Gamma-Hydroxy Butyrate

GHB was synthesized as an analgoue of GABA that would cross the blood-brain barrier as a potential sedative or anaesthetic agent.

Physiological effects

Hypotension, bradycardia, hypoventilation, hypothermia, miosis, EEG and behavioural changes (including absence-like seizures and slow-wave sleep).

Indistinguishable clinically from benzo or alcohol OD.

Half life 20-30 min, plasma levels peak 40 minutes after ingestion.

Doses 20-30 mg/kg cause euphoria/amnesia/drowsiness/sleep. Double doses can cause coma i.e. narrow therapeutic window.


Supportive only: no specific antidote.


Usually initially used for euphoric effects or for anxiety/depression. Ultimately may escalate to use every 2-4 hours.