Irbesartan E Idroclorotiazide Mylan (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, reducing cardiovascular risk.
• Hypertension requiring diuretic therapy: adds thiazide diuretic effect to improve fluid balance and enhance antihypertensive efficacy.
• Hypertension uncontrolled by monotherapy: provides a fixed‑dose combination that simplifies treatment and may improve adherence.

• Irbesartan selectively blocks angiotensin II type 1 (AT1) receptors, preventing vasoconstriction and aldosterone release, while hydrochlorothiazide inhibits sodium‑chloride reabsorption in the distal convoluted tubule, increasing urinary excretion of water and electrolytes. The combined actions reduce peripheral vascular resistance and blood volume, resulting in lowered arterial pressure.

The combination of irbesartan and hydrochlorothiazide may cause a range of adverse reactions, which are categorized by frequency.

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 allergic reaction (anaphylaxis)
• Significant drop in blood pressure (hypotension)
• Acute kidney injury
• Hyperkalemia
• Pancreatitis
• Blood disorders such as agranulocytosis

When prescribing Irbesartan/Hydrochlorothiazide, clinicians should observe several precautionary measures to ensure patient safety.

• Monitor blood pressure: adjust therapy if target levels are not achieved.
• Check electrolytes: especially potassium and sodium levels during treatment.
• Assess renal function: periodic serum creatinine and eGFR testing is recommended.
• Use caution in hepatic impairment: dose adjustments may be required.
• Avoid use in pregnancy: drug may harm the fetus; contraindicated.
• Store at room temperature: keep in the original container, protect from moisture and direct sunlight.

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

Major Interactions (Avoid)

• Aliskiren (especially in diabetes): may increase risk of renal impairment and hyperkalemia.
• Potassium‑sparing diuretics or supplements: risk of dangerous hyperkalemia.
• Lithium: concurrent use can raise lithium levels, leading to toxicity.
• ACE inhibitors or other ARBs: combined use may cause excessive potassium rise and renal dysfunction.
• NSAIDs (e.g., ibuprofen): may reduce antihypertensive effect and impair kidney function.

Moderate Interactions (Monitor Closely)

• Other antihypertensive agents (beta‑blockers, calcium channel blockers): may cause additive blood pressure lowering.
• CYP3A4 inhibitors (ketoconazole, itraconazole): can increase irbesartan plasma concentrations.
• Antacids containing aluminum or magnesium: may decrease absorption of irbesartan.
• Thiazide diuretics with other diuretics: monitor electrolyte balance.
• Warfarin: may enhance anticoagulant effect; monitor INR.