Antidepressant Overdose

Question 1

Describe overdose of tricyclics?

Answer 1

• High mortality and morbidity
• Due to effects from:
  
  • Anti-cholinergic
  • Sodium channel blocking
  • α-adrenoreceptor blocking

Question 2

Describe the clinical effects of tricyclic poisoning?

Answer 2

• Anti-cholinergic effects
• VT, VF, heart block
• Hypotension from inappropriate vasodilation or impaired cardiac contractilty

Question 3

What is pictured here?

Answer 3

• Tricyclic poisoning ECG
  
  • Broad QRS due to impaired conduction

Question 4

Name some anticholinergic clinical features?

Answer 4

• Dry mucous membranes
• Flushed
• Tachycardia
• Delirium
• Myoclonus

Question 5

Describe the management of tricyclic poisoning?

Answer 5

• If patients presents within 1 hour:
  
  • Activated charcoal
• Continuous ECG monitoing
• Patients with ECG changes or acidosis:
  
  • IV Sodium bicarbonate
• Correct hypoxia and electrolytes
• Benzodiazepines for prolonged seizures

Question 6

The toxicity of which antidepressants can cause serotonin syndrome?

Answer 6

• SSRIs
• SSNRIs
  
  • More toxic in overdose

Question 7

Describe the clinical features and management of toxicity from SSRI antidepressants?

Answer 7

• N/V
• Insomnia
• Sinus tachycardia
• Arrythmias (rare)

SUPPORTIVE CARE ONLY

Question 8

Describe toxicity from SNRI antidepressants?

Answer 8

• Tachycardia
• Hypo/hypertension
• ECG changes more prominent
  
  • QRS and QT prolongation
• Hypoglycaemia

Question 9

Complications of toxicity from anti-cholinergic antidepressants?

Answer 9

Seizures

Question 10

Complications of toxicity from serotonin antidepressants?

Answer 10

• Seizures
• Rhabdomyolysis
• Metabolic acidosis