Loop diuretics nephrotic syndrome

Loop diuretics are the drugs of choice for the treatment of edematous patients with congestive heart failure, cirrhosis of the liver, and nephrotic syndrome. Excretion of Na is helpful only to the extent that some of the... 

Loop diuretics are used in the treatment of edema associated with CHF, cirrhosis of the liver, and renal disease, including the nephrotic syndrome. These drug s are particularly useful when a greater diuretic effect is desired. Furosemide is the drug of choice when a rapid diuresis is needed or if the patient has renal insufficiency. Furosemide and torsemide are also used to treat hypertension. Ethacrynic acid is also used for the short-term management of ascites caused by a malignancy, idiopathic edema, or lymphedema. 

Hypotonic hyponatremia with an increase in ECF is also known as dilutional hyponatremia. In this scenario, patients have an excess of total body sodium and TBW however, the excess in TBW is greater than the excess in total body sodium. Common causes include CHF, hepatic cirrhosis, and nephrotic syndrome. Treatment includes sodium and fluid restriction in conjunction with treatment of the underlying disorder—for example, salt and water restrictions are used in the setting of CHF along with loop diuretics, angiotensin-converting enzyme inhibitors, and spironolactone.15... 

Nephrotic syndrome (loop diuretic protein binding in tubule lumen)... 

Nephrotic syndrome is characterized by proteinuria and edema due to some form of glomerulonephritis. The resulting fall in plasma protein concentration decreases vascular volume, which leads to diminished renal blood flow. This in turn causes secondary aldosteronism characterized by Na and water retention and K+ depletion. Rigid control of dietary Na is essential. Therapy of the nephrotic syndrome using a thiazide (possibly with a K -sparing diuretic) to control the secondary aldosteronism, is a useful initial approach to treatment Since nephrotic edema is frequently more difficult to control than cardiac edema, it may be necessary to switch to a loop diuretic (and spironolactone) to obtain adequate diuresis. 

See Table 15-6. Potassium-sparing diuretics are most useful in states of mineralocorticoid excess or hyperaldosteronism (also called aldosteronism), due either to primary hypersecretion (Conn s syndrome, ectopic adrenocorticotropic hormone production) or secondary hyperaldosteronism (evoked by heart failure, hepatic cirrhosis, nephrotic syndrome, or other conditions associated with diminished effective intravascular volume). Use of diuretics such as thiazides or loop agents can cause or exacerbate volume contraction and may cause secondary hyperaldosteronism. In the setting of enhanced mineralocorticoid secretion and excessive delivery of Na+ to distal nephron sites, renal K+ wasting occurs. Potassium-sparing diuretics of either type may be used in this setting to blunt the K+ secretory response. 

Nephrotic syndrome. Thiazide or loop diuretics are used in the treatment of this kidney disorder that causes increased protein in the urine. 

Loop diuretics induce renal prostaglandin synthesis, and these prostaglandins participate in the renal actions of these drugs. NSAIDs (eg, indomethacin) can interfere with the actions of the loop diuretics by reducing prostaglandin synthesis in the kidney. This interference is minimal in otherwise normal subjects but may be significant in patients with nephrotic syndrome or hepatic cirrhosis. 

Acute renal failure, e.g. cuninoglycosides, cisplatin Nephrotic syndrome, e.g. penicillamine, gold, cap-topril (only at higher doses than now recommended) Chronic renal failure, e.g. NSAIDs Functional impairment, i.e. reduced ability to dilute and concentrate urine (lithium), potassium loss in urine (loop diuretics), acid-base imbalance (acetazolamide). 

Four children with the nephrotic syndrome developed transient hypercalciuria and intraluminal calcification in renal histopathological specimens without radiological evidence of renal calcification. These children were resistant to corticosteroids and were receiving furosemide plus albumin for the management of edema (10). This result stresses the pervasive effect of furosemide, and probably all loop diuretics, in increasing urinary calcium excretion, with resultant nephrocalcinosis. Whenever possible, steps should be taken to limit the hypercalciuric effect of loop diuretics. Such maneuvers could include limiting the sodium content of the diet and/or combining the loop diuretic with a thiazide diuretic. 

Patients with nephrotic syndrome commonly develop diuretic resistance. It is suggested that the impaired natriuretic response may be overcome by using higher doses to increase the delivery of free drug to the secretory site in the proximal nephron. Another approach is to use the combination of a loop diuretic with a distal diuretic. 

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. 

Diuretics are used widely for the treatment of hypertension, and controlled clinical trials demonstrating reduced morbidity and mortality have been conducted with N - CL symport (thiazides and thiazide-like diuretics) but not N -K+-2C1 symport inhibitors. Nonetheless, N+-K+-2CL symport inhibitors appear to lower blood pressure as effectively as N+-C1 symport inhibitors while causing smaller perturbations in the lipid profile. However, the short ehmination half-lives of loop diuretics render them less useful for hypertension than thiazide-type diuretics. The edema of nephrotic syndrome often is refractory to other classes of... 

Diuretics are used widely for the treatment of hypertension see Chapter 32), and loop diuretics appear to lower blood pressure as effectively as Na+-CL symporter inhibitors e.g., thiazides and thiazide-hke diuretics) while causing smaller perturbations in the Upid profile. However, the short elimination half-lives of loop diuretics render them less useful for hypertension than thiazide-type diuretics. The edema of nephrotic syndrome often is refractory to other classes of diuretics, and loop diuretics often are the only drugs capable of reducing the massive edema associated with this disease. Loop diuretics also are employed in the treatment of edema and ascites of hepatic cirrhosis however, care must be taken not to induce encephalopathy or hepatorenal syndrome. In patients with a drug overdose, loop diuretics can be used to induce a forced diuresis to facilitate more rapid renal elimination of the offending drug. Loop diuretics, combined with isotonic saline administration to prevent volume depletion, are used to treat hypercalcemia. Loop diuretics interfere with the kidney s capacity to produce a concentrated urine. Consequently, loop diuretics combined with hypertonic saline are useful for the treatment of hfe-threatening hyponatremia. Loop diuretics also are used to treat edema associated with chronic renal insufficiency. Most patients with ARE receive... 

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