Diuretics are medications that are used to stimulate the secretion of water and electrolytes from the kidneys by increasing the production of and excretion of urine (diuresis). They are used for treating hypertension, edematous states, in cases of hypervolemia and in cases where it is necessary to quickly remove waste and toxic substances from the body.


Depending on the mechanism of action of the diuretic drug, they can be divided into six main groups:


  • Thiazide diuretics: inhibiting the reabsorption of sodium and chloride in the renal tubules, causing a corresponding increase in potassium excretion (chlorothiazide and compounds with similar structures such as chlorthalidone, indapamide, metolazone, and mefruside);


  • Loop diuretics: these produce an intense dose-dependent diuresis of relatively short duration (furosemide, bumetanide, ethacrynic acid);


  • Diuretics that reduce the loss of potassium (amiloride, triamterene, aldosterone inhibitors);


  • Carbonic anhydrase inhibitors: used primarily to reduce intraocular pressure in glaucoma patients (acetazolamide, diclorofenamide);


  • Osmotic diuretics: they are used to reduce or prevent cerebral edema and to reduce intraocular pressure (mannitol, urea);


  • Mercurial diuretics (Mersalyl): these drugs are now of little importance from a therapeutic point of view;


How should diuretics be taken?


Diuretics are commercially available in the form of tablets or capsules to be taken orally or in the form of solutions for injection.

Diuretics should always be used under prescription and by strictly following the instructions of a doctor regarding the dosage and mode of application. Not doing so can reduce the absorption of the drug or render the treatment useless.


Contraindications and warnings associated with the use of diuretics

Side effects due to the consumption of diuretics vary by medication and dosage. However, the common side effects include the following:


  • Headache
  • Blurred vision
  • Diarrhea
  • Dizziness
  • Orthostatic hypotension

Moreover, in some cases these medications can cause potentially severe side effects such as dehydration or electrolyte imbalance, which are generally characterized by the following symptoms:


  • Nausea or vomiting
  • Weakness or fatigue
  • Weak pulse or irregular
  • Increased thirst
  • Dry mouth
  • Muscle cramps
  • Mood alterations
  • Mental confusion


In rare cases, diuretics can cause the appearance of blood in the urine or blood in the stool, increased susceptibility to bleeding and/or rashes.