How does it work?
Atarax tablets contain the active ingredient hydroxyzine, which is a type of medicine called a sedating antihistamine.
Histamine is a substance produced by the body as part of an allergic reaction. It causes an increase in blood flow to the area of the allergy, and the release of other chemicals that add to the allergic response. All this results in the symptoms of allergic reactions. Histamine is responsible for causing the itching associated with nettle rash and allergic eczema.
Hydroxyzine blocks histamine receptors and so stops these actions of histamine.
Hydroxyzine enters the brain in significant quantities and causes drowsiness.
The antihistamine action and the fact that it causes drowsiness make hydroxyzine useful for relieving itching associated with nettle rash and allergic eczema. It may be especially helpful for itching that is worse at night. This is often the case in children, who notice itching less during the day when they are active, but are bothered by it at night when they are still and have nothing else to focus on.
Hydroxyzine is also sometimes used in the short-term treatment of anxiety in adults. It produces a calming effect in anxious, tense adults because it causes drowsiness and may suppress activity in certain regions of the central nervous system.
What is it used for?
- Relief of itching associated with acute and chronic nettle rash (hives or urticaria) and atopic or contact eczema.
- Anxiety in adults.
How do I take it?
- Atarax tablets should be taken with a drink of water. They can be taken with or without food.
- The dose prescribed and how often to take the medicine depends on the age of the person taking it, the condition being treated and how well it responds. It is important to follow the instructions given by your doctor. These will also be printed on the dispensing label that your pharmacist has put on the packet of medicine.
- This medicine may cause drowsiness. If affected do not drive or operate machinery. Don't drink alcohol while taking this medicine.
- If you are due to have any skin prick or patch tests to diagnose allergies you should stop taking your antihistamines a week before the tests. This is because antihistamines can prevent or lessen the skin reactions that indicate an allergy, and so can make the test results unreliable.
Use with caution in
- Elderly people.
- Decreased liver function (this medicine should be avoided in people with severe liver disease or liver failure).
- Decreased kidney function.
- People having kidney dialysis.
- People with conditions that cause difficulty passing urine or urine retention, eg enlarged prostate gland or blockage of the drainage of urine out of the bladder (bladder neck obstruction).
- People with any obstruction or decreased activity in the gut.
- Abnormal muscle weakness (myasthenia gravis).
- People with heart disease or an irregular heartbeat (arrhythmia).
- People with an overactive thyroid gland (hyperthyroidism).
- People with breathing problems such as emphysema or bronchitis.
Not to be used in
- Children aged under six months.
- Hereditary blood disorders called porphyrias.
- People with asthma who have previously had a severe asthma attack brought on by taking an antihistamine.
- People who have previously had an allergic reaction to hydroxyzine, cetirizine, other piperazine derivatives, aminophylline or ethylenediamine.
- Atarax tablets contain lactose and should not be taken by people with rare hereditary problems of galactose intolerance, the Lapp lactase deficiency or glucose-galactose malabsorption.
This medicine should not be used if you are allergic to one or any of its ingredients. Please inform your doctor or pharmacist if you have previously experienced such an allergy.
If you feel you have experienced an allergic reaction, stop using this medicine and inform your doctor or pharmacist immediately.
Pregnancy and breastfeeding
Certain medicines should not be used during pregnancy or breastfeeding. However, other medicines may be safely used in pregnancy or breastfeeding providing the benefits to the mother outweigh the risks to the unborn baby. Always inform your doctor if you are pregnant or planning a pregnancy, before using any medicine.
- The safety of this medicine for use during pregnancy has not been established. It should not be used during pregnancy. Consult your doctor for further advice.
- It is expected that this medicine will pass into breast milk. As it could potentially be harmful to a nursing infant, you should not take this medicine if you are breastfeeding. Seek further medical advice from your doctor.
Medicines and their possible side effects can affect individual people in different ways. The following are some of the side effects that are known to be associated with this medicine. Just because a side effect is stated here does not mean that all people using this medicine will experience that or any side effect.
- Dry mouth.
- Difficulty sleeping (insomnia).
- Difficulty passing urine (urinary retention).
- Nausea and vomiting.
- Feeling weak or generally unwell.
- Feeling confused or disorientated.
- Blurred vision.
- Increased heart rate (tachycardia).
- Low blood pressure.
- Thickened secretions in the respiratory tract.
For more information about any other possible risks associated with this medicine, please read the information provided with the medicine or consult your doctor or pharmacist.
How can this medicine affect other medicines?
It is important to tell your doctor or pharmacist what medicines you are already taking, including those bought without a prescription and herbal medicines, before you start treatment with this medicine. Similarly, check with your doctor or pharmacist before taking any new medicines while taking this one, to make sure that the combination is safe.
There may be an increased risk of drowsiness if this medicine is taken with any of the following (which can also cause drowsiness):
- antipsychotic medicines, eg chlorpromazine, haloperidol
- barbiturates, eg phenobarbital, amobarbital
- benzodiazepines, eg diazepam, temazepam
- muscle relaxants, eg baclofen
- other sedating antihistamines, eg chlorphenamine, promethazine
- sleeping tablets, eg zopiclone
- strong opioid painkillers, eg morphine, codeine, fentanyl
- tricyclic antidepressants, eg amitriptyline, imipramine.
There may be an increased risk of side effects such as dry mouth, blurred vision, difficulty passing urine and constipation if hydroxyzine is taken with anticholinergic medicines that can cause these type of side effects, such as the following:
- anticholinergic medicines for Parkinson's symptoms, eg procyclidine, orphenadrine, trihexyphenidyl
- anticholinergic medicines for urinary incontinence, eg oxybutynin, flavoxate, tolterodine, propiverine, trospium
- antipsychotics, eg chlorpromazine, clozapine
- antispasmodics, eg hyoscine, atropine
- MAOI antidepressants, eg phenelzine
- tricyclic antidepressants, eg amitriptyline, imipramine.
This medicine may oppose the effect of histamine used to treat leukaemia and is not recommended for people having this treatment.
This medicine may oppose the effect of betahistine used to treat Ménière's disease.
Other medicines containing the same active ingredient