Renal Pharmacology

The term diuretic describes a drug that increases urinary solute and water excretionExcretion thus affecting the extracellular volume status of the individual. In addition, they alter the excretion of other cations such as K + , H + , Ca +  + , and Mg +  + and anions such as Cl − , HCO3 − , and H2PO4 − , and uric acid. They thus have a significant effect on the body’s electrolyte balance. The diuretic effect largely depends on the volume of the extracellular fluid. Chronic diuretic administration to a patient with a fixed sodium intake produces «diuretic braking,» also known as post diuretic sodium retention, which describes avid sodium retention occurring in response to rapid diuresis. Increasing the dose of diuretic to counter this can be detrimental in patients. When you fail to initiate an adequate response to a diuretic, you would need addition or substitution from a different class of diuretic in order to obtain a response.