Prescription medication · Thiazide Diuretic / ARB Combination
hydrochlorothiazide/losartan
Also sold as Hyzaar. Hyzaar is used to treat high blood pressure.
Data updated 2026-05-15
- 75,364
- FDA reports
- 7
- InteractionsFew interactions
- $6.17
- Brand price (NADAC)
What the data shows
hydrochlorothiazide/losartan (Hyzaar) is a prescription Thiazide Diuretic / ARB Combination, with 75,364 FDA adverse-event reports on file, with 7 documented drug interactions.
Reporting volume reflects how widely a drug is used and studied, not how dangerous it is, a FAERS report documents a temporal association, never proof of cause.
hydrochlorothiazide/losartan (Hyzaar) is a prescription Thiazide Diuretic / ARB Combination. Hyzaar is used to treat high blood pressure.
Hyzaar is a combination medicine that contains losartan and hydrochlorothiazide. It is used to lower high blood pressure.
Verify with FDA → · CMS NADAC pricing →
Drug Pricing (NADAC)
Brand Price
$6.17/unit
Generic Available
No
Pricing data from NADAC (CMS), effective December 18, 2024. Compare all drug costs →
What it does
Hyzaar is used to treat high blood pressure.
Common side effects
Dizziness, Upper respiratory infection, Cough
Key warnings
If you are pregnant or plan to become pregnant, stop taking Hyzaar and tell your doctor right away.
The sections below are summarized in plain English from hydrochlorothiazide/losartan's FDA-approved prescribing information. They describe what the official label says, and are not personal medical advice.
How It Works
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.
How to Take It
The usual starting dose is one 50/12.5 mg tablet once a day. Your doctor may increase the dose after 3 weeks, up to a maximum of one 100/25 mg tablet daily. You can take Hyzaar with or without food. Follow your doctor's instructions carefully.
This is a plain-language summary of hydrochlorothiazide/losartan's FDA labeling, not individualized dosing advice. Ask a pharmacist or prescriber before changing how you take this medication.
Pregnancy & Breastfeeding
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.
This is a plain-language summary of hydrochlorothiazide/losartan's FDA labeling, not individualized advice. Ask a pharmacist or prescriber about pregnancy or breastfeeding on this medication.
Missed Dose
If you miss a dose, take it as soon as you remember. If it is close to your next dose, skip the missed dose and continue with your regular schedule.
This is a plain-language summary of hydrochlorothiazide/losartan's FDA labeling, not individualized advice. Ask a pharmacist or prescriber what to do about your specific missed dose.
Storage
Store Hyzaar at room temperature (77°F or 25°C) in a tightly closed container, away from light.
Side Effects (from patient reports)
Based on 75,364 FDA adverse event reports.
Most-reported reactions
Adverse reactions in FAERS for hydrochlorothiazide/losartan, by number of reports
- Tiredness
Tiredness
10,013 reports
- Feeling sick to your stomach
Feeling sick to your stomach
9,706 reports
- Loose stools
Loose stools
8,311 reports
- Discomfort
Discomfort
7,665 reports
- Difficulty breathing
Difficulty breathing
7,584 reports
- Head pain
Head pain
7,516 reports
- Feeling lightheaded
Feeling lightheaded
7,310 reports
- Joint pain
Joint pain
6,080 reports
- Weakness
Weakness
5,629 reports
- Accidentally falling down
Accidentally falling down
5,550 reports
What this shows Bars show how often each reaction was reported, not how likely it is to happen, a report records a temporal association, never proof that the drug caused it.
Serious Warnings
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.
Known Drug Interactions
7.4 Dual Blockade of the Renin-Angiotensin System (RAS) Dual blockade of the RAS with angiotensin receptor blockers, ACE inhibitors, or aliskiren is associated with increased risks of hypotension, syncope, hyperkalemia, and changes in renal function (including acute renal failure) compared to monotherapy. Do not coadminister aliskiren with HYZAAR in patients with diabetes. Avoid use of aliskiren with HYZAAR in patients with renal impairment (GFR <60 mL/min).
Mechanism: These drugs work on the same pathway to lower blood pressure, and taking both can lead to dangerously high potassium or sudden kidney failure.
What to do: This combination should not be used in patients with diabetes or kidney disease.
( 7.1 ) Lithium: Risk of lithium toxicity. 7.2 Lithium Increases in serum lithium concentrations and lithium toxicity have been reported with concomitant use of angiotensin II receptor antagonists or thiazide diuretics. Monitor lithium levels in patients receiving HYZAAR and lithium.
Mechanism: These blood pressure medications can cause the amount of lithium in your body to rise to dangerous levels. This happens because the drugs change how your kidneys get rid of lithium.
What to do: Your doctor should monitor your lithium blood levels closely. They may need to adjust your lithium dose while you are taking this medication.
The Veterans Affairs Nephropathy in Diabetes (VA NEPHRON-D) trial enrolled 1448 patients with type 2 diabetes, elevated urinary-albumin-to-creatinine ratio, and decreased estimated glomerular filtration rate (GFR 30 to 89.9 mL/min), randomized them to lisinopril or placebo on a background of losartan therapy and followed them for a median of 2.2 years. Patients receiving the combination of losartan and lisinopril did not obtain any additional benefit compared to monotherapy for the combined endpoint of decline in GFR, end-stage renal disease, or death, but experienced an increased...
Mechanism: Combining these two similar types of blood pressure drugs does not offer extra protection for your heart or kidneys and increases the risk of side effects.
What to do: Your doctor will likely avoid using this combination because it provides no additional benefit over taking a single medication.
( 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...
Mechanism: Taking these medications together can cause your potassium levels to become dangerously high or lead to kidney problems.
What to do: Your doctor should regularly check your blood potassium levels and monitor how well your kidneys are working.
Hydrochlorothiazide The administration of a non-steroidal anti-inflammatory agent including a selective COX-2 inhibitor can reduce the diuretic, natriuretic, and antihypertensive effects of loop, potassium-sparing and thiazide diuretics. Monitor renal function periodically in patients receiving hydrochlorothiazide, losartan, and NSAID therapy. 7.5 The Use of Hydrochlorothiazide with Other Drugs When administered concurrently, the following drugs may interact with thiazide diuretics [see Clinical Pharmacology (12.3) ]: Antidiabetic drugs (oral agents and insulin) — dosage adjustment of the...
Mechanism: Pain relievers like NSAIDs can stop blood pressure medicines and water pills from working as well as they should. Taking these together can also put extra stress on your kidneys.
What to do: Your doctor should check your kidney function regularly while you are taking these medicines. You may also need to monitor your blood pressure more closely.
This is a plain-language summary of interactions documented in FDA labeling, not individualized advice. Ask a pharmacist or prescriber before combining medications.
Common Questions
Can I take Hyzaar if I have diabetes?
Can I drink alcohol while taking Hyzaar?
What should I do if I feel dizzy after taking Hyzaar?
Can Hyzaar affect my kidneys?
Does Hyzaar interact with other medications?
How long does it take for Hyzaar to lower my blood pressure?
Can I stop taking Hyzaar if my blood pressure is normal?
Will Hyzaar cure my high blood pressure?
Are there any foods I should avoid while taking Hyzaar?
Can Hyzaar cause any changes in my potassium levels?
What are the common side effects of hydrochlorothiazide/losartan?
Does hydrochlorothiazide/losartan interact with other medications?
What drug class is hydrochlorothiazide/losartan?
Is hydrochlorothiazide/losartan safe during pregnancy?
Related Medications in Thiazide Diuretic / ARB Combination
Other drugs grouped near hydrochlorothiazide/losartan - same-class peers and common alternatives.
acebutolol
Sectral
Acebutolol is a medicine that helps lower blood pressure and control irregular heartbeats.
Compare with hydrochlorothiazide/losartan →
aliskiren
Tekturna
Tekturna is a medicine used to treat high blood pressure.
Compare with hydrochlorothiazide/losartan →
amiloride
Midamor
Amiloride is a water pill that helps your body hold onto potassium.
Compare with hydrochlorothiazide/losartan →
amlodipine
Norvasc
Amlodipine (Norvasc) is a drug that lowers blood pressure and treats chest pain.
Compare with hydrochlorothiazide/losartan →
amlodipine/benazepril
Lotrel
Lotrel is a combination medicine that contains amlodipine and benazepril.
Compare with hydrochlorothiazide/losartan →
Compare hydrochlorothiazide/losartan vs acebutolol side-by-side →
Medication Guides
Understanding Drug Interactions
How CYP450 enzymes, inhibitors, and inducers affect your medications
Generic vs Brand Name Drugs
FDA requirements, cost savings, and when the difference matters
Narrow Therapeutic Index Drugs
Why some drugs demand precise dosing and monitoring
Common Drug Interactions
Dangerous medication combinations and how to protect yourself
Save on hydrochlorothiazide/losartan
Compare prices and find discounts at pharmacies near you. Free coupons can save up to 80% on prescriptions.
Disclosure: This link may earn us a commission at no extra cost to you. See our terms.
What the FDA Data Shows for hydrochlorothiazide/losartan
The FDA label for hydrochlorothiazide/losartan (sold under brand names such as Hyzaar) classifies it as a prescription-only medication in the Thiazide Diuretic / ARB Combination class. Hyzaar is used to treat high blood pressure. Official labeling lists 4 commonly reported side effects, including Dizziness, Upper respiratory infection, Cough.
Post-market surveillance from the FDA Adverse Event Reporting System (FAERS) captures real-world experience. For this drug, FAERS contains 75,364 voluntary reports. The database also lists 7 documented drug interactions derived from FDA labeling, with the top-flagged interaction rated major severity. NADAC pricing from CMS.
Report counts do not establish causation, a FAERS entry documents a temporal association, not proof that the drug produced the outcome. Widely prescribed medications naturally accumulate more reports than niche therapies, so raw totals must be interpreted alongside total exposure. Shortage status, recall history, and patent information further shape supply and switching decisions. This page summarizes public FDA data for educational purposes only and is not a substitute for professional medical advice, always consult a licensed healthcare provider before starting, stopping, or changing any medication.
Data Sources
Drug labeling: FDA Drug Labels (SPL/DailyMed). Adverse events: FDA Adverse Event Reporting System (FAERS). Pricing: CMS National Average Drug Acquisition Cost (NADAC).
FAERS reports are voluntary and do not establish causation. Drug interactions are derived from FDA labeling and clinical references. Always consult a healthcare professional before making medication decisions.
Last updated: November 26, 2025
Read our methodology - how this data is sourced, computed, and verified.
Data currency: FDA FAERS adverse-event reports through 2025, CMS NADAC acquisition-cost pricing effective December 2024, compiled and last refreshed May 2026. See our methodology for per-source dates and refresh cadence. Spot a figure that looks wrong? Report a correction.
All federal data sources used on this page
- FDA Orange Book - approved drug products with therapeutic equivalence. accessdata.fda.gov/cder/ob
- FDA DailyMed - NIH-hosted drug labeling for FDA-approved meds. dailymed.nlm.nih.gov
- FDA Adverse Event Reporting System (FAERS) - post-marketing safety surveillance. fda.gov/drugs/faers
- NLM RxNorm - standardized clinical drug nomenclature. nlm.nih.gov/research/umls/rxnorm
- CMS Medicare Part B Drug Average Sales Price Files - federal drug pricing data. cms.gov/medicare/part-b-drugs/asp
- FDA Drug Shortages Database - current and resolved drug shortage tracking. accessdata.fda.gov/drugshortages