detect as these are often the same symptoms that are being treated. To avoid rebound congestion, individuals using nasal spray decongestants should closely follow the directions on the label and discontinue use after several days, as directed.

Patients should contact their physician if there are any questions on dosage or potential side effects.

Drug or other interactions with decongestants

Patients should consult their physicians before taking any additional prescriptions, over-the-counter medications, nutritional supplements or herbal medications. Of particular concern to individuals taking decongestants are:

  • Beta blockers. Drugs that help to control blood pressure by interfering with epinephrine (hormone used to increase blood pressure). Decongestants can interfere with these medicines, reducing their effectiveness and increasing the chance of side effects.

  • Monoamine oxidase (MAO) inhibitors. These drugs are frequently used to slow the breakdown of certain neurotransmitters (often to treat depression). Using a decongestant within two weeks of a MAO inhibitor can increase the risk of serious side effects.

  • Cocaine. Using cocaine and decongestants together can interfere with the heart, potentially causing irregularities. Their combined use also increases the chance of side effects developing.

  • Caffeine. Using caffeine with a decongestant can cause some of the side effects of decongestants (e.g., heart palpitations, tremors) to worsen.

  • Diet pills. Taking diet pills with a decongestant can increase stimulation of the central nervous system and other side effects of the diet aids.

Symptoms of decongestant overdose

Symptoms of overdose can be similar to the medication’s side effects, but are usually more severe. A severe overdose can result in a coma or death. Patients exhibiting any of these symptoms should contact their physicians immediately:

  • Extreme tiredness
  • Sweating
  • Dizziness
  • Slow heartbeat

When decongestant nasal sprays are used more frequently or longer than recommended (usually more than three to five days) rebound congestion (rhinitis medicamentosa) can result. This condition usually consists of nasal swelling and congestion, which are often the same symptoms the nasal spray was being used to treat. Once symptoms appear, they will often not subside even after the use of the nasal spray is discontinued. For this reason, using nasal spray decongestants longer than directed can lead to a type of dependency. Individuals using nasal spray decongestants should be careful to follow the directions on the package and should use the sprays only when necessary.

Pregnancy use issues with decongestants

The U.S. Food and Drug Administration (FDA) has placed pseudoephedrine (the active ingredient in most decongestants) in risk category C. This means that although there are no studies linking the loss of pregnancy or birth defects to pseudoephedrine use in humans, there is evidence of an increased risk in some animal studies. Pregnant women should not take pseudoephedrine without first consulting their physician. In addition, women who become pregnant while taking the drug should alert their physician immediately.

The American Academy of Pediatrics approves the use of pseudoephedrine in breastfeeding mothers because the drug is secreted into breast milk in very low doses (less than 1 percent). However, pseudoephedrine is believed to cause a decreased milk supply in some breastfeeding mothers. Women who experience this effect should drink plenty of fluids to compensate and consult their physician if they are concerned their child is not receiving enough milk.

Child use issues with decongestants

Decongestants can sometimes make children jittery because the drug is closely related to adrenaline. In particular, small children and infants are susceptible to this effect. Most physicians agree that children under the age of 6 months should avoid taking decongestants. Older children should try to take decongestants formulated for kids. To receive the proper dosage, parents should make sure their child’s physician is aware of the child’s age.

With children, physicians will often recommend a nasal spray decongestant rather than an oral decongestant. This is because nasal sprays treat a concentrated area, which reduces the amount of decongestant that is passed into the rest of the child’s body. This helps limit side effects.
It is very important that children understand that they should use nasal sprays only as directed. Using a spray longer or more frequently than directed can result in rebound congestion (rhinitis medicamentosa), which consists of nasal swelling and congestion. Some children may overuse their sprays unless carefully supervised.

Elderly use issues with decongestants

Though there have been no studies to evaluate the use of decongestants among the elderly, older users are generally believed to be more likely to experience side effects when taking this type of drug. For this reason physicians often recommend that users of decongestants – particularly those using pseudoephedrine (a common ingredient in decongestants) – who are over 60 use a short-acting form of the drug to reduce the chance of side effects. Older users should refrain from using a controlled-release or long-acting form of the drug.

Questions for your doctor

Preparing questions in advance can help patients to have more meaningful discussions with their physicians. Patients may wish to ask their doctors the following questions about decongestants:

  1. Are decongestants safe for me to take? What type of decongestant is best for me?
  2. Can you explain to me how decongestants work?
  3. How and when should I take this drug?
  4. How long can I safely use this drug?
  5. How will I know if the drug is working?
  6. What will be the next step if the drug fails to relieve my symptoms?
  7. How will this drug affect my current medical conditions other than allergies?
  8. How will this drug interact with other medications I am currently taking?
  9. What side effects may I develop from taking this drug?
  10. What side effects warrant a call to you?
  11. I am thinking about becoming pregnant. Can I continue to take decongestants when I am pregnant?
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