What are the guidelines for using mannitol (osmotic diuretic) if tampering is suspected?

Guidelines for Using Mannitol When Tampering is Suspected

If tampering of mannitol is suspected, the medication should be immediately discontinued, the container should be visually inspected for particulate matter, discoloration, or crystallization, and a new, properly sealed container should be used if administration is still indicated. 1

Visual Inspection and Container Integrity

When tampering is suspected:

• Inspect the container for damage and the solution for clarity 1
• Do not administer 25% mannitol if the fliptop vial seal is not intact 1
• Check for white flocculent precipitate which may form from contact with PVC surfaces 1
• Examine for crystallization, which can occur when mannitol is exposed to low temperatures 1

Administration Safety Measures

If a new container of mannitol is to be administered after suspected tampering:

• Use only for intravenous administration; never administer intramuscularly or subcutaneously 1
• When infusing 25% mannitol, the administration set should include a filter 1
• Do not infuse mannitol solution if crystals are present 1
• If crystals are observed, the container should be warmed to redissolve, then cooled to body temperature before administering 1

Proper Dosing and Administration

For intracranial pressure reduction:

• Adults: 0.25 to 2 g/kg body weight as a 15% to 25% solution administered over 30-60 minutes 2, 1
• Pediatric patients: 1 to 2 g/kg body weight or 30 to 60 g/m² body surface area over 30-60 minutes 1
• For small or debilitated patients: 500 mg/kg may be sufficient 1

Monitoring Requirements

When administering mannitol after suspected tampering, increased monitoring is essential:

• Carefully evaluate circulatory and renal reserve prior to and during administration 1
• Monitor fluid and electrolyte balance, particularly sodium and potassium 1
• Track body weight and total input/output 1
• Observe for evidence of reduced cerebral spinal fluid pressure within 15 minutes after starting infusion 1
• Monitor renal function closely during mannitol infusion due to risk of osmotic nephrosis and renal failure 1

Special Precautions

• Avoid concomitant administration of nephrotoxic drugs (e.g., aminoglycosides) or other diuretics with mannitol 1
• If urine output declines during mannitol infusion, suspend administration if necessary 1
• Mannitol should be administered carefully and is contraindicated in patients with oligoanuria 3
• Never add mannitol to whole blood for transfusion 1
• If blood must be given simultaneously, add at least 20 mEq of sodium chloride to each liter of mannitol solution to avoid pseudoagglutination 1

Documentation and Reporting

• Document the suspected tampering incident
• Report to pharmacy and appropriate regulatory authorities
• Save the remainder of the fluid for examination if deemed necessary 1
• Document all patient monitoring parameters and clinical response

Common Errors to Avoid

• Continuous infusion instead of bolus administration - a study from Nigeria found 42.9% of patients received non-bolus administration when bolus was indicated 4
• Overdosing - the same study found 20% of patients received excessive doses 4
• Improper concentration - some patients incorrectly received continuous 10% mannitol infusion 4
• Failure to recognize mannitol intoxication, which can present with hyponatremia and an elevated osmolal gap 5

Careful attention to these guidelines can help ensure patient safety when tampering of mannitol is suspected, minimizing the risk of serious adverse effects including renal failure, fluid and electrolyte imbalances, and central nervous system toxicity.