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 Avapro (Irbesartan). If you are concerned about side effects, discuss the risks and benefits of Avapro (Irbesartan) with your doctor.

The following side effects have been reported by at least 1% of people taking Avapro (Irbesartan). 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.

• Diarrhea
• dizziness
• headache
• lightheadedness
• rash
• trouble sleeping
• 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 seek medical attention.

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

• back leg muscle cramps
• dark brown urine
• dizziness when rising from a sitting or lying position
• fainting
• muscle pain, tenderness, or weakness
• ringing in the ears
• signs of clotting problems (e.g., unusual nosebleeds, bruising, blood in urine, coughing blood, bleeding gums, cuts that don't stop bleeding)
• signs of kidney problems (e.g., increased urination at night, decreased urine production, blood in the urine)
• signs of liver problems (e.g., nausea, vomiting, diarrhea, loss of appetite, weight loss, yellowing of the skin or whites of the eyes, dark urine, pale stools)
• signs of too much potassium in the blood (e.g., muscle weakness, irregular heartbeat, general feeling of being unwell)

Stop taking the medication and seek immediate medical attention if any of the following occur:

• signs of a serious allergic reaction (e.g., abdominal cramps, difficulty breathing, nausea and vomiting, or swelling of the face and throat)

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 Avapro (Irbesartan).

75 mg
Each white-to-off-white, biconvex, oval tablet, with a heart shape debossed on one side and the digits "2771" on the other, contains 75 mg of Avapro (Irbesartan). Nonmedicinal ingredients: croscarmellose sodium, lactose, magnesium stearate, microcrystalline cellulose, poloxamer 188, pregelatinized starch, and silicon dioxide.

150 mg
Each white-to-off-white, biconvex, oval tablet, with a heart shape debossed on one side and the digits "2772" on the other, contains 150 mg of Avapro (Irbesartan). Nonmedicinal ingredients: croscarmellose sodium, lactose, magnesium stearate, microcrystalline cellulose, poloxamer 188, pregelatinized starch, and silicon dioxide.

300 mg
Each white-to-off-white, biconvex, oval tablet, with a heart shape debossed on one side and the digits "2773" on the other, contains 300 mg of Avapro (Irbesartan). Nonmedicinal ingredients: croscarmellose sodium, lactose, magnesium stearate, microcrystalline cellulose, poloxamer 188, pregelatinized starch, and silicon dioxide.

Do not take Avapro (Irbesartan) if you:

• are allergic to Avapro (Irbesartan) or any ingredients of the medication
• have experienced a serious allergic reaction to another angiotensin II receptor blocker (ARB) (e.g., Candesartan, Losartan, Valsartan)
• have diabetes mellitus, kidney damage caused by diabetes, or severely reduced kidney function and are taking the medication Aliskiren or an angiotensin-converting enzyme (ACE) inhibitor
• are pregnant
• are breast-feeding
• have galactose intolerance or glucose malabsorption (a rare hereditary disease)

There may be an interaction between Avapro (Irbesartan) and any of the following:

