What is mannitol, and how does it work (mechanism of action)?

Mannitol is a naturally occurring substance that causes the body to lose water (diuresis) through osmosis. Mannitol promotes diuresis in kidneys by increasing the concentration of filtrates in the kidney and blocking reabsorption of water by kidney tubules. The FDA approved mannitol in June 1964.

What brand names are available for mannitol-injectable?


Is mannitol-injectable available as a generic drug?


Do I need a prescription for mannitol-injectable?


What are the side effects of mannitol?

Side effects of Mannitol are:


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What is the dosage for mannitol?


  • Prevention of acute renal railure (oliguria): 50 to100 g of mannitol given as 5%, 10%, or 15% solution depending on the patient's fluid requirements.
  • Treatment of oliguria: 100 g administered as a 15 or 20% solution.
  • Reduction of intracranial pressure and brain mass: 0.25 g/kg given every 6 to 8 hours.
  • Reduction of intraocular pressure: 1.5 to 2 g/kg body weight, as 15% to 25% solution administered over 30 to 60 minutes.
  • Adjunctive therapy for intoxications: Adults may receive a 5% to 25% solution for as long as urinary output remains high.

Which drugs or supplements interact with mannitol?

Mannitol should not be used with tobramycin, because mannitol increases tobramycin levels significantly through an unknown mechanism.

Is mannitol safe to take if I'm pregnant or breastfeeding?

There are no adequate studies done on mannitol to determine safe and effective use in pregnant women.

It is not known whether Mannitol enters breast milk; therefore, it is best to be cautious before using it in nursing mothers.

What else should I know about mannitol?

What preparations of mannitol-injectable are available?

Mannitol intravenous injections are available in following strengths and sizes: 5% and 10% in 1000 ml containers; 15% in 500 ml containers, 20% in 250 ml and 500 ml containers; and 25% in 50 ml flip-top vials.

How should I keep mannitol-injectable stored?

Store mannitol injections at room temperature between 20 C to 25 C (68 F to 77 F).


Mannitol (Osmitrol) is an injection medication used for diuresis for treatment and prevention of decreased urine production in acute kidney failure. Mannitol is also used to decrease intracranial pressure and brain mass with patients with swelling in the brain. Side effects, drug interactions, dosing, storage, and pregnancy safety information should be reviewed prior to administering this medication.

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Medically reviewed by John P. Cunha, DO, FACOEP; Board Certified Emergency Medicine


FDA Prescribing Information.