Chloral hydrate toxicity

Background

• Sedative-hypnotic used for insomnia
• Binds GABA-A receptor
• Active metabolite trichloroethanol (TCE)
• ‘Mickey Finn’ most commonly refers to a mixture of ethanol and chloral hydrate, aka a "knockout drink."

Pharmacokinetics

• Onset: 30-60 min
• Duration: 4-8 hr
• Half-Life: 5 mins (for chloral hydrate)
  • 8-11 hr (active metabolite)
• Metabolism: Hepatic metabolism
• Excretion: Mostly in urine; some feces
• Potential toxic dose
  • <6 years old: 50 mg/kg
  • Adults: 3-10g

Clinical Features

• Similar to barbiturates and hydrocarbons
• Neuro
  • Sedation, ataxia, coma
• GI
  • Erosive gastritis, UGIB, strictures
  • Hepatitis
  • Breath smells like pears
• Renal
  • Nephrotixicity, proteinuria
• CV
  • Hypotension
  • Myocardial depression
  • Tachydysrhythmias secondary to catecholamine hypersensitivity: Sinus tachycardia, PVCs, VT, VF, Torsades
• Resp
  • Resp depression, airway obstruction (from muscle relaxation)
  • Aspiration pneumonitis

Differential Diagnosis

Sedative/hypnotic toxicity

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

Diagnosis

Clinical

• EKG: Dysrhythmias
• CXR: Pneumonitis or pulmonary edema
• LFTs: monitor for hepatic injury
• BUN/Cr: monitor for renal injury
• Trop: Myocardial injury
• Consider endoscopy

Management

Generally supportive care

• Airway management
• BP monitoring
  • IVF. Try to avoid catecholaminergic pressors
• Monitor for dysrhythmias

• Decontamination not useful for isolated chloral hydrate ingestions due to rapidl absorption
• Assume corrosive GI injury until ruled out.

Disposition

• Asymptomatic
  • Observe for 4 hours
• Symptomatic
  • Admit for monitoring
  • GI: Endoscopy within 24 hrs
  • CV: Telemetry