Pharm 101: Irbesartan

Class

Angiotensin-II Receptor Bloker

Pharmacodynamics

• Competitive selective antagonist of angiotensin II type 1 (AT1) receptor
• Causes vasodilation and inhibition of aldosterone secretion
• More selective blockers of angiotensin effects than ACE-I, benefits include:
  • More complete inhibition of angiotensin action, because there are enzymes other than ACE capable of generating angiotensin II
  • No effect on bradykinin metabolism so reduced incidence of cough, angioedema

Pharmacokinetics

• 90% protein bound
• Half-life 12 hours
• Liver metabolism

Clinical uses

• Hypertension
• CCF
• Chronic renal failure:
  • Diminish proteinuria and stabilise renal function (even in absence of lowering BP)

Adverse effects

• Similiar to those of ACE-inhibitors, except for cough and angioedema which are uncommon

Precautions/contraindications

• Non-diabetic renal failure
• Pregnancy
• Hyperkalaemia
• Renal artery stenosis

Further Reading

• Buttner R. Pharm 101: Ramipril