Changes

===Aldosterone Antagonists===

===Aldosterone Antagonists===

Without aldosterone the cells of the collecting duct are impermeable to sodium.  Therefore if you compete with aldosterone for its receptors you reduce the permeability of the cells to sodium and therefore more sodium and water is excreted.  As aldosterone causes the excretion of potassium and calcium from the tubules these two molecules are retained with these drugs.

Without [[Aldosterone]] the cells of the [[Collecting Duct - Anatomy & Physiology|collecting duct]] are impermeable to sodium.  Therefore if you compete with aldosterone for its receptors you reduce the permeability of the cells to sodium and therefore more sodium and water is excreted.  As aldosterone causes the excretion of potassium and calcium from the tubules these two molecules are retained with these drugs.

===Osmotic Diuretics===

===Osmotic Diuretics===

These are compounds which are filtered but not reabsorbed.  They increase the osmolarity of the fluid and therefore hold more water in the tubules.  However they require intravenous administration.  They mainly act on sites freely permeable to water - the proximal tubule, the descending limb of the loop of henle and the collecting ducts.  However they also reduce the sodium uptake as relatively sodium concentration drops in the lumen when they are present.

These are compounds which are filtered but not reabsorbed.  They increase the osmolarity of the fluid and therefore hold more water in the tubules.  However they require intravenous administration.  They mainly act on sites freely permeable to water - the proximal tubule, the descending limb of the loop of henle and the collecting ducts.  However they also reduce the sodium uptake as relatively sodium concentration drops in the lumen when they are present.