Irbesartan Generics [uk] (Irbesartan)

Irbesartan is an angiotensin II receptor blocker used to treat conditions related to the renin‑angiotensin system.

• Hypertension: lowers elevated blood pressure, reducing risk of cardiovascular complications.
• Diabetic nephropathy: slows the progression of renal disease in patients with type 2 diabetes and proteinuria.

• Irbesartan selectively antagonises the angiotensin II type 1 (AT1) receptor, preventing angiotensin II from inducing vasoconstriction and aldosterone secretion. This blockade leads to relaxation of vascular smooth muscle, reduced sodium and water retention, and ultimately a decrease in systemic blood pressure and renal workload.

Irbesartan may be associated with adverse reactions that vary in frequency and severity.

Common Side Effects

• Dizziness: sensation of light‑headedness, especially after standing.
• Headache: mild to moderate pain in the head region.
• Fatigue: feeling unusually tired or weak.
• Nausea: upset stomach with urge to vomit.
• Abdominal pain: discomfort in the stomach area.
• Elevated serum potassium: mild increase in blood potassium levels.

Serious or Rare Side Effects

• Angioedema: swelling of face, lips, tongue, or throat that may compromise breathing.
• Severe hypotension: marked drop in blood pressure causing faintness or shock.
• Acute renal impairment: sudden decline in kidney function.
• Hepatic injury: signs of liver damage such as jaundice.
• Neutropenia: significant reduction in white blood cells.
• Anaphylaxis: life‑threatening allergic reaction with rash, difficulty breathing, and circulatory collapse.

When prescribing Irbesartan, clinicians should consider several safety measures.

• Blood pressure monitoring: regularly assess to avoid excessive hypotension.
• Renal function assessment: check serum creatinine and eGFR before and during therapy.
• Serum potassium evaluation: monitor for hyperkalaemia, especially with concomitant potassium‑sparing agents.
• Pregnancy caution: avoid use in pregnancy due to fetal risk (Category D).
• Hepatic impairment: use with caution in patients with severe liver disease.
• Store at below 25°C: keep in the original packaging, protect from moisture and direct sunlight.

Irbesartan can interact with other medicines, requiring attention to avoid adverse outcomes.

Major Interactions (Avoid)

• Aliskiren in diabetic patients: combined use may increase renal risk.
• Dual ARB/ACE‑inhibitor therapy: heightened risk of hypotension, hyperkalaemia, and renal dysfunction.
• Potassium‑sparing diuretics or supplements: may cause dangerous elevations in serum potassium.

Moderate Interactions (Monitor Closely)

• Non‑steroidal anti‑inflammatory drugs (NSAIDs): can reduce antihypertensive effect and impair renal function.
• Strong CYP2C9 inhibitors (e.g., fluconazole): may increase Irbesartan plasma concentrations.