Furosemide: uses, dosing, side effects & brands
Furosemide is a loop diuretic sold in the U.S. under 4 brand and generic names, for ascites, edema and heart failure. Below: what the FDA label says, every product that contains it, what the pills look like, and its recall record.
Key facts
- Drug class
- Loop Diuretic
- Treats (across its forms)
- Ascites, Edema and Heart Failure
- Available as
- Injectable · Tablet
- Sold as
- 4 products — Furoscix, Furosemide and Lasix, and others
- Prescription?
- Prescription only
- Generic available?
- Yes
- Half-life
- about 2 hours (terminal elimination half-life in adults with normal kidney function)
- What the pharmacy pays
- about $0.05 per ml — not your price
How Furoscix is dosed
From the FDA label for Furoscix (application NDA209988). Other furosemide products — different forms, different strengths — are dosed differently. Follow the label for the one you were prescribed.
FUROSCIX is not for chronic use and should be replaced with oral diuretics as soon as practical. ( 2.1 ) The FUROSCIX ReadyFlow™ is pre-filled to deliver 80 mg of furosemide subcutaneously in about 10 seconds. The single-use, On-body Infusor is pre-programmed to deliver 30 mg of furosemide subcutaneously over the first hour then 12.5 mg per hour for the subsequent 4 hours. ( 2.1 ) See Full Prescribing Information for important administration instructions. ( 2.2 ) 2.1 Recommended Dosage FUROSCIX is not for chronic use and should be replaced with oral diuretics as soon as practical. Adult Patients: FUROSCIX ReadyFlow: The FUROSCIX ReadyFlow is an autoinjector that delivers 80 mg of furosemide subcutaneously in about 10 seconds [see Clinical Pharmacology ( 12 )] . Adult and Pediatric Patients 43 kg and Above: On-body Infusor for FUROSCIX: The single-use, On-body Infusor with prefilled cartridge is pre-programmed to deliver 30 mg of furosemide subcutaneously over the first hour followed by 12.5 mg per hour for the subsequent 4 hours [see Use in Specific Populations ( 8.6 ) and Clinical Pharmacology ( 12 )]. 2.2 Important Administration Instructions Inspect the parenteral drug product through the autoinjector viewing window or the prefilled cartridge for the On-body Infusor prior to administration. FUROSCIX is a clear, colorless to slightly yellow solution. Do not use FUROSCIX if…
Everything below is the FDA label for Furoscix (injectable). Furosemide is also sold as tablet, and those are different medicines to take — follow the label for the one you were prescribed.
Furoscix side effects
The following important adverse reactions are discussed elsewhere in the labeling: Fluid, Electrolyte, and Metabolic Abnormalities [see Warnings and Precautions ( 5.1 )]. Ototoxicity [see Warnings and Precautions ( 5.3 )] The following adverse reactions associated with the use of furosemide were identified in clinical trials or post-marketing reports. Because these reactions were reported voluntarily from a population of uncertain size, it is not always possible to estimate their frequency reliably, or to establish a causal relationship to drug exposure. Adverse reactions are categorized below by organ system and listed by decreasing severity. Gastrointestinal System Reactions : pancreatitis, jaundice (intrahepatic cholestatic jaundice), increased liver enzymes, anorexia, oral and gastric irritation, cramping, diarrhea, constipation, nausea, vomiting. Systemic Hypersensitivity Reactions : severe anaphylactic or anaphylactoid reactions (e.g., with shock), systemic vasculitis, interstitial nephritis, necrotizing angiitis. Central Nervous System Reactions : tinnitus and hearing loss, paresthesias, vertigo, dizziness, headache, blurred vision, xanthopsia. Hematologic Reactions : aplastic anemia, thrombocytopenia, agranulocytosis, hemolytic anemia, leukopenia, anemia, eosinophilia. Dermatologic Hypersensitivity Reactions : toxic epidermal necrolysis, Stevens-Johnson Syndrome,…
Who shouldn’t take Furoscix
FUROSCIX is contraindicated in: Patients with anuria. Patients with a history of hypersensitivity to furosemide, or any component of the FUROSCIX formulation. The On-body Infusor for FUROSCIX is contraindicated in patients with a history of hypersensitivity to medical adhesives Anuria ( 4 ) Hypersensitivity to furosemide, or components of FUROSCIX formulation ( 4 ) FUROSCIX On-body Infusor: Hypersensitivity to medical adhesives ( 4 )
Furoscix drug interactions
