Managing overdoses

Question 1

How do we manage the overdose of paracetamol?

What is an indication of poor prognosis?

How do we manage anaphylactoid reaction?

Answer 1

Often presents with no symptoms except for derranged LFTs

Treat with Acetylcysteine - Glutathione repleter

• <1 hour - activated charcoal, bloods, then treat
• <4 hours - wait for blood paracetamol levels at 4 hours then treat
• 4-15 hours - plot bloods on normogram and treat
• If staggered over 1 hour or unsure of time of overdose, then treat first and then get bloods
• Infusion over 1 hour

Poor prognosis: PT rising after day3 or >180 at any time, high bilirubin >70, metabolic acidosis, encephalopathy, raised lactate

Anaphylactoid reaction - reduce rate; give IV chlorophenamine

Question 2

What are the features of Aspirin (salicylate) overdose and how do we manage it?

Answer 2

• Panicked, fast breathing, tinnitus.
  
  • Respiratory alkalosis leading to metabilic acidosis, low glucose and low potassium
• Charcoal, Sodium bicarbonate, haemodialysis

Question 3

What are the features of TCA overdose and how do we manage it?

Answer 3

• Dilated pupila, hypertonia, hyperreflexia, Acidosis
  
  • Low BP, VT, prolonged QRS and QT (Na+ blockade)
• Charcoal, Sodium bicarbonate
  
  • NO haemodialysis

Question 4

What are the features of Opiate overdose and how do we manage it?

Answer 4

• Reduced resp rate, pinpoint pupils, low BP, increased HR, low temperature, piloerection, reduced tone/reflexes, rhabdomyolysis
• Naloxone - miu-opioid antagonist
  
  • Very short half life.
    
    • 400 micrograms IV, then continuous infusion of 60% of initial dose to resuscitate

Question 5

What are the features of benzo overdose and how do we manage it?

Answer 5

1. Reduced resp rate and reduced GCS
2. Flumazenil - only give if severe and certain its benzos

Question 6

What are the features of iron overdose and how do we manage it?

Answer 6

1. GI corrosion and multiorgan failure, Dark stools
2. Consider lavage, desferrioxamine - chelating agent

Question 7

What are the features of digoxin overdose and how do we manage it?

Answer 7

1. Nausea and vomiting, confusion, yellow-green vision, arrhythmias, gynaecomastia
2. Digibind - Ab fragment binding digoxin

Question 8

What are the features of methanol/glycol overdose and how do we manage it?

Answer 8

1. Fomepizole or Ethanol - competes with methanol

Question 9

What are the features of MAOI, SSRIs, Ecstasy, Amphetamine overdose and how do we manage it?

Answer 9

• Serotonin syndrome: Autonomic hyperactivity, change inmental state, neuromuscular excitability
• Cognitive effects:
  • Headache, agitation, hypomania, mental confusion. hallucinations, coma
• Autonomic
  
  • Shivering, sweating, hyperthermia, vasoconstriction, tachycardia, nausea, diarrhea
• Somatic effects:
  
  • Myoclonus (muscle twitching), hyperreflexia (manifested by clonus), tremor
• IV fluids, benzodiazepines