Furosemide (Lasix) is a loop diuretic (also called a water pill). It is used in fluid overload states such as heart failure, ascites, and pulmonary edema.

Furosemide (Lasix) Uses:

• Edema:

  • Associated with heart failure, management of edema and hepatic or renal disease.
  • Acute pulmonary edema.

• Hypertension:

  • Hypertension management.

Note:

• For the initial treatment of hypertension, it is not recommended.

Furosemide (Lasix) Dose in Adults

Note:

• Oral dose equivalency (approximate) for patients with normal renal function:

  • Furosemide 40 mg = bumetanide 1 mg = ethacrynic acid 50 mg = torsemide 20 mg

Furosemide (Lasix) Dose in the treatment of Acute pulmonary edema:

• IV:
• Initial:
  • 40 mg/dose.
  • May increase to 80 mg/dose, if response not adequate within 1 hour.

Note:

• • Minimal additional response is gained by single doses over 160-200 mg.
  • Max: 200 mg/dose (Brater 1998).

Furosemide (Lasix) Dose in the treatment of Edema:

• P/O:
• Initial:
  • 20-80 mg/dose.
  • May repeat the same dose or increase dose in increments of 20-40 mg/dose at intervals of 6-8 hours, if response is not adequate.
  • With severe edematous states, may titrate up to 600 mg/day.
  • Usual maintenance dose interval is once or twice daily.

Furosemide (Lasix) Dose in the treatment of Heart failure:

• Initial:
  • 20-40 mg once or twice daily.
  • Max 600 mg/day (ACCF/AHA [Yancy 2013]).

Note:

• Based on patient-specific diuretic needs, dosing frequency may be adjusted.
• IM, IV:
• Initial:
  • 20-40 mg/dose.
  • May repeat the same dose or increase dose in increments of 20 mg/dose if the response is not adequate & administer 1-2 hours after the previous dose (max: 200 mg/dose [Brater 1998]).

• Note:

  • For those receiving chronic oral diuretic therapy, a higher initial dose may be considered (the dose of chronic oral therapy may guide the IM/IV dose).
  • Although some patients may initially require dosing as frequently as every 6 hours, the individually determined dose should then be given once or twice daily.

• Continuous IV infusion:

  • Initial:

  • IV bolus dose 40-100 mg over 1-2 mins, followed by a continuous IV infusion rate of 10-40 mg/hour.
  • Before increasing the infusion rate, repeat loading dose.

  • Note:

    • Median & max doses were ≤ 20 mg/hour in clinical trials evaluating dosing strategies in acute decompensated heart failure.
    • The upper end of the initial infusion dosage range should be considered with lower baseline CrCl (eg, CrCl <25 mL/min)
    • Double as necessary to a max of 80-160 mg/hour if urine output is <1 mL/kg/hour.
    • The risk associated with higher infusion rates (80 to 160 mg/hour) must be weighed against alternative strategies.

Furosemide (Lasix) Dose as an alternative agent in the treatment of Hypertension:

• Initial:
• 20-40 mg twice daily.
• To maintain therapeutic response, individualize according to patient response and use minimal dose necessary.
• Usual dosage range:
• In 2 divided doses, 20-80 mg/day.

Furosemide (Lasix) Dose in the treatment of Ascites, due to cirrhosis (off-label dose):

• Initial:
  • 40 mg orally once daily.
  • As clinically indicated, titrate every 3-5 days (usual max: 160 mg once daily).
  • A furosemide to spironolactone dosing ratio of 40 mg (furosemide) to 100 mg (spironolactone) should be maintained.

Furosemide (Lasix) Dose in Childrens

Note:

• Oral and parenteral (IV, IM) doses may not be interchangeable.
• Oral doses are typically higher than IV due to differences in bioavailability.
• In multiple concentrations, Oral solution is available (8 mg/mL and 10 mg/mL).
• Between the different concentrations, extra precautions should be taken to verify and avoid confusion.
• The dose should be clearly presented as mg (not mL).
• Oral dose equivalency for adult patients with normal renal function (approximate):
• Furosemide 40 mg = bumetanide 1 mg = torsemide 20 mg = ethacrynic acid 50 mg.

Furosemide (Lasix) Dose in the treatment of Edema (diuresis):

• P/O:

  • Initial:

    • 0.5-2 mg/kg/dose every 6-24 hours.
    • Usual initial adult dose:
    • 20-80 mg/dose.
    • May increase dose in increments of 1-2 mg/kg/dose, if initial dose ineffective.
    • Max daily dose:
    • 6 mg/kg/day not to exceed maximum adult daily dose:
    • 600 mg/day.
  • For maintenance, adjust the dose to the minimal effective dose.

