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Loop Diuretic Pregnancy: §4.6: Results of animal work, in general, show no hazardous effect of furosemide in pregnancy. There is clinical evidence of safety of the drug in the third trimester of human pregnancy; however, furosemide crosses the placental barrier. It must not be given during pregnancy unless there are compelling medical reasons. Treatment during pregnancy requires monitoring of fetal growth. Breast-feeding: furosemide passes into breast milk and may inhibit lactation; women must not breastfeed if they are treated with furosemide. Fertility: no human data on the effect of furosemide on fertility are available.

Furosemide (Ascites / Cirrhosis)

Brand names: Lasix, Frusemide

Used in: Acute Kidney Injury

This is the use of furosemide, a loop diuretic, in managing fluid overload and ascites associated with cirrhosis, typically alongside the aldosterone antagonist spironolactone.

Adult dose

Dose: Adults (the label also covers children over 12 years) — oedema associated with cirrhosis of the liver: initially 40 mg daily in the morning; ordinarily a prompt diuresis ensues and the starting dose can then be maintained or even reduced. Maintenance dose is 20 mg daily or 40 mg on alternate days, increased in resistant oedema to 80 mg daily
Route: Oral (tablets) — this card does not cover the intravenous route
Frequency: Once daily in the morning (initial); maintenance 20 mg daily or 40 mg on alternate days
Pinned product: Furosemide 40 mg tablets — ORAL ONLY, so this card covers the oral route and does NOT cover the page's intravenous route. §4.1 verbatim: 'The treatment of oedema associated with congestive heart failure, cirrhosis of the liver, renal disease including nephrotic syndrome and pulmonary oedema.' — this covers oedema associated with cirrhosis of the liver, which is the label's wording for the page's use; the word 'ascites' does not appear in the retrieved sections. §4.2 verbatim: 'Adults and children over 12 years: Oedema : Initially 40mg daily in the morning; ordinarily a prompt diuresis ensues and the starting dose can then be maintained or even reduced. Diuresis lasts for approximately four hours following administration and hence the time of administration can be adjusted to suit the patient's requirements. Maintenance dose is 20mg daily or 40mg on alternate days, increased in resistant oedema to 80mg daily.' This is the label's GENERAL oedema posology: it prints no cirrhosis-specific or ascites-specific regimen and no maximum daily dose, so no maximum is given here. NOT IN THIS LABEL AND NOT STATED HERE: any combination regimen with spironolactone, any furosemide:spironolactone ratio, and any 160 mg/day ceiling. WARNING: §4.3 lists 'Concomitant potassium supplements or potassium sparing diuretics' and 'Pre-coma/coma associated with hepatic cirrhosis or encephalopathy' as contraindications (the retrieved text does not name spironolactone) — a clinician combining furosemide with another diuretic in cirrhosis must reconcile this with local guidance. Elderly: 'generally eliminated more slowly. The dosage should be titrated until the required response is achieved.' 'Dosage adjustment may be necessary in patients with hypoproteinaemia, liver congestion/dysfunction.' Children under 12 years: 'A more suitable dosage form should be used in this age group.' — Children: use a children's formulary. The label's hypertension posology (20-40 mg twice daily) is a different indication and is not this page's. Some sections of the product information we used were incomplete — check the full SPC.

Dose adjustments

Renal

No numeric renal dose adjustment is printed. §4.3 contraindicates anuria and impaired renal function (creatinine clearance below 30 mL/min per 1.73 m2 body surface area) and renal failure resulting from poisoning by nephrotoxic and/or hepatotoxic agents. §4.4: caution in impaired renal function and hepato-renal syndrome (monitoring required); hypoproteinaemia such as in nephrotic syndrome requires careful dose titration.

Hepatic

No numeric hepatic dose adjustment is printed. §4.2: dosage adjustment may be necessary in patients with hypoproteinaemia and liver congestion/dysfunction; §4.4: in moderate liver congestion dosage adjustment may be needed; caution in impaired hepatic function. §4.3: contraindicated in pre-coma/coma associated with hepatic cirrhosis or encephalopathy.

Dose independently re-sourced from UK Summary of Product Characteristics (SPC) via the eMC; US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — clinician-reviewed. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

  • Hypersensitivity to furosemide, any of its excipients, sulphonamides, sulphonamide derivatives/amiloride
  • Anuria and impaired renal function (creatinine clearance below 30 mL/min per 1.73 m2 body surface area), and renal failure resulting from poisoning by nephrotoxic and/or hepatotoxic agents
  • Electrolyte disturbances (severe hyponatraemia, severe hypokalaemia, hypovolaemia), dehydration and/or hypotension
  • Concomitant potassium supplements or potassium sparing diuretics
  • Pre-coma/coma associated with hepatic cirrhosis or encephalopathy
  • Addison's disease
  • Digitalis intoxication
  • Breast-feeding women
  • Patients with rare hereditary problems of galactose intolerance, total lactase deficiency or glucose-galactose malabsorption should not take this medicine (§4.4, lactose)

