Irbesartan Pharmakern (Irbesartan)

Irbesartan is used to treat conditions that involve the renin‑angiotensin‑aldosterone system, primarily hypertension and related organ damage.

• Hypertension: lowers blood pressure and reduces risk of cardiovascular events in adults.
• Diabetic nephropathy: slows progression of kidney disease in patients with type 2 diabetes.
• Heart failure: used as adjunct therapy to improve symptoms and reduce hospitalisation in patients with chronic heart failure.

• 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 reduced peripheral resistance, decreased sodium and water retention, and ultimately lower arterial pressure. These actions contribute to its antihypertensive and organ‑protective effects.

Irbesartan may cause a range of adverse reactions, which are generally classified by frequency and severity.

Common Side Effects

• Dizziness: sensation of light‑headedness, especially after standing.
• Headache: mild to moderate intensity.
• Fatigue: feeling unusually tired.
• Upper respiratory tract infection: nasopharyngitis symptoms.
• Hyperkalemia: elevated blood potassium levels.
• Diarrhoea: loose stools.

Serious or Rare Side Effects

• Angioedema: swelling of face, lips, tongue or airway.
• Severe hypotension: marked drop in blood pressure.
• Renal impairment: worsening kidney function.
• Hepatic injury: elevated liver enzymes or hepatitis.
• Myocardial infarction: rare reports of heart attack.
• Blood dyscrasias: neutropenia or agranulocytosis.

When prescribing Irbesartan, clinicians should consider several safety considerations and monitoring requirements.

• Renal function: assess baseline creatinine and monitor periodically.
• Electrolytes: check serum potassium before initiation and during therapy.
• Pregnancy: contraindicated in pregnancy due to fetal toxicity; avoid in women of childbearing potential unless effective contraception is used.
• Concomitant ARBs/ACE inhibitors: avoid combined use to reduce risk of hyperkalemia and renal failure.
• Hepatic impairment: use with caution in patients with moderate to severe liver disease.
• Store at ambient temperature: keep below 25 °C, protect from moisture and light in the original container.

Irbesartan can affect, or be affected by, several other medicines; awareness of these interactions helps prevent adverse outcomes.

Major Interactions (Avoid)

• Concomitant use with ACE inhibitors or other ARBs: may cause excessive potassium rise and renal dysfunction.
• Potassium‑sparing diuretics or supplements: increase risk of hyperkalaemia.
• Aliskiren in patients with diabetes: heightened risk of renal impairment, hypotension, and hyperkalaemia.

Moderate Interactions (Monitor Closely)

• NSAIDs (e.g., ibuprofen, naproxen): may reduce antihypertensive effect and impair renal function.
• Lithium: increased lithium levels, risk of toxicity.
• Cyclosporine or tacrolimus: may increase serum creatinine.