Mannitol
Classification
Osmotic diuretic
Indications
CCP: Reduction of intracranial pressure and cerebral edema
Contraindications
- Patients with well-established anuria as a result of severe renal disease and who do not respond to 2 test doses
- Severe pulmonary congestion or frank pulmonary edema
- Severe congestive heart failure
- Dehydration states
- Metabolic edema associated with capillary fragility or membrane permeability
- Progressive renal disease
Adult dosages
CCP: Reduction of intracranial pressure and cerebral edema
- 1.5-2 g/kg IV infused as a 15%, 20%, or 25% solution
- 0.25 g/kg IV not more frequently than every 6-8 hours
Pediatric Considerations And Dosing
CCP: Reduction of intracranial pressure and cerebral edema
- 2 g/kg IV infused as a 15% or 20% solution
How Supplied
Intravenous solution: 200 mg/mL in 500 mL bag of 20% solution
Mechanism Of Action
Mannitol increases extracellular fluid volume and dilutes extracellular stores of sodium, drawing water out of the cells into the plasma. Fluid shifts result in the reduction of cerebral edema and lowering of cerebrospinal fluid pressure.
Pharmacokinetics
Intravenous:
- CSF pressure reduced within 15 minutes
- Diuresis after 1-3 hours
- Intraocular pressure reduced within 30-60 minutes
Adverse Effects
Mannitol use may disturb other fluid and electrolyte balances
Overdose
Accumulation of mannitol caused by inadequate urinary output, or rapid adminsitration of large volumes, may result in the overexpansion of extracellular fluid and circulatory overload causing signs and symptoms of water intoxication. Overhydration may be corrected by hemodialysis or administration of a diuretic.
Warning And Precautions
There is a risk of serious electrolyte disturbances, which may be severe enough to alter the acid-base balance, or to depress respirations. Thiazides may be used if hypernatremia or hyperosmolality occurs.