Losartan / Hydrochlorothiazide

Hyzaar lowers blood pressure and can be given with other antihypertensives. Its label generally excludes initial therapy except severe hypertension when prompt control is judged to outweigh the risks of starting combination therapy. It must not be initial treatment in intravascular volume depletion.

The combination is labeled to reduce stroke risk in people with hypertension and left ventricular hypertrophy. The LIFE study did not provide evidence that the cardiovascular benefit applies to Black patients; this is a specific outcome-evidence limitation, not a prohibition on treating their blood pressure.

The 2025 adult hypertension guideline favors two first-line agents in one pill for stage 2 hypertension, alongside individualized assessment. That general recommendation does not replace Hyzaar’s product-specific initiation precautions or authorize pediatric use. Standalone losartan/HCTZ, other ARBs and other combinations require their own labels.

If BP remains uncontrolled on losartan 50 mg, initiate 50/12.5 mg; if further reduction is needed, increase to 100/12.5 mg and then 100/25 mg once daily. Add another suitable antihypertensive when further lowering is needed. The stroke-evidence limitation in Black patients remains relevant.

Correct volume/salt depletion before use. The PK section permits usual regimens when creatinine clearance is greater than 30 mL/min; safety/effectiveness below 30 mL/min are not established. Do not infer an exact 30 mL/min boundary recommendation. Initiation in hepatic impairment is not recommended because the appropriate losartan 25 mg starting dose is unavailable in these fixed strengths. Pediatric safety and effectiveness are not established.

Take with or without food. If a dose is missed, take it when remembered unless close to the next dose, then skip it and resume the usual schedule. Do not double doses. Two 50/12.5 mg tablets equal 100/25 mg; two 100/12.5 mg tablets would exceed the labeled losartan maximum and are not the labeled escalation.

Hypersensitivity to a product component, anuria, and coadministration with aliskiren in a patient with diabetes are formal contraindications. The selected Hyzaar contraindication list does not separately list every sulfonamide allergy; allergy history remains relevant to HCTZ hypersensitivity and eye-event risk.

Fetal toxicity: discontinue Hyzaar as soon as pregnancy is detected. Drugs acting directly on the renin-angiotensin system can injure or kill the developing fetus. Discuss another regimen before planned pregnancy.

Common reported reactions include dizziness, upper respiratory infection, cough and back pain. Component or combination reports include orthostasis, electrolyte disorders, renal dysfunction, gastrointestinal symptoms and photosensitivity. Serious postmarketing reports include angioedema/anaphylaxis with airway involvement or pulmonary manifestations, hepatitis, thrombocytopenia, rhabdomyolysis and skin reactions. Reported non-melanoma skin-cancer risk is associated with HCTZ. Voluntary reports do not establish incidence or causality.

Potassium-raising drugs, supplements or salt substitutes can cause hyperkalemia. Combining RAS inhibitors increases hypotension, syncope, hyperkalemia and kidney injury. Aliskiren with this product is contraindicated in diabetes and should be avoided with renal impairment (GFR below 60 mL/min). Closely monitor BP, kidney function and electrolytes when another RAS-active medicine is involved.

NSAIDs, including COX-2 inhibitors, can reduce BP/diuretic response and cause acute kidney injury, particularly with older age, dehydration or CKD. Monitor kidney function and clinical response. Losartan and thiazides may raise lithium concentrations; monitor lithium carefully.

HCTZ should be given at least 4 hours before or 4–6 hours after cholestyramine/colestipol resins to limit impaired absorption. Diabetes medicines may need adjustment. Alcohol, barbiturates or opioids can worsen orthostasis; corticosteroids, ACTH or licorice-derived glycyrrhizin can intensify electrolyte loss. Other antihypertensives add BP effects; nondepolarizing muscle relaxant responsiveness may increase.

Rifampin lowers losartan and active-metabolite exposure; fluconazole raises parent losartan but lowers active-metabolite exposure. Clinical consequences of CYP 2 C 9 inhibition were not established in the label; review response rather than inventing a fixed adjustment.

RAS blockade can cause oligohydramnios, fetal renal failure, lung/skull abnormalities and death, especially with later-pregnancy exposure; this does not imply safe first-trimester use. HCTZ crosses the placenta and can cause neonatal jaundice or thrombocytopenia. Stop on pregnancy recognition and arrange assessment. Losartan human milk data are unknown, while thiazides enter milk. The label directs a decision to discontinue nursing or discontinue the drug, considering maternal need.

Pediatric safety and effectiveness of Hyzaar are not established; single-ingredient losartan pediatric dosing cannot be applied to this fixed combination. Older adults in outcome studies had similar overall effectiveness but more adverse events; assess orthostasis, volume status, kidney function and medication burden.

Renal impairment increases exposure to both components, particularly HCTZ; monitor carefully even when usual regimens are allowed. Severe renal impairment is not an established-use population. Do not initiate this fixed combination for hepatic impairment when a lower losartan start is needed. The Black-patient LIFE subgroup limitation concerns stroke/CV evidence; BP treatment still requires individualized assessment.

Losartan and its active metabolite block angiotensin II AT1 receptors without inhibiting ACE. HCTZ increases renal sodium and chloride excretion, reducing volume and increasing potassium loss through RAS/aldosterone responses. Adding an ARB can attenuate potassium loss, but both hypokalemia and hyperkalemia remain possible.

Losartan peaks near 1 hour; its active metabolite near 3–4 hours. Parent half-life is about 2 hours and active-metabolite half-life 6–9 hours. CYP-mediated first-pass metabolism produces the active metabolite; losartan/metabolite are not removed by hemodialysis. HCTZ is not metabolized and is cleared by the kidneys, with a plasma half-life about 5.6–14.8 hours. Diuresis begins within 2 hours, peaks about 4 hours and lasts 6–12 hours; BP reassessment spans weeks.

Document baseline and follow-up BP, creatinine/renal function and potassium, sodium and other electrolytes according to risk; assess calcium, glucose and urate/gout concerns. Reassess after dose or interacting-drug changes and during vomiting, diarrhea or poor intake. Current adult guidance supports standardized home BP monitoring with a reliable cuff and clinician feedback; cuffless watches should not substitute for validated measurements.

Discuss pregnancy plans and report pregnancy immediately. Avoid unapproved potassium supplements/salt substitutes or OTC NSAID use. Report lightheadedness; dehydration can intensify hypotension. New eye pain or sudden vision reduction requires stopping and urgent assessment. Seek emergency care for swelling affecting breathing. Use sun protection and arrange skin examinations; report new skin lesions.

Excess dosing can produce hypotension, tachycardia or bradycardia, dehydration and dangerous electrolyte depletion; hypokalemia may worsen digitalis-related arrhythmias. Obtain urgent medical or poison-control help. Supportive management includes BP, fluid, renal and electrolyte assessment; losartan/metabolite are not dialyzable and HCTZ dialytic removal is uncertain.

Appearance

Yellow, oval, film-coated

Engraving

717

Example package

NDC 78206-139-01 · bottle of 30

Labeler

Organon LLC

Selected Hyzaar tablets contain losartan potassium/HCTZ 50/12.5 mg, 100/12.5 mg or 100/25 mg. Selected 100/12.5 mg is white, oval, engraved 745; 100/25 mg is light yellow, oval, engraved 747. Generic appearances vary; no pediatric liquid or standalone-component regimen is provided.

Store at 25°C; excursions permitted 15–30°C. Keep the container tightly closed and protect from light. Keep away from children and check both strengths when changing the prescription.