Mannitol
Also known as: Osmitrol, Resectisol, Am-Vet Mannitol, Isotol, Manniject, Osmofundin, Mannitol IV
Mannitol is an emergency medication that must be administered by professional veterinary staff in a hospital setting where adequate monitoring can occur. Because it causes rapid shifts of fluid within the body, your pet's hydration status, electrolytes, and urine output will be closely monitored to ensure safety and effectiveness.
Dosage must be set by your veterinarian for your specific pet. Never give human medication or another pet’s prescription without veterinary guidance.
What it is used for
- Cerebral edema
- Oliguric renal failure
- Cerebral edema
- Oliguric renal failure
- Oliguric renal failure (not anuric)
- Oliguric renal failure (rehydrated, not fluid overloaded)
- Oliguric renal failure (fluid replete)
- Acute glaucoma
- Acute glaucoma (if latanoprost fails)
- Acute primary angle-closure glaucoma
- Increased CSF pressure/cerebral edema
- Increased CSF pressure (critical/deteriorating patient)
- Cerebral edema secondary to trauma
How it is given
Possible side effects
- Fluid and electrolyte imbalances (especially hypernatremia)
- Volume overload (if oliguria persists)
- Nausea and vomiting
- Pulmonary edema
- Congestive heart failure (CHF)
- Tachycardia
- Dizziness and headache (CNS effects)
- Fluid and electrolyte imbalances
- Circulatory overload (at high doses)
- Acidosis (at high doses)
- Thrombophlebitis
- Extravasation injury (oedema and skin necrosis)
- Diarrhoea (if administered orally)
- Acute renal failure (rare)
Cautions & contraindications
- Anuria secondary to renal disease
- Severe dehydration
- Severe pulmonary congestion or pulmonary edema
- Intracranial bleeding (unless during craniotomy - human label)
- Disrupted capillary membrane in the brain (can leak into interstitium and worsen edema)
- Severe pulmonary congestion
- Pulmonary oedema
- Intracranial haemorrhage (relative contraindication; labelled 'use with care' but commonly used in traumatic brain injury)
- **Important Warnings:** * **Halt therapy** if progressive heart failure, pulmonary congestion, or progressive renal failure/damage (increasing oliguria/azotemia) develops. * **Hydration:** Adequate fluid replacement must be administered to dehydrated animals *before* mannitol therapy begins. Use with caution in hypovolemic patients as it can enhance hypotension. * **Crystallization:** Crystals frequently form in solutions >15%. Be certain crystals are dissolved (by warming) before administering. An **in-line IV filter (5 micron)** is highly recommended. * **Blood Products:** Do not give with whole blood products unless at least 20 mEq/L of NaCl is added, otherwise pseudoagglutination may result. * **Glaucoma:** Relatively contraindicated for treating secondary glaucomas, as it may cross the damaged blood-aqueous barrier and increase IOP.
Drug interactions
- Lithium: Mannitol can increase the renal elimination of lithium
- Sotalol: Mannitol's effects on potassium and magnesium may increase the risk for QT prolongation
- Potassium-depleting diuretics: May exacerbate diuretic-induced hypokalaemia
- Beta-blockers: Concurrent use with potassium-depleting diuretics requires caution
- Ciclosporin: Nephrotoxicity has been described with concurrent use in humans
- Whole blood: Mannitol should never be added to whole blood for transfusion or given through the same IV set
- KCl or NaCl: Do not add to concentrated mannitol solutions (20% or 25%) as a precipitate may form
Frequently asked questions
What is Mannitol used for in pets?
Mannitol is an emergency medication that must be administered by professional veterinary staff in a hospital setting where adequate monitoring can occur. Because it causes rapid shifts of fluid within the body, your pet's hydration status, electrolytes, and urine output will be closely monitored to ensure safety and effectiveness.
Is Mannitol safe for my pet?
Dosage must be set by your veterinarian for your specific pet. Never give human medication or another pet’s prescription without veterinary guidance.
This article is for general education and is not a substitute for professional veterinary advice. If your pet is unwell, please consult a veterinarian.
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