Classifications: angiotensin ii receptor antagonist; antihypertensive; Therapeutic: antihypertensive; angiotensin ii receptor antagonist
Pregnancy Category: C first trimester; D second and third trimester
75 mg, 150 mg, 300 mg tablets
Irbesartan is an angiotensin II receptor (type AT1) antagonist. Angiotensin II is a hormone of the reninangiotensinaldosterone system. Irbesartan selectively blocks
the binding of angiotensin II to the AT1 receptors found in many tissues (e.g., vascular smooth muscle, adrenal glands), resulting in vasodilation of vascular smooth
Binding to the angiotensin receptors results in blocking the vasoconstricting and aldosterone-secreting effects of angiotensin
II, thus resulting in an antihypertensive effect.
Hypertension, treatment of diabetic nephropathy in patients with hypertension and type 2 diabetes.
Hypersensitivity to irbesartan, losartan, or valsartan; hypovolemia; pregnancy (category C first trimester, category D second
and third trimester), lactation, children.
Patients on diuretics, arterial stenosis of the renal artery, hepatic disease; severe CHF, African American patients.
Route & Dosage
Adult: PO Start with 150 mg once daily, may increase to 300 mg/d
- Correct volume depletion prior to initiation of therapy to prevent hypotension. Titrate daily dose up to 300 mg; larger
doses, however, are not likely to provide additional benefit.
Adverse Effects (≥1%)Body as a Whole:
, pain. CNS:
Dizziness, headache, anxiety, nervousness. CV:
Tachycardia, chest pain. GI: Diarrhea
, dyspepsia, nausea, vomiting, abdominal pain. Respiratory:
Upper respiratory infection
, cough, sinus disorder, pharyngitis, rhinitis. Skin:
Rapidly absorbed from GI tract, 6080% bioavailability. Distribution:
90% protein bound. Metabolism:
In the liver primarily by CYP2C9. Elimination:
Primarily in feces. Half-Life:
Assessment & Drug Effects
- Monitor for therapeutic effectiveness: Maximum pressure lowering effect may not be evident for 612 wk; indicated by
decreases in systolic and diastolic BP.
- Monitor BP periodically; trough readings, just prior to the next scheduled dose, should be made when possible.
- Lab tests: Monitor periodically BUN and creatinine, serum potassium, and CBC with differential.
Patient & Family Education
- Inform physician immediately if you become pregnant.
- Notify physician of episodes of dizziness, especially when making position changes.