Barbiturate toxicity

Background

• Death most commonly due to respiratory arrest and cardiovascular collapse
• Assume severe poisoning if >10x hypnotic dose has been ingested

Clinical Features

Mild-moderate toxicity

• Resembles ETOH intoxication

Severe toxicity

• Respiratory depression
• Hypothermia
• Hypotension (decreased vascular tone)
• Coma, absence of corneal reflex

Differential Diagnosis

Sedative/hypnotic toxicity

• Toxic alcohols
  • Ethanol
  • Ethylene glycol
  • Methanol
  • Isopropyl alcohol
• Benzodiazepines
  • Flunitrazepam (Rohypnol)
• Gamma hydroxybutyrate (GHB)
• Barbiturates
• Opioids
  • Lomotil toxicity
• Chloral hydrate
• Absinthe

Management

1. Airway assessment and stabilization
   • Mechanical ventilation often required
2. Hypotension
   • IVF
   • Dopamine or norepinepherine
3. Hypothermia
   • Rewarming measures
4. GI Decontamination
   • Activated charcoal x1 if present within 1hr of ingestion
   • Multi-dose activated charcoal
     • Consider only if patient has ingested life-threatening amount of phenobarbital
     • Give 50-100gm PO initially; follow by 12.5-25gm PO q4hr
5. Urinary alkalinization
   • Less effective than multi-dose activated charcoal
6. Dialysis
   • Only effective for phenobarbital (long-acting barb)
   • Reserved for patients who are deteriorating despite aggressive supportive care

Disposition

• Consider discharge if improvement in neuro status / vital signs over 6-8hr
• Evidence of toxicity after 6hr requires admission

See Also

• Sedative/Hypnotic

References

Authors

Jordan Swartz, Ross Donaldson, Neil Young, Daniel Ostermayer, Claire