Furosemide

Also known as: Lasix (brand), loop diuretic

Other

In plain English

Furosemide is a strong 'water pill' that helps the body get rid of extra fluid through the urine. It is used for swelling (edema) and fluid overload from heart failure, kidney disease, or liver disease, and sometimes for blood pressure. Because it can lower potassium and cause dehydration, doctors monitor labs and adjust the dose.

The science

Furosemide inhibits the Na-K-2Cl (NKCC2) cotransporter in the thick ascending limb of the loop of Henle, blocking reabsorption of sodium, chloride, potassium, calcium, and magnesium to produce brisk diuresis. It is FDA-approved for edema of heart failure, hepatic, and renal disease; oral bioavailability averages about 50% with a short (~1.5-2 hour) half-life, so twice-daily dosing is often needed.

References

• Huxel C et al., Furosemide, StatPearls (NCBI Bookshelf) 2023
• Khan TM et al., Loop Diuretics, StatPearls (NCBI Bookshelf) 2023