Furosemide, sold under the brand name Lasix among others, is a

loop diuretic Loop diuretics are pharmacological agents that primarily inhibit the Na-K-Cl cotransporter located on the luminal membrane of cells along the thick ascending limb of the loop of Henle. They are often used for the treatment of hypertension and e ...

medication used to treat

edema Edema (American English), also spelled oedema (British English), and also known as fluid retention, swelling, dropsy and hydropsy, is the build-up of fluid in the body's tissue (biology), tissue. Most commonly, the legs or arms are affected. S ...

due to

heart failure Heart failure (HF), also known as congestive heart failure (CHF), is a syndrome caused by an impairment in the heart's ability to Cardiac cycle, fill with and pump blood. Although symptoms vary based on which side of the heart is affected, HF ...

, liver scarring, or

kidney disease Kidney disease, or renal disease, technically referred to as nephropathy, is damage to or disease of a kidney. Nephritis is an Inflammation, inflammatory kidney disease and has several types according to the location of the inflammation. Infla ...

. Furosemide may also be used for the treatment of

high blood pressure Hypertension, also known as high blood pressure, is a long-term medical condition in which the blood pressure in the arteries is persistently elevated. High blood pressure usually does not cause symptoms itself. It is, however, a major ri ...

. It can be taken

intravenously Intravenous therapy (abbreviated as IV therapy) is a medical technique that administers fluids, medications and nutrients directly into a person's vein. The intravenous route of administration is commonly used for rehydration or to provide nutr ...

or orally. When given intravenously, furosemide typically takes effect within five minutes; when taken orally, it typically metabolizes within an hour. Common side effects include

orthostatic hypotension Orthostatic hypotension, also known as postural hypotension, is a medical condition wherein a person's blood pressure drops when they are standing up ( orthostasis) or sitting down. Primary orthostatic hypotension is also often referred to as ne ...

(decrease in

blood pressure Blood pressure (BP) is the pressure of Circulatory system, circulating blood against the walls of blood vessels. Most of this pressure results from the heart pumping blood through the circulatory system. When used without qualification, the term ...

while standing, and associated

lightheadedness Lightheadedness is a common and typically unpleasant sensation of dizziness or a feeling that one may faint. The sensation of lightheadedness can be short-lived, prolonged, or, rarely, recurring. In addition to dizziness, the individual may fee ...

tinnitus Tinnitus is a condition when a person hears a ringing sound or a different variety of sound when no corresponding external sound is present and other people cannot hear it. Nearly everyone experiences faint "normal tinnitus" in a completely ...

(ringing in the ears), and

photosensitivity Photosensitivity is the amount to which an object reacts upon receiving photons, especially visible light. In medicine, the term is principally used for abnormal reactions of the skin, and two types are distinguished, photoallergy and phototoxicit ...

(sensitivity to light). Potentially serious side effects include

electrolyte abnormalities Electrolyte imbalance, or water-electrolyte imbalance, is an abnormality in the concentration of electrolytes in the body. Electrolytes play a vital role in maintaining homeostasis in the body. They help to regulate heart and neurological function ...

, low blood pressure, and

hearing loss Hearing loss is a partial or total inability to hear. Hearing loss may be present at birth or acquired at any time afterwards. Hearing loss may occur in one or both ears. In children, hearing problems can affect the ability to acquire spo ...

. It is recommended that serum

electrolytes An electrolyte is a substance that conducts electricity through the movement of ions, but not through the movement of electrons. This includes most soluble salts, acids, and bases, dissolved in a polar solvent like water. Upon dissolving, t ...

(especially

potassium Potassium is a chemical element; it has Symbol (chemistry), symbol K (from Neo-Latin ) and atomic number19. It is a silvery white metal that is soft enough to easily cut with a knife. Potassium metal reacts rapidly with atmospheric oxygen to ...

