Baclofen toxicity

Background

• Baclofen is a synthetic derivative of GABA that can be used for conditions such as multiple sclerosis or muscle spasticity
• At therapeutic doses, Baclofen acts as a GABA-B receptor agonist
• At higher doses, Baclofen loses selectivity and can cause sedation
• Primary excreted by the kidneys

Clinical Features

• Nausea and vomiting
• Drowsziness
• Delirium
• Seizures
• Coma
• Respiratory compromise
• Hypothermia

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

Evaluation

• Diagnosis of exclusion

Management

• Activated charcoal for recent ingestion
• Supportive care:
  • IV fluids, respiratory care
  • Vasopressors for persistent hypotension
  • Benzodiazepines for seizures
• Hemodialysis for very severe toxicity

References

• Jung, M. “Baclofen Overdoses”. Maryland Poison Center, University of Maryland School of Pharmacy. www.mdpoison.com Accessed April 29th, 2014.
• Nicola Y Leung, Ian M Whyte, Geoffrey K Isbister Baclofen overdose: defining the spectrum of toxicity. Emerg Med Australas: 2006, 18(1);77-82