Potassium Sparing Diuretics

Collecting duct

Potassium Sparing Diuretics

• These drugs give their effect by working is Collecting duct where they inhibits Na+ reabsorption and K+ secretion.

These are weak diuretics so mostly used in combination, because filtrate almost 90% reabsorbed before reached to collecting duct.

 

Machanism Of Action

Normally in collecting duct, there are Na+ Channel through which Na+ enter into cells which further transported into blood through Na+/K+ ATPase pump. Now, K+ get back to lumen in exchange of Na+ through k+ channel.

 When Potassium sparing diuretics Introduced they give their effects by following two michanism:

 i) Aldosterone autogonists.

 ii) Sodium channel inhibitors.

i) Aldosterone Antagonists

Aldosterone is an hormone which bind intracellularly and  increase reabsorption of Na+ and secretion  K+.

when these aldosterone antagonist introduces they inhibit the aldosterone by blocking intracellular receptors which further  decrease the reabsorption of Na+ and secretion of K+.

Uses -

• used in treatment of edema,cHF.

• Used to other Spare the potassium ions with other diurites agents.

 

ii) Sodium Channel inhibitors

These drugs give their action by blocking sodium channels results in decrease reabsorption.Thus and decreases Sodium potassium exchange retention of potassium