MANNITOL

MANNITOL (man'i-tole) Osmitrol Classifications: electrolytic and water balance agent; osmotic diuretic; Therapeutic: osmotic diuretic Pregnancy Category: C

Availability

5%, 10%, 15%, 20%, 25% injection

Action

In large doses, increases rate of electrolyte excretion by the kidney, particularly sodium, chloride, and potassium. Induces diuresis by raising osmotic pressure of glomerular filtrate, thereby inhibiting tubular reabsorption of water and solutes. Reduces elevated intraocular and cerebrospinal pressures by increasing plasma osmolality, thus inducing diffusion of water from these fluids back into plasma and extravascular space.

Therapeutic Effect

Parenteral osmotic diuretic that reduces intracranial pressure, cerebral edema, intraocular pressure, and promotes diuresis, thus preventing or treating oliguria.

Uses

To promote diuresis in prevention and treatment of oliguric phase of acute kidney failure following cardiovascular surgery, severe traumatic injury, surgery in presence of severe jaundice, hemolytic transfusion reaction. Also used to reduce elevated intraocular (IOP) and intracranial pressure (ICP), to measure glomerular filtration rate (GFR), to promote excretion of toxic substances, to relieve symptoms of pulmonary edema, and as irrigating solution in transurethral prostatic reaction to minimize hemolytic effects of water. Commercially available in combination with sorbitol for urogenital irrigation.

Contraindications

Anuria; severe renal failure with azotemia or increasing oliguria; marked pulmonary congestion or edema; severe CHF; metabolic edema; hypovolemia; organic CNS disease, intracranial bleeding; shock, severe dehydration, history of allergy; pregnancy (category C), lactation; concomitantly with blood.

Cautious Use

Older adult; electrolyte imbalance.

Route & Dosage

Acute Kidney Failure Adult: IV Test Dose 0.2 g/kg over 3–5 min Positive Response 30–50 mL of urine over next 2–3 h, may repeat test dose 1 time. If still negative, do not use. Treatment 50–100 g as 15–20% solution over 90 min to several hours Child: IV Test Dose 200 mg/kg (max: 12.5 g) over 3–5 min Positive Response Urine flow of 1 mL/kg/h for 1–2 h Maintenance 0.25–0.5 g/kg q4–6 h Edema, Ascites Adult: IV 100 g as a 10–20% solution over 2–6 h Elevated IOP or ICP Adult: IV 1.5–2 mg/kg as a 15–25% solution over 30–60 min Acute Chemical Toxicity Adult: IV 100–200 g depending on urine output Measurement of GFR Adult: IV 100 mL of 20% solution diluted with 180 mL NaCl injection infused at a rate of 20 mL/min

Administration

Intravenous Note: Verify correct IV concentration and rate of infusion for administration to infants, children with physician. PREPARE: IV Infusion: Give undiluted.   ADMINISTER: IV Infusion: Give a single dose over 30–90 min. Oliguria: A test dose is given to patients with marked oliguria to check adequacy of kidney function. Response is considered satisfactory if urine flow of at least 30–50 mL/h is produced over 2–3 h after drug administration; then rate is adjusted to maintain urine flow at 30–50 mL/h with a single dose usually being infused over ≥90 min. Concentrations higher than 15% have a greater tendency to crystallize. Use an administration set with an in-line IV filter when infusing concentrations of 15% or above.   INCOMPATIBILITIES Solution/additive: Furosemide, imipenem-cilastatin, meropenem, potassium chloride, sodium chloride, whole blood. Y-site: Cefepime, doxorubicin liposome, filgrastim.

• Store at 15°–30° C (59°–86° F) unless otherwise directed. Avoid freezing.

Adverse Effects (≥1%)

CNS: Headache, tremor, convulsions, dizziness, transient muscle rigidity. CV: Edema, CHF, angina-like pain, hypotension, hypertension, thrombophlebitis. Eye: Blurred vision. GI: Dry mouth, nausea, vomiting. Urogenital: Marked diuresis, urinary retention, nephrosis, uricosuria. Metabolic: Fluid and electrolyte imbalance, especially hyponatremia; dehydration, acidosis. Other: With extravasation (local edema, skin necrosis; chills, fever, allergic reactions).

Interactions

Drug: Increases urinary excretion of lithium, salicylates, barbiturates, imipramine, potassium.

Pharmacokinetics

Onset: 1–3 h diuresis; 30–60 min IOP; 15 min ICP. Duration: 4–6 h IOP; 3–8 h ICP. Distribution: Confined to extracellular space; does not cross blood–brain barrier except with very high plasma levels in the presence of acidosis. Metabolism: Small quantity metabolized to glycogen in liver. Elimination: Rapidly excreted by kidneys. Half-Life: 100 min.

Nursing Implications

Assessment & Drug Effects

• Take care to avoid extravasation. Observe injection site for signs of inflammation or edema.
• Lab tests: Monitor closely serum and urine electrolytes and kidney function during therapy.
• Measure I&O accurately and record to achieve proper fluid balance.
• Monitor vital signs closely. Report significant changes in BP and signs of CHF.
• Monitor for possible indications of fluid and electrolyte imbalance (e.g., thirst, muscle cramps or weakness, paresthesias, and signs of CHF).
• Be alert to the possibility that a rebound increase in ICP sometimes occurs about 12 h after drug administration. Patient may complain of headache or confusion.
• Take accurate daily weight.

Patient & Family Education

• Report any of the following: Thirst, muscle cramps or weakness, paresthesia, dyspnea, or headache.
• Family members should immediately report any evidence of confusion.

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Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; Canadian drug name; Prototype drug