irbesartan (Avapro)

Irbesartan is an oral medication that is used to treat high blood pressure (hypertension) and diabetic nephropathy or kidney disease. It belongs to a class of drugs called angiotensin receptor blockers (ARBs) which also includes valsartan (Diovan), losartan (Cozaar), and candesartan (Atacand). Angiotensin, formed in the blood by the action of angiotensin converting enzyme (ACE), is a powerful chemical that attaches to angiotensin receptors found in many tissues but primarily on smooth muscle cells of blood vessels. Angiotensin's attachment to the receptors causes the blood vessels to narrow (vasoconstrict), which leads to an increase in blood pressure (hypertension ). Irbesartan blocks the angiotensin receptor. By blocking the action of angiotensin, irbesartan dilates blood vessels and reduces blood pressure. The FDA approved irbesartan in September 1997.

Avapro

GENERIC AVAILABLE: No

Yes

The most common side effects of irbesartan are:

• dizziness,
• hyperkalemia,
• diarrhea,
• abdominal pain or
• heartburn,
• fatigue, and
• reduced blood pressure when rising from a sitting or standing position (orthostatic hypotension).

Other important side effects patients may experience include:

• impotence,
• reduced renal function, and
• allergic reactions.

Rhabdomyolysis (inflammation and destruction of muscle) and angioedema (swelling of soft tissues including those of the throat and larynx) are rare but serious side effects of irbesartan.

The recommended dose of irbesartan for treating hypertension is 75 to 300 mg once daily. Most hypertensive patients are started on 150 mg daily. Diabetic nephropathy is treated with 300 mg daily.

Combining irbesartan with potassium-sparing diuretics (for example., spironolactone [Aldactone], triamterene, amiloride), potassium supplements, or salt substitutes containing potassium may lead to hyperkalemia (elevated potassium in the blood) and toxicity from potassium.

Combining irbesartan or other ARBs with nonsteroidal anti-inflammatory drugs (NSAIDs) in patients who are elderly, fluid-depleted (including those on diuretic therapy), or with poor kidney function may result in reduced kidney function, including kidney failure. These effects usually are reversible. There have been reports that aspirin and other NSAIDs such as ibuprofen (Advil, Children's Advil/Motrin, Medipren, Motrin, Nuprin, PediaCare Fever, etc.), indomethacin (Indocin, Indocin-SR), and naproxen (Anaprox, Naprelan, Naprosyn, Aleve) may reduce the effects of ARBs.

All ARBs should not be used during pregnancy. When used in the second or third trimester of pregnancy, irbesartan and similar drugs may cause injury and even death to the fetus. Irbesartan should not be used during pregnancy. When pregnancy is detected, irbesartan should be stopped as soon as possible.

It is not known whether irbesartan is secreted into human milk. Irbesartan is secreted into the milk of rats.

What preparations of irbesartan are available?

Tablets: 75 mg, 150 mg and 300 mg.

How should I keep irbesartan stored?

Tablets should be stored at room temperature, 15 C -30 C (59 F - 86 F).