> Western Medicines > Cetirizine


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What is Cetirizine for?

Cetirizine is a non-drowsy (second-generation) antihistamine medication like Loratadine, which is used to treat and prevent allergies. Allergic conditions include hay fever (allergic rhinitis), and hives (urticaria). Antihistamines can also be used to manage the symptoms of the common cold such as runny nose and sneezing. Cetirizine relieves symptoms of itching, runny nose, watery eyes and sneezing.

How to use it?

Cetirizine is taken by mouth. The dose for adults/children between 12 and 17 years old is 10 mg once daily; whereas the dose for children between 2 and 5 years old is 2.5 mg once daily and that for children between 6 and 11 years old is 5 mg once daily. For certain uses, Cetirizine can be prescribed at higher doses and taken twice daily.

Side effects of Cetirizine

Cetirizine has very few side effects. In most people when taken at usual doses it does not cause drowsiness. However, some people may experience a small degree of drowsiness. Avoid driving or operating machinery until you know how you respond to Cetirizine.

Who should not take Cetirizine?

  • Anyone who has an allergy to Cetirizine.

Pharmacist Tips:

  • Avoid activities requiring mental alertness e.g. driving until drug effects are realised due to increased occurrence of sedation.
  • It is advised not to drink alcohol as well while taking this drug.

Common dosing schedule:
Cetirizine can be taken with or without food.


This schedule is for reference only, adjustments may be made according to individual needs.


Some common medications Cetirizine may interact with:

Please notify your doctor or pharmacist if you are taking the above medication, dosage adjustments might be needed.

Where to buy Cetirizine in Hong Kong?

In Hong Kong, Cetirizine is an over-the-counter medicine and can be purchased without a prescription from medicine shops and pharmacies. It can also be obtained from doctors. To find a pharmacy near you, refer to the list of pharmacies (“Authorized Sellers of Poisons”) from the Hong Kong Department of Health.


For more information about drug names and ingredients, you can visit Hong Kong’s Drug Office at https://www.drugoffice.gov.hk

Need more information?

For detailed information about the use of Cetirizine in children, pregnancy and breastfeeding, and for questions about drug interactions, please check with your pharmacist or doctor.

Disclaimer: our goal is to provide you with the most relevant drug information and common dosage for Hong Kong. This information does not constitute medical advice. For specific treatment recommendations and advice, always discuss with your doctor or pharmacist, and follow the instructions included with your specific medicine.

Brands in Hong Kong
Available dosage
  • 10mg (Capsules)
  • 1% (Oral Solution)
  • 5mg / 10mg (Tablets)
Drug class
Sub class
Antihistamines (Second Generation)
Other drugs in same class
Used for: Seasonal allergic rhinitis, Urticaria
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Used for: Allergies, Hay fever, Urticaria
Chinese name:
Used for: Urticaria, Allergic conditions, Hay fever
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