), serum ,

creatinine Creatinine (; ) is a breakdown product of creatine phosphate from muscle and protein metabolism. It is released at a constant rate by the body (depending on muscle mass). Biological relevance Serum creatinine (a blood measurement) is an impor ...

BUN A bun is a type of bread that is round and small enough that it can generally be eaten hand-held. Whether a bun is considered sweetened or unsweetened differs between countries: it is considered sweetened in the United Kingdom, a savory bread in ...

levels, and

liver The liver is a major metabolic organ (anatomy), organ exclusively found in vertebrates, which performs many essential biological Function (biology), functions such as detoxification of the organism, and the Protein biosynthesis, synthesis of var ...

and

kidney In humans, the kidneys are two reddish-brown bean-shaped blood-filtering organ (anatomy), organs that are a multilobar, multipapillary form of mammalian kidneys, usually without signs of external lobulation. They are located on the left and rig ...

functioning be monitored in patients taking furosemide. It is also recommended to be alert for the occurrence of any potential blood dyscrasias. Furosemide works by decreasing the reabsorption of sodium by the kidneys. Common side effects of furosemide injection include hypokalemia (low potassium level), hypotension (low blood pressure), and dizziness. Furosemide was patented in 1959 and approved for medical use in 1964. It is on the

World Health Organization's List of Essential Medicines The WHO Model List of Essential Medicines (aka Essential Medicines List or EML), published by the World Health Organization (WHO), contains the medications considered to be most effective and safe to meet the most important needs in a health s ...

. In the United States, it is available as a

generic medication A generic drug is a pharmaceutical drug that contains the same chemical substance as a drug that was originally protected by chemical patents. Generic drugs are allowed for sale after the patents on the original drugs expire. Because the active ch ...

. In 2022, it was the 24th most commonly prescribed medication in the United States, with more than 23million prescriptions. In 2020/21 it was the twentieth most prescribed medication in England. It is on the

World Anti-Doping Agency The World Anti-Doping Agency (WADA; , AMA) is an international organization co-founded by the governments of over 140 nations along with the International Olympic Committee based in Canada to promote, coordinate, and monitor the fight against d ...

's banned drug list due to concerns that it may mask other drugs. It has also been used in race horses for the treatment and prevention of

exercise-induced pulmonary hemorrhage Exercise-induced pulmonary hemorrhage (EIPH), also known as "bleeding" or a "bleeding attack", is the presence of blood in the airways of the lung in association with exercise. EIPH is common in horses undertaking intense exercise, but it has also ...

Medical uses

Furosemide is primarily used for the treatment of

, but also in some cases of

hypertension Hypertension, also known as high blood pressure, is a Chronic condition, long-term Disease, medical condition in which the blood pressure in the artery, arteries is persistently elevated. High blood pressure usually does not cause symptoms i ...

(where there is also kidney or heart impairment). It is often viewed as a first-line agent in most people with edema caused by

congestive heart failure Heart failure (HF), also known as congestive heart failure (CHF), is a syndrome caused by an impairment in the heart's ability to fill with and pump blood. Although symptoms vary based on which side of the heart is affected, HF typically pr ...

because of its anti-vasoconstrictor and diuretic effects. Compared with furosemide, however,

torasemide Torasemide, also known as torsemide, is a diuretic medication used to treat hypervolemia, fluid overload due to heart failure, kidney disease, and liver disease. It is a less preferred treatment for high blood pressure. It is taken by mouth or ...

(aka "torsemide") has been demonstrated to show improvements to heart failure symptoms, possibly lowering the rates of rehospitalization associated with heart failure, with no difference in risk of death. Torsemide may also be safer than furosemide. Providing self-administered subcutaneous furosemide has been found to reduce hospital admissions in people with heart failure, resulting in significant savings in healthcare costs. Furosemide is also used for liver

cirrhosis Cirrhosis, also known as liver cirrhosis or hepatic cirrhosis, chronic liver failure or chronic hepatic failure and end-stage liver disease, is a chronic condition of the liver in which the normal functioning tissue, or parenchyma, is replaced ...

