Irbesartan/Hydrochlorothiazide Biogaran (Hydrochlorothiazide, Irbesartan)

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

• Essential hypertension: lowers systolic and diastolic blood pressure to reduce cardiovascular risk.
• Secondary hypertension (e.g., renal‑related): provides combined vasodilation and diuresis for better control.
• Hypertension in patients with diabetes: assists in blood pressure reduction while mitigating fluid overload.

• Irbesartan selectively blocks angiotensin II type 1 (AT1) receptors, preventing vasoconstriction and aldosterone release. Hydrochlorothiazide inhibits sodium‑chloride reabsorption in the distal convoluted tubule, increasing urinary excretion of water and electrolytes, which together lower peripheral resistance and blood volume, resulting in reduced arterial pressure.

Common Side Effects

• Dizziness: feeling light‑headed, especially after the first doses.
• Headache: mild to moderate intensity.
• Increased urination: due to the diuretic component.
• Electrolyte imbalance: such as low potassium or sodium levels.
• Fatigue: general sense of tiredness.
• Mild gastrointestinal discomfort: nausea or abdominal pain.

Serious or Rare Side Effects

• Severe hypotension: markedly low blood pressure requiring medical attention.
• Acute kidney injury: sudden decline in renal function.
• Hyperkalemia: elevated potassium levels, potentially dangerous.
• Allergic reactions: rash, itching, swelling, or anaphylaxis.
• Pancreatitis: inflammation of the pancreas.
• Blood dyscrasias: rare blood cell abnormalities.

Before initiating therapy, patients should be evaluated for renal function, electrolyte status, and pregnancy risk.

• Monitor blood pressure: adjust dose based on response.
• Assess renal function: check serum creatinine and eGFR regularly.
• Check electrolytes: especially potassium and sodium levels.
• Avoid use in pregnancy: category D, may cause fetal harm.
• Use caution in elderly: increased sensitivity to blood‑pressure changes.
• Store at below 25°C: keep in the original pack, protect from moisture.

Irbesartan/Hydrochlorothiazide may interact with several medicines; monitoring is essential.

Major Interactions (Avoid)

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

Moderate Interactions (Monitor Closely)

• Other antihypertensives: may cause excessive blood‑pressure lowering.
• CYP2C9 inhibitors (e.g., fluconazole): can raise irbesartan concentrations.
• Antidiabetic agents: diuretic‑induced changes in glucose may require dose adjustment.
• Digoxin: altered electrolyte balance can affect digoxin toxicity.
• Antacids containing aluminum or magnesium: may reduce absorption of irbesartan.