How does this medication work? What will it do for me?

This is a combination medication containing irbesartan and hydrochlorothiazide. Irbesartan belongs to a class of medications called angiotensin II blockers that helps to lower blood pressure by relaxing blood vessels. Hydrochlorothiazide is a diuretic or "water pill" that helps control blood pressure by getting rid of excess salt and water. This medication is used to reduce high blood pressure.

This medication is most often prescribed when other medications have been found to be ineffective or to have side effects, and when a person's blood pressure is stabilized on irbesartan and hydrochlorothiazide taken individually.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. As well, some forms of this medication may not be used for all of the conditions discussed here. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.

What form(s) does this medication come in?

150 mg/12.5 mg
Each peach, biconvex, oval tablet, with a heart shape debossed on one side and the digits "2775" on the other, contains 150 mg of irbesartan and 12.5 mg of hydrochlorothiazide. Nonmedicinal ingredients: croscarmellose sodium, ferric oxide red, ferric oxide yellow, lactose, magnesium stearate, microcrystalline cellulose, pregelatinized starch, and silicon dioxide.

300 mg/12.5 mg
Each peach, biconvex, oval tablet, with a heart shape debossed on one side and the digits "2776" on the other, contains 300 mg of irbesartan and 12.5 mg of hydrochlorothiazide. Nonmedicinal ingredients: croscarmellose sodium, ferric oxide red, ferric oxide yellow, lactose, magnesium stearate, microcrystalline cellulose, pregelatinized starch, and silicon dioxide.

300 mg/25 mg
Each pink, film-coated, biconvex, oval tablet, with a heart shape debossed on one side and the digits "2788" on the other, contains 300 mg of irbesartan and 25 mg of hydrochlorothiazide. Nonmedicinal ingredients: black iron oxides, carnauba wax, croscarmellose sodium, ferric oxide red, ferric oxide yellow, hypromellose, lactose monohydrate, magnesium stearate, microcrystalline cellulose, polyethylene glycol, pregelatinized starch, silicon dioxide, and titanium dioxide.

How should I use this medication?

Treatment is started separately with irbesartan and hydrochlorothiazide. Once the best dose of each component (irbesartan and hydrochlorothiazide) has been determined, the combination tablets can be started. Irbesartan - hydrochlorothiazide is generally  not started until the best dose of each ingredient has been determined.

The dose ranges from 1 tablet containing 150 mg irbesartan and 12.5 mg hydrochlorothiazide once daily to 1 tablet containing 300 mg irbesartan and 25 mg hydrochlorothiazide once daily. Tablets should be taken at approximately the same time each day, with or without food, and taken in the same manner each day.

If you miss a dose, skip the missed dose and carry on as usual with your next dose. Do not take a double dose to make up for a missed dose. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.

It is important to take this medication regularly and to follow your doctor's instructions regarding monitoring blood pressure to ensure that you receive the maximum benefit from the medication.

Store this medication at room temperature and keep it in a dry place (not in the bathroom). Keep it out of the reach of children.

Do not dispose of medications in wastewater (e.g. down the sink or in the toilet) or in household garbage. Ask your pharmacist how to dispose of medications that are no longer needed or have expired.

Who should NOT take this medication?

Irbesartan - hydrochlorothiazide should not be taken by anyone who:

  • is allergic to irbesartan, hydrochlorothiazide, or to any of the ingredients of the medication
  • is pregnant
  • has anuria (no urine flow)

What side effects are possible with this medication?

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent. The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

  • anxiety or nervousness
  • belching, heartburn, and stomach discomfort
  • cold-like symptoms
  • cough
  • diarrhea
  • dizziness
  • headache
  • increased sensitivity to the sun
  • muscle or bone pain
  • rash
  • unusual tiredness

Although most of these side effects listed below don't happen very often, they could lead to serious problems if you do not check with your doctor or seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

  • difficulty breathing or swallowing
  • hoarseness
  • severe dizziness, lightheadedness, or fainting
  • swelling of the face, feet, hands, lips, or tongue
  • tightening of the throat
  • unusual bleeding or bruising
  • unusual rash or pinpoint red spots on the skin

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Are there any other precautions or warnings for this medication?

Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.


January 31, 2019

Health Canada has issued new restrictions concerning the use of hydrochlorothiazide. To read the full Health Canada Advisory, visit Health Canada's web site at

Low blood pressure: Occasionally, a larger-than-expected decrease in blood pressure occurs after taking this medication. In some cases, this happens after the first dose. It is more likely to occur if you take diuretics (water pills), have a reduced salt intake, are on dialysis, or are experiencing diarrhea or vomiting. Blood pressure should be monitored more often in these situations. Those with low blood pressure or those just starting to take this medication should move slowly from a reclining to an upright position to reduce the risk of dizziness.

Medical conditions: Be sure to tell your doctor if you have any of the following conditions, as they may affect your use of this medication:

  • congestive heart failure
  • diabetes
  • electrolyte imbalance (e.g., high low levels of potassium in blood)
  • gout
  • kidney disease
  • liver disease
  • lupus
  • pancreatitis
  • recent heart attack or stroke
  • sulfa allergy
  • valvular stenosis (narrowing of the heart valves)

Pregnancy: Irbesartan - hydrochlorothiazide should not be taken by pregnant women. If you become pregnant while taking this medication, stop taking it and contact your doctor immediately.

Breast-feeding: It is generally not recommended that you breast-feed while you are taking this medication, as there is a possibility of serious side effects to the child. Discuss this with your doctor.

Children:The safety and effectiveness of using this medication have not been established for children.

What other drugs could interact with this medication?

There may be an interaction between irbesartan - hydrochlorothiazide and any of the following:

  • cholestyramine and colestipol
  • lithium
  • medications that increase the level of potassium in the blood (e.g., spironolactone, amiloride, triamterene, or salt substitutes that contain potassium)
  • nonsteroidal anti-inflammatory drugs (NSAIDs; e.g., ASA)
  • other blood pressure medications
  • other diuretics (water pills)
  • potassium pills or potassium supplements

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

  • stop taking one of the medications,
  • change one of the medications to another,
  • change how you are taking one or both of the medications, or
  • leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. In many cases, interactions are intended or are managed by close monitoring. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications that you are taking. Also tell them about any supplements you take. Since caffeine, decongestants, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.

All material copyright MediResource Inc. 1996 – 2020. Terms and conditions of use. The contents herein are for informational purposes only. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Source: