Chapter VIB - Potassium Disturbances Associated with the Use of Diuretics

Abstract

Publisher Summary Disturbances in the serum potassium concentration are some of the most common metabolic side effects associated with the use of diuretics. Those agents that act proximal to the collecting duct are associated with hypokalemia. The development of hypokalemia is primarily the result of diuretic-induced changes in extracellular fluid (ECF) volume, mineralocorticoid activity, and distal sodium delivery. These alterations lead to enhanced potassium excretion at sites distal to where the drug exerts its diuretic effect. Diuretics that act at the level of the collecting duct are associated with hyperkalemia and are commonly referred to as potassium sparing diuretics. These agents predispose to the development of hyperkalemia by disturbing potassium transport mechanisms localized in the collecting duct. This chapter reviews both the direct and the indirect mechanisms by which diuretics disturb normal potassium homeostasis. The clinical consequences of these disturbances are also discussed. To provide a better understanding of how diuretics lead to disturbances in the serum potassium concentration, a brief overview of renal potassium handling is also presented.