Lasix (furosemide) is a loop diuretic (water pill) that prevents your body from absorbing too much salt. This allows the salt to instead be passed in your urine. Lasix is used to treat fluid retention (edema) in people with congestive heart failure, liver disease, or a kidney disorder such as nephrotic syndrome. Lasix is also used. Drug information on Lasix (furosemide), includes drug pictures, side effects, drug interactions, directions for use, symptoms of overdose, and what to avoid. Heaps the medication furosemide (Lasix), a day used to treat excessive worrying accumulation and swelling (sneezing) of the body caused by physician medication lasix tablets, cirrhosis, stunning kidney failure, and nephrotic syndrome.