, kidney impairment,

nephrotic syndrome Nephrotic syndrome is a collection of symptoms due to kidney damage. This includes proteinuria, protein in the urine, hypoalbuminemia, low blood albumin levels, hyperlipidemia, high blood lipids, and significant edema, swelling. Other symptoms ...

, in adjunct therapy for swelling of the brain or

lungs The lungs are the primary organs of the respiratory system in many animals, including humans. In mammals and most other tetrapods, two lungs are located near the backbone on either side of the heart. Their function in the respiratory syste ...

where rapid

diuresis Diuresis () is the excretion of urine, especially when excessive (polyuria). The term collectively denotes the physiologic processes underpinning increased urine production by the kidneys during maintenance of fluid balance. In healthy people, ...

is required ( IV injection), and in the management of severe

hypercalcemia Hypercalcemia, also spelled hypercalcaemia, is a high calcium (Ca2+) level in the blood serum. The normal range for total calcium is 2.1–2.6 mmol/L (8.8–10.7 mg/dL, 4.3–5.2 mEq/L), with levels greater than 2.6 mmol/L def ...

in combination with adequate rehydration.

Kidney disease

In chronic kidney diseases with

hypoalbuminemia Hypoalbuminemia (or hypoalbuminaemia) is a medical sign in which the concentration, level of human serum albumin, albumin in the blood is low. This can be due to decreased production in the liver, increased loss in the gastrointestinal tract or ki ...

, furosemide is used along with albumin to increase diuresis. It is also used along with albumin in

to reduce edema.

Other information

Furosemide is mainly excreted by tubular secretion in the kidney. In kidney impairment, clearance is reduced, increasing the risk of adverse effects. Lower initial doses are recommended in older patients (to minimize side effects) and high doses may be needed in

kidney failure Kidney failure, also known as renal failure or end-stage renal disease (ESRD), is a medical condition in which the kidneys can no longer adequately filter waste products from the blood, functioning at less than 15% of normal levels. Kidney fa ...

. It can also cause kidney damage; this is mainly by loss of excessive fluid (i.e., dehydration), and is usually reversible. Furosemide acts within 1 hour of oral administration (after IV injection, the peak effect is within 30 minutes). Diuresis is usually complete within 6–8 hours of oral administration, but there is significant variation between individuals.

Adverse effects

Furosemide also can lead to

gout Gout ( ) is a form of inflammatory arthritis characterized by recurrent attacks of pain in a red, tender, hot, and Joint effusion, swollen joint, caused by the deposition of needle-like crystals of uric acid known as monosodium urate crysta ...

caused by

hyperuricemia Hyperuricaemia or hyperuricemia is an abnormally high level of uric acid in the blood. In the pH conditions of body fluid, uric acid exists largely as urate, the ion form. Serum uric acid concentrations greater than 6 mg/dL for females, 7 ...

Hyperglycemia Hyperglycemia is a condition where unusually high amount of glucose is present in blood. It is defined as blood glucose level exceeding 6.9 mmol/L (125 mg/dL) after fasting for 8 hours or 10 mmol/L (180 mg/dL) 2 hours after eating. Blood gluc ...

is also a common side effect. The tendency, as for all loop diuretics, to cause low serum potassium concentration (

hypokalemia Hypokalemia is a low level of potassium (K+) in the blood serum. Mild low potassium does not typically cause symptoms. Symptoms may include feeling tired, leg cramps, weakness, and constipation. Low potassium also increases the risk of an a ...

