Losartan-hydrochlorothiazide (Hyzaar and others)

How Medicare covers it

Part D (combination tablets taken at home). Part A during a covered inpatient stay. No Part B clinician-administered form in the CMS Part B spending file.

What it treats

Treats high blood pressure (hypertension). It is also used to reduce the risk of stroke in patients with hypertension and left ventricular hypertrophy (thickening of the heart's main pumping chamber); the label notes there is evidence this stroke benefit does not apply to Black patients.

What it is for, in depth

Losartan-hydrochlorothiazide is a combination tablet that puts two blood pressure medicines in one tablet: losartan, which relaxes blood vessels, and hydrochlorothiazide, a water pill that helps the kidneys remove extra salt and water. It treats high blood pressure, also called hypertension. It is also used to lower the risk of stroke in patients who have high blood pressure and thickening of the heart's main pumping chamber, called left ventricular hypertrophy, though the label notes there is evidence this stroke benefit does not apply to Black patients. It is taken as one tablet once a day. It comes in three combination strengths: losartan 50 mg with hydrochlorothiazide 12.5 mg, losartan 100 mg with hydrochlorothiazide 12.5 mg, and losartan 100 mg with hydrochlorothiazide 25 mg.

How it works

It combines losartan, an angiotensin II receptor blocker (ARB) that relaxes blood vessels by blocking angiotensin II, with hydrochlorothiazide, a thiazide diuretic that helps the kidneys remove extra salt and water. Together they lower blood pressure more than either drug alone.

How it is taken

One tablet once a day. The usual starting dose is losartan 50 mg/hydrochlorothiazide 12.5 mg once daily; after about 3 weeks the dose may be increased as needed to a maximum of 100 mg/25 mg once daily.

Common side effects

The most common side effects (at least 2% and more than with placebo) are dizziness, upper respiratory infection, cough, and back pain. Most side effects in trials were mild and short-lived.

Serious warnings

Serious problems described in the label include symptomatic low blood pressure and fainting (more likely if you are dehydrated from vomiting, diarrhea, heavy sweating, or poor fluid intake); worsening kidney function; high potassium; acute myopia and secondary angle-closure glaucoma from the hydrochlorothiazide part (sudden eye pain or vision change — stop the drug and get care at once); and non-melanoma skin cancer with hydrochlorothiazide (protect skin from the sun and have regular skin cancer screening).

Boxed warning

BOXED WARNING — FETAL TOXICITY: When pregnancy is detected, discontinue losartan potassium and hydrochlorothiazide as soon as possible. Drugs that act directly on the renin-angiotensin system, like losartan, can cause injury and death to the developing fetus.

Who should be careful

Do not take it if you are allergic to any component, if you cannot produce urine (anuria), or — if you have diabetes — together with aliskiren. Tell your doctor if you are pregnant or planning pregnancy, have kidney or liver disease, gout, diabetes, lupus, or sulfonamide allergy, or become dehydrated.

Major interactions

Other drugs that raise potassium can cause hyperkalemia when combined — do not use potassium supplements or potassium salt substitutes without your doctor's advice. It can raise lithium levels and cause lithium toxicity. NSAIDs, including COX-2 inhibitors, can worsen kidney function in older, volume-depleted, or kidney-impaired patients and can blunt the blood-pressure effect. Dual blockade of the renin-angiotensin system raises the risks of kidney impairment, low blood pressure, fainting, and high potassium. Diabetes medicines may need dose adjustment, and cholestyramine or colestipol can reduce absorption of the thiazide part.

Why it is in its tier

Losartan-hydrochlorothiazide is most commonly placed on Tier 1. It is listed by 100.0% of Part D plans, and 86.31% of those listing plans place it on Tier 1. Tier 1 is the lowest, preferred generic tier, so people often pay the smallest copay on this tier, often $0-$15. This is a generic combination tablet, which helps explain the Tier 1 placement. CMS dashboard data show CMS program average spending of $53.62 per beneficiary in 2024, which is program spending and not a copay. That wide agreement on the lowest tier makes its usual cost share fairly predictable across plans, though the exact amount still depends on the plan a person has. Individual plans vary, and readers should check their own plan's formulary.

Sources

• LOSARTAN POTASSIUM AND HYDROCHLOROTHIAZIDE TABLET, FILM COATED [GRANULES PHARMACEUTICALS INC.] — DailyMed

Part D formulary coverage

Source: CMS Prescription Drug Plan Formulary, Pharmacy Network, and Pricing Information Files — Monthly file 2026-10-15 (plan year 2027), file 2027_20261008.zip (data.cms.gov dataset ed1496ea-23e7-41f1-9292-172fa842ccfb): basic drugs formulary file + plan information file, both dated 20261031 inside the zip; downloaded and aggregated 2026-10-30. Medication RxCUI sets resolved through the NLM RxNav (RxNorm) API.

What you pay

Without insurance, the cash benchmark is 0.07739 per unit (LOSARTAN-HYDROCHLOROTHIAZIDE 100-12.5 MG TAB) — about nan for 30 units. NADAC benchmark — the average price pharmacies pay (CMS, as of 2026-11-04). Pharmacy shelf prices vary.

A tier is not a price; what you pay depends on your plan, pharmacy, and benefit stage; Extra Help or Medicaid can lower it further.

Sources: CMS Plan Benefit Package + formulary data; CMS NADAC · Checked 2026-11-07

Coverage by plan and tier

Of the 5,495 Medicare drug plans we track for 2027, 5,495 list Losartan-hydrochlorothiazide (Hyzaar and others) — 100% of plans. Most of those plans put it on Tier 1: 4,743 plans, 86.3% of the plans that list it. Other plans place it on Tier 6 (712 plans), Tier 2 (37 plans) or Tier 5 (3 plans). For example: Aetna Medicare Dual Extra (HMO D-SNP) puts it on Tier 1; Aetna Medicare Dual Extra Care (PPO D-SNP) puts it on Tier 1; Aetna Medicare Value Plus (PPO) puts it on Tier 1. You can compare these plans side by side on our Medicare Advantage hub. A tier is not a price. What you pay also depends on whether you have met your plan';s deductible, whether the drug costs a flat copay or a share of the price, and whether you get Extra Help or Medicaid.

Read next

• Part D in 2027: The $700 Deductible, the $2,400 Cap, and the $35 Insulin Rule
• Extra Help in 2027: Lower Drug Copays and Who Qualifies
• Checking Medicare Savings Programs and Extra Help

Part D spending averages (2024)

Source: CMS Medicare Part D Spending by Drug (Drug Spending Dashboard), release RY26 P04 V10, data through 2024 (DSD_PTD_RY26_P04_V10_DY24_BGM.csv), downloaded 2026-10-30

Companies covering this drug

Part D and Medicare Advantage plan sponsors that list this drug on a formulary, 50 at a time.