Iprex

Irbesartan is an angiotensin II receptor blocker (ARB) primarily indicated for:

• Hypertension: Treatment of essential hypertension to lower blood pressure, either as monotherapy or in combination with other antihypertensive agents.
• Diabetic Nephropathy: To delay progression of nephropathy in patients with type 2 diabetes mellitus and hypertension, especially with proteinuria.
• Heart Failure (Off-label use): Sometimes used as adjunct therapy in heart failure management.
• Left Ventricular Hypertrophy (Off-label): To reduce left ventricular mass in hypertensive patients.

Severity specifics:

• Effective across mild to severe hypertension.
• Particularly beneficial in patients with diabetes and renal involvement.

• Adults:
• Hypertension:
• Initial dose: 150 mg once daily.
• Maintenance dose: 150–300 mg once daily.
• Max dose: 300 mg daily.
• Diabetic Nephropathy:
• Typical dose: 300 mg once daily.
• Elderly:
• No initial dose adjustment required.
• Monitor renal function and blood pressure closely.
• Pediatrics:
• Safety and efficacy not established in children under 18 years.
• Special Populations:
• Renal impairment:
• Use with caution if creatinine clearance <30 mL/min.
• Start with lower dose and monitor closely.
• Hepatic impairment:
• Dose adjustment may be necessary in severe hepatic impairment.
• Administration Route:
• Oral tablets, administered once daily.
• Can be taken with or without food.

Irbesartan selectively blocks the binding of angiotensin II to the angiotensin type 1 (AT1) receptors found in many tissues such as vascular smooth muscle and adrenal glands. This blockade prevents vasoconstriction, aldosterone secretion, sodium retention, and sympathetic activation induced by angiotensin II. The resulting vasodilation and decreased blood volume reduce blood pressure and decrease the workload on the heart. By blocking these effects, Irbesartan also helps protect renal function, especially in diabetic nephropathy, by reducing intraglomerular pressure and proteinuria.

• Absorption: Rapid and well absorbed orally with bioavailability approximately 60–80%.
• Distribution: Highly protein bound (~90%), mainly to albumin.
• Metabolism: Metabolized minimally by the liver via glucuronidation; no significant CYP450 involvement.
• Elimination: Primarily excreted via bile and feces (~65%), and urine (~20%).
• Half-life: Approximately 11–15 hours, allowing once-daily dosing.
• Onset of Action: Begins within 1.5 hours.
• Peak Plasma Concentration: 1.5–2 hours after oral administration.

• Pregnancy: FDA Category D — use contraindicated in pregnancy due to risk of fetal toxicity including renal failure, oligohydramnios, and death, especially during second and third trimesters.
• Lactation: Excreted in small amounts in breast milk. Use with caution; breastfeeding is generally not recommended during therapy.
• Advice: Women of childbearing age should use effective contraception during treatment and discontinue Irbesartan if pregnancy is detected.

• Primary: Antihypertensive
• Subclass: Angiotensin II receptor blocker (ARB)

• Known hypersensitivity to Irbesartan or any formulation excipients.
• Pregnancy (second and third trimesters).
• Severe hepatic impairment or cholestasis (use caution).
• Concomitant use with aliskiren in patients with diabetes or renal impairment.
• History of angioedema related to previous ARB or ACE inhibitor therapy.

• High-risk groups:
• Patients with renal artery stenosis.
• Patients with impaired renal function.
• Patients with volume depletion or hypotension.
• Potential serious risks:
• Hyperkalemia (monitor serum potassium).
• Hypotension, especially after initial dose or in volume-depleted patients.
• Angioedema — requires immediate discontinuation.
• Monitoring:
• Blood pressure, renal function, and electrolytes before and during treatment.
• Black box warning: Fetal toxicity — discontinue as soon as pregnancy is detected.

• Common:
• Dizziness
• Fatigue
• Nausea
• Diarrhea
• Nasopharyngitis
• Serious/Rare:
• Hyperkalemia
• Angioedema
• Renal impairment or failure
• Hypotension and syncope
• Elevated liver enzymes (rare)
• Side effects usually occur early in therapy but can appear anytime.

• Potassium-sparing diuretics, potassium supplements, or potassium-containing salt substitutes: Increased risk of hyperkalemia.
• NSAIDs: May reduce antihypertensive effect and increase risk of renal impairment.
• Lithium: Increased lithium toxicity risk.
• Other antihypertensives: Additive blood pressure lowering effects.
• Aliskiren: Contraindicated in diabetics or renal impairment due to increased risk of adverse effects.
• No significant involvement with CYP450 enzymes.

• Updated hypertension management guidelines recommend ARBs like Irbesartan as first-line therapy for hypertension, particularly in diabetic patients with nephropathy.
• Emphasis on monitoring renal function and electrolytes during therapy.
• FDA reinforced contraindication of ARBs in pregnancy due to fetal toxicity risks.
• Recent studies support Irbesartan's renal protective effects beyond blood pressure control in diabetic nephropathy.
• No changes in dosing recommendations in recent guidelines.

• Store at controlled room temperature: 20°C to 25°C (68°F to 77°F).
• Protect from moisture and light.
• Keep container tightly closed.
• Avoid excessive heat (>30°C) and freezing.
• Store out of reach of children.