Brand Name
Osmitrol, Resectisol
Class and Category
Chemical class: Hexahydroxy alcohol
Therapeutic class: Antiglaucoma, diagnostic agent,
osmotic diuretic, urinary irrigant
Pregnancy category: B
Indications and Dosages
To reduce intracranial or intraocular pressure
I.V. INFUSION
Adults and adolescents. 0.25 to 2 g/kg as 15% to 25%
solution given over 30 to 60 min. If used before eye surgery, 1.5 to 2 g/kg 60
to 90 min before procedure. Maximum: 6 g/kg daily.
DOSAGE ADJUSTMENT
For small or debilitated patients, dosage reduced to 0.5 g/kg.
To diagnose oliguria or inadequate renal function
I.V. INFUSION
Adults and adolescents. 200 mg/kg or 12.5 g as 15% to 20%
solution given over 3 to 5 min. Second dose given only if patient fails to
excrete 30 to 50 ml of urine in 2 to 3 hr. Drug discontinued if no response
after second dose. Or, 100 ml of 20% solution diluted in 180 ml normal saline
solution (forming 280 ml of 7.2% solution) and infused at 20 ml/min; followed by
measurement of urine output. Maximum: 6 g/kg daily.
To prevent oliguria or acute renal failure
I.V. INFUSION
Adults and adolescents. 50 to 100 g as 5% to 25%
solution. Maximum: 6 g/kg daily.
To treat oliguria
I.V. INFUSION
Adults and adolescents. 50 to 100 g as 15% to 25%
solution given over 90 min to several hr. Maximum: 6 g/kg daily.
To promote diuresis in drug toxicity
I.V. INFUSION
Adults and adolescents. Loading: 25 g.
Maintenance: Up to 200 g as 5% to 25% solution given
continuously to maintain urine output of 100 to 500 ml/hr with positive fluid
balance of 1 to 2 L. Maximum: 6 g/kg daily.
To promote diuresis in hemolytic transfusion reaction
I.V. INFUSION
Adults. 20 g given over 5 min and repeated if needed. Maximum: 6
g/kg daily.
To provide irrigation during transurethral resection of
prostate gland
IRRIGATION SOLUTION
Adults. 2.5% or 5% solution, as needed.
Route Onset
Peak Duration
I.V.* 1–3
hr Unknown Up to 8 hr
I.V.† 30–60
min Unknown 4–8 hr
I.V.‡ In
15 min Unknown 3–8 hr
Mechanism of Action
Elevates plasma osmolality, causing water to flow from tissues,
such as brain and eyes, and from CSF, into extracellular fluid, thereby
decreasing intracranial and intraocular pressure. As an osmotic diuretic,
mannitol increases the osmolarity of glomerular filtrate, which decreases water
reabsorption. This leads to increased excretion of water, sodium, chloride, and
toxic substances. As an irrigant, mannitol minimizes the hemolytic effects of
water used as an irrigant and reduces the movement of hemolyzed blood from the
urethra to the systemic circulation, which prevents hemoglobinemia and serious
renal complications.
Incompatibilities
Don’t administer mannitol through same I.V. line as blood or blood
products.
Contraindications
Active intracranial bleeding (except during craniotomy), anuria,
hepatic failure, hypersensitivity to mannitol or its components, pulmonary
edema, severe dehydration, severe heart failure, severe pulmonary congestion, severe
renal insufficiency
Interactions
DRUGS
digoxin: Increased risk of digitalis toxicity from hypokalemia
diuretics: Possibly increased therapeutic effects of
mannitol
Adverse Reactions
CNS: Chills, dizziness, fever, headache, seizures
CV: Chest pain, heart failure, hypertension, tachycardia,
thrombophlebitis
EENT: Blurred vision, dry mouth, rhinitis
GI: Diarrhea, nausea, thirst, vomiting
GU: Polyuria, urine retention
RESP: Pulmonary edema
SKIN: Extravasation with edema and tissue necrosis, rash, urticaria
Other: Dehydration, hyperkalemia, hypernatremia, hypervolemia,
hypokalemia, hyponatremia (dilutional), metabolic acidosis, water intoxication
Nursing Considerations
• If crystals form in mannitol solution exposed to low temperature,
place solution in hot-water bath to redissolve crystals.
• Use a 5-micron in-line filter when administering drug solution
of 15% or greater.
• During I.V. infusion of mannitol, monitor vital signs, central
venous pressure, and fluid intake and output every hour. Measure urine output
with indwelling urinary catheter, as appropriate.
• Check weight and monitor BUN and serum creatinine electrolyte
levels daily.
• Provide frequent mouth care to relieve thirst and dry mouth.
PATIENT TEACHING
• Inform patient that he may experience dry mouth and thirst
during mannitol therapy.
• Instruct patient to report chest pain, difficulty breathing, or
pain at I.V. site.
