Mannitol

What is this medication for?

• Acute oliguric renal failure, ↓intraocular pressure (acute glaucoma), ↓intracranial pressure (cerebral edema/TBI), enhanced elimination of some toxins (aspirin, some barbiturates, bromides, ethylene glycol)

How is it given?

This medication is normally given by your veterinary team (in clinic or hospital).

• Always administer through an in-line 5-micron filter and ensure crystals are fully dissolved — mannitol tends to crystallize at room/cold temperature.

What if I miss a dose?

• Give it as soon as you remember — unless it is almost time for the next dose (then skip the missed one; never double up).
• Call your clinic if you miss more than one dose in a row.

Side effects — what should I watch for?

Effects listed as common in this handout

• Volume overload if oliguria persists (Significant risk)

Worth a phone call to your veterinarian

• Fluid/electrolyte imbalance (esp. hypernatremia) (Most severe concern)

⚠️ Contact your veterinarian or an emergency clinic IMMEDIATELY if you notice

• stomach/intestinal (nausea, vomiting), cardiovascular (pulmonary edema, CHF, unusually fast heart rate), CNS (dizziness, headache) (Reported)

Before starting (or refilling), tell your veterinarian if your pet:

• has or has had: Anuria secondary to renal disease, severe dehydration, severe pulmonary congestion/edema

• is pregnant, nursing, or used for breeding
• is taking any other medications, supplements, or flea/tick products, including:
  • Whole blood products
  • Lithium
  • Sotalol

Storage and handling

Discard unused portions once prepared. Crystals may form if chilled — warm to ~37°C and use an in-line 5-micron filter before administering.

Good to know

• Confirm the patient is not anuric and is adequately volume-replete before starting — mannitol given to a dehydrated or anuric patient can precipitate serious volume overload/electrolyte crisis.
• For traumatic brain injury/cerebral edema, rapid bolus administration is preferred over slow infusion to achieve the plasma-expanding/ICP-lowering effect.
• Always administer through an in-line 5-micron filter and ensure crystals are fully dissolved — mannitol tends to crystallize at room/cold temperature.