) has given rise to combination products, either with potassium or with the

potassium-sparing diuretic Potassium-sparing diuretics or antikaliuretics refer to drugs that cause diuresis without causing potassium loss in the urine. They are typically used as an adjunct in management of hypertension, cirrhosis, and congestive heart failure. The ster ...

amiloride ( Co-amilofruse). Other electrolyte abnormalities that can result from furosemide use include hyponatremia, hypochloremia, hypomagnesemia, and hypocalcemia. In the treatment of heart failure, many studies have shown that the long-term use of furosemide can cause varying degrees of

thiamine deficiency Thiamine deficiency is a medical condition of low levels of thiamine (vitamin B1). A severe and chronic form is known as beriberi. The name beriberi was possibly borrowed in the 18th century from the Sinhala language, Sinhalese phrase (bæri ...

, so

thiamine Thiamine, also known as thiamin and vitamin B1, is a vitamin – an Nutrient#Micronutrients, essential micronutrient for humans and animals. It is found in food and commercially synthesized to be a dietary supplement or medication. Phosp ...

supplementation is also suggested. Furosemide is a known ototoxic agent generally causing transient hearing loss but can be permanent. Reported cases of furosemide-induced hearing loss appeared to be associated with rapid intravenous administration, high dosages, concomitant renal disease, and coadministration with other ototoxic medication. However, a recently reported longitudinal study showed that participants treated with loop diuretics over 10 years were 40% more likely to develop hearing loss and 33% more likely of progressive hearing loss compared to participants who did not use loop diuretics. This suggests the long-term consequences of loop diuretics on hearing could be a more significant than previously thought and further research is required in this area. Other precautions include nephrotoxicity, sulfonamide (sulfa) allergy, and increased free thyroid hormone effects with large doses.

Interactions

Furosemide has potential interactions with these medications: *

Aspirin Aspirin () is the genericized trademark for acetylsalicylic acid (ASA), a nonsteroidal anti-inflammatory drug (NSAID) used to reduce pain, fever, and inflammation, and as an antithrombotic. Specific inflammatory conditions that aspirin is ...

and other salicylates * Other diuretics (e.g.

ethacrynic acid Etacrynic acid ( INN) or ethacrynic acid ( USAN), trade name Edecrin, is a loop diuretic used to treat high blood pressure and the swelling caused by diseases like congestive heart failure, liver failure, and kidney failure. A disadvantage with e ...

hydrochlorothiazide Hydrochlorothiazide, sold under the brand name Hydrodiuril among others, is a diuretic medication used to treat hypertension and swelling due to fluid build-up. Other uses include treating diabetes insipidus and renal tubular acidosis and t ...

) * Synergistic effects with other

antihypertensive Antihypertensives are a class of drugs that are used to treat hypertension (high blood pressure). Antihypertensive therapy seeks to prevent the complications of high blood pressure, such as stroke, heart failure, kidney failure and myocardial infa ...

s (e.g.

doxazosin Doxazosin, sold under the brand name Cardura among others, is a medication used to treat symptoms of benign prostatic hyperplasia (enlarged prostate), hypertension (high blood pressure), and post-traumatic stress disorder (PTSD). For high bloo ...

) *

Sucralfate Sucralfate, sold under various brand names, is a medication used to treat stomach ulcers, gastroesophageal reflux disease (GERD), radiation proctitis, and stomach inflammation and to prevent stress ulcers. Its usefulness in people infected b ...

Potentially hazardous interactions with other drugs: *

Analgesic An analgesic drug, also called simply an analgesic, antalgic, pain reliever, or painkiller, is any member of the group of drugs used for pain management. Analgesics are conceptually distinct from anesthetics, which temporarily reduce, and in s ...

s: increased risk of kidney damage (nephrotoxicity) with

nonsteroidal anti-inflammatory drug Non-steroidal anti-inflammatory drugs (NSAID) are members of a Indication (medicine), therapeutic drug class which Analgesic, reduces pain, Anti-inflammatory, decreases inflammation, Antipyretic, decreases fever, and Antithrombotic, prevents bl ...

