No

Angiotensin II Antagonists

Treatment of hypertension alone or in combination with other antihypertensives

C/D (2nd and 3rd trimesters)

Hypersensitivity to irbesartan or any component; hypersensitivity to other A-II receptor antagonists; primary hyperaldosteronism; bilateral renal artery stenosis; pregnancy (2nd and 3rd trimesters)

Avoid use or use smaller doses in patients who are volume depleted; correct depletion first. Deterioration in renal function can occur with initiation. Use with caution in unilateral renal artery stenosis and pre-existing renal insufficiency; significant aortic/mitral stenosis. Safety and efficacy have not been established in pediatric patients.

Central nervous system: Fatigue (4%)

Gastrointestinal: Diarrhea (3%), dyspepsia (2%)

Respiratory: Upper respiratory infection (9%), cough (2.8% versus 2.7% in placebo)

>1% but frequency less than or equal to placebo: Abdominal pain, anxiety, nervousness, chest pain, dizziness, edema, headache, influenza, musculoskeletal pain, pharyngitis, nausea, vomiting, rash, rhinitis, sinus abnormality, tachycardia, urinary tract infection, dizziness, syncope, vertigo

<1% (Limited to important or life-threatening symptoms): Hypotension, orthostatic hypotension, fever, chills, facial edema, upper extremity edema, flushing, hypertension, myocardial infarction, angina, arrhythmia, cardiopulmonary arrest, heart failure, hypertensive crisis, pruritus, dermatitis, ecchymosis, erythema, urticaria, sexual dysfunction, decreased libido, gout, constipation, gastroenteritis, flatulence, abdominal distension, muscle cramps, arthritis, muscle aches, chest pain (noncardiac), bursitis, muscle weakness, sleep disturbance, numbness, somnolence, depression, paresthesia, tremor, TIA, cerebrovascular accident, abnormal urination, prostate disorder, epistaxis, bronchitis, congestion, pulmonary congestion, dyspnea, wheezing, vision disturbance, hearing abnormality, ear infection, ear pain, conjunctivitis, increased serum creatinine (0.7% versus 0.9% in placebo). May be associated with worsening of renal function in patients dependent on renin-angiotensin-aldosterone system.

Most likely manifestation of an overdosage would be hypotension and tachycardia; bradycardia could occur from parasympathetic (vagal) stimulation

If symptomatic hypotension should occur, institute supportive treatment

CYP2C9 enzyme substrate

Lithium: Risk of toxicity may be increased by irbesartan; monitor lithium levels.

Potassium-sparing diuretics (amiloride, potassium, spironolactone, triamterene): Increased risk of hyperkalemia.

Potassium supplements may increase the risk of hyperkalemia.

Trimethoprim (high dose) may increase the risk of hyperkalemia.

Irbesartan is an angiotensin receptor antagonist. Angiotensin II acts as a vasoconstrictor. In addition to causing direct vasoconstriction, angiotensin II also stimulates the release of aldosterone. Once aldosterone is released, sodium as well as water are reabsorbed. The end result is an elevation in blood pressure. Irbesartan binds to the AT1 angiotensin II receptor. This binding prevents angiotensin II from binding to the receptor thereby blocking the vasoconstriction and the aldosterone secreting effects of angiotensin II.

Onset of action: Peak levels in 1-2 hours

Duration: >24 hours

Distribution: V_d: 53-93 L

Protein binding, plasma: 90%

Metabolism: Hepatic

Bioavailability: 60% to 80%

Half-life: Terminal: 11-15 hours

Time to peak serum concentration: 1.5-2 hours

Elimination: Urine (20%), feces (80%)

Adults: Oral: 150 mg once daily with or without food; patients may be titrated to 300 mg once daily

The angiotensin II receptor antagonists appear to have similar indications as the ACE inhibitors. While these drugs have been shown to be effective in treating hypertension, their efficacy in heart failure is being vigorously evaluated. The angiotensin II antagonists are especially useful in providing an alternative therapy in those patients who have intractable cough in response to ACE-inhibitor therapy. Similar to ACE inhibitors, pre-existing volume depletion caused by diuretic therapy may potentiate hypotension in response to angiotensin II antagonists.

May cause anxiety, dizziness, nervousness

None reported

No information available to require special precautions

No effects or complications reported

Take exactly as directed; do not discontinue without consulting prescriber. Take first dose at bedtime. This drug does not eliminate need for diet or exercise regimen as recommended by prescriber. May cause dizziness, fainting, lightheadedness (use caution when driving or engaging in tasks that require alertness until response to drug is known); nausea, vomiting, or abdominal pain (small frequent meals, frequent mouth care, sucking lozenges, or chewing gum may help); diarrhea (buttermilk, boiled milk, yogurt may help). Report chest pain or palpitations, skin rash, fluid retention (swelling of extremities), difficulty in breathing or unusual cough, or other persistent adverse reactions. Pregnancy/breast-feeding precautions: Inform prescriber if you are pregnant or if you intend to get pregnant. Do not breast-feed.

Tablet: 75 mg, 150 mg, 300 mg

Munger MA and Furniss SM, "Angiotensin II Receptor Blockers: Novel Therapy for Heart Failure?" Pharmacotherapy, 1996, 16(2 Pt 2):59S-68S.