• Note:

  • Smaller doses on a mg/kg basis may be needed in larger children, especially in those who are diuretic naive.

• IM, intermittent IV:

  • Initial:

    • 0.5-2 mg/kg/dose every 6-12 hours.
    • Usual initial adult dose:
    • 20-40 mg/dose.
    • May increase dose by 1 mg/kg/dose, if initial dose ineffective after 2 hours.
    • Max dose:
    • 6 mg/kg/dose not to exceed max adult dose:
    • 200 mg/dose.
  • For maintenance, adjust to the minimum effective dose.

• Note:

  • Smaller doses on a mg/kg basis may be needed in larger children, especially in those who are diuretic naive.
  • In adult and pediatric patients, dosing in adolescents based on experience.

• Continuous IV infusion:

  • Initial:
    • IV bolus dose of 0.1 mg/kg followed by continuous IV infusion of 0.05-0.4 mg/kg/hour.
    • Titrate dosage to clinical effect.
    • In adolescents, dosing based on reported experience in adult and pediatric patients:
    • IV bolus dose of 0.1 mg/kg.
    • Usual adult bolus dose:
    • 40-100 mg over 1-2 mins.
    • Followed by continuous IV infusion of 0.1 to 0.4 mg/kg/hour.
    • Usual adult dosing range:
    • 10-40 mg/hour.

Furosemide Pregnancy Risk Category: C

• Studies on animal reproduction have revealed negative outcomes.
• The placenta is crossed by furosemide (Riva 1978).
• Pregnant women with cardiac disease can be treated with furosemide.
• Monitor fetal growth if used during pregnancy
• May increase the birth weight

Furosemide use during breastfeeding:

• Furosemide can be found in breast milk.
• Lactation may be affected by maternal use.
• Manufacturers recommend that caution is used when administering the medication to a nursing woman.
• Some sources recommend furosemide be used in combination with breastfeeding (Garg 2015), but others suggest avoiding it if you can, as usual maternal doses can cause lactation suppression (WHO 2002).

Furosemide (Lasix) Dose in Kidney Disease:

• Acute renal failure:

  • To initiate the desired response doses up to 1 to 3 g daily may be necessary.
  • In oliguric states, avoid use.

• Dialysis:

  • Not removed by hemodialysis or peritoneal dialysis.
  • The supplemental dose is not necessary.

Furosemide (Lasix) Dose in Liver disease:

Reduced natriuretic action in cirrhosis, along with greater vulnerability to hypokalemia and volume depletion. Watch the consequences, especially while using excessive doses.

Furosemide (Lasix) Side effects:

• Cardiovascular:

  • Necrotizing Angiitis
  • Orthostatic Hypotension
  • Thrombophlebitis
  • Vasculitis

• Central Nervous System:

  • Dizziness
  • Headache
  • Paresthesia
  • Restlessness
  • Vertigo

• Dermatologic:

  • Acute Generalized Exanthematous Pustulosis
  • Bullous Pemphigoid
  • Erythema Multiforme
  • Exfoliative Dermatitis
  • Pruritus
  • Skin Photosensitivity
  • Skin Rash
  • Stevens-Johnson Syndrome
  • Toxic Epidermal Necrolysis
  • Urticaria

• Endocrine & Metabolic:

  • Glycosuria
  • Hyperglycemia
  • Hyperuricemia
  • Increased Serum Cholesterol
  • Increased Serum Triglycerides

• Gastrointestinal:

  • Abdominal Cramps
  • Anorexia
  • Constipation
  • Diarrhea
  • Gastric Irritation
  • Mouth Irritation
  • Nausea
  • Pancreatitis
  • Vomiting

• Genitourinary:

  • Bladder Spasm

• Hematologic & Oncologic:

  • Agranulocytosis
  • Anemia
  • Aplastic Anemia
  • Eosinophilia
  • Hemolytic Anemia
  • Leukopenia
  • Purpura
  • Thrombocytopenia

• Hepatic:

  • Hepatic Encephalopathy
  • Intrahepatic Cholestatic Jaundice
  • Liver Enzymes Increased

• Hypersensitivity:

  • Anaphylaxis
  • Anaphylactoid Reaction
  • Anaphylactic Shock

• Immunologic:

  • DRESS Syndrome

• Local:

  • Pain At Injection Site (Following IM Injection)

• Neuromuscular & Skeletal:

  • Muscle Spasm
  • Weakness

• Ophthalmic:

  • Blurred Vision
  • Xanthopsia

• Otic:

  • Deafness
  • Tinnitus

• Renal:

  • Interstitial Nephritis (Allergic)
  • Renal Disease

• Miscellaneous:

  • Fever

Contraindications to Furosemide (Lasix):

