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Mannitol (Systemic)

Medically reviewed on Nov 15, 2018


(MAN i tole)

Index Terms

  • D-Mannitol

Dosage Forms

Excipient information presented when available (limited, particularly for generics); consult specific product labeling. [DSC] = Discontinued product

Solution, Intravenous:

Osmitrol: 5% (1000 mL); 10% (500 mL); 15% (500 mL); 20% (250 mL, 500 mL)

Generic: 5% (1000 mL [DSC]); 10% (1000 mL [DSC]); 15% (500 mL [DSC]); 20% (250 mL, 500 mL); 25% (50 mL)

Solution, Intravenous [preservative free]:

Generic: 25% (50 mL)

Solution, Irrigation:

Resectisol: 5% (2000 mL)

Brand Names: U.S.

  • Osmitrol
  • Resectisol

Pharmacologic Category

  • Diuretic, Osmotic
  • Genitourinary Irrigant


Produces an osmotic diuresis by increasing the osmotic pressure of glomerular filtrate, which inhibits tubular reabsorption of water and electrolytes and increases urinary output . Mechanism of action in reduction of intracranial pressure (ICP) is less clear. However, it is thought that mannitol reduces ICP by reducing blood viscosity which transiently increases cerebral blood flow and oxygen transport and constricts pial arterioles. This in turn reduces cerebral blood volume and ICP. Furthermore, mannitol reduces ICP by withdrawing water from the brain parenchyma and excretes water in the urine (Allen 1998; BTF [Carney 2016]).


34.3 L; remains confined to extracellular space (except in extreme concentrations); does not penetrate the blood-brain barrier (generally, penetration is low)


Minimally hepatic to glycogen


Urine (~55% to 87% as unchanged drug)

Onset of Action

Diuresis: 1 to 3 hours; Reduction in intracranial pressure: ~15 to 30 minutes

Duration of Action

Reduction in intracranial pressure: 3 to 6 hours

Half-Life Elimination

0.25 to 1.7 hours; 6 to 36 hours in renal failure

Use: Labeled Indications

Injection: Reduction of increased intracranial pressure associated with cerebral edema; reduction of increased intraocular pressure; promoting urinary excretion of toxic substances

Note: Although FDA-labeled indications, the use of mannitol for the prevention of acute renal failure and/or promotion of diuresis is not routinely recommended (Kellum 2008).

Genitourinary irrigation solution: Irrigation in transurethral prostatic resection or other transurethral surgical procedures

Off Label Uses

Improve renal transplant function


Injection: Hypersensitivity to mannitol or any component of the formulation; severe renal disease (anuria); severe dehydration; active intracranial bleeding except during craniotomy; progressive heart failure, pulmonary congestion, or renal dysfunction after mannitol administration; severe pulmonary edema or congestion

Genitourinary irrigation solution: Anuria

Dosing: Adult

Intracranial pressure (ICP), cerebral edema, reduction (off-label dosing): IV: 0.25 to 1 g/kg/dose; may repeat every 6 to 8 hours as needed (BTF [Carney 2016]; Grape 2012). Some suggest maintaining serum osmolality <320 mOsm/kg (Rabinstein 2006). However, this value is routinely exceeded without ill effect. A better marker for mannitol toxicity may be the serum osmole gap (or osmolal gap) and the target is <18 to 20 (Erstad 2016; García-Morales 2004).

Intraocular pressure (IOP), reduction: IV: 1.5 to 2 g/kg administered over 30 to 60 minutes 1 to 1.5 hours prior to surgery

IOP (traumatic hyphema), reduction: IV: 1.5 g/kg administered over 45 minutes twice daily for IOP >35 mm Hg; may administer every 8 hours in patients with extremely high pressure (Crouch 1999)

Kidney transplant:

Donor: 12.5 g (with adequate hydration) prior to nephrectomy; may repeat (Morris 2008)

Recipient: 50 g before kidney revascularization (Sprung 2000; Tiggeler 1984; van Valenberg 1987; Weimar 1983)

Transurethral irrigation: Use 5% urogenital solution as required for irrigation.

Dosing: Geriatric

Refer to adult dosing. Consider initiation at lower end of dosing range.

