Hyzaar is a prescription medication combining two active ingredients, losartan potassium and hydrochlorothiazide, designed for the comprehensive management of hypertension. This fixed-dose combination therapy works synergistically to relax blood vessels and eliminate excess fluid, providing a dual-action approach to lowering blood pressure and reducing the strain on the cardiovascular system. It is specifically indicated for patients whose blood pressure is not adequately controlled on monotherapy, offering a convenient and potent treatment option to help achieve target blood pressure goals and mitigate long-term cardiovascular risks.

Features

• Active Ingredients: Contains 50 mg or 100 mg of losartan potassium and 12.5 mg of hydrochlorothiazide per tablet.
• Pharmacological Class: Angiotensin II receptor blocker (ARB) and thiazide diuretic combination.
• Dosage Forms: Film-coated tablets for oral administration.
• Mechanism of Action: Losartan blocks the vasoconstrictor effects of angiotensin II, while hydrochlorothiazide promotes diuresis, together reducing peripheral vascular resistance.
• Bioavailability: Losartan is approximately 33% bioavailable; hydrochlorothiazide is about 70% bioavailable.
• Half-life: Losartan has an active metabolite with a half-life of 6-9 hours; hydrochlorothiazide has a half-life of 5-15 hours.

Benefits

• Achieves significant and sustained reduction in systolic and diastolic blood pressure.
• Lowers the risk of stroke in patients with hypertension and left ventricular hypertrophy.
• Provides convenient once-daily dosing, improving adherence compared to multiple pill regimens.
• Reduces fluid retention through its diuretic component, alleviating edema.
• Offers renal protective benefits in patients with type 2 diabetes and proteinuria.
• Helps decrease cardiac afterload, potentially improving long-term cardiovascular outcomes.

Common use

Hyzaar is primarily prescribed for the treatment of hypertension in cases where monotherapy does not provide sufficient blood pressure control. It is also used in the management of hypertensive patients with left ventricular hypertrophy to lower the risk of stroke, though it does not treat the hypertrophy itself. This medication is not indicated for initial therapy; it is typically reserved for patients who have shown an inadequate response to losartan or hydrochlorothiazide alone. Clinical decisions should be based on individual patient profiles and comorbid conditions.

Dosage and direction

The usual starting dose of Hyzaar is one tablet (losartan 50 mg/hydrochlorothiazide 12.5 mg) taken orally once daily. Dosage may be titrated up to two tablets of the 50/12.5 mg strength or one tablet of the 100/12.5 mg strength after several weeks, based on blood pressure response. It can be taken with or without food, though consistency in administration relative to meals is advised. For patients already on losartan monotherapy, the diuretic component may be added cautiously, transitioning to this combination if appropriate. Dose adjustment is necessary in patients with renal impairment or hepatic dysfunction; not recommended if CrCl ≤30 mL/min.

Precautions

Patients should be monitored for electrolyte imbalances, particularly hypokalemia, hyponatremia, and hypomagnesemia, especially when initiating therapy or adjusting dosage. Regular assessment of renal function and serum electrolytes is advised. Use with caution in patients with impaired hepatic function or history of liver disease, as hydrochlorothiazide may precipitate complications. Avoid excessive dehydration, which could lead to reduced renal perfusion. Photosensitivity reactions may occur; advise sun protection. Orthostatic hypotension may develop, particularly in volume-depleted patients. Not recommended during pregnancy due to potential fetal harm.

Contraindications

Hyzaar is contraindicated in patients with known hypersensitivity to losartan, hydrochlorothiazide, or any component of the formulation. It must not be used in patients with anuria or severe renal impairment (CrCl ≤30 mL/min). Contraindicated in patients with refractory hypokalemia, hypercalcemia, or symptomatic hyperuricemia. Do not administer to patients with a history of angioedema related to previous angiotensin-converting enzyme inhibitor or angiotensin II receptor blocker therapy. Avoid use during pregnancy, especially in the second and third trimesters.

Possible side effect

Common side effects may include dizziness, fatigue, upper respiratory infection, cough, hyperkalemia or hypokalemia, and orthostatic hypotension. Less frequently, patients may experience gastrointestinal disturbances such as diarrhea or abdominal pain. Photosensitivity, rash, and muscle cramps have been reported. Serious side effects, though rare, include angioedema, acute renal failure, severe hypotension, electrolyte imbalances leading to arrhythmias, pancreatitis, and hepatic dysfunction. Patients should seek medical attention for symptoms such as swelling of the face, difficulty breathing, or significant dizziness.

Drug interaction

Hyzaar may interact with lithium, increasing lithium levels and risk of toxicity. Concurrent use with other antihypertensive agents may potentiate hypotension. Nonsteroidal anti-inflammatory drugs (NSAIDs) may reduce the antihypertensive effect and increase risk of renal impairment. Potassium-sparing diuretics or potassium supplements may lead to hyperkalemia. Use with caution alongside corticosteroids or ACTH, due to increased risk of hypokalemia. Alcohol, barbiturates, or narcotics may enhance orthostatic hypotension. Hydrochlorothiazide may increase the risk of digoxin toxicity due to hypokalemia.

Missed dose

If a dose of Hyzaar is missed, it should be taken as soon as remembered on the same day. However, if it is nearly time for the next scheduled dose, the missed dose should be skipped, and the regular dosing schedule resumed. Doubling the dose to make up for a missed one is not recommended, as it may increase the risk of hypotension or electrolyte disturbances. Patients should be advised to maintain a consistent daily routine to support adherence and optimize therapeutic outcomes.

Overdose

Overdose of Hyzaar may manifest as severe hypotension, tachycardia, or bradycardia, and electrolyte disturbances such as hypokalemia or hyponatremia. Symptoms could include dizziness, fainting, dehydration, and renal impairment. Management is primarily supportive and symptomatic, including IV fluids and electrolyte correction. Hemodialysis is not effective for losartan removal but may be considered for hydrochlorothiazide elimination in severe cases. Vital signs, renal function, and electrolyte levels should be closely monitored. Gastric lavage or activated charcoal may be considered if ingestion was recent.

Storage

Hyzaar tablets should be stored at controlled room temperature, between 20°C to 25°C (68°F to 77°F), in a dry place protected from light and moisture. Keep the medication in its original container with the lid tightly closed to maintain stability. Do not store in bathrooms or near sinks where humidity levels are high. Keep out of reach of children and pets. Dispose of any unused or expired medication properly, following local guidelines, to prevent accidental ingestion or environmental contamination.

Disclaimer

This information is intended for educational purposes and does not replace professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider before starting, changing, or stopping any medication. Individual patient needs and responses may vary. Do not disregard or delay seeking medical advice based on content provided here. In case of a medical emergency, contact emergency services immediately.

Reviews

Clinical studies and patient reports generally reflect positive outcomes with Hyzaar, noting effective blood pressure control and convenient dosing. Some users report mild side effects such as dizziness, especially upon initiation, which often subsides with continued use. Healthcare professionals appreciate its dual mechanism for patients requiring combination therapy. However, experiences can vary; a minority of patients may not achieve desired results or experience adverse effects. Always follow your prescriber’s guidance and report any concerns during treatment.