s; antagonism of diuretic effect with NSAIDs * Antiarrhythmics: a risk of cardiac toxicity exists with

antiarrhythmic Antiarrhythmic agents, also known as cardiac dysrhythmia medications, are a class of drugs that are used to suppress abnormally fast rhythms (tachycardias), such as atrial fibrillation, supraventricular tachycardia and ventricular tachycardia. M ...

s if

occurs; the effects of

lidocaine Lidocaine, also known as lignocaine and sold under the brand name Xylocaine among others, is a local anesthetic of the amino amide type. It is also used to treat ventricular tachycardia and ventricular fibrillation. When used for local anae ...

and mexiletine are antagonized. *

Antibacterial An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting bacterial infections, and antibiotic medications are widely used in the treatment and prevention ...

s: increased risk of

ototoxicity Ototoxicity is the property of being toxic to the ear (''oto-''), specifically the cochlea or auditory nerve and sometimes the vestibular system, for example, as a side effect of a drug. The effects of ototoxicity can be reversible and tempora ...

with

aminoglycoside Aminoglycoside is a medicinal and bacteriologic category of traditional Gram-negative antibacterial medications that inhibit protein synthesis and contain as a portion of the molecule an amino-modified glycoside (sugar). The term can also refer ...

s, polymyxins and

vancomycin Vancomycin is a glycopeptide antibiotic medication used to treat certain bacterial infections. It is administered intravenously ( injection into a vein) to treat complicated skin infections, bloodstream infections, endocarditis, bone an ...

; avoid concomitant use with lymecycline *

Antidepressant Antidepressants are a class of medications used to treat major depressive disorder, anxiety disorders, chronic pain, and addiction. Common side effects of antidepressants include Xerostomia, dry mouth, weight gain, dizziness, headaches, akathi ...

s: increased risk of hypokalemia with reboxetine; enhanced hypotensive effect with

MAOI Monoamine oxidase inhibitors (MAOIs) are a drug class, class of drugs that inhibit the activity of one or both monoamine oxidase enzymes: monoamine oxidase A (MAO-A) and monoamine oxidase B (MAO-B). They are best known as effective antidepressa ...

s; increased risk of postural hypotension with

tricyclic antidepressant Tricyclic antidepressants (TCAs) are a class of medications that are used primarily as antidepressants. TCAs were discovered in the early 1950s and were marketed later in the decade. They are named after their chemical structure, which contains ...

s *

Antiepileptic Anticonvulsants (also known as antiepileptic drugs, antiseizure drugs, or anti-seizure medications (ASM)) are a diverse group of pharmacological agents used in the treatment of epileptic seizures. Anticonvulsants are also used in the treatmen ...

s: increased risk of

hyponatremia Hyponatremia or hyponatraemia is a low concentration of sodium in the Serum (blood), blood. It is generally defined as a sodium concentration of less than 135 mmol/L (135 mEq/L), with severe hyponatremia being below 120 mEq/L. Symp ...

with

carbamazepine Carbamazepine, sold under the brand name Tegretol among others, is an anticonvulsant medication used in the treatment of epilepsy and neuropathic pain. It is used as an adjunctive treatment in schizophrenia along with other medications and as ...

Antifungal An antifungal medication, also known as an antimycotic medication, is a pharmaceutical fungicide or fungistatic used to treat and prevent mycosis such as athlete's foot, ringworm, candidiasis (thrush), serious systemic infections such as ...

s: increased risk of hypokalemia with amphotericin *

Antihypertensive Antihypertensives are a class of drugs that are used to treat hypertension (high blood pressure). Antihypertensive therapy seeks to prevent the complications of high blood pressure, such as stroke, heart failure, kidney failure and myocardial infa ...

s: enhanced hypotensive effect; increased risk of first dose hypotensive effect with alpha-blockers; increased risk of ventricular arrhythmias with

sotalol Sotalol, sold under the brand name Betapace among others, is a medication used to treat and prevent abnormal heart rhythms. Evidence does not support a decreased risk of death with long term use. It is taken by mouth or given by injection into ...