• Hypersensitivity to furosemide and any other component of the formulation
• Anuria

Canadian labeling:Additional contraindications not listed in the US labeling:

• Hypersensitivity to sulfonamide-derived medications
• Complete renal shut down
• Precoma and hepatic coma.
• Uncorrected electrolyte depletion, hypovolemia or dehydration states that are not corrected.
• Infants born jaundiced or with the disease(s), capable of causing hyperbilirubinemia and possibly kernicterus.
• Breastfeeding

Notice:

• The manufacturer labeling of Lasix Special and Furosemide Special Injection also includes the following:
  • GFR 5 mg/min or GFR 20 mg/min
  • Hepatic cirrhosis.
  • Hepatic coma and precoma can be accompanied by renal failure.
  • Renal failure caused by poisoning with hepatotoxic or nephrotoxic substances

Notice:

• The scientific basis of this statement has been challenged, although the approved product labeling states this medication is contraindicated with other sulfonamide-containing drug classes.

Warnings and precautions

• Fluid and electrolyte losses: [US Boxed Warn]

  • Furosemide is similar to other loop diuretics and can cause severe diuresis if taken in large amounts. This can result in electrolyte and fluid depletion.
  • A dosage assessment and close medical management are necessary.
  • Correct any imbalances in the electrolytes.
  • To avoid dehydration, adjust the dose.
  • Therapy should not be started if electrolyte depletion has occurred unless the serum electrolytes, particularly potassium, have been normalized.
• Hypokalemia risk may be increased by:
  • It is possible to experience rapid diuresis, poor oral potassium intake, cirrhosis, and concomitant use of significant doses of licorice or corticosteroids (chronic usage).
  • A loop diuretic can lower serum calcium levels, unlike thiazide diuretics.
  • Electrolyte imbalances can put patients at risk for life-threatening arrhythmias.

• Hyperuricemia:

  • Use has been linked to the signs and symptoms of hyperuricemia.
  • Rarely, gout may be precipitated.

• Nephrotoxicity:

  • It's critical to assess your fluid status and renal function in order to avoid oliguria, azotemia, and irreversible increases in BUN or creatinine.
  • It is important to have close medical supervision for aggressive diuresis.
  • In high-risk patients, may increase the risk of radiocontrast-induced nephropathy.

• Ototoxicity:

  • Rapid IV administration is associated with ototoxicity. This can lead to severe renal impairment, hyperproteinemia, and concurrent use of other toxic substances.

• Photosensitivity

  • Photosensitization can occur.

• Allergy to sulfonamide ("sulfa")

  • Patients should be aware that many drugs containing a chemical class of sulfonamides have a broad contraindication if there has been an adverse response on the authorised product labelling.
  • It is feasible for members of the same class to interact with one another (e.g., two antibiotics sulfonamides).
  • Crossreactivity concerns have been raised for compounds containing the sulfonamide structural.
  • A deeper understanding of allergy mechanisms shows that there is little chance of cross-reactivity between antibiotic and non-antibiotic sulfonamides.
  • With nonantibiotic sulfuramides, it is unlikely that anaphylaxis (cross-reaction) mechanisms resulting from antibody development will happen.
  • Type IV T-cell-mediated reactions, such maculopapular skin rash, are less well known but can't be fully ruled out at this time.
  • These classes are sometimes avoided by some clinicians in severe cases of reactions (Stevens Johnson syndrome/TEN).

• Thyroid effects:

  • Doses >80 mg can cause a temporary increase in thyroid hormone levels.

• Insufficiency of the adrenals:

  • Patients with primary adrenal dysfunction should avoid diuretics (Addison disease) for treatment of high blood pressure.
  • To treat hypertension, adjustment of glucocorticoid/mineralocorticoid therapy & the use of other antihypertensive agents is preferred (Bornstein 2016; Inder 2015).

• Cirrhosis

  • Avoid acid/base and electrolyte imbalances, which could lead to cirrhosis-related hepatic enzymephalopathy.
  • Correct electrolyte imbalances and acid/base imbalances if hepatic impairment is present before initiation.
  • When necessary, supplemental potassium and an aldosterone antagonist may be used to reduce hypokalemia and metabolic alkalosis.
  • It is important to monitor closely the progress of any therapy.

• Diabetes:

  • Take care when administering insulin to patients suffering from prediabetes and diabetes mellitus.
  • Possibly will have a shift in glucose regulation

• Prostatic hyperplasia/urinary restriction:

  • An increase in urine production, especially after the start of therapy, may result in urinary retention.

• Systemic lupus erythematosus (SLE):

  • SLE activation or exacerbation may occur.