Aminoglycoside antibiotics : Increased potential ototoxicity of the antibiotics. Avoid combination. ( 7.1 ) Ethacrynic acid : Risk of ototoxicity. Avoid combination ( 7.1 ) Salicylates : Risk of salicylate toxicity. ( 7.1 ) Cisplatin and nephrotoxic drugs : Risk of ototoxicity and nephrotoxicity. ( 7.1 ) Lithium : Risk of lithium toxicity. ( 7.1 ) Renin-angiotensin inhibitors : Increased risk of hypotension and renal failure. ( 7.1 ) Adrenergic blocking drugs : Risk of potentiation. ( 7.1 ) Drugs undergoing renal tubular secretion : Risk of toxicity potentiation. ( 7.1 ) See 17 for PATIENT COUNSELING INFORMATION . 7.1 Effects of Furosemide on Other Drugs Drug/Substance Class or Name Drug Interaction Effect Recommendations Aminoglycoside antibiotics Furosemide may increase the ototoxic potential of aminoglycoside antibiotics, especially in the presence of impaired renal function [see Warnings and Precautions ( 5.3 )]. Avoid combination except in life-threatening situations. Ethacrynic acid Possibility of ototoxicity [see Warnings and Precautions ( 5.3 )]. Avoid concomitant use with ethacrynic acid. Salicylates May experience salicylate toxicity at lower doses because of competitive renal excretory sites. Monitor for symptoms of salicylate toxicity. Cisplatin There is a risk of ototoxic effects if cisplatin and furosemide are given concomitantly [see Warnings and Precautions ( 5.3 )]. Administer furosemide at lower doses and with positive fluid balance when used to achieve forced diuresis during cisplatin treatment. Monitor renal function. Cisplatin and nephrotoxic drugs Nephrotoxicity Paralytic agents Furosemide has a tendency to antagonize the skeletal muscle relaxing effect of tubocurarine and may potentiate the action of succinylcholine. Monitor for skeletal muscle effect. Lithium Furosemide reduces lithium’s renal clearance and add a high-risk of lithium toxicity. Avoid concomitant use with lithium. Angiotensin converting enzyme inhibitors or angiotensin II receptor blockers May lead to severe hypotension and deterioration in renal function, including renal failure. Monitor for changes in blood pressure and renal function and interrupt or reduce the dosage of furosemide, angiotensin converting enzyme inhibitors, or angiotensin receptor blockers if needed. Antihypertensive drugs Furosemide may add to or potentiate the therapeutic effect of other antihypertensive drugs. Monitor for changes in blood pressure and adjust the dose of other antihypertensive drugs if needed. Adrenergic blocking drugs or peripheral adrenergic blocking drugs Potentiation occurs. Monitor for changes in blood pressure and adjust the dose of adrenergic blocking drugs if needed. Norepinephrine Furosemide may decrease arterial responsiveness (vasoconstricting effect) to norepinephrine. Monitor blood pressure (or mean arterial pressure). Chloral hydrate In isolated cases, intravenous administration of furosemide within 24 hours of taking chloral hydrate may lead to flushing, sweating attacks, restlessness, nausea, increase in blood pressure, and tachycardia. Concomitant use with chloral hydrate is not recommended. Methotrexate and other drugs undergoing renal tubular secretion Furosemide may decrease renal elimination of other drugs that undergo tubular secretion. High-dose treatment of furosemide may result in elevated serum levels of these drugs and may potentiate their toxicity. Monitor serum levels of drugs undergoing renal tubular secretion and adjust the dose if needed. Cephalosporin Furosemide can increase the risk of cephalosporin-induced nephrotoxicity even in the setting of minor or transient renal impairment. Monitor for changes in renal function. Cyclosporine Increased risk of gouty arthritis secondary to furosemide-induced hyperuricemia and cyclosporine impairment of renal urate excretion. Monitor serum urate levels. Thyroid hormones High-doses (> 80 mg) of furosemide may inhibit the binding of thyroid hormones to carrier proteins and result in transient increase in free thyroid hormones, followed by an overall decrease in total thyroid hormone levels. Monitor the total thyroid hormone levels. 7.2 Effect of Other Drugs on Furosemide Drug/Substance Class or Name Drug Interaction Effect Recommendations Phenytoin Phenytoin interferes directly with renal action of furosemide. Monitor diuretic effects of furosemide and adjust the dose of furosemide if needed. Methotrexate and other drugs undergoing renal tubular secretion May reduce the effect of furosemide. High-dose treatment of methotrexate and these other drugs may result in elevated serum levels of furosemide and may potentiate the toxicity of furosemide. Monitor for enhanced toxicity of furosemide. Indomethacin Coadministration of indomethacin may reduce the natriuretic and antihypertensive effects of furosemide in some patients by inhibiting prostaglandin synthesis. Indomethacin may also affect plasma renin levels, aldosterone excretion, and renin profile evaluation. Patients receiving both indomethacin and furosemide should be observed closely to determine if the desired diuretic and/or antihypertensive effect of furosemide is achieved. 