Diuretics in the treatment of hypertension. Part 2: loop diuretics and potassium-sparing agents.
BACKGROUND
Diuretics enhance the renal excretion of Na(+) and water due to a direct action at different tubular sites of the nephron where solute re-absorption occurs.


METHODS
This paper focuses on the mechanism of action, pharmacodynamics, antihypertensive effects, adverse effects, interactions and contraindications of loop diuretics and potassium-sparing agents (including mineralocorticoid receptor antagonists (MRAs) and epithelial Na(+) channel blockers).


CONCLUSIONS
Loop diuretics are less effective than thiazide diuretics in lowering blood pressure, so that their major use is in edematous patients with congestive heart failure (HF), cirrhosis with ascites and nephritic edema. MRAs represent a major advance in the treatment of resistant hypertension, primary and secondary hyperaldosteronism and in patients with systolic HF to reduce the risks of hospitalization and of premature death. Potassium-sparing diuretics when coadministered with diuretics (thiazides and loop diuretics) working at more proximal nephron locations reduce the risk of hypokalemia and hypomagnesemia and the risk of cardiac arrhythmias. At the end of the article, the basis for the combination of diuretics with other antihypertensive drugs to achieve blood pressure targets is presented.
Universidad Complutense, School of Medicine, Department of Pharmacology , Madrid , Spain.
Juan
J
Tamargo
Julian
J
Segura
Luis M
LM
Ruilope
D000959:Antihypertensive Agents / Q000627:therapeutic use*; D001794:Blood Pressure / Q000187:drug effects; D000075202:Contraindications; D004232:Diuretics / Q000627:therapeutic use*; D062865:Diuretics, Potassium Sparing / Q000627:therapeutic use*; D004347:Drug Interactions; D004359:Drug Therapy, Combination; D062686:Epithelial Sodium Channel Blockers / Q000627:therapeutic use; D006333:Heart Failure / Q000188:drug therapy; D006801:Humans; D006973:Hypertension / Q000188:drug therapy* / Q000503:physiopathology; D000451:Mineralocorticoid Receptor Antagonists / Q000627:therapeutic use; D049994:Sodium Potassium Chloride Symporter Inhibitors / Q000627:therapeutic use*
D000959:Antihypertensive Agents; D004232:Diuretics; D062865:Diuretics, Potassium Sparing; D062686:Epithelial Sodium Channel Blockers; D000451:Mineralocorticoid Receptor Antagonists; D049994:Sodium Potassium Chloride Symporter Inhibitors