Mannitol acts as an osmotic diuretic, that is, it increases the volume of urine. To do so it does not act on a specific point of the kidney, but rather accumulates in the intercellular spaces causing the loss of water by the cells. The fluids thus accumulated are rapidly eliminated in the form of urine.


What is Mannitol?


The mannitol is used in case of acute renal failure to prevent or treat the reduction of urine production before it becomes irreversible.

It is also useful in cases of intracranial hypertension, spinal and brain masses, to reduce the pressure inside the eye (intraocular pressure), as well as to facilitate the elimination of toxic substances. It can finally be used to measure the activity of the kidneys.


How should Mannitol be taken?


Mannitol is mainly administered intravenously. Oral intake may in fact have a laxative effect. The doses administered will vary depending on age, weight and the individual’s clinical circumstances, but generally it is administered as infusion of 50-200 grams of active ingredient over of 24 hours.


Side effects associated with Mannitol


The possible side effects associated with the administration of mannitol may include:


  • Disorders of acid-base
  • Angina
  • Chills
  • Convulsions
  • Raised temperature
  • Phlebitis
  • Headache
  • Nausea
  • Tissue necrosis
  • Vision problems
  • Electrolyte problems
  • Reduction of pressure
  • Retention of urine
  • Congestive heart failure
  • Feeling faint
  • Tachycardia
  • Thrombosis
  • Vomiting


Contraindications and warnings associated with the use of Mannitol

The use of mannitol is contraindicated in the following cases:


  • No production of urine associated with severe kidney problems
  • Pulmonary congestion
  • Pulmonary edema
  • Cerebral hemorrhage in progress
  • Intracranial hemorrhage in progress
  • Severe dehydration
  • Hypersensitivity to the active substance


Mannitol must be used with caution in cases of:


  • Taking corticosteroids or corticotrophin drugs
  • Edemas
  • Pregnancy or breastfeeding
  • Severe renal impairment
  • Salt and water retention
  • Congestive heart failure