Irbesartan

Medically reviewed by Dena Westphalen, PharmD on May 12, 2023
Written by Sarah Lewis, PharmD

This article describes irbesartan’s uses and dosage, ways to save on cost, and more. Below you’ll find some coupon options for irbesartan.

Boxed warning: Risks of fetal harm or pregnancy loss

Irbesartan has a boxed warning about the risks of fetal harm or pregnancy loss. Boxed warnings are serious warnings from the Food and Drug Administration (FDA).

For details, see the “Interactions and warnings for irbesartan” section below.

Below you’ll find answers to a few commonly asked questions about irbesartan.

Is it safe to take irbesartan and hydrochlorothiazide together?

Yes, irbesartan and hydrochlorothiazide are safe to take together. In fact, there is a drug that combines these two ingredients into one product. The brand name is Avalide. It’s for people who need more than one medication to manage their blood pressure.

To learn more about taking irbesartan and hydrochlorothiazide together, talk with your doctor or pharmacist.

How does irbesartan compare with other similar drugs, such as losartan or telmisartan?

Irbesartan is an angiotensin II receptor blocker (ARB). Other ARBs include candesartan, losartan, telmisartan, and valsartan. Because these drugs belong to the same group of drugs, they have similar side effects and warnings. They also have similar uses, but some have additional approved uses.

If you’d like to know whether another ARB is an option for you, talk with your doctor. They may recommend one drug over the other to manage your condition.

Does irbesartan cause long-term side effects?

No, long-term side effects aren’t expected with irbesartan. In studies, specific side effects weren’t seen in people who had taken the drug for a long time. Long lasting side effects after treatment ended also weren’t reported.

Talk with your doctor if you have questions about possible long-term side effects with irbesartan.

Can irbesartan 300 mg cause more side effects than irbesartan 150 mg?

No, more side effects aren’t expected with a higher dose of irbesartan. In studies, the side effects that occurred weren’t dose-related. This means there weren’t any more side effects at higher doses than there were at lower doses of irbesartan.

If you notice new symptoms after a dosage increase, tell your doctor. They can determine the most likely cause of a symptom and suggest ways to help manage it.

Is it safe to stop taking irbesartan?

No, you should not stop taking irbesartan without talking with your doctor. Stopping it without another medication to manage your condition could lead to serious complications.

Tell your doctor if you want to stop irbesartan. They can help you do it safely and still manage your condition.

How does irbesartan work? And how long does it take to start working?

Irbesartan blocks the angiotensin II receptor. (A receptor is a binding site on a cell.) The hormone that usually binds to this receptor is angiotensin II. Angiotensin II causes blood vessels to tighten and narrow. This increases the pressure the inside blood vessels.

When irbesartan blocks the receptor, it stops angiotensin II from binding to it. This lowers blood pressure since angiotensin II can’t have an effect.

Irbesartan will have an effect on blood pressure within about 4 hours. But it can take up to 2 weeks to see the full effect.

To learn more about what you can expect with irbesartan, talk with your doctor or pharmacist.

Irbesartan may cause mild or serious side effects. More common mild side effects of irbesartan and its serious side effects are listed below. This article doesn’t include all possible side effects of the drug. Side effects can vary based on your age, overall health, and any other medications you take.

To learn more about irbesartan’s side effects, talk with your doctor or pharmacist. You can also read the prescribing information* for irbesartan.

* To view irbesartan’s prescribing information, see the “Article resources” section below.

Mild side effects

More common mild side effects reported with some forms of irbesartan are listed below.

This article doesn’t include all possible mild side effects of the drug. To learn more about irbesartan’s side effects, see the prescribing information* for irbesartan.

With many drugs, mild side effects may go away within a few days or a couple of weeks. If the side effects are bothersome, tell your doctor or pharmacist. They may be able to suggest ways to manage them.

Irbesartan oral tablet’s mild side effects include:

• diarrhea
• dizziness
• fatigue (lack of energy)
• heartburn
• mild allergic reaction†

* To view irbesartan’s prescribing information, see the “Article resources” section below.
† For details about this side effect, see the “Interactions and warnings for irbesartan” section below.

Serious side effects

Serious side effects of irbesartan are listed below.

This article doesn’t include all possible serious side effects of the drug. To learn more about irbesartan’s side effects based on the form, see the prescribing information* for irbesartan.

With many drugs, serious side effects are possible but not common. If you have serious side effects from this drug, call your doctor right away. If you’re having severe symptoms or a medical emergency, call 911 or a local emergency number.

In general, irbesartan’s serious side effects include:

• high blood potassium level
• low blood pressure or dizziness upon standing, which can lead to fainting
• problems with kidney function
• very low blood pressure
• boxed warning: risks of fetal harm or pregnancy loss†
• severe allergic reaction†

* To view irbesartan’s prescribing information, see the “Article resources” section below.
† For details about this side effect, see the “Interactions and warnings for irbesartan” section below.

The Food and Drug Administration (FDA) approves prescription drugs such as irbesartan for certain conditions. Approved uses for irbesartan are described below.

Use for high blood pressure

Doctors may prescribe irbesartan oral tablet to help manage high blood pressure. It’s used for this purpose in adults. It’s usually prescribed as a long-term treatment.

With high blood pressure, there are usually no symptoms. But people with high blood pressure are at risk of serious problems, including heart attack and stroke. Because these problems can be life threatening, high blood pressure is sometimes called “the silent killer.”

Irbesartan can be prescribed together with other medications for high blood pressure.

Doctors may not prescribe irbesartan oral tablet in certain situations. This includes for people with diabetes who also take aliskiren (Tekturna).

