hydrochlorothiazide/losartan vs losartan

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Side-by-side comparison of hydrochlorothiazide/losartan and losartan. Data from FDA drug databases (Orange Book, NDC Directory, recalls, shortages) covering 20,000+ approved drugs, plus CMS pricing; see our methodology.

minor Known Drug Interaction

( 7.5 ) 7.1 Agents Increasing Serum Potassium Coadministration of losartan with other drugs that raise serum potassium levels may result in hyperkalemia. 7.3 Non-Steroidal Anti-Inflammatory Agents Including Selective Cyclooxygenase-2 Inhibitors Losartan Potassium In patients who are elderly, volume-depleted (including those on diuretic therapy), or with compromised renal function, coadministration of NSAIDs, including selective COX-2 inhibitors, with angiotensin II receptor antagonists (including losartan) may result in deterioration of renal function, including possible acute renal...

Drug Class
hydrochlorothiazide/losartan Thiazide Diuretic / ARB Combination
losartan Angiotensin II Receptor Blocker (ARB)
Type
hydrochlorothiazide/losartan Prescription
losartan Prescription
Summary
hydrochlorothiazide/losartan

Hyzaar is a combination medicine that contains losartan and hydrochlorothiazide. It is used to lower high blood pressure.

losartan

Losartan is a medicine that lowers blood pressure. It can also help prevent strokes in some people with high blood pressure and an enlarged heart.

What It Treats
hydrochlorothiazide/losartan

Hyzaar is used to treat high blood pressure. Lowering blood pressure reduces your risk of strokes and heart attacks. It is also used to lower the risk of stroke in patients with high blood pressure and an enlarged left ventricle of the heart.

losartan

Losartan is used to treat high blood pressure in adults and children over 6 years old. Lowering blood pressure reduces the risk of strokes and heart attacks. It is also used to treat kidney problems in people with type 2 diabetes and high blood pressure. Losartan can also reduce the risk of stroke in patients with high blood pressure and an enlarged left ventricle of the heart.

How It Works
hydrochlorothiazide/losartan

Losartan blocks a substance in your body that tightens blood vessels. This helps blood vessels relax, which lowers blood pressure. Hydrochlorothiazide is a diuretic that helps your body get rid of extra salt and water, which also lowers blood pressure.

losartan

Losartan blocks a substance in your body that tightens blood vessels. This helps blood vessels relax, which lowers blood pressure. It also helps the kidneys work better in people with diabetes.

Common Side Effects
hydrochlorothiazide/losartan
  • Dizziness
  • Upper respiratory infection
  • Cough
  • Back pain
losartan
  • Dizziness
  • Upper respiratory infection
  • Nasal congestion
  • Back pain
FAERS Reports
hydrochlorothiazide/losartan
  • Tiredness 10,013
  • Feeling sick to your stomach 9,706
  • Loose stools 8,311
  • Discomfort 7,665
  • Difficulty breathing 7,584
losartan
  • Fatigue 11,852
  • Diarrhoea 9,870
  • Nausea 9,207
  • Dyspnoea 8,439
  • Dizziness 7,999
Serious Warnings
hydrochlorothiazide/losartan

If you are pregnant or plan to become pregnant, stop taking Hyzaar and tell your doctor right away. This medicine can harm or kill your unborn baby.

losartan

Losartan can harm your unborn baby, even causing death. If you are pregnant or plan to become pregnant, tell your doctor right away. Stop taking losartan as soon as you know you are pregnant.

Pregnancy
hydrochlorothiazide/losartan

Do not take Hyzaar if you are pregnant. It can cause serious harm to your unborn baby, including kidney problems, lung problems, skeletal problems and even death. If you are breastfeeding, talk to your doctor about whether Hyzaar is right for you.

losartan

Do not take losartan if you are pregnant. It can cause serious harm or death to the developing fetus. If you are breastfeeding, talk to your doctor about whether losartan is right for you.

Also Compare, Nearby Drugs

How to Read This hydrochlorothiazide/losartan vs losartan Comparison

hydrochlorothiazide/losartan is classified in the Thiazide Diuretic / ARB Combination drug class, while losartan sits within the Angiotensin II Receptor Blocker (ARB) class. Drugs from different classes work through distinct mechanisms, so a head-to-head comparison illustrates trade-offs rather than equivalence. Both drugs are prescription-only, so a licensed provider must authorize use.

Adverse event totals above are pulled from the FDA's Adverse Event Reporting System (FAERS). For these top-ranked reactions alone, hydrochlorothiazide/losartan has 43,279 submissions while losartan has 47,367. Those figures reflect cumulative reporting volume, not per-patient risk, so older, widely dispensed drugs typically look worse on count alone. These two drugs have a known minor interaction flagged in FDA labeling, attributed to taking these medications together can cause your potassium levels to become dangerously high or lead to kidney problems.. Serious warnings, pregnancy guidance, and contraindications can differ even when indications overlap.

A table cannot represent individual circumstances. Data here is sourced from FDA Structured Product Labels (SPL) and FAERS, both of which update as manufacturers and clinicians submit new information. This registry does not provide medical, treatment, substitution, or medication-change directions for hydrochlorothiazide/losartan or losartan.

Registry boundary: This comparison displays source-record fields and does not provide individualized medical direction.