Abstract

Most patients with heart failure and oedema should be treated with thiazide diuretics, which are effective, cheap, safe and easy to use. However, in severe congestive cardiac failure and renal failure haemodynamic and perhaps hormonal disturbances cause salt and water retention which resists thiazide diuretics. Patients with acute pulmonary oedema need a rapid intense diuresis which a thiazide diuretic cannot provide. In these circumstances a drug is needed which can cause the excretion of a substantial fraction of filtered sodium.