7.1 Effects of Furosemide on Other Drugs Drug/Substance Class or Name Drug Interaction Effect Recommendations Aminoglycoside antibiotics Furosemide may increase the ototoxic potential of aminoglycoside antibiotics, especially in the presence of impaired renal function [see Warnings and Precautions ( 5.3 )]. Avoid combination except in life-threatening situations. Ethacrynic acid Possibility of ototoxicity [see Warnings and Precautions ( 5.3 )]. Avoid concomitant use with ethacrynic acid. Salicylates May experience salicylate toxicity at lower doses because of competitive renal excretory sites. Monitor for symptoms of salicylate toxicity. Cisplatin There is a risk of ototoxic effects if cisplatin and furosemide are given concomitantly [see Warnings and Precautions ( 5.3 )]. Administer furosemide at lower doses and with positive fluid balance when used to achieve forced diuresis during cisplatin treatment. Monitor renal function. Cisplatin and nephrotoxic drugs Nephrotoxicity Paralytic agents Furosemide has a tendency to antagonize the skeletal muscle relaxing effect of tubocurarine and may potentiate the action of succinylcholine. Monitor for skeletal muscle effect. Lithium Furosemide reduces lithium’s renal clearance and add a high-risk of lithium toxicity. Avoid concomitant use with lithium. Angiotensin converting enzyme inhibitors or angiotensin II receptor blockers May lead to severe hypotension and deterioration in renal function, including renal failure. Monitor for changes in blood pressure and renal function and interrupt or reduce the dosage of furosemide, angiotensin converting enzyme inhibitors, or angiotensin receptor blockers if needed. Antihypertensive drugs Furosemide may add to or potentiate the therapeutic effect of other antihypertensive drugs. Monitor for changes in blood pressure and adjust the dose of other antihypertensive drugs if needed. Adrenergic blocking drugs or peripheral adrenergic blocking drugs Potentiation occurs. Monitor for changes in blood pressure and adjust the dose of adrenergic blocking drugs if needed. Norepinephrine Furosemide may decrease arterial responsiveness (vasoconstricting effect) to norepinephrine. Monitor blood pressure (or mean arterial pressure). Chloral hydrate In isolated cases, intravenous administration of furosemide within 24 hours of taking chloral hydrate may lead to flushing, sweating attacks, restlessness, nausea, increase in blood pressure, and tachycardia. Concomitant use with chloral hydrate is not recommended. Methotrexate and other drugs undergoing renal tubular secretion Furosemide may decrease renal elimination of other drugs that undergo tubular secretion. High-dose treatment of furosemide may result in elevated serum levels of these drugs and may potentiate their toxicity. Monitor serum levels of drugs undergoing renal tubular secretion and adjust the dose if needed. Cephalosporin Furosemide can increase the risk of cephalosporin-induced nephrotoxicity even in the setting of minor or transient renal impairment. Monitor for changes in renal function. Cyclosporine Increased risk of gouty arthritis secondary to furosemide-induced hyperuricemia and cyclosporine impairment of renal urate excretion. Monitor serum urate levels. Thyroid hormones High-doses (> 80 mg) of furosemide may inhibit the binding of thyroid hormones to carrier proteins and result in transient increase in free thyroid hormones, followed by an overall decrease in total thyroid hormone levels. Monitor the total thyroid hormone levels. 7.2 Effect of Other Drugs on Furosemide Drug/Substance Class or Name Drug Interaction Effect Recommendations Phenytoin Phenytoin interferes directly with renal action of furosemide. Monitor diuretic effects of furosemide and adjust the dose of furosemide if needed. Methotrexate and other drugs undergoing renal tubular secretion May reduce the effect of furosemide. High-dose treatment of methotrexate and these other drugs may result in elevated serum levels of furosemide and may potentiate the toxicity of furosemide. Monitor for enhanced toxicity of furosemide. Indomethacin Coadministration of indomethacin may reduce the natriuretic and antihypertensive effects of furosemide in some patients by inhibiting prostaglandin synthesis. Indomethacin may also affect plasma renin levels, aldosterone excretion, and renin profile evaluation. Patients receiving both indomethacin and furosemide should be observed closely to determine if the desired diuretic and/or antihypertensive effect of furosemide is achieved.