• aliskiren
• alpha agonists (e.g., Clonidine, methyldopa)
• alpha blockers (e.g., Alfuzosin, Doxazosin, Tamsulosin)
• amifostine
• Amiodarone
• amphetamines (e.g., Dextroamphetamine, Lisdexamfetamine)
• angiotensin converting enzyme (ACE) inhibitors (e.g., Captopril, Ramipril, Enalapril)
• antipsychotics (e.g., Aripiprazole, Clozapine, Olanzapine, Pimozide) beta-adrenergic blockers (e.g., Atenolol, Propranolol, Sotalol)
• Bosentan
• brimonidine
• calcium channel blockers (e.g., Amlodipine, Diltiazem, Nifedipine, Verapamil)
• Canagliflozin
• Celecoxib
• ciprofloxacin
• Cyclosporine
• Dapsone
• dasabuvir
• Dipyridamole
• diuretics (water pills; e.g., hydrochlorothiazide, Furosemide)
• Enzalutamide
• fluconazole
• ginger
• Guanfacine
• ginseng (American)
• Heparin
• Hydralazine
• isosorbide dinitrate or isosorbide mononitrate
• lithium
• Lomitapide
• low molecular weight heparins (e.g., Dalteparin, Enoxaparin, Tinzaparin)
• Methylphenidate
• monoamine oxidase inhibitors (M.O.S. e.g., Moclobemide, Phenelzine, Rasagiline, Selegiline, Tranylcypromine)
• nonsteroidal anti-inflammatory medications (e.g., Diclofenac, Ibuprofen, Ketoprofen, Naproxen)
• other angiotensin receptor blockers (ARBs; e.g., candesartan, losartan)
• Paclitaxel
• Pentoxifylline
• Phenobarbital
• Phenytoin
• phosphodiesterase 5 inhibitors (e.g., Sildenafil, Tadalafil, Vardenafil)
• Pioglitazone
• potassium pills or potassium supplements
• potassium-sparing diuretics (e.g., Amiloride, spironolactone, triamterene)
• quinine
• Repaglinide
• rifabutin
• rifampin
• Rituximab
• Rosiglitazone
• sacubitril
• salt substitutes that contain potassium
• sodium phosphates
• sulfonamide anti-diabetes medications (e.g., chlorpropamide, Gliclazide, Glyburide)
• sulfonamide antibiotics (e.g., sulfamethoxazole, sulfisoxazole)
• Tamoxifen
• Tolvaptan
• Trimethoprim
• tretinoin
• Warfarin
• Yohimbine
• Zafirlukast

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. 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 Avapro (Irbesartan). Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, 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.

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 Avapro (Irbesartan).

Drowsiness/reduced alertness: Avapro (Irbesartan), like other medications for blood pressure may cause dizziness and lightheadedness, especially if you have been taking a diuretic (water pill). This may affect your ability to drive or operate machinery. Avoid these and other activities until you have determined that Avapro (Irbesartan) does not affect you in this way.

Heart disease: If you have a history of heart problems, such as a recent Heart Attack or Stroke, narrowing of the heart valves (valvular stenosis) or other heart disease, discuss with your doctor how Avapro (Irbesartan) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Avapro (Irbesartan), and whether any special monitoring is needed.

Kidney function: Avapro (Irbesartan) may affect the function of the kidneys, especially for people who already have kidney problems. Certain people may be more likely to experience changes in kidney function (e.g., people with narrowed blood vessels in their kidneys, or those with severe Congestive Heart Failure). The use of diuretics (water pills) or aliskiren may further increase risk of kidney problems for those at risk for this problem. If you have reduced kidney function or Kidney Disease, discuss with your doctor how Avapro (Irbesartan) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Avapro (Irbesartan), and whether any special monitoring is needed.

Liver function: Liver disease or reduced liver function may cause Avapro (Irbesartan) to build up in the body, causing side effects. If you have liver problems, discuss with your doctor how Avapro (Irbesartan) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Avapro (Irbesartan), and whether any special monitoring is needed. Your doctor may want to test your liver function regularly with blood tests while you are taking Avapro (Irbesartan).

If you experience symptoms of liver problems such as fatigue, feeling unwell, loss of appetite, nausea, yellowing of the skin or whites of the eyes, dark urine, pale stools, abdominal pain or swelling, and itchy skin, contact your doctor immediately.

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

Potassium levels: Avapro (Irbesartan) may affect potassium levels in the blood, especially when used for heart failure, or when taken with other medications called ACE inhibitors or diuretics such as Spironolactone. Your doctor will monitor your potassium levels while you are on Avapro (Irbesartan). Avoid using salt substitutes that contain potassium while you are taking Avapro (Irbesartan).

Pregnancy: Avapro (Irbesartan) can cause severe harm or death to a developing baby if it is taken by the mother during pregnancy. Therefore, Avapro (Irbesartan) should not be taken by pregnant women. If you become pregnant while taking Avapro (Irbesartan), contact your doctor immediately.

Breast-feeding: It is not known if Avapro (Irbesartan) passes into breast milk. If you are a breast-feeding mother and are taking Avapro (Irbesartan), it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.

Children: The safety and effectiveness of using Avapro (Irbesartan) have not been established for children.

Seniors: Older adults may be more likely to experience side effects of Avapro (Irbesartan).