Lasix is known as the “water pill” it’s a diuretic administrated orally.(1) The active ingredient of Lasix is furosemide, but also includes a number of inactive ingredients including lactose monohydrate NF, magnesium stearate NF, starch NF, talc USP, and colloidal silicon dioxide NF. (1) The peak effects of furosemide are typically seen within the first hour of two after a dose of the medication. (1). Lasix is prescribed for individuals to treat edema that may arise from congestive heart failure, liver cirrhosis or renal disease. (1) In adults, furosemide may also be taken to treat hypertension itself.(1) Furosemide comes in 20, 40, and 80mg tablets as well as oral suspensions.(2) Furosemide is absorbed rapidly from oral suspension at 50 minutes, and from tablets at 87 minutes.(2) Food may slow down the absorption of the drug and alter the bioavalibitly.(1) Furosemide binds to plasma proteins, albumin being the main plasma protein that furosemide binds to, at 91-99%, and peak plasma concentrations increase with the increase of a single dose.(2) Furosemide is excreted through the urine and the remainder is excreted in the feces. (2) The half-life for furosemide is approximately 2 hours but the diuretic effects last 6-8 hours. (2)
Dosage Schedules and Routes of Administration
Furosemide is available in tablets, sublingual tablets, oral suspension, and intravenously. (2) The recommended schedule dose for adults for an initial dose is 20 to 80mg. (3) The same dose as well as higher doses may be administered 6 to 8 hours following the previous dose if needed. (2) When titrating doses it may be raised by 20 to 40mg but not within 6 to 8 hours after the initial dose, and this may continue until the desired results has been achieved. (2) A single strength may be administered once to twice daily as maintenance therapy. (3) For ease children are typically administered the oral suspension of furosemide. (2) Initial dosing of the medication is typically 2mg/kg body weight taken as a single dosage. (3) When being titrated the dosage can be increased by 1mg/kg to 2mg/kg but not within 6 to 8 hours of the initial dose. (2) There are no established maximum doses for the approved indications for adults but for children the maximum dose is 6mg/kg.(3) The elderly should be begin with very low dosing regimens and increase with careful monitoring.(1)
Mechanism of Action
Furosemide functions as a loop diuretic. Loop diuretics inhibit sodium and chloride reabsorption in the distal and the proximal tubules of the nephron and the loop of Henle.(2) Furosemide interferes with the binding site of chloride at the cotransport system of 1Na+, 1K+, 2Cl- which in turn increases the rate of delivery of the fluid in the tubules and electrolytes to the sites for secretion of hydrogen and potassium ions.(2) Thus the plasma volume difference increases aldosterone production and the high aldosterone levels promote sodium reabsorption at the...