Pharmacology · Angiotensin II receptor blockers (ARBs)
Irbesartan !
An ARB used for high blood pressure and to slow diabetic kidney disease in hypertensive people with type 2 diabetes and proteinuria.
Updated 2026-11-01
The figure shows olmesartan, another ARB, in the same binding pocket of the human AT1 receptor; no structure with irbesartan bound is available.
Mechanism of action
Irbesartan blocks the AT1 receptor. Arterioles dilate, aldosterone falls and the efferent arteriole of the glomerulus relaxes, lowering pressure inside the glomerulus. That reduces proteinuria and slows the loss of kidney function in diabetic nephropathy.
- Irbesartan blocks the AT1 receptor
- The efferent arteriole relaxes and glomerular pressure falls
- Less proteinuria and slower loss of kidney function
Pharmacokinetics
- Absorption
- Rapid and complete absorption; food does not change it
- Half-life
- About 11 to 15 hours
Indications
- High blood pressure Arterial hypertension →
- Diabetic nephropathy in hypertensive type 2 diabetes with raised creatinine and proteinuria Chronic kidney disease →
Adverse effects
Common
- Dizziness and orthostatic dizziness
- Hyperkalaemia, more in diabetic kidney disease
- Fatigue
Contraindications
- Pregnancy
- Hypersensitivity to the drug
- Use with aliskiren in people with diabetes
Key interactions
- Potassium-sparing diuretics, potassium supplements or salt substitutes
- Hyperkalaemia
- NSAIDs, including COX-2 inhibitors
- Weaker effect and risk of kidney injury
- Lithium
- Higher lithium levels and toxicity
What is monitored
- Blood pressure, including standing
- Potassium and creatinine
- Urine protein in diabetic kidney disease
Administration and safety
- Given by mouth once a day, with or without food
- Several «-sartan» names look alike: the name is checked on every order
Nursing care
- Check blood pressure, potassium and creatinine when starting and after changes
- Watch for dizziness, especially in patients on diuretics
- Ask women of childbearing age about pregnancy plans
- Teach the patient that face, lip or tongue swelling is an emergency
Pregnancy and breastfeeding
Contraindicated: drugs acting on the renin-angiotensin system can injure and kill the developing fetus; it is stopped as soon as pregnancy is detected.
Test yourself
Think of the answer, then tap the question to see it.
How does irbesartan reduce proteinuria?
By relaxing the efferent arteriole, which lowers pressure inside the glomerulus.
Which adverse effect was the most common in diabetic kidney disease trials with irbesartan?
Hyperkalaemia, together with dizziness and orthostatic hypotension.
Does food change irbesartan absorption?
No. Absorption is rapid and complete with or without food.
Related drugs
Related conditions
← Back to the class: Angiotensin II receptor blockers (ARBs)
Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.
Sources: DailyMed - IRBESARTAN tablet (DailyMed (U.S. National Library of Medicine), 2026); ATCDDD - ATC/DDD Index (WHO Collaborating Centre for Drug Statistics Methodology, 2026).
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Representative model, for educational purposes only.