Digitalis Toxicity Protocol

Digitalis (Digoxin) toxic dose:

• 💊 Adults:
  Toxicity may occur at doses > 2 mg (acute) or with serum digoxin levels > 2.0 ng/mL.
  However, toxicity can occur even at lower levels in patients with:

  • Renal impairment
  • Hypokalemia / Hypomagnesemia / Hypercalcemia
  • Hypothyroidism
  • Advanced age

• 🧒 Children:
  Toxic dose ≈ > 0.1 mg/kg (100 µg/kg).

• ⚠️ Lethal dose:

  • Adults: around 10 mg or more.
  • Children: > 4 mg can be fatal.

Decontamination

• GL within 1 h of poisoning with atropine pre-treatment. If patient presented with vomiting no need for lavage
• NO Lavage in chronic toxicity without overdose
• Activated charcoal administration (1 g/kg of body weight every 2–4 hours for up to 4 doses and 1 dose in chronic)

* ABCD & supportive therapy (See later)

Indication of Fab Therapy

• Life threatening dysrhythmias (VT, VF, or atropine resistant symptomatic sinus bradycardia, or 2nd or 3rd degree HB)
• K > 5 mEq/L
• SDC ≥ 15 ng/mL at any time or ≥ 10 ng/mL 6h post-ingestion
• Acute ingestion of 10 mg of digoxin in adult or 4 mg in child

No. of vials = SDC (ng/mL) × Pt. weight (kg) / 100

Empiric therapy for acute poisoning: 10–20 vials

Empiric therapy for chronic poisoning: Adults: 3–6 vials, Children: 1–2 vials

Management

Supraventricular arrhythmias: phenytoin.

Bradyarrhythmias: Atropine (see later), Temporary transvenous pacemaker, Transthoracic pacing if unresponsive to atropine and no Fab available.

Ventricular arrhythmias: Phenytoin or Lidocaine, Magnesium sulfate, cardioversion, defibrillation for unstable VT/VF if no Fab. If no response → give Fab.

Supportive Therapy

• Atropine: 0.5 mg IV (0.02 mg/kg in child, min 0.1 mg). Repeat every 5 min if needed. Max 3 mg.
• Phenytoin: 100 mg/5 min IV (1.5 mg/kg in children), up to 1 g (adult) or 15 mg/kg (child). Continue PO maintenance 300–400 mg/day adults, 6–10 mg/kg/day children.
• Lidocaine: 1–1.5 mg/kg IV bolus, then infusion 1–4 mg/min adults or 30–50 μg/kg/min children.
• Magnesium sulfate: 2 g (20%) over 20 min; child 25–50 mg/kg (max 2 g). Maintenance 6–12 g/day with monitoring.
• Contraindicated in bradycardia, AV block, hypermagnesemia, renal failure.
• Hyperkalemia treatment: glucose, insulin, sodium bicarbonate if no Fab. (1 mEq/kg NaHCO₃, insulin 1 U/kg + 0.5–1 g/kg dextrose bolus).