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What is Cetirizine?

Going by the full name cetirizine dihydrochloride, cetirizine is an  antihistamine medicine used to relieve allergy symptoms caused by hay fever and hives. For most people, it’s a non-drowsy antihistamine.
While cetirizine tablets can be prescribed by your doctor, they’re also readily available over the counter as tablets, and liquid that you swallow.
Let’s look at how cetirizine dihydrochloride works in the body and its importance in managing allergic reactions.

What are cetirizine tablets used for?

Cetirizine is used to relieve the symptoms of allergic reactions such as:

  • Itchy eyes or nose

  • Body itching

  • Hives break out

  • Runny nose

  • Watery eyes

How do cetirizine dihydrochloride tablets work?

Cetirizine dihydrochloride tablets relieve allergy symptoms by blocking histamine, a natural substance in your body. Histamine is usually released by the body when it detects something harmful, such as an infection. It can cause your skin to swell as your blood vessels expand to protect the body.

For people with allergies, though, the body mistakes something harmless like dust or pollen as harmful, releasing histamine. This causes an unpleasant allergic reaction with accompanying symptoms.

While cetirizine is effective at treating some allergy symptoms, it cannot prevent or treat a more serious allergic reaction, such as anaphylaxis – where the body goes into shock.

Anaphylaxis can be indicated by swelling, breakouts of hives and/or difficulty breathing. If you or someone else has these symptoms, call 999 or seek medical treatment right away.

How to take over the counter cetirizine

If you’re taking over the counter cetirizine, such as BENADRYL® One a Day tablets to relieve your allergy symptoms, make sure you’re following the below advice:

  • Read all directions on the product package carefully before taking the medication.

  • If you have any questions about the product, consult your pharmacist.

How often can you take cetirizine?

Adults can take cetirizine once a day, while children aged under 12 can take it twice a day – at a lower dosage than adults, as indicated in the package leaflet.

Potential cetirizine side effects

As is the case with all types of medicine, cetirizine can cause side effects in some people. Common cetirizine side effects can include:

  • Dry mouth

  • Headaches

  • Dizziness

  • Feeling sic

  • Diarrhoea

Additionally, while cetirizine dihydrochloride is classified as a non-drowsy antihistamine for most people, you may find that cetirizine can make you drowsy or sleepy.

If these side effects are causing you bother or don’t resolve themselves, consult your GP or a pharmacist.

Cetirizine FAQs

Cetirizine is a non-drowsy antihistamine, meaning that it’s less likely to make some people feel sleepy compared to first generation antihistamine medication1 . However, some people might still feel tired and sleepy as a side effect of cetirizine1 .

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If you’re pregnant, ask your doctor or pharmacist for advice before taking cetirizine. Medicines can affect the unborn baby, so always talk to a doctor or pharmacist before taking any medicine in pregnancy. If you’re breastfeeding, you should not take cetirizine (including BENADRYL® One a Day), as it can be passed on into breast milk.

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BENADRYL® provides a range of cetirizine options that are suitable for children, including:

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