Lasix is a loop diuretic. It violates the reabsorption of sodium and chlorine ions in the thick segment of the ascending part of Henle’s loop. Due to the increase in the sodium ions’ release, there is a secondary (mediated by osmotically bound water) enhanced excretion of water and an increase in the secretion of potassium ions in the distal part of the renal tubule. At the same time, the excretion of calcium and magnesium ions increases.

It has secondary effects due to the release of intrarenal mediators and the redistribution of intrarenal blood flow. There is no effect weakening against the background of the course of treatment.


  • Edema syndrome of various origins, incl. with chronic heart failure stage II-III, liver cirrhosis (portal hypertension syndrome), nephrotic syndrome.
  • Pulmonary edema, cardiac asthma, cerebral edema, eclampsia, forced diuresis, severe arterial hypertension, some forms of hypertensive crisis, hypercalcemia.


Set individually, depending on indications, clinical situation, patient’s age. In the course of treatment, the dosage regimen is adjusted depending on the magnitude of the diuretic response and the dynamics of the patient’s condition.

When administered orally, the initial dose for adults is 20-80 mg/day, then, if necessary, the dose is gradually increased to 600 mg/day. For children, a single dose is 1-2 mg/kg. The maximum oral dose for children is 6 mg/kg.

Side effects

  • The cardiovascular system: lowering blood pressure, orthostatic hypotension, collapse, tachycardia, arrhythmias, decreased volume resuscitation.
  • The central nervous system and peripheral nervous system: dizziness, headache, myasthenia gravis, cramps of the calf muscles (tetany), paresthesia, apathy, weakness, weakness, lethargy, drowsiness, confusion.
  • The senses: impaired vision and hearing.
  • The digestive system: decreased appetite, dry mouth, thirst, nausea, vomiting, constipation or diarrhea, cholestatic jaundice, pancreatitis (exacerbation).
  • The genitourinary system: oliguria, acute urinary retention (in patients with prostatic hypertrophy), interstitial nephritis, hematuria, decreased potency.
  • The hematopoietic system: leukopenia, thrombocytopenia, agranulocytosis, aplastic anemia.
  • The water and electrolyte metabolism: hypovolemia, dehydration (risk of thrombosis and thromboembolism), hypokalemia, hyponatremia, hypochloremia, hypocalcemia, hypomagnesemia, metabolic alkalosis.
  • The side of metabolism: hypovolemia, hypokalemia, hyponatremia, hypochloremia, hypokalemic metabolic alkalosis (as a consequence of these disorders – arterial hypotension, dizziness, dry mouth, thirst, arrhythmia, muscle weakness, convulsions), hyperuricemia (with possible exacerbation of gout).
  • Allergic reactions: purpura, urticaria, exfoliative dermatitis, exudative erythema multiforme, vasculitis, necrotizing angiitis, pruritus, chills, fever, photosensitivity, anaphylactic shock.


There are the following contraindication for Lasix application:

  • acute glomerulonephritis;
  • stenosis of the urethra;
  • obstruction of the urinary tract with a stone;
  • acute renal failure with anuria;
  • hypokalemia;
  • alkalosis;
  • precomatous conditions;
  • severe hepatic failure;
  • hepatic coma and precoma;
  • diabetic coma;
  • precomatous states;
  • hyperglycemic coma;
  • hypertrophic obstructive cardiomyopathy;
  • increased central venous pressure;
  • arterial hypotension;
  • acute myocardial infarction;
  • pancreatitis;
  • impaired water and electrolyte metabolism (hypovolemia, hyponatremia, hypokalemia, hypochloremia, hypocalcemia), hypomigiesaemia intoxication;
  • hypersensitivity to furosemide.

Pregnancy and lactation

During pregnancy, the use of furosemide is possible only for a short time and only if the intended benefit of therapy to the mother outweighs the potential risk to the fetus.

Since furosemide can be excreted in breast milk, and also suppress lactation, if necessary, breastfeeding should be discontinued.

Drug interactions

Simultaneous use with antibiotics of the aminoglycoside group (including gentamicin, tobramycin) provides an increase in nephro- and ototoxic action. Furosemide reduces the clearance of gentamicin and increases plasma concentrations of gentamicin and tobramycin.

The simultaneous use with beta-adrenergic agonists (including fenoterol, terbutaline, salbutamol) and with corticosteroids, provokes hypokalemia.

The simultaneous use with furosemide enhances the effects of non-depolarizing muscle relaxants.

The simultaneous use with indomethacin, other NSAIDs obtains a decrease in the diuretic effect is possible, apparently due to inhibition of the synthesis of prostaglandins in the kidneys and sodium retention in the body under the influence of indomethacin, which is a nonspecific COX inhibitor; decrease in antihypertensive action.

Also, get acquainted with other interactions. You doctor should inform you about this information.