Irbesartan Actavis (Irbesartan)

Irbesartan is an angiotensin II receptor blocker that addresses disorders of the renin‑angiotensin system.

• Hypertension: Reduces systemic blood pressure, decreasing cardiovascular risk.
• Diabetic nephropathy: Slows progression of kidney damage in patients with type 2 diabetes.
• Heart failure: Improves symptoms and reduces hospitalizations in patients with mild to moderate heart failure.

• Irbesartan selectively blocks the AT1 subtype of angiotensin II receptors on vascular smooth‑muscle and adrenal cells. By preventing angiotensin II binding, it inhibits vasoconstriction and aldosterone release, leading to vasodilation, reduced sodium and water retention, and lower systemic vascular resistance. This pharmacologic action results in decreased blood pressure and mitigates the deleterious effects of chronic renin‑angiotensin activation on the heart and kidneys.

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

Common Side Effects

• Dizziness: Light‑headed sensation, especially after standing.
• Headache: Mild to moderate pain in the head region.
• Fatigue: General feeling of tiredness.
• Nasal congestion: Stuffy or blocked nose.
• Diarrhea: Loose stools occurring intermittently.

Serious or Rare Side Effects

• Hyperkalemia: Elevated blood potassium that can affect heart rhythm.
• Acute kidney injury: Sudden decline in renal function.
• Angioedema: Swelling of the face, lips, tongue or throat.
• Liver enzyme elevation: Increased transaminases indicating hepatic stress.

When prescribing Irbesartan, clinicians should consider several safety and handling precautions.

• Renal impairment: Adjust therapy and monitor creatinine in patients with reduced kidney function.
• Hyperkalemia risk: Check serum potassium before initiation and periodically during treatment.
• Pregnancy: Contraindicated in pregnancy (Category D) due to fetal toxicity.
• Concomitant NSAIDs: Use caution as they may diminish antihypertensive effect and affect renal function.
• Volume depletion: Avoid in patients with dehydration or on diuretic therapy without adequate fluid replacement.
• Store at ambient temperature: Keep below 25 °C, retain in original packaging, protect from moisture and direct sunlight.

Irbesartan can interact with other medicines, altering its efficacy or safety profile.

Major Interactions (Avoid)

• Potassium‑sparing diuretics (e.g., spironolactone): May cause dangerous hyperkalemia.
• ACE inhibitors or other ARBs: Combined use increases risk of renal dysfunction and hyperkalemia.
• Aliskiren in diabetic patients: Heightens risk of renal impairment, hypotension, and hyperkalemia.

Moderate Interactions (Monitor Closely)

• NSAIDs (e.g., ibuprofen): May reduce antihypertensive effect and impair renal function.
• Lithium: Increased lithium levels can lead to toxicity.
• Cyclosporine: May raise serum irbesartan concentrations.