Dosing: Pediatric

Intracranial pressure (ICP), reduction: Infants, Children, and Adolescents: IV: Usual range: 0.25 to 1 g/kg/dose infused over 20 to 30 minutes; repeat as needed to maintain serum osmolality <300 to 320 mOsm/kg (BTF [Carney 2016]; Hegenbarth 2008; Kochanek 2012). Note: The manufacturer’s labeling allows for higher single doses up to 2 g/kg/dose.

Intraocular pressure (IOP), reduction: Infants, Children, and Adolescents: IV: 1 to 2 g/kg/dose or 30 to 60 g/m2/dose infused over 30 to 60 minutes administered 1 to 1.5 hours prior to surgery

IOP (traumatic hyphema), reduction: Infants, Children, and Adolescents: IV: 1.5 g/kg administered over 45 minutes twice daily for IOP >35 mm Hg; may administer every 8 hours in patients with extremely high pressure (Crouch 1999)

Dosing: Renal Impairment

Contraindicated in severe renal impairment. Use caution in patients with underlying renal disease. May be used to reduce the incidence of acute tubular necrosis when administered prior to revascularization during kidney transplantation.

Dosing: Hepatic Impairment

No dosage adjustment necessary.


IV: Concentration and rate of administration depends on indication/severity, or may be adjusted to urine flow. For cerebral edema or elevated ICP, administer over 30 to 60 minutes. Inspect for crystals prior to administration. If crystals are present, redissolve by warming solution. Use filter-type administration set (≤5 micron) for infusion solutions containing mannitol ≥20% (WHO 2011). Do not administer with blood. Crenation and agglutination of red blood cells may occur if administered with whole blood.

Vesicant (at concentrations >5%); ensure proper catheter or needle position prior to and during IV infusion. Avoid extravasation of IV infusions.

Extravasation management: If extravasation occurs, stop infusion immediately and disconnect (leave needle/cannula in place); gently aspirate extravasated solution (do NOT flush the line); initiate hyaluronidase antidote; remove needle/cannula; apply dry cold compresses (Hurst 2004; Reynolds 2014); elevate extremity.

Hyaluronidase: Intradermal or SubQ: Inject a total of 1 to 1.7 mL (15 units/mL) as five separate 0.2 to 0.3 mL injections (using a 25-gauge needle) into area of extravasation at the leading edge in a clockwise manner (Reynolds 2014) or SubQ: Administer multiple 0.5 to 1 mL injections of a 15 units/mL solution around the periphery of the extravasation (Kumar 2003).

Irrigation: Administer using only the appropriate transurethral urologic instrumentation.


Injection: Should be stored at room temperature of 15°C to 30°C (59°F to 86°F); do not freeze. In concentrations ≥15%, crystallization may occur at low temperatures; do not use solutions that contain crystals. Heating in a hot water bath and vigorous shaking may be utilized for resolubilization. Cool solutions to body temperature before using.

Irrigation: Store at room temperature of 25°C (77°F); excursions permitted up to 40°C. Avoid excessive heat; do not warm above 150°F (66°C). Do not freeze.

Drug Interactions

Amikacin (Oral Inhalation): May enhance the nephrotoxic effect of Mannitol (Systemic). Avoid combination

Aminoglycosides: Mannitol (Systemic) may enhance the nephrotoxic effect of Aminoglycosides. Avoid combination

Diacerein: May enhance the therapeutic effect of Diuretics. Specifically, the risk for dehydration or hypokalemia may be increased. Monitor therapy

Opioid Analgesics: May enhance the adverse/toxic effect of Diuretics. Opioid Analgesics may diminish the therapeutic effect of Diuretics. Monitor therapy

Sodium Phosphates: Diuretics may enhance the nephrotoxic effect of Sodium Phosphates. Specifically, the risk of acute phosphate nephropathy may be enhanced. Management: Consider avoiding this combination by temporarily suspending treatment with diuretics, or seeking alternatives to oral sodium phosphate bowel preparation. If the combination cannot be avoided, hydrate adequately and monitor fluid and renal status. Consider therapy modification

Tobramycin (Oral Inhalation): Mannitol (Systemic) may enhance the nephrotoxic effect of Tobramycin (Oral Inhalation). Avoid combination

Adverse Reactions

Frequency not defined:

Cardiovascular: Chest pain, cardiac failure, hypertension, hypotension, local thrombophlebitis, peripheral edema, tachycardia

