mannitol
Brand: Osmitrol
Prototype Drug
Drug Class: osmotic diuretic
Drug Family: diuretic
Subclass: polyol osmotic agent
Organ Systems: renalcns
Mechanism of Action
Freely filtered but not reabsorbed; increases tubular osmolarity preventing water reabsorption; draws water from tissues into intravascular space reducing cerebral edema.
proximal tubule osmotic retention (prevents reabsorption)
Indications
- cerebral edema (increased ICP)
- oliguric renal failure (flush)
- acute hemolytic transfusion reaction (forced diuresis)
- rhabdomyolysis (forced diuresis)
Contraindications
- anuria
- severe dehydration
- pulmonary edema
- active intracranial bleeding
Adverse Effects
Common
- electrolyte disturbances
- dehydration
- increased intravascular volume (initial)
- headache
Serious
- severe hypovolemia
- acute pulmonary edema (from initial volume expansion)
- renal tubular damage (high doses)
Pharmacokinetics (ADME)
| Absorption | IV only |
| Distribution | intravascular initially then CSF distribution |
| Metabolism | not metabolized |
| Excretion | renal unchanged |
| Half-life | not applicable |
| Onset | immediate IV |
| Peak | immediate |
| Duration | minutes to hours |
| Protein Binding | low |
| Vd | extracellular |
Drug Interactions
| Drug / Agent | Mechanism | Severity |
|---|---|---|
| loop diuretics | additive diuresis; risk of severe dehydration | moderate |
Nursing Considerations
- Monitor serum osmolality (osmol gap target <320 mOsm/kg) and electrolytes
- Assess urine output: minimum 30-50 mL/hr during therapy
- Infuse via filter (crystallizes at low temperatures)
- Monitor ICP if placed for cerebral edema
- Avoid in patients with CHF (volume expansion worsens)
Clinical Pearls
- Initial volume expansion (draws water from cells) then sustained diuresis
- ICP reduction: draws water from brain tissue reducing cerebral edema; onset 15-30 minutes
Safety Profile
Pregnancy use-with-caution
Lactation avoid
Renal Adjustment Not required
Hepatic Adjustment Not required
TDM Not required
Concordance Terms
Cross-referenced clinical concepts — click any term to see all content where it appears.