Irbesartan is used alone or together with other medicines to treat high blood pressure (hypertension). High blood pressure adds to the workload of the heart and arteries. If it continues for a long time, the heart and arteries may not function properly. This can damage the blood vessels of the brain, heart, and kidneys, resulting in a stroke, heart failure, or kidney failure. Lowering blood pressure can reduce the risk of stroke and heart attacks.

Irbesartan is also used to treat high blood pressure with diabetic nephropathy. Diabetic nephropathy is a complication of type 2 diabetes which causes the kidneys to not work properly.

Irbesartan is an angiotensin II receptor blocker (ARB). It works by blocking a substance in the body that causes blood vessels to tighten. As a result, irbesartan relaxes the blood vessels. This lowers blood pressure and increases the supply of blood and oxygen to the heart.

This medicine is available only with your doctor's prescription.

In addition to the use of this medicine, treatment for your high blood pressure may include weight control and changes in the types of foods you eat, especially foods high in sodium (salt). Your doctor will tell you which of these is most important for you. You should check with your doctor before changing your diet.

Many patients who have high blood pressure will not notice any signs of the problem. In fact, many may feel normal. It is very important that you take your medicine exactly as directed and that you keep your appointments with your doctor even if you feel well.

Remember that this medicine will not cure your high blood pressure but it does help control it. Therefore, you must continue to take it as directed if you expect to lower your blood pressure and keep it down. You may have to take high blood pressure medicine for the rest of your life. If high blood pressure is not treated, it can cause serious problems such as heart failure, blood vessel disease, stroke, or kidney disease.

You may take this medicine with or without food.

Take all other medicines your doctor has prescribed to treat your condition.

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur:

More common

Chills

cold sweats

confusion

dizziness, faintness, or lightheadedness when getting up from lying or sitting position

Less common

Bladder pain

bloody or cloudy urine

chest pain

difficult, burning, or painful urination

fast, pounding, or irregular heartbeat or pulse

frequent urge to urinate

lower back or side pain

Rare

Chest discomfort

decreased urine output

dilated neck veins

extreme fatigue

feeling of warmth

fever

irregular breathing

irregular heartbeat

nausea

pain or discomfort in the arms, jaw, back, or neck

redness of the face, neck, arms, and occasionally, upper chest

shortness of breath

sweating

swelling of the face, fingers, feet, or lower legs

tightness in the chest

troubled breathing

vomiting

weight gain

Incidence not known

Abdominal or stomach pain

black, tarry stools

bleeding gums

clay-colored stools

dark urine

decreased frequency of urine

headache

increased thirst

itching

large, hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, or sex organs

loss of appetite

muscle cramps or spasms

muscle pain or stiffness

nervousness

numbness or tingling in the hands, feet, or lips

pinpoint red spots on the skin

rash

unpleasant breath odor

unusual bleeding or bruising

unusual tiredness or weakness

vomiting of blood

weakness or heaviness of the legs

weight gain

yellow eyes or skin

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

Less common

Acid or sour stomach

belching

body aches or pain

bone pain

congestion

cough

diarrhea

dryness or soreness of the throat

feeling of indigestion

general feeling of discomfort or illness

heartburn

hoarseness

joint pain

pain in the chest below the breastbone

runny nose

shivering

sneezing

stomach discomfort or upset

stuffy nose

sweating

tender, swollen glands in the neck

trouble sleeping

trouble with swallowing

voice changes

Rare

Blistering, crusting, irritation, itching, or reddening of the skin

bloated or full feeling

blurred or loss of vision

burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings

change in hearing

cracked, dry, scaly skin

decreased interest in sexual intercourse

depression

difficulty having a bowel movement (stool)

disturbed color perception

double vision

ear drainage

earache or pain in the ear

excess air or gas in the stomach or intestines

halos around lights

hives or welts

inability to have or keep an erection

large, flat, blue or purplish patches in the skin

loss in sexual ability, desire, drive, or performance

night blindness

overbright appearance of lights

pain, swelling, or redness in the joints

passing gas

sleepiness or unusual drowsiness

tunnel vision

Incidence not known

Feeling of constant movement of self or surroundings

sensation of spinning

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

It is very important that your doctor check the progress of you or your child at regular visits to make sure that this medicine is working properly. Blood tests may be needed to check for unwanted effects.

Using this medicine while you are pregnant can harm your unborn baby. Use an effective form of birth control to keep from getting pregnant. If you think you have become pregnant while using this medicine, tell your doctor right away.

Dizziness, lightheadedness, or fainting may occur, especially when you get up from a lying or sitting position. Make sure you know how you react to this medicine before you drive, use machines, or do anything else that could be dangerous if you are dizzy or not alert. If you feel dizzy, lie down so you do not faint. Then sit for a few moments before standing to prevent the dizziness from returning.

Check with your doctor right away if you become sick while taking this medicine, especially with severe or continuing nausea and vomiting or diarrhea. These conditions may cause you to lose too much water and may lead to low blood pressure. You can also loose water by sweating, so drink plenty of water during exercise or in hot weather.

Ask your doctor before you use medicines, supplements, or salt substitutes that contain potassium.

Do not take other medicines unless they have been discussed with your doctor. This especially includes over-the-counter (nonprescription) medicines for appetite control, asthma, colds, cough, hay fever, or sinus problems, since they may tend to increase your blood pressure.