Irbesartan and hydrochlorothiazide combination 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 strokes and heart attacks.

Irbesartan is an angiotensin II receptor blocker (ARB). It works by blocking a substance in the body that causes the 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.

Hydrochlorothiazide is a thiazide diuretic (water pill). It reduces the amount of water in the body by increasing the flow of urine, which helps lower the blood pressure.

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

In addition to the use of the medicine your doctor has prescribed, treatment for your high blood pressure may include weight control and care 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.

If you are taking cholestyramine or colestipol, take Avalide® at least 1 hour before or 4 hours after these medicines.

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:

Less common

Abdominal or stomach pain

bloody or cloudy urine

chest pain

confusion

difficult with breathing

difficult, burning, or painful urination

fast, pounding, or irregular heartbeat or pulse

frequent urge to urinate

lower back or side pain

nausea or vomiting

numbness or tingling in the hands, feet, or lips

swelling

weakness or heaviness of the legs

Rare

Blurred vision

convulsions

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

loss of appetite

muscle pain or cramps

sweating

unusual tiredness or weakness

Incidence not known

Dark-colored urine

fever

hives or welts, itching, or skin rash

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

muscle spasms or stiffness

upper right abdominal or stomach pain

yellow eyes and 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:

More common

Headache

sunburn

Less common

Acid or sour stomach

chills

congestion

cough

diarrhea

dryness or soreness of the throat

joint pain

sneezing

stomach discomfort or upset

tender, swollen glands in the neck

trouble sleeping

trouble swallowing

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 your progress at regular visits to make sure that this medicine is working properly. Blood and urine 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.

This medicine may cause dizziness, lightheadedness, or fainting, especially when you get up suddenly 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. 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. If you faint, call your doctor right away.

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

Check with your doctor immediately if blurred vision, difficulty with reading, eye pain, or any other change in vision occurs during or after treatment. This could be a sign of a serious eye problem. Your doctor will want you to have your eyes checked by an ophthalmologist (eye doctor).

This medicine may affect blood sugar levels. If you notice a change in the results of your blood or urine sugar tests, or if you have any questions, check with your doctor.

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

Drinking alcohol or taking narcotic pain relievers or sleeping pills with this medicine may intensify feeling lightheaded, dizzy, or faint. Tell your doctor if you are drinking alcohol or using pain relievers or sleeping pills.

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.