Metabolic alkalosis, hypokalemic loop diuretics causing

By inhibiting salt reabsorption in the TAL, loop diuretics increase delivery to the collecting duct. Increased delivery leads to increased secretion of K+ and H+ by the duct, causing hypokalemic metabolic alkalosis (Table 15-2). This toxicity is a function of the magnitude of the diuresis and can be reversed by K+ replacement and correction of hypovolemia. 

Toxicity Loop diuretics usually induce hypokalemic metabolic alkalosis. Because large amounts of sodium are presented to the collecting tubules, wasting of potassium (which is excreted by the kidney in an effort to conserve sodium) may be severe. Because they are so efficacious, the loop diuretics can cause hypovolemia and cardiovascular complications. Ototoxicity is an important toxic effect of the loop agents. The sulfonamides in this group may cause typical sulfonamide allergy. 

B. Effects In full doses, thiazides produce moderate but sustained sodium and chloride diuresis. Hypokalemic metabolic alkalosis may occur (Table 15-2). Reduction in the transport of sodium into the tubular cell reduces intracellular sodium and promotes sodium-calcium exchange. As a result, reabsorption of calcium from the urine is increased and urine calcium content is decreased— the opposite of the effect of loop diuretics. Because they act in a diluting segment of the nephron, thiazides may interfere with excretion of water and cause dHutional hyponatremia. 

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