Every furosemide product we track (4)
Same active ingredient — different manufacturer, form, price and FDA recall record. That last one is what our independent score measures.
| # | Drug | Rating | Type | Form | Generic? | Pharmacy pays | |
|---|---|---|---|---|---|---|---|
| 1 | Not yet rated | Prescription | Injectable | Generic | $0 | View → | |
| 2 | Not yet rated | Prescription | Injectable | Generic | $0 | View → | |
| 3 | Not yet rated | Prescription | Tablet | Generic | $0 | View → | |
| 4 | Not yet rated | Prescription | Injectable | Generic | $0 | View → |
What furosemide pills look like
Imprint codes, colour and shape from the FDA’s labelling data. Match the imprint on your pill — or search any imprint.
| Imprint | Strength | Colour | Shape | Maker |
|---|---|---|---|---|
| EP;116 | 20 mg | white | round | — |
| RE;22 | 20 mg | white | round | — |
| EP;116 | 20 mg | white | round | — |
| 3169;V | 20 mg | white | oval | — |
| 3170;V | 40 mg | white | round | — |
| 17;0 | 40 mg | white | round | — |
| EP;117;40 | 40 mg | white | round | — |
| G164 | 20 mg | white | round | — |
| G;165 | 40 mg | white | round | — |
| G;166 | 80 mg | white | round | — |
| EP;116 | 20 mg | white | round | — |
| 3169;V | 20 mg | white | oval | — |
Furosemide recalls
From the FDA Enforcement database. A recall covers specific lots — not the drug as a whole.
How long furosemide keeps
No furosemide label we read sets a separate limit for after opening, but they do specify how it must be stored — and the stability behind any date assumes those conditions.
Does furosemide expire? The in-use limits and storage rules from its labelsFurosemide and breastfeeding
From LactMed, the US National Library of Medicine’s Drugs and Lactation Database — quoted, not rewritten.
Full LactMed record for furosemide: levels in milk, effects in breastfed infants, and the drugs it would consider insteadBecause little information is available on the use of furosemide during breastfeeding and because intense diuresis from high doses might decrease lactation, an alternate drug may be preferred, especially while nursing a newborn or preterm infant. Low doses of furosemide (20 mg daily) do not suppress lactation.
National Institute of Child Health and Human Development, record revised January 15, 2025. LactMed states its information is not a substitute for professional judgement.
What people report to the FDA about furosemide
The FDA Adverse Event Reporting System (FAERS) collects reports from patients and clinicians. It holds 274,012 reports naming furosemide, and the FDA flagged 83% of those reports as serious. The effects reported most often — leaving out reports about overdose, misuse or the condition being treated, which dominate the raw list for common medicines:
- dyspnoea18,961 reports
- acute kidney injury16,839 reports
- fatigue13,597 reports
- diarrhoea13,556 reports
- nausea11,882 reports
- fall11,390 reports
- hypotension10,591 reports
- pneumonia10,421 reports
Read these as a signal, not a rate. A report does not mean furosemide caused the effect — anyone can file one, and many describe people taking several medicines for several conditions. Crucially there is no denominator: FAERS does not record how many people took the drug, so these counts cannot be turned into “X% of patients” — a bigger number often just means a more widely used or more talked-about drug. Duplicates exist, and publicity drives reporting. For what is actually established, read the FDA label section above.
Source: openFDA drug/event (FAERS), retrieved August 25, 2026.
How long furosemide stays in your system
The elimination half-life of furosemide is about 2 hours (terminal elimination half-life in adults with normal kidney function). Linear kinetics — the label gives a single terminal half-life ("approximately 2 hours"). Furosemide is not a prodrug and has no clinically important active metabolite: its major biotransformation product, furosemide glucuronide, is not described as active. The half-life is prolonged when clearance falls — in reduced kidney function, in heart or liver failure, and especially in neonates — so the drug lingers longer in those groups. In a healthy adult, roughly 4–5 half-lives (about 8–10 hours) clears essentially all of a dose from the blood.
Furosemide Tablet — FDA label (DailyMed SPL), Clinical Pharmacology ↗Half-life is how long the body takes to clear half a dose. It is not the same as how long a drug test can detect it, and it varies with age, kidney and liver function.
Related calculators
Frequently asked questions
What is Furoscix?
Furoscix (Furosemide) is a loop diuretic used to treat Ascites, Edema, Heart Failure, Hypertension.
What kind of drug is furosemide?
