> Western Medicines > Hydrochlorothiazide


Used for: High blood pressure, Oedema
Chinese name:

What is Hydrochlorothiazide for?

Hydrochlorothiazide is a medicine which helps increase the production of urine making it easier to get rid of salt and water (sometimes called a “water pill”). Low doses of hydrochlorothiazide are used to treat high blood pressure. It can also be used to treat swelling caused by fluid accumulation.

How to use it?

Hydrochlorothiazide is taken by mouth. Usual adult doses for high blood pressure range from 12.5 mg to 50 mg taken once daily (usually in the morning). Higher doses, ranging from 25-100 mg per day are used to treat swelling from fluid accumulation (edema).

What are the side effects of Hydrochlorothiazide?

Common side effects of Hydrochlorothiazide include dizziness, electrolyte imbalance, and sensitivity to sunlight.

Who should not take Hydrochlorothiazide?

  • People allergic to Hydrochlorothiazide, any ingredient in the formulation, or sulfonamide-derived medicines
  • Patients with anuria (reduced urine production) or Addison’s disease
  • People whose blood level of calcium or uric acid is high
  • People whose blood level of sodium or potassium is low

Pharmacist Tips:

  • Continue taking Hydrochlorothiazide even when you feel well.
  • Avoid prolonged exposure to sunlight or ultraviolet light. Wear sunscreen when taking Hydrochlorothiazide.

Common dosing schedule:
You may take Hydrochlorothiazide with or without food.

Do not take Hydrochlorothiazide in the late afternoon to avoid going to the toilet while sleeping.


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


Some common medications Hydrochlorothiazide may interact with:

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

Where to buy Hydrochlorothiazide in Hong Kong?

In Hong Kong, Hydrochlorothiazide 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 Hydrochlorothiazide 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
  • 25mg / 50mg (Tablets)
Drug class
Sub class
Thiazide-Like Diuretics
Other drugs in same class
Used for: High blood pressure, Oedema
Chinese name:
Used for: Oedema, High blood pressure
Chinese name: