metolazone
Brand names: Zaroxolyn
Metolazone is a water pill that helps your body get rid of extra salt and water. It can also lower blood pressure.
Drug Pricing (NADAC)
Generic Price
$0.43/unit
Generic Available
Yes (10 manufacturers)
Pricing data from NADAC (CMS), effective December 18, 2024. Compare all drug costs →
What it does
Metolazone treats water retention (edema) caused by heart failure or kidney problems.
Common side effects
Dizziness, Lightheadedness, Drowsiness
Key warnings
If you have trouble urinating, are in a hepatic coma or precoma, or are allergic to metolazone, you should not take this medicine.
How It Works
Metolazone is a diuretic, which means it helps your kidneys remove salt and water from your body. This reduces the amount of fluid in your blood vessels, which can lower blood pressure and reduce swelling. It belongs to a class of drugs called thiazide-like diuretics.
How to Take It
Take metolazone once a day. Your doctor will adjust your dose to find what works best for you. It may take a few days to weeks to see the full effect, especially for blood pressure. Follow your doctor's instructions carefully and don't change your dose without talking to them.
Pregnancy & Breastfeeding
Using diuretics during pregnancy can expose the mother and fetus to unnecessary risks. Talk to your doctor about the risks and benefits of taking metolazone while pregnant or breastfeeding. It should only be used if medically necessary.
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.
Storage
Store metolazone tablets at room temperature (68° to 77°F) and protect them from light. Keep out of the reach of children.
Side Effects (from patient reports)
Based on 7,458 FDA adverse event reports.
FDA Adverse Event Report Analysis
Detailed analysis of 10,872 reports from the FDA Adverse Event Reporting System (FAERS). Reports span 2003–2025.
Total Reports
10,872
Death-Related Reports
2,165
Hospitalization Reports
5,657
Top Indication
Product Used For Unknown Indication
Gender Distribution
Age Distribution
Most Reported Adverse Reactions (FAERS)
| # | Reaction | Reports |
|---|---|---|
| 1 | DYSPNOEA | 1,204 |
| 2 | DEATH | 867 |
| 3 | ACUTE KIDNEY INJURY | 790 |
| 4 | NAUSEA | 736 |
| 5 | RENAL FAILURE | 713 |
| 6 | CARDIAC FAILURE CONGESTIVE | 674 |
| 7 | FATIGUE | 648 |
| 8 | DIARRHOEA | 639 |
| 9 | DIZZINESS | 600 |
| 10 | CHRONIC KIDNEY DISEASE | 589 |
| 11 | HYPOTENSION | 579 |
| 12 | ASTHENIA | 572 |
| 13 | HEADACHE | 537 |
| 14 | OEDEMA PERIPHERAL | 524 |
| 15 | FALL | 507 |
Reactions in Death Reports
Reactions in Hospitalization Reports
Source: FDA FAERS (Adverse Event Reporting System) FDA FAERS (Adverse Event Reporting System) Reports are voluntary and do not establish causation
Serious Warnings
If you have trouble urinating, are in a hepatic coma or precoma, or are allergic to metolazone, you should not take this medicine. Using diuretics when pregnant can be dangerous to the baby. Only use this medicine during pregnancy if absolutely necessary for a medical condition.
Common Questions
Can I take metolazone if I'm pregnant?
What should I do if I feel dizzy after taking metolazone?
How long does it take for metolazone to start working?
Can I drink alcohol while taking metolazone?
What if I miss a dose?
Does metolazone interact with other medications?
Can metolazone cause dehydration?
How often will I need blood tests?
Can I stop taking metolazone suddenly?
What are the ingredients in metolazone tablets?
What are the common side effects of metolazone?
What drug class is metolazone?
Is metolazone safe during pregnancy?
Related Medications in Thiazide-Like Diuretic
Other drugs grouped near metolazone — same-class peers and common alternatives.
acebutolol
Sectral
Acebutolol is a medicine that helps lower blood pressure and control irregular heartbeats.
Compare with metolazone →
aliskiren
Tekturna
Tekturna is a medicine used to treat high blood pressure.
Compare with metolazone →
amiloride
Midamor
Amiloride is a water pill that helps your body hold onto potassium.
Compare with metolazone →
amlodipine
Norvasc
Amlodipine (Norvasc) is a drug that lowers blood pressure and treats chest pain.
Compare with metolazone →
amlodipine/benazepril
Lotrel
Lotrel is a combination medicine that contains amlodipine and benazepril.
Compare with metolazone →
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
Related Health & Safety Data
🩺 Find a Doctor
Search prescribers for Thiazide-Like Diuretic
🏨 Hospital Quality
CMS hospital ratings, safety scores & patient outcomes
💊 Supplement Data
NIH DSLD — check supplement ingredients & label claims
🍽️ Food Safety Alerts
FDA recalls, inspections & outbreak investigations
⚠️ Product Recalls
FDA, CPSC & NHTSA recall search
💉 Procedure Costs
Medicare procedure pricing for 9,297 procedures
Save on metolazone
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 metolazone
The FDA label for metolazone (sold under brand names such as Zaroxolyn) classifies it as a prescription-only medication in the Thiazide-Like Diuretic class. Metolazone treats water retention (edema) caused by heart failure or kidney problems. Official labeling lists 7 commonly reported side effects, including Dizziness, Lightheadedness, Drowsiness.
Post-market surveillance from the FDA Adverse Event Reporting System (FAERS) captures real-world experience. For this drug, FAERS contains 7,458 voluntary reports. Interaction data is drawn directly from FDA-approved prescribing information. NADAC pricing from CMS shows a generic unit cost of $0.43.
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: December 24, 2024
Read our methodology — how this data is sourced, computed, and verified.
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