Clinical presentation

The onset of GHB effects is rapid (25 to 60 minutes) and duration of toxicity is short. Recovery from poisoning usually occurs over about 2 to 4 hours; however, toxicity may be prolonged with large ingestions taken in deliberate self-poisonings.

Central nervous system (CNS) effects of GHB poisoning include:

• rapidly developing CNS depression, coma and collapse (may be preceded by transient agitation and restlessness)
• loss of airway protection, dose-dependent respiratory depression, respiratory failure and resulting respiratory acidosis
• movement disorders—myoclonus, tremor, dystonias, ataxia
• disorientation, confusion, hallucinations, delirium
• agitation and combativeness after waking
• euphoria, headache, dizziness
• hypotonia, hyporeflexia
• seizures (uncommon).

Other effects of GHB poisoning include:

• cardiovascular effects—mild bradycardia, mild hypotension (rare unless GHB is co-ingested with other drugs), electrocardiographic changes (occasionally present)
• miosis
• mild hypothermia
• vomiting
• metabolic acidosis (following large ingestions).