Gamma hydroxybutyrate withdrawal

Background

• Abbreviation: GHB
• Frequently referred to as the "date rape drug"
• Central nervous system depressant
• GABA-B agonist (as opposed to GABA-A agonists - alcohol, benzodiazepines, etc)
• Abused for:
  • Body building or sleep enhancement
  • euphoric, sexual, stimulant, and relaxant effects
  • Surreptitious drugging to facilitate sexual assault
• Also used therapeutically in the treatment of narcolepsy

Pharmacokinetics

• Effects start in 15-20 minutes, peak in 30-60 minutes,
• Lipid soluble, readily crosses the blood brain barrier
• Elimination is dose-dependent; half-life of 20-50 minutes
• The duration of GHB's clinical effects depends upon the dose, and ranges from 2.5-4 hours

Pharmacology

• Is a metabolite and precursor of GABA
• Interacts with GHB-specific receptors and also acts as a direct agonist of GABA-B receptors
• Affects multiple neurotransmitter systems, including those of opioids, dopamine, serotonin, glutamate, and acetylcholine
• Gamma butyrolactone (GBL) and 1,4 butanediol (BD) are GHB analogs that are rapidly metabolized to GHB after ingestion, with the same toxic and recreational effects

Clinical Features

• Similar to alcohol withdrawal
• tremor, agitation, hallucinations, tachycardia, hypertension
• Withdrawal only if have long term use, not episodic binging
  • Occur a few hours after use

Differential Diagnosis

Sedative/hypnotic withdrawal

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

Evaluation

• Typically a clinical diagnosis

Management

• Benzodiazepines (may need large doses)
• Neuroleptics
• Beta-blockers

See Also

• Gamma hydroxybutyrate withdrawal
• Toxicology (main)