Lasix is a fast-acting diuretic derived from sulfonamide. It blocks the Na +, K +, Cl + ion transport system in the thick segment of the ascending limb of Henle’s loop. Its saluretic effect depends on how the drug enters the lumen of the renal tubules.


Lasix belongs to diuretic, natriuretic. It acts throughout the thick segment of the ascending limb of the Henle loop. It blocks the reabsorption of 15–20% of the filtered sodium ions. It is excreted into the lumen of the proximal renal tubules. It increases the excretion of bicarbonates, phosphates, calcium, magnesium, and potassium. It increases the pH of urine.

It provides secondary effects due to the release of intrarenal mediators and the redistribution of intrarenal blood flow. It quickly absorbed in any route of administration. The half-life is 0.5-1 hours. 88% is excreted by kidneys, 12% – bile. The diuretic effect is characterized by significant severity, short duration. It depends on the dose. After oral administration, it occurs within 15-30 minutes. It reaches a maximum effect is within 1-2 hours and lasts 6-8 hours. With intravenous injection, the effect manifests itself within 5 minutes, the peak is reached after 30 minutes, the duration – 2 hours.

During the period of action, the excretion of sodium ions increases significantly, but after its termination, the rate of excretion of sodium ions decreases below the initial level (the phenomenon of “rebound” or recoil). Lasix stimulates arginine-vasopressin and sympathetic systems, it reduces the level of an atrial natriuretic factor in plasma and causes vasoconstriction.

It is effective in heart failure (both acute and chronic), improves the functional class of heart failure because it reduces the filling pressure of the left ventricle. It reduces peripheral edema, congestion in the lungs, vascular pulmonary resistance. It remains effective at a low glomerular filtration rate; therefore, it is used to treat arterial hypertension in patients with renal failure.


  • Edema in chronic heart failure;
  • Arterial hypertension;
  • Pulmonary and brain edema;
  • Poisoning with various drugs and chemical compounds.


Applied orally before meals. The recommended single dose is 40-120 mg. The recommended daily dose is 500 mg. It is also used intravenously and intramuscularly. The dose selection is dependent on the severity of the disease and the observed effect.

Side effects

  • Hypotension;
  • Arrhythmia;
  • Dry mouth;
  • Nausea;
  • Vomiting;
  • Diarrhea;
  • Pancreatitis;
  • Hypovolemia;
  • Dehydration;
  • Hypokalemia;
  • Hyponatremia;
  • Hypochloraemia;
  • Metabolic alkalosis;
  • Hypocalcemia;
  • Hyperuricemia;
  • Dermatitis;
  • Hearing impairment;
  • Mild weakness;
  • Prostate adenoma;
  • Hypercholesterolemia;
  • Hypertriglyceridemia;
  • Decreased glucose tolerance;
  • Acute pancreatitis;
  • Allergic reactions (rash, fever, vasculitis, interstitial nephritis).


Lasix tablets 40 mg

Aminoglycosides, methacrylic acid and cisplatin increase ototoxicity (especially with impaired renal function). It increases the risk of kidney damage on the background of amphotericin B. When prescribing high doses of salicylates, the risk of developing salicylism, cardiac glycosides – hypokalemia and associated arrhythmia, corticosteroids – electrolyte imbalance increases.

It reduces the muscle relaxant activity of tubocurarine, potentiates the effect of succinylcholine. It reduces the renal clearance of lithium. Under furosemide influence, the effect of ACE inhibitors and antihypertensive agents, warfarin, diazoxide, theophylline increases, it decreases – antidiabetic drugs, norepinephrine. Sucralfate and indomethacin reduce effectiveness. Probenecid increases the concentration in the serum.


In the presence of ascites without peripheral edema, it is recommended to use Lasix in doses that provide additional diuresis in the amount of not over 700–900 ml/day in order to avoid the development of oliguria, azotemia and electrolyte metabolism disorders.

Long-term use can result in weakness, fatigue, decreased blood pressure and cardiac output, and excessive diuresis during myocardial infarction with congestion in the pulmonary circulation may contribute to the cardiogenic shock development.

A temporary withdrawal (for several days) is required before the appointment of ACE inhibitors. During the first months of therapy, it is recommended to control blood pressure, electrolytes (especially potassium), CO2, creatinine, urea nitrogen, uric acid, periodically determining the activity of liver enzymes, calcium and magnesium levels, glucose in the blood and urine (with diabetes).

If oliguria is maintained for 24 hours, furosemide should be discontinued.