if hypokalemia occurs *

Antipsychotic Antipsychotics, previously known as neuroleptics and major tranquilizers, are a class of Psychiatric medication, psychotropic medication primarily used to manage psychosis (including delusions, hallucinations, paranoia or disordered thought), p ...

s: increased risk of ventricular arrhythmias with

amisulpride Amisulpride, sold under the brand names Socian and Barhemsys, is a medication used in the treatment of schizophrenia, acute psychotic episodes, depression, and nausea and vomiting. It is specifically used at lower doses intravenously to prev ...

sertindole Sertindole, sold under the brand name Serdolect among others, is an antipsychotic medication. Sertindole was developed by the Danish pharmaceutical company Lundbeck and marketed under license by Abbott Labs. Like other atypical antipsychotics, ...

, or

pimozide Pimozide (sold under the brand name Orap) is a neuroleptic medication, drug of the diphenylbutylpiperidine class. It was discovered at Janssen Pharmaceutica in 1963. It has a high potency compared to chlorpromazine (ratio 50-70:1). On a weigh ...

(avoid with pimozide) if hypokalemia occurs; enhanced hypotensive effect with phenothiazines *

Atomoxetine Atomoxetine, formerly sold under the brand name Strattera, is a selective norepinephrine reuptake inhibitor (sNRI) medication used to treat attention deficit hyperactivity disorder (ADHD) and, to a lesser extent, cognitive disengagement syndr ...

: hypokalemia increases risk of ventricular arrhythmias *

Cardiac glycoside Cardiac glycosides are a class of organic compounds that increase the output force of the heart and decrease its rate of contractions by inhibiting the cellular sodium-potassium ATPase pump. Their beneficial medical uses include treatments for ...

s: increased toxicity if hypokalemia occurs *

Cyclosporine Ciclosporin, also spelled cyclosporine and cyclosporin, is a calcineurin inhibitor, used as an immunosuppressant medication. It is taken orally or intravenously for rheumatoid arthritis, psoriasis, Crohn's disease, nephrotic syndrome, ecz ...

: variable reports of increased nephrotoxicity, ototoxicity and hepatotoxicity *

Lithium Lithium (from , , ) is a chemical element; it has chemical symbol, symbol Li and atomic number 3. It is a soft, silvery-white alkali metal. Under standard temperature and pressure, standard conditions, it is the least dense metal and the ...

: risk of toxicity.

Mechanism of action

Furosemide, like other loop diuretics, acts by inhibiting the luminal

Na–K–Cl cotransporter The Na–K–Cl cotransporter (NKCC) is a transport protein that aids in the secondary active transport of sodium, potassium, and chloride into cells. In humans there are two isoforms of this membrane transport protein, NKCC1 and NKCC2, encod ...

in the

thick ascending limb Within the nephron of the kidney, the ascending limb of the loop of Henle is a segment of the heterogenous loop of Henle downstream of the descending limb, after the sharp bend of the loop. This part of the renal tubule is divided into a thin and ...

of the

loop of Henle In the kidney, the loop of Henle () (or Henle's loop, Henle loop, nephron loop or its Latin counterpart ''ansa nephroni'') is the portion of a nephron that leads from the proximal convoluted tubule to the distal convoluted tubule. Named after it ...

, by binding to the Na-K-2Cl transporter, thus causing more sodium, chloride, and potassium to be excreted in the urine. The action on the distal tubules is independent of any inhibitory effect on carbonic anhydrase or aldosterone; it also abolishes the corticomedullary osmotic gradient and blocks negative, as well as positive, free water clearance. Because of the large NaCl absorptive capacity of the loop of Henle, diuresis is not limited by the development of acidosis, as it is with the carbonic anhydrase inhibitors. Additionally, furosemide is a noncompetitive subtype-specific blocker of GABA-A receptors. Furosemide has been reported to reversibly antagonize GABA-evoked currents of α₆β₂γ₂ receptors at μM concentrations, but not α₁β₂γ₂ receptors. During development, the α₆β₂γ₂ receptor increases in expression in cerebellar granule neurons, corresponding to increased sensitivity to furosemide.

