High-ceiling loop diuretics

Potassium Sparing Diuretics. Triamterene and amiloride, potassium sparing diuretics, by themselves produce only slight antihypertensive effects. The main use is to prevent or to treat the hypokalemia induced by thiazide-type and high ceiling loop diuretics, such as furosemide and bumetanide. 

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. 

High-ceiling loop diuretics. Diuretics that cause a substantial diuresis, up to 20% of the filtered load of NaCl and water. Loop diuretics, such as furosemide, inhibit the re-absorbtion of sodium at the ascending loop, which leads to a retention of water in the urine. Other examples of high-ceihng loop diuretics include ethacrynic acid, torsemide and bumetanide. 

No interactions are expected at standard therapeutic doses. At higher doses or with long-term use, licorice may potentiate potassium depletion of high-ceiling loop diuretics and thiazide diuretics, stimulant laxatives (Mills and Bone 2005), and corticosteroids such as prednisolone (Cheng et al. 2004 De Smet 1993), and may potentiate the action of cardiac glycosides such as digoxin (Kelly 1990). 

High Ceiling fLoop Diuretics. The principal action of the loop diuretics is inhibition of sodium and chloride rcabsorption in the thick ascending limb of the loop of Henle. They can produce an excretion of 20 to 30% of the filtered sodium ion load. Most loop diuretics have a rapid onset of action, steep diuretic dose-response curves, and usually are short acting. 

Diuretics are needed to return to normal the expanded extracellular volume that other antihypertensive agents produce, such as fluid retention and blood volume expansion, via compensatory mechanisms of the body. The loss of efficacy of antihypertensive agents can be restored if a diuretic is used concomitandy. In the treatment of hypertension, high ceiling or loop diuretics, such as furosemide, ethacrynic acid, and bumetanide, are no more efficacious than the thiazide-type of diuretics. In fact, these agents cause more side effects, such as dehydration, metaboHc alkalosis, etc, and therefore, should not be used except in situations where rapid elimination of duid volume is cleady indicated. 

Loop diuretics include furosemide (frusemide), piretanide, and bumeta-nide. With oral administration, a strong diuresis occurs within 1 h but persists for only about 4 h. The effect is rapid, intense, and brief (high-ceiling diuresis). 

Furosemide has a general effect of the reabsorption of sodium and chloride throughout the tubule system especially in the loop of Henle and is also a high-ceiling diuretic because of its potent, prompt onset of action (5 minutes after i.v. administration, within 1 hour when taken orally). Its mode of action is to inhibit the Na /K /2 Cl" transport mechanism. This drug has been involved in... 

Schafer JA, Troutman SL, Andreoli TE (1974) Volume reabsorption, transepithelial potential differences, and ionic permeability properties in mammalian superficial proximal straight tubules. J Gen Physiol 64 582-607 Schlatter E, Greger R, Weidtke C (1983) Effect of high ceiling diuretics on active salt transport in the cortical thick ascending limb of Henle s loop of rabbit kidney. Correlation of chemical structure and inhibitory potency. Pfltigers Arch 396 210-217... 

Furosemide is the classic member of the group of so-called high-ceiling or loop diuretics, which can achieve a much greater peak diuresis than the thiazides. It is widely and frequently used both orally and parenterally over a wider dosage range than the thiazide diuretics, because its concentration-effect curve is steeper and because it is effective in patients with moderate renal insufficiency (creatinine clearance 5-25 ml/minute), in... 

Loop (high ceiling) diuretics 159 Benzothiadiazides or thiazide-type diuretics 163... 

All diuretics that act at site 2 arc equally efficacious and far more efficacious than diuretics that act at sites I. 3. or 4. As mentioned above, because of their site of action and efficacy, these agents are commonly referred to as loop and high-ceiling diuretics. ... 

Loop or High-Ceiling Diuretics Bumetanlde, U5P (Bumex, Generic)... 

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