Hyperaldosteronism, diuretic therapy

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]. 

Hypokalaemia during diuretic therapy is also more likely in hyperaldosteronism, whether primary or more conunonly secondary to severe liver disease, congestive cardiac failure or nephrotic syndrome. 

One complication of long-term diuretic therapy in otherwise healthy individuals is edema, and it has been suggested that surreptitious use of diuretics can explain some otherwise paradoxical cases of idiopathic edema presumably the diuretic induces a persistent increase in plasma renin activity and secondary hyperaldosteronism, and attempts to stop the diuretic intake can at first actually aggravate the condition (127). However, three studies have furnished strong evidence that diuretic abuse is not an important cause of idiopathic edema (128-130). 

Hypokalemia is common in the patient with liver failure who has normal renal function. Poor nutritional intake and vomiting may initiate this disorder. Severe vomiting may lead to volume contraction metabolic alkalosis, with increased renal excretion of potassium. Secondary hyperaldosteronism, seen in the liver failure patient with intravascular depletion, also increases renal excretion of potassium. Loop diuretic therapy causes increased renal excretion of potassium, whereas diarrhea from lactulose therapy increases fecal excretion of potassium. All these conditions can lead to profound hypokalemia. Therefore, potassium requirements in the liver failure patient receiving specialized nutritional support often are increased substantially. 

However, resistance to loop diuretics can occur by various mechanisms (36). These include poor adherence to therapy, poor absorption, progressive worsening of heart failure, excess volume loss, renal insufficiency, secondary hyperaldosteronism, and hypertrophy of the tubular cells of the distal nephron. Resistance due to inadequate drug absorption—either its speed or extent—is common with furosemide, which is poorly absorbed (34). Once recognized, this hurdle to response can be overcome by using loop diuretics that are predictably well absorbed, such as bumetanide and torasemide or by giving intravenous furosemide (37). 

Like all diuretics, the thiazides can cause electrolyte abnormalities, such as hypokalemia and hyponatremia, and dehydration. These complications are uncommon in patients with uncomplicated hypertension, but are more common in patients with heart failure or decompensated hepatic cirrhosis with secondary hyperaldosteronism. Until a patient is accustomed to the effect of a diuretic, dizziness may be experienced. Serum lipid concentrations are slightly raised acutely and hyperglycemia can occur during long-term therapy. Rare effects are thrombocytopenia, rashes, drug fever, cholestatic jaundice, pancreatitis, and precipitation of hepatic... 

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. 

Triamterene is usually recommended in the treatment of oedema associated with nephrotic syndrome, cirrhosis of liver, and congestive heart failure. It has also been used for the control and management of idiopathic oedema, steroid-induced oedema, oedema caused by hyperaldosteronism and in such oedematus patients who fail to respond to other therapy. It is usually used in conjunction with other diuretics like thiazides. 

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