Diuretics, Kidney Diseases Diuretics and TheirMechanisms of Action The many diuretics available for clinical use have different mechanisms of action and, therefore,
inhibit tubular reabsorption at different sites along the renal nephron.The general classes of diuretics
and their mechanisms of action are shown in Table 31-1.
Osmotic Diuretics Decrease Water Reabsorptionby Increasing Osmotic Pressure of Tubular Fluid Large volumes of urine are also formed in certain diseases associated with excess
solutes that fail to be reabsorbedfrom the tubular fluid. For example, when theblood glucose
concentration rises to high levels in diabetesmellitus, the increased filtered load of glucose into
thetubules exceeds their capacity to reabsorb glucose (i.e., exceeds their transport maximum for
glucose .
