Telmisartan is a member of a family of drugs called angiotensin receptor blockers (ARBs), which includes losartan (Cozaar), valsartan (Diovan), irbesartan (Avapro), 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 muscle cells of blood vessels. Angiotensin's attachment to the receptors causes muscle cells to shorten and narrow the blood vessels (vasoconstrict), which leads to an increase in blood pressure (hypertension). Telmisartan blocks the angiotensin receptor. By blocking the action of angiotensin, telmisartan widens blood vessels (vasodilate) and reduces blood pressure. Telmisartan was approved by the FDA in November 2000.

Micardis

GENERIC AVAILABLE: No

Yes

Like other angiotensin receptor blockers, telmisartan generally is well-tolerated. The most common side effects are:

• headache,
• dizziness,
• back pain,
• fatigue,
• stomach upset,
• upper respiratory tract infections,
• hyperkalemia, and
• diarrhea.

Patients also may experience 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 telmisartan.

The recommended dose for treating hypertension is 20-80 mg daily. The recommended dose for cardiovascular risk reduction is 80 mg daily.

Telmisartan can increase blood concentrations of digoxin (Lanoxin) and lithium (Eskalith, Lithobid). Therefore blood levels of digoxin and lithium should be monitored and doses adjusted if necessary.

Combining telmisartan 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).

Combining telmisartan 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.

Medications that interfere with the angiotensin converting enzyme system, such as telmisartan, have been found to cause fetal and neonatal toxicity and death when taken by pregnant women. Pregnant mothers should discontinue use of telmisartan as soon as they know they are pregnant.

It is not known if telmisartan is secreted into breast milk. Since most medicines are secreted into breast milk, potential risks and benefits need to be assessed in women who are nursing to determine if breast feeding or telmisartan should be discontinued.

What preparations of telmisartan are available?

Tablets: 20, 40, and 80 mg.

How should I keep telmisartan stored?

Telmisartan should be stored at room temperature, 15 C - 30 C (59 F - 86 F). The tablets should be kept in their blister-pack packaging until they are used.