Drugs used in pulmonary oedema (excess fluid in the lungs), caused by failure of the left VENTRICLE of the HEART. DIURETICS cause an increase in excretion of URINE, thus reducing the amount of fluid in the body. Intravenous administration of loop diuretics relieves patients’ breathlessness. They work by inhibiting resorption of fluid in the renal tubule loops of the KIDNEYS. Frusemide and bumetanide are commonly used loop diuretic drugs that act quickly and last for six hours, and thus can be given twice in 24 hours without disturbing the patient's sleep.