Pharmacokinetics

* Molecular weight (daltons) 330.7 * %

Bioavailability In pharmacology, bioavailability is a subcategory of absorption and is the fraction (%) of an administered drug that reaches the systemic circulation. By definition, when a medication is administered intravenously, its bioavailability is 100%. H ...

47 – 70% ** Bioavailability with end-stage renal disease 43 – 46% * % Protein binding 91 – 99 * Volume of distribution (L/kg) 0.07 – 0.2 ** Volume of distribution may be higher in patients with cirrhosis or nephrotic syndrome * Excretion ** % Excreted in urine (% of total dose) 60 – 90 ** % Excreted unchanged in urine (% of total dose) 53.1 – 58.8 ** % Excreted in feces (% of total dose) 7 – 9 ** % Excreted in bile (% of total dose) 6 – 9 * Approximately 10% is metabolized by the liver in healthy individuals, but this percentage may be greater in individuals with severe kidney failure * Renal clearance (mL/min/kg) 2.0 * Elimination half-life (hrs) 2 ** Prolonged in congestive heart failure (mean 3.4 hrs) ** Prolonged in severe kidney failure (4 – 6 hrs) and anephric patients (1.5 – 9 hrs) * Time to peak concentration (hrs) ** Intravenous administration 0.3 ** Oral solution 0.83 ** Oral tablet 1.45 The pharmacokinetics of furosemide are not significantly altered by food. No direct relationship has been found between furosemide concentration in the plasma and furosemide efficacy. Efficacy depends upon the concentration of furosemide in urine.

Names

Furosemide is the

INN Inns are generally establishments or buildings where travelers can seek lodging, and usually, food and drink. Inns are typically located in the country or along a highway. Before the advent of motorized transportation, they also provided accomm ...

and BAN. The previous BAN was frusemide. Brand names under which furosemide is marketed include Aisemide, Apo-Furosemide, Beronald, Desdemin, Discoid, Diural, Diurapid, Dryptal, Durafurid, Edemid, Errolon, Eutensin, Farsiretic, Flusapex, Frudix, Frusemide, Frusetic, Frusid, Fulsix, Fuluvamide, Furantril, Furesis, Furix, Furo-Puren, Furon, Furosedon, Fusid.frusone, Hydro-rapid, Impugan, Katlex, Lasilix, Lasix, Lodix, Lowpston, Macasirool, Mirfat, Nicorol, Odemase, Oedemex, Profemin, Rosemide, Rusyde, Salix, Seguril, Teva-Furosemide, Trofurit, Uremide, and Urex.

Veterinary uses

The diuretic effects are put to use most commonly in horses to prevent bleeding during a race. In the United States of America, under the racing rules of most states, horses that bleed from the nostrils (

) three times are permanently barred from racing. Sometime in the early 1970s, furosemide's ability to prevent, or at least greatly reduce, the incidence of bleeding by horses during races was discovered accidentally. Clinical trials followed, and by the decade's end, racing commissions in some states in the USA began legalizing its use on race horses. In 1995,

New York New York most commonly refers to: * New York (state), a state in the northeastern United States * New York City, the most populous city in the United States, located in the state of New York New York may also refer to: Places United Kingdom * ...

became the last state in the United States to approve such use, after years of refusing to consider doing so. Some states allow its use for all racehorses; some allow it only for confirmed "bleeders". Its use for this purpose is still prohibited in many other countries. Furosemide is also used in horses for pulmonary edema, congestive heart failure (in combination with other drugs), and allergic reactions. Although it increases circulation to the kidneys, it does not help kidney function and is not recommended for kidney disease. It is also used to treat congestive heart failure (pulmonary edema, pleural effusion, and/or ascites) in cats and dogs.

