Hydroxyzine

Fact Checked

Medically reviewed by Joseph Blais, Pharmacist

Last updated on 18/03/2021.

GENERIC NAME: Hydroxyzine

CHINESE NAME: 羥嗪

BRAND NAME(S) IN HONG KONG: Atarax, Qualidrozine

DRUG CLASS: Antihistamine (first generation); Antiemetic

USED FOR: Allergic conditions, anxiety, control of nausea and vomiting

OTHER DRUGS IN THE SAME CLASS: Chlorpheniramine, Dimenhydrinate, Diphenhydramine, Promethazine

What is Hydroxyzine for?

Hydroxyzine is a sedating (first generation) antihistamine that can relieve itchiness associated with allergies such as hay fever, hives, food allergy, drug reactions. It can also be used to manage anxiety in the short-term and as a sedative before or after surgery.

How to use it?

Hydroxyzine can be taken by mouth as tablets or capsules and the dosages for different age groups and uses are listed below.

For itchiness

Adult
Start with 25 mg daily at night and increase the dose to 25 mg 3-4 times daily if necessary.

Child 6 months – 5 years
5-15 mg daily in divided doses and the dose is adjusted according to their weights. The maximum daily dose is 2 mg/kg.

Child 6-17 years (body weight below 40 kg)
Start with 15-25 mg daily in divided doses. The dose is adjusted according to their weights and may increase if necessary. The maximum daily dose is 2 mg/kg.

Child 6-17 years (body weight 40 kg or above)
Start with 15-25 mg daily in divided doses. The dose is adjusted according to their weights and may increase to 50-100 mg daily if necessary.

For management of anxiety in short term

Adult
50-100 mg daily in divided doses. The maximum daily dose is 100 mg.

What are the side effects of Hydroxyzine?

Common side effects of Hydroxyzine include drowsiness and dizziness, dry mouth, blurred vision, and constipation. Avoid driving or operating machinery until you know how you respond to Hydroxyzine.

Who should not take Hydroxyzine?

– People allergic to Hydroxyzine or any component of the formulation
– Patients with QT interval prolongation or have risk factors for it, or who are taking other QT interval prolonging drugs

Pharmacist Tips:

– Hydroxyzine can cause drowsiness. If affected, do not perform tasks that require mental alertness, such as driving or using machinery.
– Avoid taking Hydroxyzine if you are 65 years and older as you are at higher risk of side effects, such as confusion, dry mouth and constipation.

Common dosing schedule:
This drug can be taken with or without food.
Avoid alcohol while taking this drug.

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

Some common medications Hydroxyzine may interact:
– Alcohol
– Amiodarone
– Clozapine
– Ipratropium
– Other antihistamine, e.g. Chlorpheniramine, Diphenhydramine, Fexofenadine, Levocetirizine, Loratadine, Promethazine

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

Where to buy Hydroxyzine in Hong Kong?

In Hong Kong, Hydroxyzine is a prescription only medicine, and requires a prescription from a doctor to be purchased in a pharmacy. 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 Hydroxyzine 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.