Lasix (Furosemide) is a fast-acting loop diuretic. This drug contributes to a relatively strong and short-term diuretic effect. It is released in the dosages of 40 and 100 mg.


  • Edema in chronic congestive heart failure (if treatment with diuretics is necessary);
  • Swelling with chronic renal failure;
  • Swelling in pregnant women or during childbirth;
  • Edema with nephrotic syndrome (if treatment with diuretics is necessary);
  • Edema in liver diseases (if necessary, to supplement treatment with aldosterone antagonists);
  • Arterial hypertension.

Mode of administration and dosage

When prescribing Lasix, it is recommended to use its smallest doses sufficient to achieve the required therapeutic effect. Consult your physician to find out the right dosage of Lasix.

Side effects

The water-electrolyte and acid-base balance:

  • hyponatremia, hypochloremia, hypokalemia, hypomagnesemia, hypercalcemia, metabolic alkalosis, which can develop as either a gradual increase in electrolyte deficiency or massive electrolyte loss over a very short time, for example, in the case of high doses of furosemide in patients with normal renal function. Symptoms indicating the development of electrolyte and acid-base disorders may include headache, confusion, seizures, tetany, muscle weakness, cardiac arrhythmias, and dyspeptic disorders. Factors contributing to the development of electrolyte disturbances are underlying diseases (eg, cirrhosis of the liver or heart failure), concomitant therapy, and nutrition. In particular, vomiting and diarrhea may increase the risk of hypokalemia;
  • hypovolemia and dehydration (more often in elderly patients), which can result in hemoconcentration with a tendency to develop thrombosis.

The cardiovascular system:

an excessive decrease in blood pressure, which, especially in elderly patients, can manifest itself with the following symptoms: impaired concentration and reaction, feeling of “emptiness” in the head, feeling of pressure in the head, headache, dizziness, drowsiness, weakness, visual disturbances, dry mouth, violation of orthostatic regulation of blood circulation. Collapse, tachycardia, arrhythmias, and a decrease in circulating blood volume are possible.

The side of metabolism:

  • increased serum cholesterol and triglyceride levels; a transient increase in the level of creatinine and urea in the blood; an increase in serum uric acid concentration, which can cause or intensify the manifestations of gout;
  • decreased glucose tolerance (manifestation of latent diabetes mellitus).

The urinary system:

  • the appearance or intensification of symptoms due to partial obstruction of the urinary tract (for example, with prostatic hyperplasia, narrowing of the urethra);
  • rarely – interstitial nephritis;
  • nephrocalcinosis/nephrolithiasis in premature babies.

The digestive tract:

rarely – nausea, vomiting, diarrhea, isolated cases of intrahepatic cholestasis, increased levels of “liver” enzymes, acute pancreatitis.

The central nervous system, organ of hearing:

  • rarely – paresthesia;
  • in rare cases, hearing impairment, usually reversible, and/or tinnitus, especially in patients with renal insufficiency or hypoproteinemia (nephrotic syndrome).

The skin, allergic reactions:

  • rarely – allergic skin reactions: itching, urticaria, other types of rash or bullous skin lesions, polymorphic erythema, exfoliative dermatitis, purpura, fever, vasculitis, photosensitivity;
  • extremely rarely – severe anaphylactic or anaphylactoid reactions up to shock, which until now have been described only after intravenous administration.

The peripheral blood:

  • rarely – thrombocytopenia, eosinophilia;
  • in rare cases, leukopenia;
  • in some cases – agranulocytosis, aplastic anemia or hemolytic anemia.


  • in premature infants, the formation of calcium-containing kidney stones (nephrolithiasis) and the deposition of calcium salts in the renal parenchyma (nephrocalcinosis) is possible;
  • in premature babies, during the first weeks of life, furosemide may increase the risk of preserving the arterial duct;
  • with intramuscular injection, soreness at the injection site.


