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Second-generation (non-drowsy) antihistamine (H1 receptor antagonist)

Cetirizine: uses, side effects & precautions

Also known as Zyrtec, Reactine, Piriteze, Benadryl Allergy (cetirizine formulation), Zirtek.

Esta información es solo orientativa de carácter general y no constituye un consejo médico. Consulta siempre a un profesional sanitario cualificado para cualquier asunto médico personal. En caso de emergencia, llama al número de emergencias de tu zona.

What it is used for

  • Hay fever (allergic rhinitis)
  • Sneezing, runny or itchy nose
  • Itchy, watery eyes
  • Hives (urticaria) and itchy skin rashes
  • General allergy symptoms (e.g. pet, dust, pollen allergies)

How it works

Cetirizine blocks histamine, a chemical your body releases during an allergic reaction. By stopping histamine from acting on its receptors, it reduces sneezing, itching, watering, and swelling.

How it is taken

Comes as tablets, capsules, dissolvable/chewable tablets, and a liquid syrup (often used for children). It is usually taken by mouth and can generally be taken with or without food. Always take it exactly as your doctor, pharmacist, or the product label directs, and do not take more than recommended.

No doses here on purpose. The right strength and schedule depend on you — only a doctor or pharmacist should set them. Always follow your prescription and the label.

Common side effects

  • Drowsiness or sleepiness (less common than with older antihistamines, but possible)
  • Dry mouth
  • Headache
  • Dizziness
  • Tiredness
  • Sore throat or stomach upset

Serious effects — get help

  • Signs of a severe allergic reaction (swelling of the face, lips, tongue or throat; trouble breathing)
  • Fast or irregular heartbeat
  • Difficulty passing urine
  • Severe or unusual restlessness

If a reaction is severe — for example trouble breathing, swelling of the face or throat, or collapse — go to the nearest emergency room now or call your local emergency number. Do not wait for an online consultation.

Interactions to watch

  • Alcohol (may increase drowsiness)
  • Other sedating medicines (sleeping tablets, strong painkillers, some antidepressants)
  • Other antihistamines or cold/allergy combination products

Who should take care

  • Tell your clinician if you are pregnant, planning pregnancy, or breastfeeding
  • Caution with kidney problems (dose may need adjusting by a clinician)
  • Avoid if you have had an allergic reaction to cetirizine, levocetirizine, or hydroxyzine
  • It may cause drowsiness in some people, so see how it affects you before driving or operating machinery

Frequently asked questions

Will cetirizine make me drowsy?
It is classed as a non-drowsy antihistamine and is less sedating than older ones, but a small number of people still feel sleepy. See how it affects you before driving.
Can I take cetirizine every day?
Many people take it daily during allergy season. If you need it for long periods, check with your doctor or pharmacist.
Can I drink alcohol with cetirizine?
Alcohol can add to any drowsiness. It is best to limit or avoid alcohol until you know how the medicine affects you.
Is cetirizine safe in pregnancy?
Discuss this with your doctor or pharmacist, who can advise on the safest option for your situation.

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