Three low-efficacy (potassium-sparing) diuretics are:

They act in the late distal tubule and collecting duct, where only a small fraction of sodium is reabsorbed. Therefore, they produce weak natriuresis when used alone but help prevent potassium loss caused by loop or thiazide diuretics. Aldosterone antagonists such as spironolactone have low sodium-removing efficacy compared with other diuretics.