Name

mannitol (Osmitrol®)

Class

Osmotic Diuretic

Description/Mechanism

Because of mannitol’s osmotic properties, it promotes the movement of fluid from the intracellular into the extracellular space. In emergency care, mannitol is used in the treatment of closed head injury to decrease cerebral edema and intracranial pressure, and in the promotion of urinary excretion of toxic substances.

Onset

Diuretic effect: 1-3 hours

Reduction of ICP: 15 min

Duration

Diuretic effect: 4-6 hours

Reduction of ICP: 3-8 hours

Indications

Cerebral edema

Other causes of increased intracranial pressure (space occupying lesions)

Rhabdomyolyses (myoglobinuria)

Blood transfusion reactions

Contraindications

Severe hypotension

Intracerebral hemmorhage

Profound hypovolemia

Dehydration

Hyponatremia

Pulmonary edema

CHF

Adverse Reactions

Transient volume overload

Pulmonary edema

Renal failure

CHF

Hypotension (from excessive diuresis)

Sodium depletion

Drug Interactions

When given concurrently with digitalis glycosides, an increase in digitalis toxicity may develop

Supplied

250 and 500 ml of a 20% solution for IV infusion (200 mg/ml), 25% solution in 50 ml for slow IV push.

Dose/Administration

Adult

IV Infusion: 0.5 g/kg in a 20% solution over 20 minutes.

Pediatric

IV Infusion: 0.2 – 0.5 g/kg/dose over 30-60 minutes (maximum 1 g/kg/dose)

Special Consideration

Pregnancy Safety: Category C

Hyperventilation should be supplemented with mannitol.

Mannitol may crystalize at low temperatures (~7.8 C) and may need to be warmed in boiling water until clear (cool to body temperature before use).

In-line filter should always be used.

Effectiveness depends on large doses and an intact blood-brain barrier.

The use of mannitol and its dosages in emergency care are controversial.