Furosemide passes into breast milk and may also partially reduce the amount of breast milk produced. Results are seen within the first two hours. Lasix usually is taken once a day in the morning and afternoon. Lasix comes as a tablet and liquid to take by mouth. Furosemide is a very strong diuretic which can cause water and salt depletion. Diuretics are drugs that cause the body to be depleted be sure to include foods high in potassium in your diet. If taken on an empty stomach.