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 associated with 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 with 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 patient wt) / 100
  • Chronic toxicity without severe signs
    • Give half the recommended dose
      • Otherwise may unmask the condition for which the patient is taking digoxin
  • Cardiac Arrest
    • 20 vials administered undiluted by IV bolus

See Also

References

Authors:

Ross Donaldson