  • Renal failure with anuria not responding to the introduction of furosemide;
  • Hepatic precoma and coma;
  • Severe hypokalemia;
  • Severe hyponatremia;
  • Hypovolemia (with or without arterial hypotension) or dehydration;
  • Pronounced violations of the outflow of urine of any etiology (including unilateral urinary tract damage);
  • Pregnancy;
  • Hypersensitivity to the active substance or to any of the components of the drug;
  • Patients who are allergic to sulfonamides (sulfonamide antimicrobials or sulfonylureas) may develop cross-allergy to furosemide.

Take Lasix with caution in the following cases:

  • arterial hypotension;
  • conditions in which an excessive decrease in blood pressure is especially dangerous (stenosing lesions of the coronary and / or cerebral arteries);
  • acute myocardial infarction (increased risk of developing cardiogenic shock);
  • latent or manifest diabetes mellitus;
  • gout;
  • hepatorenal syndrome;
  • hypoproteinemia (for example, nephrotic syndrome, when it is possible to reduce the diuretic effect and increase the risk of developing the ototoxic effect of furosemide, therefore, the dose selection in such patients should be carried out with extreme caution);
  • violation of the urine outflow (hyperplasia of the prostate gland, narrowing of the urethra or hydronephrosis);
  • hearing loss;
  • pancreatitis, diarrhea;
  • a history of ventricular arrhythmia;
  • systemic lupus erythematosus.

Lasix during pregnancy and lactation

Lasix (Furosemide) crosses the placental barrier, so it should not be prescribed during pregnancy. If, for health reasons, Lasix is prescribed to pregnant women, then careful monitoring of the fetus is necessary. During breastfeeding, taking furosemide is contraindicated. Furosemide suppresses lactation.


The clinical picture of acute or chronic drug overdose depends mainly on the degree and consequences of fluid and electrolyte loss. Overdose can be manifested by hypovolemia, dehydration, hemoconcentration, cardiac arrhythmias and conduction disturbances (including atrioventricular block and ventricular fibrillation). Symptoms of these disorders are a decrease in blood pressure (up to the shock), acute renal failure, thrombosis, delusional state, flaccid paralysis, apathy and confusion.

Treatment is aimed at correcting clinically significant violations of the water-electrolyte and acid-base state under the control of serum electrolyte concentrations, indicators of the acid-base state, hematocrit, as well as preventing or treating possible severe complications developing on the background of these disorders.


Cardiac glycosides, drugs that cause prolongation of the QT interval – if electrolyte disturbances (hypokalemia or hypomagnesemia) develop on the background of the furosemide introduction, the toxic effect of cardiac glycosides and drugs that cause prolongation of the QT interval increases (the risk of rhythm disturbances increases).

Glucocorticosteroids, carbenoxolone, licorice preparations in large quantities, and prolonged use of laxatives when combined with furosemide increase the risk of hypokalemia.

Aminoglycosides – slowing the excretion of aminoglycosides by the kidneys when used simultaneously with furosemide and increasing the risk of developing ototoxic and nephrotoxic effects of aminoglycosides. For this reason, the use of this combination of drugs should be avoided except in cases where it is necessary for health reasons with dose adjustment.

Medications with nephrotoxic action – when combined with furosemide, the risk of developing their nephrotoxic action increases.

Cisplatin – when used simultaneously with furosemide, there is a risk of developing an ototoxic effect. In addition, in the case of the combined administration of cisplatin and Lasix at doses above 40 mg (with normal renal function), the risk of developing the nephrotoxic effect of cisplatin increases.

Non-steroidal anti-inflammatory drugs (NSAIDs), including acetylsalicylic acid, can reduce the diuretic effect of furosemide. In patients with hypovolemia and dehydration (including those taking furosemide), NSAIDs can cause the development of acute renal failure. Furosemide can enhance the toxic effect of salicylates.

Antihypertensive drugs, diuretics or other drugs that can lower blood pressure – when combined with furosemide provides a more pronounced hypotensive effect.