Spironolactone aldosterone ascites

Ascites. Patients with cirrhosis, especially fiver cirrhosis, very often develop ascites, ie, accumulation of fluid in the peritoneal cavity. This is the final event resulting from the hemodynamic disturbances in the systemic and splanchnic circulations that lead to sodium and water retention. When therapy with a low sodium diet fails, the dmg of choice for the treatment of ascites is furosemide, a high ceiling (loop) diuretic, or spironolactone, an aldosterone receptor antagonist/potassium-sparing diuretic. 

Cirrhosis is a high aldosterone state spironolactone is a direct aldosterone antagonist and a primary treatment for ascites. 

Diuretics are often required in addition to the sodium restriction described previously. Spironolactone and jurosemide form the basis of pharmacologic therapy for ascites. Spironolactone is an aldosterone antagonist and counteracts the effects of activation of the renin-angiotensin-aldosterone system. In hepatic disease not only is aldosterone production increased, but its half-life is prolonged because it is hepatically metabolized. Spironolactone acts to conserve the potassium that would be otherwise excreted because of elevated aldosterone levels. 

The diuretic effect of spironolactone develops fully only with continuous administration for several days. Two possible explanations are (1) the conversion of spironolactone into and accumulation of the more slowly eliminated metabolite canrenone (2) an inhibition of aldosterone-stimulated protein synthesis would become noticeable only if existing proteins had become nonfunctional and needed to be replaced by de novo synthesis. A particular adverse effect results from interference with gonadal hormones, as evidenced by the development of gynecomastia (enlargement of male breast). Clinical uses include conditions of increased aldosterone secretion, e.g., liver cirrhosis with ascites. 

When ascites and edema become severe, diuretic therapy can be very useful. However, cirrhotic patients are often resistant to loop diuretics because of decreased secretion of the drug into the tubular fluid and because of high aldosterone levels. In contrast, cirrhotic edema is unusually responsive to spironolactone and eplerenone. The combination of loop diuretics and an aldosterone receptor antagonist may be useful in some patients. 

Spironolactone, an aldosterone antagonist, is the drug of choice since secondary hyperaldosteronism often coexists in patients with hepatic ascites. Aldosterone is usually metabolised by the liver and is highly protein bound, therefore the free aldosterone levels are raised in cirrhosis. Spironolactone competes with aldosterone for receptor sites in the distal tubule, resulting in potassium retention and sodium and water loss. The initial dose of spironolactone is 100-200 mg and can be slowly increased according to response. There is a lag of 3-5 days between the beginning of spironolactone treatment and the onset of the natriuretic effect. 

Metoclopramide has been shown to significantly reduce spironolactone-induced diuresis in cirrhotic patients with ascites. When administered to patients with secondary hyperaldosteronism, metoclopramide significantly reduced urinary sodium excretion, with a corresponding increase in urinary potassium excretion and a significant increase in plasma aldosterone. This effect was not seen with domperidone. From this study it is recommended that metoclopramide is avoided during diuretic therapy in cirrhotic patients with ascites [15]. 

D Arienzo A, Ambrogio G, Di Siervi P, et al. (1985) A randomised comparison of metoclopramide and domperidone on plasma aldosterone concentration and on spironolactone-induced diuresis in ascitic cirrhotic patients. Hepatology 5 854-857. 

The findings and observations described in the literature as well as the convincing efficacy of the aldosterone antagonist spironolactone confirm the importance of the RAAS in the genesis of renal sodium retention and hence also in the formation of ascites. 

Rerez-Ayuso, RM., Arroyo, V, Rlanas, R., Gaya, J., Bory, F., Rimola, A., Rivera, F., Rodes, X Randomized comparative study of efficacy of furosemide versus spironolactone in nonazotemic cirrhosis with ascites. Relationship between the diuretic response and the activity of the renin-aldosterone system. Gastroenterology 1983 84 961 -968... 

As with other K+-sparing diuretics, spironolactone often is coadministered with thiazide or loop diuretics in the treatment of edema and hypertension. Such combinations result in increased mobilization of edema fluid while causing lesser perturbations of K+ homeostasis. Spironolactone is particularly useful in the treatment of primary hyperaldosteronism (adrenal adenomas or bilateral adrenal hyperplasia) and of refractory edema associated with secondary aldosteronism (cardiac failure, hepatic cirrhosis, nephrotic syndrome, and severe ascites). Spironolactone is considered the diuretic of choice in patients with hepatic cirrhosis. Added to standard therapy, spironolactone substantially reduces morbidity and mortality and ventricular arrhythmias in patients with heart failure. 

Spironolactone/hydrochlorothiazide is a diuretic combination. Spironolactone competitively inhibits aldosterone in distal tubules, resulting in increased excretion of sodium and water and decreased excretion of potassium. Hydrochlorothiazide increases chloride, sodium, and water excretion by interfering with transport of sodium ions across renal tubular epithelium. It is indicated in edematous conditions for patients with CHF, cirrhosis of the liver accompanied by edema or ascites, nephrotic syndrome, or essential hypertension. 

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