Irbesartan + Hidroclorotiazida Generis Phar (Hydrochlorothiazide, Irbesartan)

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

• Hypertension: lowers systolic and diastolic blood pressure, helping to reduce cardiovascular risk.
• Essential hypertension: provides effective blood pressure control when monotherapy is insufficient.
• Hypertension requiring combination therapy: combines an ARB with a thiazide diuretic to achieve target pressures in patients needing multiple mechanisms.
• Renal hypertension: assists in blood pressure reduction in patients with mild renal impairment.

• Irbesartan selectively blocks angiotensin II type 1 (AT1) receptors, preventing vasoconstriction and aldosterone‑mediated sodium retention. Hydrochlorothiazide acts on the distal convoluted tubule, inhibiting the Na⁺/Cl⁻ cotransporter, which promotes excretion of sodium, chloride, and water, leading to a reduction in plasma volume. The combined actions result in decreased peripheral resistance and lowered blood pressure.

The combination may cause a range of adverse reactions, varying from mild to serious.

Common Side Effects

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

Serious or Rare Side Effects

• Severe allergic reactions such as angioedema
• Acute kidney injury
• Significant drops in blood pressure (hypotension)
• Elevated blood urea nitrogen or creatinine
• Pancreatitis
• Severe skin reactions (e.g., Stevens‑Johnson syndrome)

When prescribing Irbesartan/HCTZ, clinicians should observe several precautionary measures.

• Monitor blood pressure: ensure adequate control and avoid hypotension.
• Assess renal function: check serum creatinine and eGFR before and during therapy.
• Check electrolytes: especially potassium and sodium levels.
• Avoid use in pregnancy: drug is classified as pregnancy category D.
• Use caution in elderly patients: increased sensitivity to blood pressure changes.
• Store at room temperature: keep in the original container, protect from moisture and light.

Irbesartan/HCTZ can interact with other medicines, affecting efficacy or safety.

Major Interactions (Avoid)

• Concomitant use with ACE inhibitors or aliskiren in diabetic patients: risk of hyperkalemia and renal impairment.
• Potassium‑sparing diuretics or supplements: may cause dangerous hyperkalemia.
• Lithium: increased lithium levels leading to toxicity.
• NSAIDs (e.g., ibuprofen, naproxen): may reduce antihypertensive effect and impair renal function.

Moderate Interactions (Monitor Closely)

• Other antihypertensives (beta‑blockers, calcium channel blockers): may enhance blood pressure lowering, requiring dose adjustment.
• CYP2C9 inhibitors (e.g., fluconazole, amiodarone): can increase irbesartan plasma concentrations.
• Thiazide‑type diuretics: additive electrolyte disturbances.
• Antidiabetic agents: may require monitoring of blood glucose as blood pressure changes can affect glucose control.