A sedating antihistamine for allergy symptoms
Dexbrompheniramine
An older, sedating antihistamine used to relieve allergy symptoms such as a runny nose, sneezing and itching.
What is Dexbrompheniramine?
Dexbrompheniramine is an older, sedating antihistamine used to ease allergy symptoms such as sneezing, a runny or itchy nose, watery eyes and itching. It is often found in combination cold and allergy products alongside other ingredients. Because it is a sedating antihistamine, the main thing to expect is drowsiness, so it can affect driving and concentration, and it adds to the effect of alcohol. It also causes drying, antimuscarinic effects such as a dry mouth, and is used with care in older people and certain conditions. Newer, non-drowsy antihistamines are often preferred for everyday allergy relief.
Education and reference only. This is a plain-language guide to Dexbrompheniramine — it deliberately contains no doses. Doses depend on the person, the brand and the reason for treatment, and belong with your prescriber. Always check the BNF, the product labelling (SmPC) and follow medical advice.
What it is
Dexbrompheniramine is an antihistamine, a medicine that blocks histamine, the chemical the body releases during an allergic reaction. It belongs to the older, sedating group of antihistamines, which tend to cause drowsiness, unlike the newer non-drowsy ones used for everyday hay fever. It is used to relieve allergy symptoms such as a runny nose, sneezing, itchy eyes and itchy skin, and is commonly included in combination cold and allergy remedies alongside ingredients like decongestants. It is taken by mouth, often as part of a multi-ingredient product, so it is important to know everything a combined product contains.
How it works
When the body meets something it is allergic to, it releases histamine, which causes the familiar allergy symptoms of sneezing, a runny and itchy nose, watery eyes and itchy skin. Dexbrompheniramine blocks histamine's action, so these symptoms ease. Because it is an older antihistamine, it also crosses into the brain, which is why it commonly causes drowsiness, and it blocks other receptors, giving drying effects such as a dry mouth. In combination cold products it is paired with other ingredients aimed at different symptoms, such as a blocked nose or cough.
Company & origin
Originated / developed by: Various manufacturers.
An older, sedating antihistamine used to relieve allergy symptoms, often as part of combination cold and allergy products.
What it treats
Conditions Dexbrompheniramine is used for
Practical use
How to take Dexbrompheniramine
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- Take it as directed, and be aware it commonly causes drowsiness, so plan activities accordingly.
- Do not drive or operate machinery until you know how it affects you.
- Avoid alcohol and other sedating medicines, as they add to the drowsiness.
- Check the ingredients if it is part of a combination cold or allergy product, to avoid doubling up.
- Take care in older people and tell your pharmacist about conditions such as glaucoma or prostate problems.
Weighing it up
Advantages & disadvantages of Dexbrompheniramine
Advantages
- Effectively relieves allergy symptoms such as sneezing, a runny nose, itchy eyes and itching.
- Its sedating effect can be helpful when symptoms disturb sleep at night.
- Often combined with other ingredients to tackle several cold or allergy symptoms at once.
Disadvantages
- Commonly causes drowsiness, which can affect driving, concentration and daily activities.
- Causes drying effects such as a dry mouth, blurred vision and constipation.
- Less suitable for older people and is often outclassed by newer non-drowsy antihistamines for daytime use.
Practical use
Good to know
The main thing to expect from dexbrompheniramine is drowsiness, since it is a sedating antihistamine. This means it can affect your ability to drive, operate machinery or concentrate, and the effect is stronger if you also drink alcohol or take other sedating medicines, so these should be avoided or used with caution. It also causes drying, antimuscarinic effects such as a dry mouth, blurred vision, constipation and difficulty passing urine, which is why it is used with care in older people and in conditions such as glaucoma or an enlarged prostate. A very important point is that it is often part of a combination cold or allergy product, so check the full list of ingredients to avoid accidentally doubling up on the same type of medicine. For ongoing, daytime allergy relief, a newer non-drowsy antihistamine is often a better choice.
Who should not take it / use with caution
- People who have had a reaction to it or to similar antihistamines should not take it.
- It is used with caution in older people, who are more sensitive to drowsiness and drying effects.
- It is used with care in people with glaucoma, an enlarged prostate or difficulty passing urine.
- Combination products containing it are not suitable for very young children unless specifically advised.
Monitoring
- Reviewing how well allergy symptoms are controlled and whether a non-drowsy antihistamine would suit better.
- Watching for excessive drowsiness or drying effects, especially in older people.
- Checking that combination products are not leading to a double dose of the same medicine type.
Side effects
- Drowsiness, and sometimes dizziness or a feeling of being slowed down.
- Dry mouth, blurred vision, constipation and difficulty passing urine.
- Occasionally, in children and some older people, restlessness or agitation instead of drowsiness.
- Rarely, a fast or irregular heartbeat.
Key interactions
- Alcohol and other sedating medicines, such as sleeping tablets or strong painkillers, add to its drowsiness.
- Other medicines with drying (antimuscarinic) effects increase the risk of a dry mouth, constipation and urine problems.
- Check combination cold and allergy products carefully to avoid taking more than one antihistamine at once.
Available as: Tablets or liquid taken by mouth, often as part of a combination product.
Answers
Dexbrompheniramine: frequently asked questions
What is dexbrompheniramine used for?
It is an older antihistamine used to relieve allergy symptoms such as sneezing, a runny or itchy nose, watery eyes and itching, often as part of combination cold and allergy products.
Will it make me drowsy?
Yes, it is a sedating antihistamine, so drowsiness is the main effect to expect, which can affect driving and concentration.
Can I drink alcohol with it?
It is best to avoid alcohol, as it adds to the drowsiness; the same goes for other sedating medicines.
Why should I check the ingredients?
It is often part of a combination product, so checking the label helps you avoid accidentally taking two medicines of the same type.
Is a non-drowsy antihistamine better?
For ongoing daytime allergy relief, a newer non-drowsy antihistamine is often a better choice, though a sedating one can help when symptoms disturb sleep.
The wider class
About Sedating (older) antihistamine
Dexbrompheniramine belongs to the sedating (older) antihistamine class. For how the class as a whole works, its shared safety principles and monitoring, see the full guide.
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Authoritative sources
- BNF
- NICE CKS
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