The FDA classifies furosemide as a loop diuretic. Loop diuretics such as furosemide block a salt-transport protein (the Na-K-2Cl cotransporter) in a part of the kidney called the loop of Henle. This stops sodium and chloride from being reabsorbed, so the body flushes out extra salt and water, relieving fluid buildup and swelling. If you are checking whether it is safe to combine with something else, the class is what matters — two drugs from the same class usually should not be stacked.
How long does furosemide stay in your system?
The elimination half-life of furosemide is about 2 hours (terminal elimination half-life in adults with normal kidney function) — that is how long the body takes to clear half of a dose. Linear kinetics — the label gives a single terminal half-life ("approximately 2 hours"). Furosemide is not a prodrug and has no clinically important active metabolite: its major biotransformation product, furosemide glucuronide, is not described as active. The half-life is prolonged when clearance falls — in reduced kidney function, in heart or liver failure, and especially in neonates — so the drug lingers longer in those groups. In a healthy adult, roughly 4–5 half-lives (about 8–10 hours) clears essentially all of a dose from the blood. Half-life is not the same as how long a drug test can detect the drug, and it varies with age, kidney and liver function.
Can you take furosemide with other medicines?
It depends on the medicine. We check it against the FDA labels rather than guessing: our interaction checker searches each drug's own label for the other and quotes what it says, naming the section it came from. Run furosemide against whatever else you take — and remember that a label not naming a drug is not the same as that combination being safe.
What brand names is furosemide sold under?
We track 4 furosemide-containing products in the U.S.: Furoscix, Furosemide, Lasix and Lasix Onyu. They are the same active ingredient; they differ in form, manufacturer, price and FDA recall record.
What forms does furosemide come in?
Across the brands we track, furosemide is currently marketed as injectable and tablet, per the FDA's National Drug Code Directory. Each form is dosed differently — follow the label for the exact product you were prescribed.
Is there a generic furosemide?
Yes. Our catalog lists 1 generic furosemide product alongside the brand versions. A generic has the same active ingredient and must meet the FDA's bioequivalence standard; it usually costs less. Ask your pharmacist which one your plan covers.
Has furosemide been recalled?
The FDA's Enforcement database lists 2 recall records whose product description mentions furosemide. The most recent: Furosemide Tablets (Mar 20, 2026). A recall applies to specific lots, not to the drug as a whole — check the record for the affected lot numbers.
What are the common side effects of furosemide, and do they go away?
The most common effect is simply urinating more often, which is the drug working; it is heaviest in the first few hours after a dose and eases as your body adjusts. Dizziness or lightheadedness when standing up is also common and usually fades over the first week or two as your dose settles. Other frequent effects include headache and muscle cramps. Take it early in the day so the increased urination does not disrupt sleep.
Which furosemide side effects are dangerous and mean I should call a doctor?
Furosemide's main risk is losing too much fluid and too many electrolytes. Call your doctor for muscle cramps, unusual weakness, an irregular or pounding heartbeat, or numbness and tingling, which can signal low potassium, sodium, or magnesium. Signs of dehydration such as very little urine, extreme thirst, dry mouth, confusion, or fainting also need prompt attention. Sudden ringing in the ears or hearing loss is a warning of ototoxicity and should be reported right away.
Can furosemide damage your hearing?
Yes, though it is uncommon with normal oral doses. Hearing loss or ringing in the ears (usually temporary) is linked mainly to high intravenous doses given too quickly, and to use in people with kidney problems or alongside other ear-toxic drugs like certain antibiotics. Any new ringing, muffled hearing, or hearing loss should be reported to your doctor promptly.
How do I tell normal furosemide effects from ones that mean stop and get help?
Urinating more, mild thirst, and passing lightheadedness when you stand are expected and manageable. What is not routine: fainting, a racing or irregular heartbeat, severe or persistent cramps and weakness, confusion, sudden hearing changes, or signs of a serious allergic reaction (rash, swelling of the face or throat, trouble breathing). Those mean stop and seek care. Because furosemide can strongly deplete fluid and electrolytes, your doctor will usually monitor blood tests periodically.
Cite this page
- APA
- pharmaranks. (2026, July 24). Furosemide: uses, dosing, side effects & brands. https://pharmaranks.com/drugs/furosemide
- MLA
- “Furosemide: uses, dosing, side effects & brands.” pharmaranks, 24 July 2026, https://pharmaranks.com/drugs/furosemide.
We summarise public FDA and NIH sources — for a clinical claim, cite the primary source we link to as well.
Sources: FDA openFDA drug label, National Drug Code Directory, and Enforcement (recall) database. This page reproduces public FDA data and is not medical advice. Dosing is set by your prescriber.
Read the full FDA label for furosemide on DailyMed (NIH) ↗.