Central nervous system: Chills, dizziness, headache, seizure

Dermatologic: Bullous rash, urticaria

Endocrine & metabolic: Dehydration (secondary to rapid diuresis), dilutional hyponatremia, electrolyte disturbance (increased osmolar gap), fluid and electrolyte disturbance, hypovolemia (secondary to rapid diuresis), hyperglycemia, hyperkalemia (hyperosmolality-induced), hypernatremia, hypervolemia, metabolic acidosis (dilutional), water intoxication

Gastrointestinal: Nausea, vomiting, xerostomia

Genitourinary: Dysuria

Hypersensitivity: Hypersensitivity reaction

Local: Local pain

Ophthalmic: Blurred vision

Renal: Acute renal failure, tubular necrosis (adult dose: >200 g/day; serum osmolality >320 mOsm/L), polyuria

Respiratory: Pulmonary edema, rhinitis

Miscellaneous: Fever, tissue necrosis


Concerns related to adverse effects:

• Extravasation: Vesicant (at concentrations >5%); ensure proper catheter or needle position prior to and during IV infusion. Avoid extravasation of IV infusions.

• Fluid/electrolyte loss: Excess amounts can lead to profound diuresis with fluid and electrolyte loss; close medical supervision and dose evaluation are required. Watch for and correct electrolyte disturbances; adjust dose to avoid dehydration.

• Nephrotoxicity: May cause renal dysfunction especially with high doses; use caution in patients taking other nephrotoxic agents, with sepsis or preexisting renal disease. To minimize adverse renal effects, adjust to keep serum osmolality less than 320 mOsm/L. Discontinue if evidence of acute tubular necrosis.

Disease-related concerns:

• Cerebral edema: In patients being treated for cerebral edema, mannitol may accumulate in the brain (causing rebound increases in intracranial pressure) if circulating for long periods of time as with continuous infusion; intermittent boluses preferred. Cardiovascular status should also be evaluated; do not administer electrolyte-free mannitol solutions with blood. If hypotension occurs, monitor cerebral perfusion pressure to ensure adequate.

Other warnings/precautions:

• Adequate renal function: Should not be administered until adequacy of renal function and urine flow is established; use 1 to 2 test doses to assess renal response.

Monitoring Parameters

Renal function, daily fluid I & O, serum electrolytes, serum and urine osmolality. Monitor infusion site.

For treatment of elevated intracranial pressure, some suggest maintaining serum osmolality <320 mOsm/kg due to the potential risk of acute renal tubular damage (Grape 2012; Rabenstein 2006). However, this value is routinely exceeded without ill effect. A better marker for mannitol toxicity may be the serum osmole gap and the target used by most clinicians is <18 to 20 (Erstad 2016; García-Morales 2004).

Pregnancy Risk Factor


Pregnancy Considerations

Reproduction studies have not been conducted.

Patient Education

• Discuss specific use of drug and side effects with patient as it relates to treatment. (HCAHPS: During this hospital stay, were you given any medicine that you had not taken before? Before giving you any new medicine, how often did hospital staff tell you what the medicine was for? How often did hospital staff describe possible side effects in a way you could understand?)

• Patient may experience rhinorrhea, nausea, or vomiting. Have patient report immediately to prescriber shortness of breath, severe dizziness, passing out, severe headache, excessive weight gain, swelling in the arms or legs, angina, tachycardia, signs of fluid and electrolyte problems (mood changes, confusion, muscle pain or weakness, abnormal heartbeat, severe dizziness, passing out, tachycardia, increased thirst, seizures, loss of strength and energy, lack of appetite, urinary retention or change in amount of urine passed, dry mouth, dry eyes, or nausea or vomiting), signs of skin infection, vision changes, severe edema, chills, injection site edema, pain, skin breakdown, or irritation (HCAHPS).

• Educate patient about signs of a significant reaction (eg, wheezing; chest tightness; fever; itching; bad cough; blue skin color; seizures; or swelling of face, lips, tongue, or throat). Note: This is not a comprehensive list of all side effects. Patient should consult prescriber for additional questions.

Intended Use and Disclaimer: Should not be printed and given to patients. This information is intended to serve as a concise initial reference for healthcare professionals to use when discussing medications with a patient. You must ultimately rely on your own discretion, experience and judgment in diagnosing, treating and advising patients.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.