Kalium-sparing diuretics

Kalium-sparing diuretics act as aldosterone antagonists in the collection canal and in the lower part of the distal tubule. It can be a direct antagonism – for example, spironolactone acts as a blocker of the mineralocorticoid receptor. In contrast, e.g. amilorid inhibits transport to ionic channels in the luminal membrane, thus reducing sodium resorption. This also reduces the loss of potassium in the urine, as resorption of Na from the collection ducts creates a negative electrical potential in their lumen, which facilitates the secretion of K and H into the urine.

Representatives
The main representatives include:
 * spironolactone, and its active metabolite, kalium-canrenoate
 * amilorid

Indications
Increased mineralocorticoid influence due to primary or secondary aldosteronism. Secondary aldosteronism is a consequence of heartfailure, hepatic cirrhosis, nephrotical syndrome and the administration of thiazide and loop diuretics.

Side effects and toxicity

 * Hyperkalemia can also reach life-threatening levels. The risk of this complication is intensified if the kidneys are affected or with the simultaneous administration of drugs (beta-blockers, nonsteroidal antirheumatics or ACE inhibitors).
 * Hyperchloroemical metabolic acidosis can be provoked when inhibiting secretion H + under simultaneous K + secretion..
 * Gynekomastia – spironolactone.

Related articles

 * Diuretics
 * Renin-angiotensin-aldosterone system
 * Hypertension
 * Hypertensive crisis

Source


Cathegory:Patophysiology Cathegory:Cardiology Cathegory:Pharmacology Cathegory:Internal medicine Cathegory:Nephrology