ENT / Respiratory
Decongestants
Nasal and oral congestion relievers (e.g. xylometazoline, pseudoephedrine) — Short-term relief of a blocked nose — nasal sprays must not be used for more than a few days.
Education and reference only. This is a plain-language class overview — it deliberately contains no doses. Always check the current Summary of Product Characteristics (SmPC), the BNF and your local formulary before prescribing or administering any medicine.
Quick answer
What is Decongestants?
Decongestants relieve a blocked, stuffy nose by shrinking swollen nasal lining. They come as nasal sprays and drops for fast local relief, and as oral tablets, and are intended for short-term use.
- How it works: They narrow the small blood vessels in the swollen lining of the nose, reducing the swelling and opening the airway so it feels clearer.
- In practice: In practice decongestants give quick, short-term relief of a blocked nose from colds and sinus congestion, as nasal sprays/drops (xylometazoline, oxymetazoline) or oral tablets (pseudoephedrine).
What it is
Decongestants relieve a blocked, stuffy nose by shrinking swollen nasal lining. They come as nasal sprays and drops for fast local relief, and as oral tablets, and are intended for short-term use.
How it works
They narrow the small blood vessels in the swollen lining of the nose, reducing the swelling and opening the airway so it feels clearer. Because the body adapts to the nasal sprays, the vessels swell back worse when they wear off — which is the rebound congestion that limits how long sprays can be used.
In practice
In practice decongestants give quick, short-term relief of a blocked nose from colds and sinus congestion, as nasal sprays/drops (xylometazoline, oxymetazoline) or oral tablets (pseudoephedrine). The single most important practical rule applies to the nasal sprays: they should not be used for more than about a week, because longer use causes "rebound" congestion (rhinitis medicamentosa) where the nose blocks up worse as each dose wears off, trapping people in a cycle of overuse. Oral decongestants are stimulant-like and can raise blood pressure and heart rate, cause insomnia and restlessness, and are used with caution or avoided in people with high blood pressure, heart disease, an overactive thyroid or closed-angle glaucoma — and they interact dangerously with certain antidepressants (MAOIs). For a persistently blocked or allergic nose, a steroid nasal spray is a better long-term choice. They relieve a symptom rather than treating infection, and most colds settle by themselves.
Examples
Practical use
How to take it & use it well
- Use a nasal spray decongestant only for a few days at a time, as using it for longer can cause the blockage to come back worse, known as rebound congestion.
- Before spraying, gently clear your nose, then aim the nozzle slightly away from the middle of your nose and sniff gently as you spray for the best effect.
- For decongestant tablets containing pseudoephedrine, avoid taking them late in the evening, as they can be stimulating and keep you awake.
- Check the labels of any other cold and flu remedies you take, as many already contain a decongestant, and doubling up can raise your blood pressure and heart rate.
- Drink plenty of fluids and consider simple measures such as steam inhalation or saline drops, which can ease a blocked nose without the rebound risk.
- If your congestion lasts beyond a week or two, or keeps returning, see a pharmacist or GP rather than continuing to use a spray, as something else may need treating.
Common uses
- Short-term relief of nasal congestion in colds and sinusitis
- Easing a blocked nose to help sleep or ear pressure
- Not for long-term or allergic congestion (use a steroid spray)
Monitoring
- Symptom relief and duration of nasal-spray use
- Blood pressure/heart rate with oral use where relevant
- Whether a steroid nasal spray is more appropriate
Weighing it up
Advantages & disadvantages
Advantages
- They quickly relieve a blocked nose from colds and hayfever, making it easier to breathe.
- Nasal sprays act directly in the nose and work fast for short-term relief.
- Tablets can ease congestion in the nose and sinuses across the whole head.
- They are widely available without prescription for short-term use.
- They can make you more comfortable and help you sleep when a cold blocks your nose.
Disadvantages
- Nasal sprays must not be used for more than a few days, as longer use causes rebound congestion that is worse than the original.
- Tablet decongestants can raise blood pressure and heart rate and may keep you awake.
- They are not suitable for everyone, including some people with high blood pressure, heart problems or an overactive thyroid.
- They treat the symptom rather than the cause of the blockage.
- Pseudoephedrine sales are limited and monitored because it can be misused.
Key safety principles
What to watch for
- Do not use decongestant nasal sprays for more than about a week — longer use causes rebound congestion.
- Oral decongestants can raise blood pressure and heart rate and disturb sleep — caution/avoid in hypertension, heart disease, overactive thyroid and glaucoma.
- Dangerous interaction with MAOI antidepressants; they relieve symptoms only and do not treat infection.
Key interactions
What to avoid or check alongside
- Decongestant tablets must not be taken with certain antidepressants known as MAOIs, or close to stopping them, as together they can dangerously raise blood pressure.
- Taken with other stimulants, including some ADHD medicines and large amounts of caffeine, they can add to effects on the heart and blood pressure.
- Several cold and flu products contain a decongestant, so combining them can lead to too much without realising.
- They can work against some blood-pressure medicines, raising readings in people being treated for hypertension.
- Tell your pharmacist about heart, blood-pressure or thyroid conditions and all your medicines before using one.
Patient & carer advice
- Use nasal sprays for only a few days to avoid making the blockage worse
- If you have high blood pressure or heart problems, check before using the oral tablets
- For an ongoing or allergic blocked nose, a steroid nasal spray works better long term
Answers
Decongestants: frequently asked questions
Why can't I use my nasal spray for more than a few days?
Using a decongestant nasal spray for longer than a few days can cause rebound congestion, where your nose becomes even more blocked once it wears off, leading you to use more. To avoid this, limit it to a few days and switch to saline or steam if you need longer relief.
Can I take a decongestant if I have high blood pressure?
Decongestant tablets can raise blood pressure and heart rate, so they are not always suitable if you have high blood pressure or heart problems. Ask your pharmacist for advice, as they can suggest gentler options such as saline drops.
Why does pseudoephedrine keep me awake?
Pseudoephedrine has a stimulating effect, which is why it can make it hard to sleep if taken late in the day. Take it earlier where possible, and avoid combining it with caffeine close to bedtime.
Is it safe to take a decongestant with cold and flu tablets?
Many cold and flu remedies already contain a decongestant, so taking them together can give you too much and raise your heart rate and blood pressure. Always check labels and avoid taking more than one decongestant-containing product at once.
My nose is still blocked after a week — what should I do?
If congestion lasts beyond a week or two or keeps coming back, see a pharmacist or GP rather than continuing a spray, as it could be hayfever, a sinus problem or rebound congestion. They can advise on the right treatment.
Authoritative sources
Always verify against the source
This overview is for orientation. For doses, interactions, contra-indications and the full monograph, use:
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