Overview of disorders of GHB use

Gamma-hydroxybutyrate (GHB, also known as ‘GBH’, ‘fantasy’, ‘G’, ‘Gina’ or ‘liquid ecstasy’) is a sedative and anaesthetic drug usually ingested as a precursor drug, such as gamma-butyrolactone (GBL) or 1,4-butanediol, which the body rapidly converts to GHB. It is used therapeutically (as sodium oxybate) overseas but is not approved by the Australian Therapeutic Goods Administration (TGA).

GHB is usually distributed as a colourless liquid and is taken orally. Effects are very similar to those of alcohol or benzodiazepines and include sedation, euphoria, disinhibition and amnesia. Like amyl nitrate and stimulants, GHB is used to enhance sexual experience (‘chemsex’)Phan, 2020. Because of its sedative effects, it is also sometimes used to mitigate the effects of stimulants such as metamfetamine. Prevalence of GHB use in the previous 12 months is estimated at 0.1% of the Australian populationAustralian Institute of Health and Welfare (AIHW), 2020.

The spectrum of substance use in these guidelines is described by the terms ‘hazardous use’, ‘harmful use’ or ‘substance dependence’, outlined in Terminology describing the spectrum of substance use.

Potential harms from GHB and its precursors include:

  • toxicity—overdose is common because the difference between the doses for desired and toxic effects is very small; vulnerability while intoxicated (including to physical and sexual assault) is also a risk
  • withdrawal—severe withdrawal may require treatment in an intensive care unit
  • local tissue damage—oral burns can occur from residual sodium hydroxide used in manufacturing.

GHB overdose is characterised by confusion, agitation, hallucinations, respiratory depression, hypotension, bradycardia, involuntary movements (sometimes interpreted as seizures) and coma1. Overdose typically lasts only a few hours with spontaneous (often abrupt) waking from coma. GHB overdoses are common; some are fatal. The risk of toxicity and respiratory depression is increased if GHB is taken with other sedatives such as alcohol. Concurrent alcohol use can cause delayed onset of GHB toxicity.

GHB dependence can present with withdrawal similar to severe alcohol withdrawal.

1 Patients experiencing GHB overdose may have the drug in their possession because of their need to use it frequently; it is useful to be aware of this when seeking the cause of a person’s intoxication.Return