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Decongestants are medicines that are used to help reduce the symptoms of a blocked or stuffy nose. They may be helpful for congestion caused by various conditions. Most commonly, decongestants are used for a cold, sinusitis, hay fever, allergies and rhinitis. These medicines are available as nose drops or nasal sprays and also as tablets, capsules and syrup. Decongestant nose drops or nasal sprays should not be used for more than five days at a time.

These medicines are not suitable for children under 6 years old.

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What are decongestants?

Decongestants are medicines that are used to help ease a blocked or stuffy nose (nasal congestion). Conditions which cause congestion include:

These conditions cause swelling of the tissues and blood vessels that line the nasal passageway and sinuses. This, in turn, causes the nose to become blocked.

A number of decongestants are available in the UK. They include:

Some are available as nasal sprays or drops (sometimes referred to as topical decongestants). Some are available to take by mouth as a tablet or syrup. Some are available in both forms.

These medicines come in various brand names. Many are available to buy over the counter from your pharmacy. They may also be available as a combined tablet that contains a decongestant and a painkiller such as paracetamol.

There are a number of other options that are sometimes used to treat nasal congestion. For example, the following may be helpful:

  • Salt water (saline) nose drops. These are a popular treatment for a stuffy nose in a baby.

  • Steam inhalations. Steam may help to clear the nasal congestion but only has an effect for a short time. This may be useful before bedtime to help you get off to sleep.

Do decongestants help?

How do decongestants work?

Most decongestants work by reducing the swelling of the blood vessels in your nose, throat and sinuses. As it is this swelling causing the congestion, the medication improves the blocked-up feeling.

Ipratropium nasal spray works slightly differently by drying up the secretions of the nose.

Decongestant nasal sprays tend to have an immediate effect to clear a blocked nose. Oral tablets and capsules may take a little longer to work because they need to be absorbed into the body from the gut.

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When are decongestants used or prescribed?

As discussed above, these medicines may be used or prescribed by your doctor to ease nasal congestion for people with the common cold, sinusitis, hay fever, other allergies or rhinitis.

If you have hay fever, they are helpful to use for a few days to clear a blocked nose when you first use a steroid nasal spray. The steroid can then get to the lining of the nose more effectively. If you have acute sinusitis, decongestants can relieve symptoms whilst you are waiting for your immune system to clear the infection. However, they are not thought to shorten the duration of sinusitis.

Decongestant nasal sprays and nose drops should only be used for about 3-5 days at a time. If they are used for longer than this a rebound, more severe congestion of the nose often develops. Oxymetazoline and xylometazoline nasal preparations are thought to be more likely to cause rebound nasal congestion because they are the strongest.

Oral decongestants are not thought to cause this problem when they are stopped. Decongestant sprays and drops are thought to work better than oral tablets or capsules.

Some important considerations

Some important considerations about decongestants relate to:

  • Children under 6 years old.

  • Taking other medicines.

Children under 6 years old

These medicines should not be used in children under 6 years old. The risk of side-effects is higher than any benefit they may have. Children aged 6 to 12 can use some decongestants following discussion with a pharmacist.

Taking other medicines

It is important to remember that some medicines that treat colds or sinusitis contain other medicines as well. For example, some may contain paracetamol or ibuprofen and some contain alcohol.

This is important if you are already taking paracetamol or ibuprofen to help the symptoms of your infection (for example, a high temperature). You may take too much paracetamol or ibuprofen (overdose) without realising. Taking too much paracetamol can damage your liver.

You should also not use these decongestants while you are taking a certain type of antidepressant called a monoamine-oxidase inhibitor (MAOI) and for two weeks after you stop it. This is because, when taken at the same time as an MAOI antidepressant, decongestants may cause very large increases in blood pressure.

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Side-effects of decongestants

Most people are able to take or use decongestant medicine with very few, or no, side-effects. If side-effects do occur, they usually go away after a few days. Some nasal decongestants may produce side-effects such as:

Oral decongestants may cause side-effects such as:

  • Anxiety.

  • Restlessness.

  • Problems with sleeping.

  • Being aware of a fast or fluttering heartbeat.

See the leaflet that came with your medicines for more detailed information on the side-effects of these medicines.

Can I buy decongestants?

There are a large number of oral and nasal decongestants that you can buy from your local pharmacy or supermarket. They have many different brand names.

Who cannot take decongestants?

Some people should avoid taking decongestants. This includes people who have:

  • Heart problems, such as coronary artery disease, heart failure or arrhythmias (irregular heart beat).

  • High blood pressure.

  • Kidney problems, such as chronic kidney disease.

  • Diabetes.

  • Glaucoma.

  • An overactive thyroid gland.

  • Prostate problems, such as difficulty passing urine due to prostate enlargement.

  • Depression and take an MAOI antidepressant.

  • Circulation problems, including Raynaud’s phenomenon.

See the leaflet that came with your medicines for more detailed information on who should avoid taking these medicines. If you are unsure whether these medicines are safe for you, always ask your pharmacist or doctor for advice.

Further reading and references

Article history

The information on this page is written and peer reviewed by qualified clinicians.

  • Next review due: 16 Feb 2028
  • 3 Apr 2023 | Latest version

    Last updated by

    Dr Surangi Mendis

    Peer reviewed by

    Dr Hayley Willacy, FRCGP
  • 2 Oct 2012 | Originally published

    Authored by:

    Jenny Whitehall
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