Molecule

Drug Groups

approved; investigational

Description

Mannitol is an osmotic diuretic that is metabolically inert in humans and occurs naturally, as a sugar or sugar alcohol, in fruits and vegetables. Mannitol elevates blood plasma osmolality, resulting in enhanced flow of water from tissues, including the brain and cerebrospinal fluid, into interstitial fluid and plasma. As a result, cerebral edema, elevated intracranial pressure, and cerebrospinal fluid volume and pressure may be reduced. Mannitol may also be used for the promotion of diuresis before irreversible renal failure becomes established; the promotion of urinary excretion of toxic substances; as an Antiglaucoma agent; and as a renal function diagnostic aid.

Indication

Used for the promotion of diuresis before irreversible renal failure becomes established, the reduction of intracranial pressure, the treatment of cerebral edema, and the promotion of urinary excretion of toxic substances.

Pharmacology

Chemically, mannitol is an alcohol and a sugar, or a polyol; it is similar to xylitol or sorbitol. However, mannitol has a tendency to lose a hydrogen ion in aqueous solutions, which causes the solution to become acidic. For this reason, it is not uncommon to add a substance to adjust its pH, such as sodium bicarbonate. Mannitol is commonly used to increase urine production (diuretic). It is also used to treat or prevent medical conditions that are caused by an increase in body fluids/water (e.g., cerebral edema, glaucoma, kidney failure). Mannitol is frequently given along with other diuretics (e.g., furosemide, chlorothiazide) and/or IV fluid replacement.

Toxicity

LD₅₀=1700 mg/kg (rat oral)

Affected Organisms

Biotransformation

Mannitol is metabolized only slightly, if at all, to glycogen in the liver.

Absorption

Approximately 7% of ingested mannitol is absorbed during gastrointestinal perfusion in uremic patients.

Half Life

100 minutes

Protein Binding

None

Elimination

It is rapidly excreted in the urine.

References

External Links