Irbesartan/Hydrochlorothiazide Evolugen Pharma (Hydrochlorothiazide, Irbesartan)

Irbesartan/Hydrochlorothiazide is used to manage hypertension, a condition characterized by elevated arterial pressure.

• Hypertension: lowers systolic and diastolic blood pressure, helping to reduce cardiovascular risk.
• Essential hypertension: provides sustained blood pressure control when monotherapy is insufficient.
• Hypertension with renal impairment: assists in blood pressure management while supporting renal protection.

• Irbesartan selectively blocks angiotensin II type 1 (AT₁) receptors, preventing vasoconstriction and aldosterone‑mediated sodium retention. Hydrochlorothiazide acts on the distal convoluted tubule to inhibit Na⁺/Cl⁻ reabsorption, promoting diuresis and reducing plasma volume. The combined effect decreases peripheral vascular resistance and blood volume, producing an additive antihypertensive response that is greater than either component alone.

Irbesartan/Hydrochlorothiazide may cause a range of adverse reactions, which are grouped by frequency and severity.

Common Side Effects

• Dizziness or light‑headedness
• Headache
• Increased urination
• Mild electrolyte disturbance (e.g., low potassium)

Serious or Rare Side Effects

• Severe dehydration or electrolyte imbalance
• Acute kidney injury
• Allergic reactions such as rash or angioedema

When prescribing Irbesartan/Hydrochlorothiazide, clinicians should observe several safety considerations.

• Monitor blood pressure: ensure adequate control without excessive hypotension.
• Assess renal function: check serum creatinine and eGFR before initiation and periodically.
• Check electrolytes: especially potassium and sodium levels.
• Use caution in patients with diabetes: monitor glucose as the diuretic may affect glycaemic control.
• Avoid in severe hepatic impairment: limited safety data are available.
• Store at ambient temperature: keep in the original container, protect from moisture and light.

Irbesartan/Hydrochlorothiazide can interact with other medicines, requiring attention to avoid reduced efficacy or increased toxicity.

Major Interactions (Avoid)

• Concomitant use with potassium‑sparing diuretics or supplements: risk of hyperkalaemia.
• Strong CYP2C9 inhibitors (e.g., fluconazole): may increase irbesartan concentrations.
• Lithium: thiazide component can raise lithium levels, leading to toxicity.

Moderate Interactions (Monitor Closely)

• NSAIDs: may blunt antihypertensive effect and affect renal function.
• ACE inhibitors or other ARBs: additive risk of hyperkalaemia and renal impairment.
• Antidiabetic drugs: thiazide may increase blood glucose, requiring dose adjustment.