Irbesartan Morningside Healthcare (Irbesartan)

Irbesartan is an angiotensin II receptor blocker indicated for several cardiovascular and renal conditions.

• Hypertension: reduces systolic and diastolic blood pressure, decreasing the risk of stroke and heart attack.
• Diabetic nephropathy: slows the decline of renal function in patients with type 2 diabetes.
• Heart failure (off‑label in some regions): may improve symptoms and reduce hospitalisation when added to standard therapy.

• Irbesartan selectively blocks angiotensin II type 1 (AT1) receptors on vascular smooth muscle, adrenal gland and renal tubular cells. By preventing angiotensin II binding, it inhibits vasoconstriction, aldosterone release, and sympathetic activation, leading to vasodilation, reduced sodium retention, and lower blood pressure.

Irbesartan is generally well tolerated, but adverse reactions can occur.

Common Side Effects

• Dizziness: feeling light‑headed, especially after standing.
• Headache: mild to moderate intensity.
• Fatigue: unusual tiredness without exertion.
• Hyperkalemia: elevated blood potassium levels.
• Nasal congestion: blocked or runny nose.
• Nausea: mild stomach upset.

Serious or Rare Side Effects

• Angioedema: swelling of face, lips, tongue, or throat that may impair breathing.
• Acute renal failure: sudden loss of kidney function.
• Hepatic injury: signs of liver damage such as jaundice.
• Severe hypotension: markedly low blood pressure causing fainting.
• Neutropenia: dangerously low white blood cell count.

Before initiating Irbesartan, several safety considerations are recommended.

• Monitor blood pressure: ensure adequate control and avoid excessive drops.
• Assess renal function: check serum creatinine and eGFR periodically.
• Check serum potassium: hyperkalemia risk, especially with potassium‑sparing agents.
• Pregnancy: contraindicated in pregnancy (Category D) due to fetal toxicity.
• Bilateral renal artery stenosis: avoid use as it may worsen renal perfusion.
• Store at ambient temperature: keep below 25 °C, retain in original packaging, and protect from moisture.

Irbesartan may interact with other medicines, requiring caution.

Major Interactions (Avoid)

• Aliskiren (in diabetes): combined use can increase renal impairment and hyperkalemia.
• Potassium‑sparing diuretics: additive risk of hyperkalemia.
• ACE inhibitors: concurrent use raises risk of angioedema and hyperkalemia.
• Lithium: may increase lithium serum concentrations.
• NSAIDs (high dose): can reduce antihypertensive effect and impair renal function.

Moderate Interactions (Monitor Closely)

• Thiazide diuretics: may enhance hypotensive effect.
• CYP3A4 inhibitors (e.g., ketoconazole): can increase Irbesartan plasma levels.
• CYP3A4 inducers (e.g., rifampin): may lower drug exposure.
• Other antihypertensives: monitor for additive blood pressure lowering.
• NSAIDs (low dose): watch renal function and blood pressure.