Diuretics and clinical application

Abstract

Diuretics refers to heterogeneous groups of drugs that affect increasing urine output, which are classified by target site of action along the nephron. Most inhibit sodium reabsorption by blocking sodium-transporting proteins. Other diuretics act in different mechanism; vaptans mainly inhibit water reabsorption, and osmotic diuretics exert an osmotic gradient to hold water and solvent within the tubular lumen. Physiologic response to diuretic therapy aiming to maintain volume status increases sodium reabsorption by nephron adaptation and neuro-hormonal activation. Thus, dietary salt restriction is required to maximize the diuretic effect. Moreover, many medical conditions cause an inappropriate diuretic response called diuretic resistance. In acute heart failure, loop diuretics, which are the most potent of diuretics, are recommended for decongestion with many strategies to achieve euvolemic status including increasing diuretic dosage, using intravenous administration and combining diuretics which is also known as sequential nephron blockage strategy. Diuretics are also used as anti-hypertensive medication by reducing salt and water retention. In acute kidney injury, diuretics failed to reduce mortality and the renal replacement therapy requirement. However, they still play a role in fluid management and can also be used to predict the prognosis. Moreover, the role of diuretics prescription in chronic kidney disease increases urine output, but not clearance, and delays the loss of residual urine patients with end stage kidney disease under incident dialysis. Nephrotic syndrome is the one of many conditions causing diuretic resistance due to hypoalbuminemia and albuminuria. Intravenous albumin co-administration improves the diuretics response among patients with nephrotic syndrome especially those with severe hypoalbuminemia. In conclusion, diuretics are commonly used in many conditions. Each group has different action mechanisms and pharmacokinetic properties. Understanding the pharmacology and clinical application provides clinicians insights when prescribing diuretics in an effective manner and minimizing adverse effects.