Indications for: HYZAAR

Hypertension (not for initial therapy unless HTN is severe). To reduce stroke in hypertensive patients with left ventricular hypertrophy (LVH); this benefit may not apply to black patients.

Adult Dosage:

Initially 50/12.5mg once daily (100/12.5mg if BP not controlled on losartan 100mg alone); may increase after 3 weeks as needed to max 100/25mg daily. HTN with LVH (BP not controlled on losartan alone): initially 50/12.5mg once daily; increase as needed to 100/12.5mg, then to max 100/25mg daily.

Children Dosage:

Not established.

HYZAAR Contraindications:

Anuria. Sulfonamide allergy. Concomitant aliskiren in patients with diabetes.

Boxed Warning:

Fetal toxicity.

HYZAAR Warnings/Precautions:

Fetal toxicity may develop; discontinue if pregnancy is detected. Correct salt/volume depletion before starting therapy, or reduce initial dose. Hepatic impairment: initial therapy not recommended. Severe renal impairment (CrCl<30mL/min): not established. Severe CHF. Renal artery stenosis. Asthma. SLE. Gout. Diabetes. Postsympathectomy. Acute myopia. Secondary angle-closure glaucoma. Monitor serum electrolytes, calcium, BP, renal function periodically. Pregnancy: avoid. Nursing mothers: not recommended.

HYZAAR Classification:

Angiotensin II receptor blocker (ARB) + thiazide diuretic.

HYZAAR Interactions:

See Contraindications. Hyperkalemia with concomitant other drugs that may increase serum potassium (eg, K+ supplements, K+ sparing diuretics, K+ containing salt substitutes). Dual inhibition of the renin-angiotensin system with ARBs, ACEIs, or aliskiren may increase risk of hypotension, hyperkalemia, renal function changes; monitor closely. Avoid concomitant aliskiren in renal impairment (CrCl <60mL/min). May be antagonized by, and renal toxicity potentiated by NSAIDs, including selective COX-2 inhibitors (monitor renal function periodically in elderly and/or volume-depleted). May increase lithium toxicity (monitor). Orthostatic hypotension with alcohol, other CNS depressants. Adjust antihyperglycemics. Hypokalemia with corticosteroids, ACTH. Potentiates other antihypertensives, skeletal muscle relaxants. Concomitant cholestyramine, colestipol; administer at least 4hrs before or 4–6hrs after resin administration.

Adverse Reactions:

Dizziness, upper respiratory infection, cough, back pain; hypersensitivity reactions, renal impairment, electrolyte abnormalities; HCTZ: increased risk for non-melanoma skin cancer.


Losartan Potassium

  • Hepatic (CYP2C9, 3A4).

Drug Elimination:

Losartan Potassium

  • Fecal (60%), renal (35%).

  • Total plasma clearance: ~600 mL/min with renal clearance of ~75 mL/min.

  • Half-life: ~2 hours.


  • Renal.

  • Half-life: 5.6–14.8 hours.

Generic Drug Availability:


How Supplied:

Tabs 50/12.5mg, 100/12.5mg—30, 90, 1000; 100/25mg—30, 90