Pharmacological Properties of Loop Diuretics and Their Clinical Effects

Edematous states caused by an excessesive extracellular fluid retention are major components of cardiovascular and renal disorders including chronic kidney disease, nephrotic syndrome, and heart failure. The use of diuretic drugs from various groups including loop duiretics are important means of pharmacological correction of these clinical conditions. Moreover, diuretics used to lower bood pressure as a part of antihypertensive treatment, reduce cardiovascular events. The response of patients to the dose of a diuretic is reflected by a sigmoid dose-response curve which can be affected by changes of sodium content in the body. Loop diuretics may fail to control salt and water retention despite the use of appropriate doses. The main reasons for loop diuretic resistance may be determined by further reduction of glomerular filtration rate and reduced peak concentration of loop diuretics in primary urine. Chronic treatment with loop diuretics can cause compensatory hyperthrophy of epithelial cells along the ascending limb of the loop of Henle and thus decrease of its diuretic effect. The principles of avoiding this phenomenon are the restriction of sodium intake, correction of doses, timing and frequency of drug administration, and use of combination diuretic therapy. Loop diuretic - related adverse events that involve uricaemia and ototoxicity also should be taken into consideration.