Furosemide: Drug Interaction

Monitoring parameters:

• Examine I & O (inpatient setting) & weight daily.
• Blood pressure, orthostasis
• Serum electrolytes, renal function.
• Examine hearing with high doses or rapid IV administration

How to administer Furosemide (Lasix)?

• Parenteral:
  • May administer IM or IV.
  • Undiluted direct IV injections may be administered at a rate of 20-40 mg/min.
  • Max rate of administration for short-term intermittent infusion is 4 mg/min.
  • Exceeding this rate increases the risk of ototoxicity.
• P/O:
  • Administer on an empty stomach (Bard 2004).
  • If GI distress occurs, may administer with food or milk.
  • However, this may reduce diuretic efficacy.
• Note:
  • The sublingual route may be used, when IV or oral administration is not possible.
  • Place 1 tablet under tongue for at least 5 mins to allow for maximal absorption.
  • During disintegration time, patients should be advised not to swallow (Haegeli 2007).

Mechanism of action of Furosemide (Lasix):

• Primarily inhibits sodium & chloride reabsorption in the ascending loop Henle and proximal and distal renal tubules.
• This interferes with the chloride binding cotransport system, thereby causing the natriuretic effect of the drug (Rose 1991).

The onset of action:

• Diuresis:
  • Oral, sublingual (SL):
    • 30-60 mins.
  • IM:
    • 30 mins.
  • IV:
    • ~5 mins
  • Symptomatic improvement with acute pulmonary edema:
    • Within 15-20 mins; occurs prior to diuretic effect

Peak effect:

• P/O, SL:
• 1-2 hours.
• IV:
• 0.5 hours

Duration:

• P/O, SL:
  • 6-8 hours.
• IV:
  • 2 hours

Protein binding:

• 91%-99%.
• Primarily to albumin

Metabolism:

• Minimally hepatic

Bioavailability:

• Oral tablet:
  • 47%-64%.
• Oral solution:
  • 50%.
• SL administration of oral tablet:
  • ~60%.
  • Results of a small comparative study (n=11) showed bioavailability of SL administration of tablet was ~12% higher than oral administration of tablet (Haegeli 2007)

Half-life elimination:

• Normal renal function:
  • 0.5-2 hours.
• End-stage renal disease (ESRD):
  • 9 hours

Excretion:

• Urine (Oral: 50%, IV: 80%) within 24 hours.
• Feces (as unchanged drug).
• Nonrenal clearance prolonged in renal impairment

International Brands of Furosemide (Lasix):

• Lasix
• APO-Furosemide
• BIO-Furosemide
• Furosemide Special
• Lasix Oral
• Lasix Special
• MINT-Furosemide
• NTP-Furosemide
• PMS-Furosemide
• TEVA-Furosemide
• A Xi Ya
• A-Basedock
• Accent
• Ai Ge
• Akoset
• Anfuramide
• Aquarid
• Aquasin
• Arasemide
• Bondiur
• Busemida
• Dailix
• Daiteren F
• Depix
• Desal
• Dirine
• Disemide
• Diural
• Diuren
• Diuresal
• Diurin
• Diurmessel
• Diusemide
• Diuvar
• Edemid
• Edemin
• Errolon
• Femide 500
• Foliront
• Fretic
• Frusedan
• Frusema
• Frusid
• Fruside
• Frusovit
• Fulsix
• Fuluvamide
• Furanthril
• Furanturil
• Furetic
• Furide
• Furix
• FuroPuren
• Furolix
• Furomen
• Furomex
• Furomin
• Furon
• Furorese
• Furoretic
• Furose
• Furosedon
• Furosemid
• Furosemid Pharmavit
• Furosemid-ratiopharm
• Furosemide-Eurogenerics
• Furosemix
• Furosix
• Furovenir
• Fursemid
• Fursemid[inj.]
• Furusemide
• Fuseride
• Fusid
• Fusimex
• Fusix
• Glosix
• Impugan
• Indiurex
• Jufurix
• Katlex
• Kutrix
• Lafurex
• Lasilix
• Lasix
• Lasix Retard
• Lasix[inj.]
• Laveric
• Lowpston
• Luseck
• Maoread
• Naclex
• Nadis
• Nephron
• Odemase
• Odement
• Odemex
• Oedemex
• Pharmix
• Promedes
• Radisemide
• Radouna
• Rasitol
• Releef
• Retep
• Rosemide
• Rosis
• Roxemid
• Salinex
• Salurex
• Salurin
• Seguril
• Silax
• Sofudac
• Solax
• Synephron
• Trofurit
• Uremide
• Uresix
• Urex
• Urex Forte
• Urex-M
• Urimeg
• Urinal
• Usix
• Vusimide

Furosemide Brand Names in Pakistan: