Irbecor Comp. (Hydrochlorothiazide, Irbesartan)

• Irbecor Comp. is used to manage hypertension, a condition characterized by chronically elevated arterial pressure.
• Hypertension: reduces systolic and diastolic blood pressure, improving cardiovascular outcomes.
• Essential hypertension: provides consistent blood pressure control in patients not adequately controlled by monotherapy.
• High blood pressure: assists in achieving target blood pressure levels as part of combination therapy.

• Irbesartan selectively blocks the angiotensin II type 1 (AT1) receptors on vascular smooth muscle and adrenal cells, preventing vasoconstriction and aldosterone‑mediated sodium retention. Hydrochlorothiazide acts on the distal convoluted tubule, inhibiting the Na⁺/Cl⁻ cotransporter, which reduces sodium and water reabsorption and promotes diuresis. The combined effect lowers intravascular volume and systemic vascular resistance, resulting in a sustained reduction of arterial blood pressure.

Irbecor Comp. may cause a range of adverse reactions, which are classified by frequency and severity.

Common Side Effects

• Dizziness: sensation of light‑headedness, especially after standing.
• Headache: mild to moderate pain in the head region.
• Increased urination: due to diuretic action.
• Electrolyte imbalance: changes in potassium or sodium levels.
• Fatigue: feeling of tiredness or reduced energy.
• Dry mouth: reduced salivation.

Serious or Rare Side Effects

• Severe dehydration: marked fluid loss requiring medical attention.
• Hyperkalemia: elevated potassium that can affect heart rhythm.
• Acute kidney injury: sudden decline in renal function.
• Angioedema: swelling of face, lips, tongue or airway.
• Severe hypotension: dangerously low blood pressure.
• Allergic reaction: rash, itching, or anaphylaxis.

Before prescribing Irbecor Comp., clinicians should consider several precautionary measures to ensure patient safety.

• Monitor blood pressure: check regularly to avoid hypotension.
• Assess electrolytes: especially potassium and sodium levels during therapy.
• Evaluate renal function: test serum creatinine and eGFR before and during treatment.
• Use caution in hepatic impairment: dose adjustment may be required.
• Avoid in pregnancy unless clearly needed: limited safety data are available.
• Store at room temperature: keep in the original container, protect from moisture and light.

Irbesartan/hydrochlorothiazide can interact with other medicines, altering its efficacy or safety profile.

Major Interactions (Avoid)

• ACE inhibitors or aliskiren: combined use may increase risk of renal dysfunction and hyperkalemia.
• Potassium supplements or potassium‑sparing diuretics: can cause dangerous hyperkalemia.
• Lithium: thiazide component may raise lithium levels, risking toxicity.
• NSAIDs: may reduce antihypertensive effect and impair renal function.
• Cyclosporine: may increase serum concentrations of both agents.

Moderate Interactions (Monitor Closely)

• Other antihypertensives: may enhance blood pressure lowering, requiring dose adjustments.
• Diuretics: additive diuretic effect can lead to electrolyte disturbances.
• CYP2C9 inhibitors (e.g., fluconazole): may increase irbesartan levels.
• Antidiabetic drugs: thiazide may affect glucose control.
• Anticoagulants: thiazide may increase INR, necessitating monitoring.