Medical uses
Furosemide is primarily used  for the treatment of edema, but also in some cases of hypertension (where there is also kidney or heart impairment). It is often viewed as a first-line agent in most people with edema caused by congestive heart failure because of its anti-vasoconstrictor and diuretic effects. Compared with furosemide, however, torasemide (aka "torsemide") has been demonstrated to show improvements to heart failure symptoms, possibly lowering the rates of rehospitalisation associated with heart failure, with no difference in risk of death. Torsemide may also be safer than furosemide.Furosemide is also used for liver cirrhosis, kidney impairment, nephrotic syndrome, in adjunct therapy for swelling of the brain or lungs where rapid diuresis is required (IV injection), and in the management of severe hypercalcemia in combination with adequate rehydration. Kidney disease
In chronic kidney diseases with hypoalbuminemia, furosemide is used along with albumin to increase diuresis. It is also used along with albumin in nephrotic syndrome to reduce edema. Other information
Furosemide is mainly excreted by tubular secretion in the kidney. In kidney impairment, clearance is reduced, increasing the risk of adverse effects. Lower initial doses are recommended in older patients (to minimize side-effects) and high doses may be needed in kidney failure. It can also cause kidney damage; this is mainly by loss of excessive fluid (i.e., dehydration), and is usually reversible.Furosemide acts within 1 hour of oral administration (after IV injection, the peak effect is within 30 minutes).
Although it increases circulation to the kidneys, it does not help kidney function, and is not recommended for kidney disease.It is also used to treat congestive heart failure (pulmonary edema, pleural effusion, and/or ascites) in cats and dogs. It can also be used in an attempt to promote urine production in anuric or oliguric acute kidney failure. Horses
Furosemide is injected either intramuscularly or intravenously, usually 0.5-1.0 mg/kg twice/day, although less before a horse is raced. As with many diuretics, it can cause dehydration and electrolyte imbalance, including loss of potassium, calcium, sodium, and magnesium. Excessive use of furosemide will most likely lead to a metabolic alkalosis due to hypochloremia and hypokalemia. The drug should, therefore, not be used in horses that are dehydrated or experiencing kidney failure. It should be used with caution in horses with liver problems or electrolyte abnormalities. Overdose may lead to dehydration, change in drinking patterns and urination, seizures, gastrointestinal problems, kidney damage, lethargy, collapse, and coma. Furosemide should be used with caution when combined with corticosteroids (as this increases the risk of electrolyte imbalance), aminoglycoside antibiotics (increases risk of kidney or ear damage), and trimethoprim sulfa (causes decreased platelet count). It may also cause interactions with anesthetics, so its use should be related to the veterinarian if the animal is going into surgery, and it decreases the kidneys ability to excrete aspirin, so dosages will need to be adjusted if combined with that drug. Furosemide may increase the risk of digoxin toxicity due to hypokalemia.