Lasoride is a medication used to treat high blood pressure (hypertension) and heart failure. It is a combination of two active ingredients, furosemide and spironolactone. Furosemide is a diuretic that works by increasing urine output, which helps to reduce excess fluid in the body and lower blood pressure. Spironolactone is a potassium-sparing diuretic that works by preventing the loss of potassium in the urine, which can be a side effect of furosemide. Together, they help to reduce blood pressure and improve symptoms of heart failure. Lasoride 40/5mg tablets contain 40mg of furosemide and 5mg of spironolactone.