Digoxin immune fab

Background

• 1 Fab vial binds 0.5mg of digoxin
• Clinical improvement usually seen within 1hr
• May give as IV bolus in cardiac arrest; otherwise give over 30min

Indications

• Ventricular dysrhythmias
• Hemodynamically significant bradyarrhythmias unresponsive to standard therapy
• Hyperkalemia > 5.5 a/w toxic digoxin level or presumptive diagnosis of overdose
• Also consider for:
  • Pacemaker (may mask cardiac dysrhythmia)
  • Dig level > 10 in acute ingestion
  • Dig level > 4 in chronic ingestion
  • If adult acutely ingests > 10mg
  • If child acutely ingests > 4mg

Side Effects

• Withdrawal of dig effect:
  • CHF, A-fib w/ RVR
• Hypokalemia

How To Use

• Neither amount ingested nor digoxin level are known:
  • Adult dose
    • 10 vials over 30 min; repeat dose if clinical response is inadequate
  • Peds dose
    • 5 vials over 30 min; repeat dose if clinical response is inadequate
• Amount ingested is known but digoxin level is unknown
  • Calculate total body load (TBL)
    • TBL = Dose (in mg) ingested x 0.8
  • Calculate number of vials needed
    • Number of vials = TBL X 2 (round up to nearest whole number)
• Steady state digoxin level is known
  • Number of vials = (dig level (in ng/mL) X pt wt) / 100
• Chronic toxicity without severe signs
  • Give half the recommended dose
    • Otherwise may unmask the condition for which the pt is taking digoxin
• Cardiac Arrest
  • 20 vials administered undiluted by IV bolus

See Also

• Digoxin Toxicity