Irbesartan + Hidroclorotiazida Krka (Hydrochlorothiazide, Irbesartan)

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

• Essential hypertension: reduces systolic and diastolic blood pressure to target levels.
• Diastolic hypertension: helps achieve recommended diastolic pressure goals.
• Hypertension requiring combination therapy: provides dual mechanism for improved blood pressure control.

• Irbesartan selectively blocks the angiotensin II type 1 (AT1) receptors, preventing vasoconstriction and aldosterone‑mediated sodium retention. Hydrochlorothiazide inhibits sodium‑chloride reabsorption in the distal convoluted tubule, increasing urinary excretion of water and electrolytes. The combined effect reduces peripheral vascular resistance and plasma volume, leading to a sustained decrease in arterial blood pressure. This synergistic action enhances antihypertensive efficacy while allowing lower individual doses.

Common and serious adverse reactions have been reported with Irbesartan/Hydrochlorothiazide therapy.

Common Side Effects

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

Serious or Rare Side Effects

• Severe hypotension: marked drop in blood pressure causing fainting.
• Acute kidney injury: sudden decline in renal function.
• Hyperkalemia: elevated potassium levels that may affect heart rhythm.
• Allergic reactions: rash, itching, swelling, or anaphylaxis.
• Pancreatitis: inflammation of the pancreas with abdominal pain.
• Blood dyscrasias: rare blood cell abnormalities.

Before initiating Irbesartan/Hydrochlorothiazide, clinicians should consider several precautionary measures.

• Renal function monitoring: assess serum creatinine and eGFR periodically.
• Electrolyte assessment: check potassium and sodium levels, especially in patients on other diuretics.
• Use in hepatic impairment: exercise caution in severe liver disease.
• Elderly patients: start at lower dose and monitor for orthostatic hypotension.
• Pregnancy and lactation: safety not established; avoid unless clearly needed.
• Store below 25°C: keep in the original packaging, protect from moisture and light.

Irbesartan/Hydrochlorothiazide may interact with other medicines, altering its efficacy or safety profile.

Major Interactions (Avoid)

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

Moderate Interactions (Monitor Closely)

• Beta‑blockers: may enhance blood pressure lowering, requiring dose adjustment.
• Calcium channel blockers: possible additive hypotensive effect.
• Antidiabetic agents: diuretic may affect glucose control.
• Antihypertensive combinations: monitor for excessive hypotension.
• Thiazide‑type diuretics: cumulative electrolyte disturbances.