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Image: “Water down the drain” by David Blackwell. License: CC BY 2.0
Overview of the Different Diuretics
The following table gives an overview of the different renal target structures as well as the achieved effects associated with them.
| Diuretics | Active substances | Renal target structure | Effect on the serum electrolytes | Drainage Effectiveness |
| Carbonic anhydrase inhibitors | Acetazolamide, dorzolamide, brinzolamide | Proximal tubule inhibition of the carbonic anhydrase | Decreased sodium and bicarbonate, increased protons
Possibly hypokalaemia, hyperglycaemia |
Not commonly used as a diuretic due to loss of electrolytes and bicarbonate |
| Loop diuretics | Furosemide, bumetanide, piretanide, torasemide | Thick ascending limb of the Henle loop, luminal Na-K-Cl-cotransporter, decreased reabsorption | Decreased Na, K, Cl, Ca, Mg, decreased reabsorption of H2O in the collecting duct system (due to the changed osmotic gradient), possible hyperglycaemia, hyperuricaemia | Most effective diuretic (20–30 % of the glomular filtrates) |
| Thiazide diuretics and thiazide analogues | Hydrochlorothiazide, chlorthalidone, mefruside, xipamide | Early distal inhibition of the Na-Cl-cotransporter, resulting in decreased NaCl reabsorption | Decreased Na, Cl, Mg, decreased K (as a lot of Na can be exchanged for K in the late distal tubule)
Increased Ca Possibly hyperglycaemia, hyperuricaemia |
Moderate effects (10–15 % of the glomular filtrates) |
| Potassium sparing diuretics | Amiloride, Triamterene | Late distal tubule and collecting duct system
Inhibition of sodium channels |
Decreased Na, increased K | Low effects (2–4 % of the glomular filtrates) |
| Aldosterone antagonists | Spironolactone, potassium canrenoate, eplerenone | Late distal tubule and collecting duct system
Competitive inhibition at the cytosolic mineralcorticoid receptor |
Decreased Na, increased K | Low effects (2–3 % of the glomular filtrates) |
| Osmotic diuretics | Mannitol, sorbitol | Unspecific effect in the whole tubule lumen osmodiuretically
Filtrated glomerularily and are not reabsorbed |
Possible increased Na | Low effects (2–3 % of the glomular filtrates) |
| Methylxanthines | Theophylline, theobromine, caffeine | Antagonist at the adenosine receptor (subtype A1), presumably inhibition of the basolateral Na-HCO3–cotransporter in the proximal tubule | Decreased Na and HCO3, increased H | Little usefulness as diuretic due to adverse effects |
