Description
Diuretics have wide clinical application, mainly in reducing blood pressure and oedema. They are
often classified according to their site of action: a) proximally acting (proximal convoluted tubule) e.g.
carbonic anhydrase inhibitor and mannitol, b) loop diuretics (ascending thick segment of the loop of
Henle) e.g. frusemide and bumetanide and c) distally acting (distal convoluted tubule and cortical
collecting ducts) e.g. thiazides and potassium-sparing diuretics. Differences in potency of the different
groups relates to the proportion of sodium reabsorbed at different sites in the nephron. Diuretics
use frequently gives rise to a variety of metabolic and electrolyte abnormalities (most of which are
reversible). Despite this they remain one of the most widely prescribed drugs in clinical practice.
