Hizaar (Losartan Potassium, Hydrochlorothiazide)

Hizaar is indicated for the treatment of hypertension, particularly when monotherapy does not achieve target blood pressure. It may be considered in patients who require both an angiotensin receptor blocker and a diuretic.

• Hypertension that is uncontrolled with a single antihypertensive agent.
• Patients needing combined RAAS inhibition and diuretic therapy.
• Adjunct therapy for resistant high blood pressure.
• Situations where a once‑daily oral tablet simplifies regimen adherence.
• Use in adults as part of a comprehensive blood pressure management plan.

• Losartan potassium selectively blocks angiotensin II type 1 (AT1) receptors, preventing vasoconstriction and aldosterone‑mediated sodium retention, which reduces peripheral resistance. Hydrochlorothiazide acts on the distal convoluted tubule to inhibit NaCl reabsorption, increasing urinary excretion of sodium and water, thereby decreasing plasma volume. The combined actions result in lowered arterial pressure through reduced vascular tone and decreased fluid overload.

Adverse reactions to Hizaar can vary in frequency and severity.

Common

• Dizziness or light‑headedness, especially after the first dose.
• Headache.
• Fatigue or tiredness.
• Increased urination.
• Electrolyte disturbances such as low potassium.
• Mild gastrointestinal upset.

Serious

• Severe hypotension.
• Acute kidney injury.
• Hyperkalemia.
• Allergic reactions including rash, itching, or swelling.
• Pancreatitis.
• Liver function abnormalities.

Before starting Hizaar, certain health considerations should be reviewed to ensure safe use.

• Assess renal function and electrolyte levels, especially potassium and sodium.
• Monitor blood pressure regularly to avoid excessive lowering.
• Use caution in patients with a history of gout, as thiazides may increase uric acid.
• Evaluate liver function, as both components are metabolized hepatically.
• Discuss pregnancy or breastfeeding plans with a healthcare professional.
• Review any history of angioedema or hypersensitivity to ARBs or thiazides.
• Adjust dose or discontinue if significant hypotension or renal impairment develops.

Hizaar can interact with several other medicines, affecting its efficacy or safety.

Avoid

• Concomitant use with other potent antihypertensives that may cause additive hypotension.
• Potassium‑sparing diuretics or supplements, which can lead to hyperkalemia.
• Non‑steroidal anti‑inflammatory drugs (NSAIDs) that may reduce renal clearance.
• Lithium, as thiazides can increase lithium levels.
• Strong CYP2C9 inhibitors that may raise losartan concentrations.

Use with caution

• ACE inhibitors or other ARBs, monitoring for renal function and potassium.
• Digoxin, due to potential changes in serum potassium.
• Antidiabetic agents, as blood pressure changes may affect glucose control.
• Anticoagulants, because of possible alterations in plasma volume.
• Certain antibiotics (e.g., macrolides) that may affect drug metabolism.