DIURETIC RESISTANCE

Diuretics are agents that increase urine and solute excretion.

They maybe classified as,

High efficacy diuretics such as Loop diuretics like furosemide, bumetanide, piretanide, ethacrynic acid, torsemide, azosemide.

Moderate efficacy diuretics such as Thiazides like chlorothiazide, hydrochlorothiazide, polythiazide, bendroflumethazide, benzthiazide and Thiazide related agents like chlorthalidone, clopamide, indapamide, metolazone, xipamide.

Low efficacy diuretics such as Potassium sparing diuretics like triamterene, amiloride, spironolactone, eplerenone, Carbonic anhydrase inhibitors like acetazolamide, methazolamide, dorzolamide, Osmotic diuretics like mannitol, urea, glycerol and Methylxanthines like theophylline.

Newer agents such as Vasopressin antagonists like conivaptan, tolvaptan, lixivaptan and Sodium glucose cotransporter 2 inhibitors like dapagliflazin, canagliflazin.

Diuretic resistance may be described as the inability to reduce sodium levels in the plasma, even upon usage of full therapeutic dosage of diuretics.

There are multiple reasons causing diuretic resistance such as high sodium intake, reduction in diuretic absorption, scarce renal blood flow which lowers the amount of diuretic reaching the kidney.

Patients with nephrotic syndrome and chronic kidney disease are often refractory to diuretics.

MANAGEMENT OF DIURETIC RESISTANCE:

The following are measures to manage diuretic resistance:

• Upgrading to a high efficacy diuretic
• Selecting an appropriate combination for use
• Reduction in salt intake
• Avoid salt retention by timing the diuretic intake 30 to 60 minutes before taking food, which increases the renal diuretic level
• Avoiding NSAIDS, as they may cause salt and water retention, resulting in diuretic resistance.