Irbesartan E Idroclorotiazide Alter (Hydrochlorothiazide, Irbesartan)

Irbesartan/Hydrochlorothiazide is indicated for the management of hypertension, a condition characterized by elevated arterial pressure.

• Essential hypertension: lowers systolic and diastolic blood pressure to reduce cardiovascular risk.
• Secondary hypertension: provides effective blood‑pressure control when underlying causes are present.
• Hypertension with fluid retention: combines vasodilation and diuresis to improve overall blood‑pressure management.

• Irbesartan selectively blocks AT1 receptors, preventing angiotensin II from causing vasoconstriction and aldosterone release, which leads to vessel relaxation and reduced sodium retention. Hydrochlorothiazide inhibits NaCl reabsorption in the distal convoluted tubule, increasing urinary excretion of sodium and water, thereby decreasing plasma volume and contributing to lower blood pressure.

Common Side Effects

• Dizziness: transient light‑headedness, especially after the first dose.
• Increased urination: due to the diuretic component.
• Electrolyte imbalance: mild reductions in potassium or sodium levels.
• Headache: occasional mild to moderate intensity.
• Fatigue: general feeling of tiredness.

Serious or Rare Side Effects

• Severe hypotension: marked drop in blood pressure causing fainting.
• Acute kidney injury: sudden decline in renal function.
• Hyperkalemia: dangerously high potassium levels.
• Allergic reactions: rash, itching, or swelling.
• Blood dyscrasias: rare cases of leukopenia or thrombocytopenia.

Before initiating therapy, consider the following precautions:

• Blood pressure monitoring: ensure adequate control and avoid excessive drops.
• Renal function assessment: check serum creatinine and eGFR regularly.
• Electrolyte surveillance: monitor potassium and sodium levels, especially in patients on other diuretics.
• Hepatic impairment: use with caution in patients with liver disease.
• Pregnancy and lactation: avoid use unless clearly needed; safety not established.
• Store at below 25°C: keep in the original packaging, protect from moisture and direct sunlight.

Irbesartan/HCTZ may interact with several medicines; review patient medication lists carefully.

Major Interactions (Avoid)

• ACE inhibitors or aliskiren: combined use can cause severe hyperkalemia and renal impairment.
• Potassium‑sparing diuretics: increase risk of dangerous hyperkalemia.
• Lithium: may raise lithium levels, leading to toxicity.

Moderate Interactions (Monitor Closely)

• NSAIDs: can blunt antihypertensive effect and affect renal function.
• Other antihypertensives: additive blood‑pressure lowering may require dose adjustments.
• CYP2C9 inhibitors (e.g., fluconazole): may increase irbesartan plasma concentrations.