Management of Tricyclic Antidepressant Overdose

1. Check pulse, BP, level of coma, 12 lead ECG, arterial blood gases

2. Administer oxygen, establish IV access and start fluids

3. Intubate and ventilate if:

• Ingestion of > 10 mg/kg with impaired consciousness if < 2 hours since ingestion
• Any respiratory acidosis or failure
• Inability to protect airway

4. Decontaminate: Activated charcoal in water 1 g/kg

• All patients under 2 hours from ingestion.
• All patients who have intubation indicated in 3

5. Treat Complications

• a. Acidosis
  • i. Uncomplicated:
    • Sodium bicarbonate 1 mEq/kg bolus (or in adult 50 mEq bolus) and review
  • ii. Complicated by hypotension or QRS >120 msec:
    • Sodium bicarbonate 2 mEq/kg bolus

• b. Seizures
  • i. Diazepam 0. 1 mg/kg IV as needed. Phenobarbitone infusion (15 mg/kg IV) over 30 min if refractory
  • ii. Check the ECG and acid-base status

• c. Hypotension
  • i. If QRS < 100 milliseconds
    • 20 mL/kg normal saline stat
    • Feet up Trendelenburg position
  • ii. If QRS >120 msec:
    • Sodium bicarbonate 2 mEq/kg bolus repeated until QRS narrows or pH = 7. 55
    • Give fluid bolus if not already done
  • iii. Volume loading may require 3 to 5 litres in an adult, this is best done with central venous pressure monitoring
  • iv. Consider vasopressors

• d. Broad complex tachyarrhythmias
  • i. With detectable output
    • Sodium bicarbonate 2 mEq/kg bolus repeated until QRS narrows or pH = 7. 55
  • ii. With no output
    • Sodium Bicarbonate 3 – 6 mEq/kg bolus repeat until pH is 7. 55 or above
    • Standard but prolonged ACLS resuscitation, do not stop until you have a toxicology consultation
  • iii. Other measures
    • Consider magnesium
    • Overdrive pacing
    • Consider hypertonic saline*

• e. Broad complex bradyarrhythmias
  • i. With detectable output
    • Sodium bicarbonate 2 mEq/kg bolus repeated until QRS narrows or pH = 7. 55
  • ii. With no output
    • Sodium Bicarbonate 3 – 6 mEq/kg bolus repeat until pH is 7. 55 or above
    • Standard but prolonged ACLS resuscitation, do not stop until you have a toxicology consultation
  • iii. Other measures
    • Consider pacing or isoprenaline
    • Consider hypertonic saline*

Hypertonic Saline*

• Ensure you have achieved a pH of at least 7. 55
• Give 3 mEq of hypertonic saline as a bolus injection.
• The role of this treatment is not well defined. Note the clinical effects and report your findings