Side effects

  • Very common: dehydration, hyponatraemia, hypochloraemic metabolic alkalosis, hypocalcaemia, hypomagnesaemia (incidences of the last three are reduced by triamterene); nephrocalcinosis in infants; decreased blood pressure (if pronounced, may cause impaired concentration, light-headedness, headache, dizziness, drowsiness, weakness, disorders of vision, dry mouth, orthostatic intolerance)
  • Common: hypovolaemia, hypochloraemia
  • Uncommon: impaired glucose tolerance, hyperuricaemia, gout, reduced serum HDL-cholesterol, raised serum LDL-cholesterol and triglycerides, hyperglycaemia; visual disturbance, blurred vision, yellow vision; deafness (sometimes irreversible); orthostatic intolerance, cardiac arrhythmias, increased risk or persistence of patent ductus arteriosus in premature infants; hypotension; dry mouth, thirst, nausea, bowel motility disturbances, vomiting, diarrhoea, constipation; aplastic anaemia
  • Rare: bone marrow depression (necessitates withdrawal of treatment), eosinophilia, leucopenia; paraesthesia, confusion, headache, dizziness; tinnitus and reversible or irreversible hearing loss (particularly in renal failure and hypoproteinaemia); vasculitis, thrombosis, shock; acute pancreatitis (long-term treatment); pure intrahepatic cholestasis (jaundice), abnormal hepatic function; rash, pruritus, photosensitivity, toxic epidermal necrolysis; psychiatric disorder
  • Very rare: haemolytic anaemia, agranulocytosis, thrombocytopenia, vasculitis; tetany
  • Frequency not known: aggravated pre-existing metabolic alkalosis (in decompensated cirrhosis of the liver), fluid and electrolyte disturbances, dizziness, fainting and loss of consciousness (symptomatic hypotension), urticaria, erythema multiforme, purpura, exfoliative dermatitis and other allergic skin reactions
  • Note: §4.8 was cut off at the source-fetch limit part-way through the skin disorders, so this list is not complete — consult the full SPC

Interactions

  • ACE inhibitors — enhanced hypotensive effect; reduce the furosemide dose for at least three days, or stop it, before starting or increasing an ACE inhibitor (§4.5)
  • Angiotensin-II receptor antagonists, alpha-blockers, beta-blockers, MAOIs, tricyclic antidepressants and phenothiazines — enhanced hypotensive effect or postural hypotension (§4.5)
  • NSAIDs and other analgesics — increased risk of nephrotoxicity and antagonism of the diuretic effect (especially indomethacin and ketorolac); salicylate toxicity may be increased (§4.5)
  • Aminoglycosides, polymyxins, vancomycin — increased risk of ototoxicity; high-dose certain cephalosporins — impairment of renal function (§4.5)
  • Cardiac glycosides, amiodarone, disopyramide, flecainide, sotalol, amisulpride, sertindole, pimozide, atomoxetine — hypokalaemia from loop diuretics increases the risk of toxicity or ventricular arrhythmias (§4.5)
  • Potassium supplements or potassium-sparing diuretics — contraindicated (§4.3)
  • Phenytoin antagonises the effect of furosemide; carbamazepine — increased risk of hyponatraemia (§4.5)
  • Amphotericin — increased risk of hypokalaemia; ciclosporin — increased risk of nephrotoxicity and possibly hypermagnesaemia; cisplatin — increased ototoxic effects (§4.5)
  • Colestyramine and colestipol — administer 2 to 3 hours apart (§4.2)
  • Note: §4.5 was cut off at the source-fetch limit part-way through the cisplatin entry, so this list is not complete — consult the full SPC

Monitoring

  • Hypotension, hypovolaemia and acid-base disturbances should be corrected before furosemide is started (§4.4)
  • Serum electrolytes with replacement as appropriate; frequent BUN in the first few months of treatment, periodically thereafter (§4.4)
  • Serum creatinine and urea tend to rise; serum cholesterol and triglycerides may rise (§4.4)
  • Regular monitoring for blood dyscrasias — if they occur, stop furosemide immediately; also liver damage and idiosyncratic reactions (§4.4)
  • Impaired hepatic function and impaired renal function / hepato-renal syndrome — monitoring required (§4.4)
  • Hypoproteinaemia (e.g. nephrotic syndrome) — careful dose titration (reduced effect, increased risk of ototoxicity) (§4.4)
  • Diabetes mellitus — latent diabetes may become overt and insulin requirements may increase; discontinue before a glucose tolerance test (§4.4)
  • Premature infants — risk of nephrocalcinosis/nephrolithiasis: monitor renal function and perform renal ultrasonography (§4.4)
  • Pregnancy: treatment requires monitoring of fetal growth (§4.6)

Clinical monograph

How it works

Furosemide inhibits the sodium-potassium-chloride co-transporter in the thick ascending limb of the loop of Henle, producing a potent diuresis that helps mobilise ascitic and oedema fluid.

Prescribing in practice

  • In cirrhotic ascites furosemide is usually combined with spironolactone rather than used alone, and overly rapid diuresis must be avoided as it can precipitate hypovolaemia, renal impairment and hepatic encephalopathy.
  • It can cause hypokalaemia, hyponatraemia and metabolic alkalosis, which are particularly hazardous in liver disease and warrant close electrolyte surveillance.
  • Diuretics should be withheld if there is hyponatraemia, worsening renal function, tense or refractory ascites needing paracentesis, or clinical encephalopathy.

Monitoring

Monitor body weight, renal function and electrolytes regularly, titrating the diuretic to a controlled rate of weight loss rather than aggressive fluid removal.

Counselling the patient

  • You will be weighed regularly so the dose can be adjusted to remove fluid gradually and safely.
  • Report increasing confusion, drowsiness, severe thirst or cramps, as these may mean the dose needs changing.

Evidence & guidelines

Combined spironolactone and furosemide diuretic therapy is the established standard for managing cirrhotic ascites in national and international guidance.

Reference: EASL Cirrhosis Guidelines 2018; Baveno VII Consensus 2022; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Related

Curated clinical cross-links plus same-class fallbacks.

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