Use for diabetic nephropathy

Doctors may prescribe irbesartan oral tablet for treating diabetic nephropathy. It’s used for this purpose in adults with diabetes who have a high creatinine level, protein in the urine, and high blood pressure. It’s usually prescribed as a long-term treatment.

With diabetic nephropathy, high blood sugar damages the kidneys of people who have diabetes. The damage means the kidneys can’t work as well as they should. Irbesartan can slow this kind of kidney damage.

Doctors can find out how well your kidneys are working with a creatinine urine test. If your creatinine is high, it could be a sign of kidney damage. Protein in the urine is another sign that your kidneys aren’t working the way they should.

Doctors may not prescribe irbesartan oral tablet in certain situations. This includes for people with diabetes who also take aliskiren (Tekturna).

The dosage of irbesartan your doctor prescribes may vary based on your condition and certain other factors. Talk with your doctor about the dosage you should follow.

Taking irbesartan

Irbesartan oral tablet is taken by mouth, with or without food.

Your doctor will talk with you about how to take irbesartan. They’ll explain how much to take and how often. Always follow your doctor’s recommendation.

Overdose of irbesartan

You should not take more irbesartan than your doctor prescribes. For some drugs, doing so may lead to serious side effects or overdose.

If you think you’ve taken too much irbesartan, call your doctor or pharmacist right away. Or you could call 800-222-1222 to speak with someone at America’s Poison Centers. You can also use its online resource. If you have concerning symptoms, call 911 or a local emergency number immediately. You can also go to the closest emergency room.

You may be able to save money on your prescription for irbesartan by using our Perks discount coupons. They can be found at the end of this article.

If you have questions about how to pay for irbesartan, talk with your doctor or pharmacist.

Note: Optum Perks coupons cannot be used with insurance copays or benefits.

Below, you’ll find information about irbesartan’s possible interactions and warnings.

Interactions of irbesartan

For some medications, certain things may affect how the drug works. These include getting vaccines, consuming alcohol or certain foods, or taking the drug with other medications. This effect is called a drug interaction.

Before you take irbesartan, ask your doctor to check for possible interactions. Be sure to tell them about any of the following you take or use:

• prescription drugs
• over-the-counter medications
• vitamins, herbs, or supplements

To learn about drug-condition interactions, see the “Warnings for irbesartan” section below.

Warnings for irbesartan

Irbesartan should not be taken or should be taken cautiously by certain people.

Boxed warning: Risks of fetal harm or pregnancy loss

Irbesartan has a boxed warning about the risks of fetal harm or pregnancy loss. Boxed warnings are serious warnings from the Food and Drug Administration (FDA).

For details, see the “Pregnancy or breastfeeding and irbesartan” section below.

Other warnings

Irbesartan could cause harm to people with certain health conditions. This effect is called a drug-condition interaction. Other factors can also affect whether irbesartan is a safe option for you.

Ask your doctor about specific warnings for irbesartan, and be sure to tell your doctor about your:

• current health, including any allergies to medications
• past health conditions or surgeries

Allergic reaction

Irbesartan can cause an allergic reaction in some people. Severe allergic reactions are rare but possible.

If you’ve had an allergic reaction to irbesartan or any of its ingredients, your doctor will likely not prescribe irbesartan. They can tell you about medications that are safer options for you.

A mild allergic reaction may cause the following symptoms:

• skin rash
• itchiness
• flushing (temporary warmth, redness, or deepening of skin color)

A severe allergic reaction may cause the following symptoms:

• swelling under your skin, usually in your hands, feet, eyelids, or lips
• swelling of your mouth, throat, or tongue, which can cause breathing problems

If you have an allergic reaction to irbesartan, call your doctor right away. If you have severe symptoms, call 911 or a local emergency number.

Pregnancy or breastfeeding and irbesartan

Information about irbesartan and pregnancy and breastfeeding is described below.

Irbesartan and pregnancy

Irbesartan should not be taken during pregnancy. In fact, irbesartan has a boxed warning about the risks of fetal harm or pregnancy loss. See below for details.

If you’re planning a pregnancy or can become pregnant, talk with your doctor before taking this medication. Your doctor may suggest birth control options to use during treatment with irbesartan.

Risks of fetal harm or pregnancy loss

Irbesartan has a boxed warning about the risks of fetal harm or pregnancy loss. Boxed warnings are serious warnings from the FDA.

Taking irbesartan during pregnancy can cause harm to the developing fetus and, in some cases, pregnancy loss. If you become pregnant while taking irbesartan, tell your doctor immediately and stop taking irbesartan as soon as possible.

To learn more, talk with your doctor or pharmacist.

Irbesartan and breastfeeding

Irbesartan should not be taken while breastfeeding. If you’re currently breastfeeding or planning to do so, talk with your doctor before taking this medication. Your doctor may recommend other ways to feed your child during treatment with irbesartan.

This article describes irbesartan’s uses and dosage, ways to save on cost, and more. Let your doctor know if you have questions about irbesartan or would like more details about it.

Here’s a list of some possible questions you may want to ask your doctor:

• Can irbesartan cause hair loss?
• How does irbesartan compare with an ACE inhibitor?*
• Is irbesartan safe to take with my other medications?

* ACE stands for angiotensin converting enzyme. ACE inhibitors are a group of drugs that stop the body producing angiotensin II (which causes blood vessels to tighten and narrow).

• Irbesartan tablets, for oral use. (2023). https://nctr-crs.fda.gov/fdalabel/services/spl/set-ids/4725e842-8d01-4204-af6f-ae71531ccd0d/spl-doc
• Food and Drug Administration. (2023). Orange Book: Approved drug products with therapeutic equivalence evaluations. https://www.accessdata.fda.gov/scripts/cder/ob/index.cfm

Disclaimer: Optum Perks has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.