NAME OF DRUG
digoxin immune Fab

CLASSIFICATION

Digoxin Antibody

ALTERNATE NAMES

DIGIBIND

 INDICATIONS

•  treatment of potentially life-threatening digoxin intoxication in the following situations:
  • serum digoxin level > 12.8 nmol/L in an acute ingestion OR
  • acute ingestion of > 10mg in an adult (4mg in a child) OR
  • serum potassium > 5.0 mmol/L in an acute ingestion OR
  • potentially life-threatening cardiotoxicity including severe ventricular dysrhythmias such as ventricular tachycardia or ventricular fibrillation, or progressive bradydysrhythmias such as severe sinus bradycardia, or second- or third-degree heart block not responsive to atropine

 RECONSTITUTION AND STABILITY

• refrigerate
• reconstitute each vial with 4mL sterile water by gentle mixing to provide a concentration of 38mg/4mL (9.5mg/mL)
• use reconstituted solution immediately
• reconstituted solution stable for only 4 hours in refrigerator
• use only saline solutions for dilution
• inspect vials for particulate matter prior to dilution; administer using a 0.22micron filter to remove any protein aggregates that may be present following reconstitution

 COMPATIBILITY

• compatible with normal saline

 ROUTES OF ADMINISTRATION

Administer using a 0.22micron filter

• IV direct - only if cardiac arrest is imminent
• IV intermittent - preferred route; administer dose in 50mL NS over 30 minutes

 VH & HSC ADMINISTRATION POLICY

DPIC Approval must be obtained prior to use (604-682-5050)

Continuous ECG monitoring required

D - Direct IV route restricted to physicians only

 DOSAGE

• varies according to amount of digoxin to be neutralized
• average adult dose is 10 vials (380mg)

Acute ingestion based on:

a) *known amount:

• each vial (38mg) DIGIBIND is capable of binding 500mcg of digoxin
• Dose (in # vials) = (total digoxin dose ingested (mg) x 0.8) / 0.5mg

b) *known post-distribution serum digoxin concentration: (only meaningful at least 8 hours post ingestion)

• Dose (in # vials) = (serum digoxin concentration (nmol/L) x 0.781 x weight (kg)) / 100

* if both amount and serum level known, calculate dose based on amount ingested

c) unknown amount:

• 10 vials (380 mg) IV over 30 minutes. If no response within one hour of completion of infusion, repeat an additional 10 vials (380 mg) - contact DPIC first.

Toxicity during chronic therapy:

• 3 vials (114 mg) IV over 30 minutes. If no response within one hour of completion of infusion, repeat an additional 3 vials (114 mg) - contact DPIC first.
• if known serum digoxin concentration - can use formula (b) as listed above

 POTENTIAL HAZARDS OF PARENTERAL ADMINISTRATION

• anaphylaxis, hypersensitivity or febrile reactions are rare
• rapid IV injection associated with increased risk of allergic reactions
• patients with a history of allergy, especially to antibiotics, papain, chymopapain or other papaya extracts, may have an increased risk for allergic reactions

 IMPORTANT IMPLICATIONS

• baseline potassium, calcium, magnesium, BUN and creatinine should be determined
• hyperkalemia and cardiac dysrhythmias begin to respond within 15-60 minutes, and complete resonse is usually noted within 4 hours
• monitor serum potassium levels closely (q2h x 3) as hypokalemia may occur
• serum digoxin levels should not be repeated until Digibind is eliminated (3-4 days normal renal function, > 1 weeks renal failue) due to interference with the digoxin assay
• patients with severe renal failure should be monitored for a prolonged period for possible recurrence of digoxin toxicity

Rev. Dec 2007