Irbesartan/Hydrochlorothiazide Teva (Hydrochlorothiazide, Irbesartan)

Irbesartan/Hydrochlorothiazide is indicated for the management of hypertension, acting on the renin‑angiotensin system and fluid balance.

• Essential hypertension: lowers systolic and diastolic blood pressure to target levels.
• Stage 1 or 2 high blood pressure: provides effective blood‑pressure control when monotherapy is insufficient.
• Combination therapy for elevated blood pressure: offers dual action through vasodilation and diuresis for patients requiring more than one antihypertensive agent.

• Irbesartan selectively blocks the angiotensin II type 1 (AT1) receptor, preventing vasoconstriction and aldosterone release, while hydrochlorothiazide inhibits Na⁺/Cl⁻ reabsorption in the distal convoluted tubule, increasing urinary sodium and water excretion. The combined effect reduces peripheral vascular resistance and plasma volume, resulting in lowered arterial pressure.

Common Side Effects

• Dizziness or light‑headedness
• Headache
• Fatigue or weakness
• Increased urination
• Electrolyte disturbances (e.g., low potassium)
• Mild gastrointestinal discomfort

Serious or Rare Side Effects

• Severe dehydration or electrolyte imbalance
• Acute kidney injury or worsening renal function
• Hypotension (significant drop in blood pressure)
• Allergic reactions such as rash, angioedema, or anaphylaxis
• Elevated blood urea nitrogen or creatinine levels
• Rare cases of pancreatitis or hepatic dysfunction

Before initiating therapy, consider the following precautions:

• Renal function monitoring: assess serum creatinine and electrolytes regularly.
• Electrolyte balance: watch for hypokalemia, especially when combined with other diuretics.
• Elderly patients: start at lower doses and monitor for orthostatic hypotension.
• Concomitant use with other antihypertensives: adjust dose to avoid excessive blood‑pressure reduction.
• Pregnancy and lactation: safety not established; avoid unless clearly needed.
• Store at ambient temperature: keep below 25 °C, retain in original packaging, protect from moisture and direct sunlight.

Irbesartan/Hydrochlorothiazide may interact with several medicines.

Major Interactions (Avoid)

• Aliskiren in patients with diabetes or renal impairment: risk of hyperkalemia and renal dysfunction.
• Potassium‑sparing diuretics or supplements: may cause dangerous hyperkalemia.
• Lithium: increased lithium levels leading to toxicity.
• NSAIDs (e.g., ibuprofen, naproxen): can reduce antihypertensive effect and impair renal function.

Moderate Interactions (Monitor Closely)

• ACE inhibitors or other ARBs: additive effect on potassium and renal function.
• Other antihypertensives (beta‑blockers, calcium channel blockers): may require dose adjustments.
• CYP3A4 inhibitors (e.g., ketoconazole, erythromycin): may increase irbesartan plasma concentrations.
• Antidiabetic agents: diuretic‑induced changes in glucose may affect glycemic control.