Horses

Furosemide is injected either intramuscularly or

, usually 0.5-1.0 mg/kg twice/day, although less before a horse is raced. As with many diuretics, it can cause

dehydration In physiology, dehydration is a lack of total body water that disrupts metabolic processes. It occurs when free water loss exceeds intake, often resulting from excessive sweating, health conditions, or inadequate consumption of water. Mild deh ...

and

electrolyte imbalance Electrolyte imbalance, or water-electrolyte imbalance, is an abnormality in the concentration of electrolytes in the body. Electrolytes play a vital role in maintaining homeostasis in the body. They help to regulate heart and neurological function ...

, including loss of

calcium Calcium is a chemical element; it has symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar to it ...

sodium Sodium is a chemical element; it has Symbol (chemistry), symbol Na (from Neo-Latin ) and atomic number 11. It is a soft, silvery-white, highly reactive metal. Sodium is an alkali metal, being in group 1 element, group 1 of the peri ...

, and

magnesium Magnesium is a chemical element; it has Symbol (chemistry), symbol Mg and atomic number 12. It is a shiny gray metal having a low density, low melting point and high chemical reactivity. Like the other alkaline earth metals (group 2 ...

. Excessive use of furosemide will most likely lead to a

metabolic alkalosis Metabolic alkalosis is an acid-base disorder in which the pH of tissue is elevated beyond the normal range (7.35–7.45). This is the result of decreased hydrogen ion concentration, leading to increased bicarbonate (), or alternatively a dire ...

due to

hypochloremia Hypochloremia (or Hypochloraemia) is an electrolyte disturbance in which there is an abnormally low level of the chloride ion in the blood. Normal serum range for chloride is 97 to 107 mmol/L with levels less than 96 mmol/L defining hypochloremia. ...

and

. The drug should, therefore, not be used in horses that are dehydrated or experiencing kidney failure. It should be used with caution in horses with liver problems or electrolyte abnormalities. Overdose may lead to dehydration, change in drinking patterns and urination, seizures, gastrointestinal problems, kidney damage, lethargy, collapse, and coma. Furosemide should be used with caution when combined with corticosteroids (as this increases the risk of electrolyte imbalance), aminoglycoside antibiotics (increases the risk of kidney or ear damage), and trimethoprim sulfa (causes decreased platelet count). It may also cause interactions with anesthetics, so its use should be related to the veterinarian if the animal is going into surgery, it decreases the kidneys' ability to excrete

aspirin Aspirin () is the genericized trademark for acetylsalicylic acid (ASA), a nonsteroidal anti-inflammatory drug (NSAID) used to reduce pain, fever, and inflammation, and as an antithrombotic. Specific inflammatory conditions that aspirin is ...

, so dosages will need to be adjusted if combined with that drug. Furosemide may increase the risk of

digoxin Digoxin (better known as digitalis), sold under the brand name Lanoxin among others, is a medication used to treat various heart disease, heart conditions. Most frequently it is used for atrial fibrillation, atrial flutter, and heart failure. ...

toxicity due to hypokalemia. It is recommended that furosemide not be used during pregnancy or in a lactating mare, as it is passed through the placenta and milk in studies with other species. It should not be used in horses with pituitary pars intermedia dysfunction (Equine Cushing's Disease). Furosemide is detectable in urine 36–72 hours following injection. Its use is restricted by most equestrian organizations. US major racetracks ban the use of furosemide on race days.

References

External links

*
Lasix and horse bleeding
{{Authority control Anthranilic acids Carbonic anhydrase inhibitors Chemical substances for emergency medicine Chloroarenes Equine medications 2-Furyl compounds GABAA receptor negative allosteric modulators Glycine receptor antagonists Loop diuretics Nephrotoxins NMDA receptor antagonists Wikipedia medicine articles ready to translate Sanofi Sulfonamides World Anti-Doping Agency prohibited substances World Health Organization essential medicines