Irbesartan Activase Pharmaceuticals (Irbesartan)

• Irbesartan acts on the renin‑angiotensin‑aldosterone system to lower blood pressure and protect renal function.
• Hypertension: reduces systolic and diastolic pressure, improving cardiovascular risk profile.
• Diabetic nephropathy: slows progression of kidney damage in patients with type 2 diabetes.
• Heart failure (off‑label): may improve symptoms and reduce hospitalisations 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‑water retention, and lower systemic blood pressure.

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

Common Side Effects

• Dizziness or light‑headedness
• Headache
• Fatigue
• Cough
• Hyperkalaemia
• Abdominal discomfort

Serious or Rare Side Effects

• Angioedema (swelling of face, lips, tongue)
• Severe hypotension
• Acute renal failure
• Hepatic injury
• Neutropenia or agranulocytosis
• Anaphylactic reaction

• When prescribing Irbesartan, clinicians should consider several safety measures.
• Monitor blood pressure: ensure adequate control without excessive lowering.
• Assess renal function: check serum creatinine and eGFR before and during therapy.
• Check serum potassium: avoid hyperkalaemia, especially with potassium‑sparing agents.
• Avoid use in pregnancy: drug is contraindicated due to fetal toxicity.
• Review concomitant potassium‑sparing agents: adjust dose or discontinue as needed.
• Store at ambient temperature: keep in the original pack, protect from moisture.

Irbesartan can interact with several medicines; interactions are categorised by clinical significance.

Major Interactions (Avoid)

• Aliskiren in patients with diabetes: increased risk of renal impairment.
• Potassium‑sparing diuretics (e.g., spironolactone): risk of hyperkalaemia.
• Non‑steroidal anti‑inflammatory drugs (NSAIDs): may reduce renal function.
• Lithium: increased lithium serum concentrations.
• ACE inhibitors: additive effect on potassium and renal function.

Moderate Interactions (Monitor Closely)

• CYP2C9 inhibitors (e.g., fluconazole): may raise Irbesartan levels.
• Other antihypertensives: additive blood‑pressure lowering effect.
• Loop or thiazide diuretics: monitor volume status.
• Antacids containing aluminium or magnesium: may affect absorption.
• Rifampin: may decrease plasma concentrations of Irbesartan.