Irbesartan/Hydrochlorothiazid Aurobindo (Hydrochlorothiazide, Irbesartan)

Irbesartan/Hydrochlorothiazide is used in the management of hypertension, a condition characterized by persistently high arterial pressure.

• Essential hypertension: lowers systolic and diastolic blood pressure to target levels.
• Secondary hypertension: assists in controlling blood pressure when caused by other underlying disorders.
• Hypertensive patients with fluid retention: provides additional diuretic effect to reduce volume overload.

• Irbesartan selectively blocks angiotensin II type 1 (AT1) receptors, preventing vasoconstriction and aldosterone‑mediated sodium retention. Hydrochlorothiazide inhibits Na⁺/Cl⁻ reabsorption in the distal convoluted tubule, promoting natriuresis and diuresis. The combined actions reduce peripheral vascular resistance and intravascular volume, resulting in a sustained decrease in arterial blood pressure.

The combination may cause a range of adverse reactions, most of which are dose‑related and reversible upon discontinuation.

Common Side Effects

• Dizziness or light‑headedness
• Headache
• Fatigue
• Increased urination
• Electrolyte disturbances (e.g., low potassium)
• Mild gastrointestinal upset

Serious or Rare Side Effects

• Severe hypotension
• Acute kidney injury
• Hyperkalemia or hyponatremia
• Angioedema
• Liver function abnormalities
• Blood dyscrasias (e.g., agranulocytosis)

Before initiating therapy, clinicians should evaluate patient‑specific factors and monitor relevant parameters.

• Renal function: assess creatinine clearance and adjust if impaired.
• Electrolytes: monitor potassium and sodium levels regularly.
• Cardiovascular status: watch for symptomatic hypotension, especially after the first dose.
• Concomitant drugs: review for potential interactions that affect blood pressure or renal handling.
• Pregnancy and lactation: avoid use unless clearly indicated and benefits outweigh risks.
• Store at ambient temperature: keep below 25 °C, retain in original packaging, protect from moisture and direct sunlight.

Irbesartan/Hydrochlorothiazide may alter the pharmacokinetic or pharmacodynamic profile of several co‑administered medicines.

Major Interactions (Avoid)

• Dual renin‑angiotensin system blockade (e.g., ACE inhibitors, other ARBs): risk of additive renal impairment and hyperkalemia.
• Potassium‑sparing diuretics or supplements: may cause dangerous hyperkalemia.
• Lithium: increased lithium levels leading to toxicity.

Moderate Interactions (Monitor Closely)

• NSAIDs: may reduce antihypertensive efficacy and impair renal function.
• Antidiabetic agents: diuretic‑induced electrolyte changes can affect glucose control.
• CYP2C9 substrates (e.g., warfarin): irbesartan may alter metabolism, requiring INR monitoring.