> Western Medicines > Irbesartan


Chinese name:

What is Irbesartan for?

Irbesartan belongs to a class of medications called angiotensin receptor blockers (ARBs), just like Losartan. ARBs block the substances that constrict the blood vessels and hence more blood and oxygen can reach the heart. Irbesartan is therefore commonly used to treat high blood pressure and diabetic nephropathy (a kidney disease) in hypertensive patients with type 2 diabetes, especially when medications such as Lisinopril or Ramipril (angiotensin-converting enzyme inhibitor) cannot be used.

How to use it?

Irbesartan is taken by mouth as tablets.


The adult dose for treating high blood pressure is 150 mg once daily. Your doctor will adjust the dose based on your response. If you are over 75 years old, with volume depletion or are on haemodialysis, you may take a lower dose of 75 mg instead. The maximum daily dose is 300 mg.


The starting adult dose for treating diabetic nephropathy is 150 mg once daily. The maintenance dose is 300 mg once daily.

What are the side effects of Irbesartan?

Common side effects of Irbesartan include diarrhoea, dizziness, headache, high potassium levels, low blood pressure, and kidney impairment. If you have intravascular volume depletion, for example, those taking high-dose other blood pressure-lowering drugs, you may also experience postural hypotension, that is your blood pressure falls when you stand up from sitting or lying down.

Who should not take Irbesartan?

  • People with an allergy to Irbesartan or any formulation ingredient
  • Patients who are on Aliskiren and have diabetes

Pharmacist Tips:

  • Inform your doctor or pharmacist immediately if you know you are pregnant while on this medication.
  • Avoid alcohol while you are taking Irbesartan to reduce dizziness.
  • If you experience postural hypotension, get up slowly from lying or sitting positions or sit down until you feel better.

Common dosing schedule: 
You can take Irbesartan with or without food.


Take the first dose at bedtime to avoid dizziness. You can take it at any time of day afterwards. Take the drug at the same time every day.


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


Some common medications Irbesartan may interact with:

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

Where to buy Irbesartan in Hong Kong?

In Hong Kong, Irbesartan 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 Irbesartan 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
  • 75mg / 150mg / 300mg (Tablets)
Drug class
Sub class
Angiotensin II Receptor Blockers (ARBs)