Irbesartan E Idroclorotiazide Eg (Hydrochlorothiazide, Irbesartan)

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

• Primary hypertension: lowers both systolic and diastolic pressure through vasodilation and diuresis.
• Secondary hypertension: assists in controlling blood pressure when it results from another underlying disorder.
• Hypertension with fluid retention: combines vasodilatory and diuretic actions to improve overall blood pressure control.

• Irbesartan selectively blocks AT1 receptors, preventing angiotensin II–mediated vasoconstriction and aldosterone release, which reduces peripheral resistance. Hydrochlorothiazide inhibits NaCl reabsorption in the distal convoluted tubule, increasing urinary sodium and water excretion, thereby decreasing plasma volume and contributing to blood pressure reduction.

Common Side Effects

• Dizziness: feeling light‑headed, especially after standing.
• Headache: mild to moderate pain in the head region.
• Increased urination: more frequent need to void due to diuretic action.
• Electrolyte imbalance (low potassium): mild reductions in serum potassium levels.

Serious or Rare Side Effects

• Severe dehydration: excessive fluid loss leading to low blood pressure.
• Acute kidney injury: sudden decline in renal function.
• Allergic reaction: rash, itching, swelling, or difficulty breathing.
• Hyperkalemia: elevated potassium levels, potentially causing cardiac arrhythmia.
• Severe hypotension: markedly low blood pressure requiring medical attention.

Before initiating therapy, consider the following precautions:

• Renal function monitoring: assess serum creatinine and eGFR regularly.
• Electrolyte surveillance: check potassium and sodium levels periodically.
• Hepatic impairment: use with caution in patients with liver disease.
• Severe hypotension: avoid in individuals with markedly low blood pressure.
• Pregnancy and lactation: safety not established; consult a specialist.
• Store at room temperature: keep in the original container, protect from moisture and direct sunlight.

Irbesartan/Hydrochlorothiazide may interact with several medicines:

Major Interactions (Avoid)

• Aliskiren: combined use can increase risk of renal dysfunction and hyperkalemia.
• Potassium‑sparing diuretics or supplements: may cause dangerous hyperkalemia.
• Lithium: increased lithium levels leading to toxicity.
• ACE inhibitors or other ARBs: additive effects on potassium and renal function.
• NSAIDs (high dose): can reduce antihypertensive efficacy and impair renal function.

Moderate Interactions (Monitor Closely)

• Antidiabetic agents: diuretic may affect glucose control, requiring dose adjustment.
• Other antihypertensives: additive blood pressure lowering effect.
• CYP2C9 inhibitors (e.g., fluconazole): may increase irbesartan plasma concentrations.
• Thiazide‑type diuretics: overlapping diuretic effect may increase electrolyte disturbances.
• Antacids containing aluminum or magnesium: may reduce absorption of irbesartan.