A sedating antihistamine for itch and anxiety
Hydroxyzine
A sedating antihistamine used to relieve itching and hives, and for short-term help with anxiety.
What is Hydroxyzine?
Hydroxyzine is a sedating, first-generation antihistamine used mainly to relieve itching and hives (urticaria), and for short-term help with anxiety. Because it crosses into the brain, it commonly causes drowsiness.
Education and reference only. This is a plain-language guide to Hydroxyzine — 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
Hydroxyzine is a sedating, "first-generation" antihistamine. It is used mainly to relieve itching and hives (urticaria), and also for short-term help with anxiety, where its calming, sedating effect is useful. In the UK it is known by brands such as Atarax and Ucerax, though most prescriptions are generic. Because it gets into the brain, it causes drowsiness — helpful for night-time itch or anxiety, but a drawback during the day. It is taken as a tablet or liquid, usually for a defined period rather than indefinitely.
How it works
Hydroxyzine blocks histamine, the chemical responsible for the itching, redness and swelling of allergic reactions and hives — which is how it eases itch. Because it also crosses into the brain and has a calming effect there, it reduces anxiety and causes drowsiness. This brain effect is what separates it from the modern non-drowsy antihistamines, and is why it can both settle an anxious person and help with itch that disturbs sleep.
Company & origin
Originated / developed by: Union Chimique Belge (UCB).
Hydroxyzine was first synthesized in the mid-1950s by Union Chimique Belge (UCB) in Belgium and was brought to the US market by Pfizer around 1956 as the antihistamine Atarax.
What it treats
Conditions Hydroxyzine is used for
Practical use
How to take Hydroxyzine
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- Expect drowsiness, so avoid driving or operating machinery until you know how it affects you.
- Avoid alcohol, which adds to the sedation.
- It is generally used for short courses rather than long term.
- Check with a pharmacist before combining it with other sedating or cold and flu medicines.
- Tell your doctor about heart-rhythm problems or other heart conditions before starting, as it can affect the heart's electrical activity.
- Take it regularly as prescribed for itching and report if symptoms do not improve.
Weighing it up
Advantages & disadvantages of Hydroxyzine
Advantages
- Relieves troublesome itching and hives.
- Can help with short-term anxiety and associated tension.
- Its sedating effect may aid sleep when itching disturbs it.
- Long-established and widely available on prescription.
Disadvantages
- Commonly causes drowsiness, dry mouth and blurred vision.
- Can affect heart rhythm, so caution is needed in some heart conditions.
- Adds to the effects of alcohol and other sedatives.
- Best used short term rather than continuously.
Practical use
Good to know
The drowsiness is the main thing to plan around — take care with driving and concentration, especially at first, and be cautious about combining it with alcohol or other sedating medicines. For anxiety it is intended for short-term use, not as a long-term treatment. It has anticholinergic effects (dry mouth, blurred vision, constipation, urinary difficulty), which make it less suitable for older people, where it can also cause confusion or falls. Hydroxyzine can affect the heart's electrical rhythm (the QT interval), so it is used with care in people with heart-rhythm risks or who take other medicines that have the same effect, and the lowest effective amount for the shortest time is preferred.
Who should not take it / use with caution
- People with a known heart-rhythm problem affecting the QT interval, or significant risk factors for it.
- People with certain types of glaucoma, an enlarged prostate or urinary retention, severe liver or kidney problems, or who are pregnant or breastfeeding (used only if clearly needed).
- Used with particular caution in older people (drowsiness, confusion, falls and anticholinergic effects) and alongside other sedating or heart-rhythm medicines.
Monitoring
- Response of itch or anxiety, and any drowsiness
- In those at risk, attention to heart-rhythm (QT) factors and the medicines used alongside it
- In older people, any confusion, falls or urinary problems
Side effects
- Drowsiness, dry mouth, blurred vision and constipation.
- Dizziness, headache, or difficulty passing urine.
- Rarely, effects on the heart's rhythm (QT prolongation) — report fainting or palpitations; in older people, confusion or agitation.
Key interactions
- Adds to the drowsiness of alcohol, sleeping tablets, strong painkillers and other sedating medicines.
- Care alongside other medicines that can affect heart rhythm (the QT interval), such as certain antibiotics, antipsychotics and some other medicines.
- Adds to the anticholinergic (dry mouth, constipation, urinary) effects of some other medicines; not used close to MAOI antidepressants.
Available as: Tablets and a liquid (oral solution). Usually used for a defined, shorter period rather than long-term.
Answers
Hydroxyzine: frequently asked questions
Will hydroxyzine make me drowsy?
Yes — hydroxyzine is a sedating antihistamine and drowsiness is its main effect. This can be helpful for itch that disturbs sleep or for short-term anxiety, but take care with driving and tasks needing concentration, especially when you start it, and avoid alcohol, which adds to the drowsiness.
Is hydroxyzine addictive like some anxiety medicines?
No — unlike benzodiazepines, hydroxyzine is an antihistamine and is not habit-forming. It is, however, intended for short-term help with anxiety rather than long-term use. If anxiety is an ongoing problem, talk to your GP about longer-term approaches such as talking therapies or other treatments.
Why does hydroxyzine need care with the heart?
Hydroxyzine can slightly affect the heart's electrical rhythm (the QT interval). For most people this is not a problem, but it means it is used with caution in those with heart-rhythm conditions or who take other medicines that have the same effect, using the lowest effective amount for the shortest time. Report any fainting or palpitations.
Is hydroxyzine suitable for older people?
It is used with extra caution in older people. Its sedating and anticholinergic effects (dry mouth, constipation, blurred vision, difficulty passing urine) can cause confusion and increase the risk of falls, so a non-sedating alternative is often preferred where possible. Any use is usually short-term and at the lowest effective amount.
What is the difference between hydroxyzine, Atarax and Ucerax?
They are the same medicine — hydroxyzine is the generic (active-ingredient) name, and Atarax and Ucerax are brand names. Generic hydroxyzine contains the identical active ingredient.
The wider class
About Antihistamines
Hydroxyzine belongs to the antihistamines 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: Hydroxyzine hydrochloride.
- electronic Medicines Compendium (SmPC): Atarax; MHRA Drug Safety Update — hydroxyzine and QT.
- NICE CKS: Hydroxyzine.
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