​Pharmacology - Spironolactone

​Pharmacology -  Spironolactone 
Restricts the reabsorption of salt in the distal nephron; its diuretic effect is only moderately effective.
K+ excretion is decreased as a result.

Method of Operation 
Being a competitive antagonist of aldosterone, it induces diuresis by inhibiting the generation of the aldosterone mediator that is ordinarily responsible for the accumulation of sodium. This is accomplished by activating the sodium channel that is located in the luminal membrane of the collecting tubule system.

Oral administration results in the production of the active metabolite canrenone, which has a plasma half-life of sixteen hours.
Although it has a shorter half-life, eplerenone does not have any active metabolites.

Use in Clinical Settings 
Treatment of hypertension using K+-losing diuretics (thiazides, loop diuretics) in order to reduce the amount of K+ that is lost.
The hyperaldosteronism of primary and secondary origin

Adverse Effects
Hyperchloraemic acidosis and hyperkalemia are synonyms. When used with eplerenone, the risk of developing gynecomastia is reduced.