LASIX 40mg tablets contain furosemide, a potent diuretic (water pill). It is used to treat conditions like edema (fluid retention) caused by heart failure, liver disease, or kidney problems, as well as high blood pressure (hypertension). Furosemide works by helping the kidneys remove excess salt and water from the body, reducing swelling and lowering blood pressure. The 600-tablet packaging is intended for long-term use under medical supervision.