GHB/GBL overdose in Recreational Settings

GHB/GBL overdose in Recreational Settings

GHB and GBL are two drugs of abuse frequently used as stimulants at parties for various reasons. Acute intoxication quickly leads to coma, respiratory depression, cardiac arrest and death.

One of the usage of these agents is for psychoactive substances in sexual contexts. With respect to jargon, we speak of Party and Play (PNP). Psychoactive substances are taken both recreational purposes and because they reduce self-control and inhibitions, they act as a sexual enhancer. In some cases, gamma hydroxybutyrate/gamma butyrolactone (GHB/GBL) mixed with alcoholic drinks facilitate criminal actions, such as robbery or non-consensual sexual acts (date rape drugs).Use of these drug is not very common in the general population and can be ascribed to distinct user groups[1].

What are the psychoactive substances most used in these parties?

The most frequent psychoactive substances used these parties are usually five:

  • GHB (gamma hydroxybutyrate)
  • GBL (gamma-butyrolactone)
  • Cathinones (Mephedrone, methylenedioxypyrovalerone [MDPV], methylone)
  • Methamphetamine
  • Ketamine

However, concomitant use of other abuse drugs [2], such as cocaine, ethanol, benzodiazepines, cannabinoids, and methamphetamines, can lead to the more significant severity of poisoning caused by GHB/GLB.

What are the effects of GHB?

GHB is a drug used in liquid or powder form. In liquid form, it is a clear, salty, and odorless. GHB is gamma aminobutyric acid (GABA) sodium salt, a molecule present in many body tissues; it is linked to GABA neurotransmitters, which are inhibitory to the neurons to which it binds. It activates its receptors (GHB receptors) and also activates GABA-B receptors [3]. Binding of GHB o to the latter group of receptors leads to a release of dopamine in the brain and causes the depression of the central nervous system (CNS), which can lead to decreased consciousness or unconsciousness, especially when ingested together with other depressants, such as alcohol.

From a pharmacological point of view, GHB has a narrow therapeutic range. At low doses (20–30 mg/kg), it produces a euphoric effect. Higher doses (> 50 mg/kg) provoke a sedative–hypnotic effect, which can further induce coma, bradycardia, and hypoventilation. Absorption into the body is relatively fast (5–15 min.) With a relatively short half-life, the peak of plasma concentrations occurs after 20 to 45 min. The clinical symptoms and the duration of the symptoms are dose-dependent so that it is almost not present in the body after 4 to 6 hours.

Structural formula of GBL
Structural formula of the chemical compound gamma-hydroxybutyrate (from Wikipedia – Neurotiker – Public Domain)
Metabolic pathway of GBL and GHB.
Metabolic pathway of 1,4-butanediol, GBL and GHB. (from Wikipedia-Anypodetos – Public Domain)

What are the effects of GBL?

GBL is a liquid product of the chemical industry. GBL differs from GHB because it has a chemical smell and acid taste, but after ingestion, our body converts GBL to GHB. Compared to GHB, we have seen how GBL has faster absorption, a longer-lasting effect, and higher plasma concentrations. These characteristics indicate quicker absorption and explain how GBL intake rapidly evolves toward an overdose characterized by coma, respiratory depression, cardiac arrest, and death. The pharmacodynamics of GBL are even faster than those of GBH.

2D structure of GBL (from Wikipedia-Harbin – Public Domain)

What are the symptoms of GHB / GBL overdose?

Symptoms of GHB / GBL overdose include several features:

  • Unconsciousness (GCS 3–7)
  • Reduced consciousness (narcolepsy, cataplexy)
  • Psycho-motor agitation
  • Cardio-circulatory problems (bradycardia, hypotension)
  • Respiratory depression
  • Seizures

How to diagnose GHB/GBL overdose?

The diagnosis of acute GBL and GHB intoxication is clinical. The symptoms include two main forms of depression:

  • CNS depression
  • Respiratory depression

GHB/GBL blood or urine tests are not always available in all hospital settings, while diagnostic confirmation through chromatography or mass spectrometry takes several days. Obtaining a patient’s medical history is difficult, if not impossible, due to his/her altered mental state or coma onset. However, the discovery of bottles and participation in a rave/nightclub event can help recreate the events and form the clinical picture.

What to do in front of a patient with a GBL/GHB overdose?

Treatment of the patient suffering from a GBL/GBH overdose is primarily supportive. The patient should be monitored via pulse oximetry, cardiorespiratory monitoring, capnography, and temperature monitoring.

The patient’s airway should be protected and the patient should be managed conservatively (if possible). Ways to treat the airways are highly debated and are currently left to the treating physician’s discretion.  Intubation [4] should be avoided in the patient which he used only GHB as the half-life of this drug is extremely short, and the patient could awaken in 2 to 3 hours. On the other hand, if poly-intoxication is present, the patient is in critical condition, or there is a real risk of aspiration pneumonia, intubation should be performed. It should also be remembered that GBL is a highly inflammatory molecule for the upper respiratory tract tissues.

Atropine or catecholamines if the perfusion is not adequate should be used, but this event is rare in these patients.Moreover, the onset of the withdrawal symptoms [5] such as anxiety, insomnia, tremors, tachycardia, agitation, delirium, and hallucinations should be monitored and treated with benzodiazepines and muscle relaxants [6].

What are the other risks?

Patients who inject drugs via the intravenous route should be informed of the risk of contracting infectious diseases [7], such as human immunodeficiency virus, hepatitis C and B viruses (HIV, HCV, and HBV, respectively). Those on retroviral therapy should be notified that these agents decrease the effectiveness of antiretroviral drugs [8].

The patient should be informed that taking GBL/GHB with other drugs can lead to severe and potentially fatal conditions. It should be remembered that GHB and cocaine mixed with alcohol react by forming toxic metabolites, such as cocaethylene, or that GHB and opioids can lead to coma and death.

The patient who is dependent on GHB should be informed about the onset of withdrawal symptoms, which is of rapid onset and progression and can often be fatal as hallucinatory, delusional, upon sudden drug cessation. Epileptic seizures can occur and can endanger a patient’s life. Planning for reductions in GHB/GBL use before stopping altogether can reduce withdrawal symptoms and make them less severe. If a person is  a regular user of one or more of these drugs, a doctor should be consulted before discontinuing use as sudden withdrawal can be life-threatening. Also, withdrawal symptoms can last up to 15 days.

Useful links

References and Further Reading

  1. Tomkins A, Ahmad S, Cannon L, Higgins SP, Kliner M, Kolyva A, Ward C, Vivancos R. Prevalence of recreational drug use reported by men who have sex with men attending sexual health clinics in Manchester, UK. Int J STD AIDS. 2018 Mar;29(4):350-356. doi: 10.1177/0956462417725638. Epub 2017 Aug 23. PMID: 28835196.
  2. Madah-Amiri, D., Myrmel, L. & Brattebø, G. Intoxication with GHB/GBL: characteristics and trends from ambulance-attended overdoses. Scand J Trauma Resusc Emerg Med 25, 98 (2017).
  3. Le JK, Richards JR. Gamma-Hydroxybutyrate Toxicity. [Updated 2020 Oct 21]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020 Jan-. Available from:
  4. P Dietze, D Horyniak, P Agius, V Munir, de Villiers Smit, J Johnston, C L Fry, L Degenhardt. Effect of intubation for gamma-hydroxybutyric acid overdose on emergency department length of stay and hospital admission Acad Emerg Med2014 Nov;21(11):1226-31
  5. Wojtowicz JM, Yarema MC, Wax PM. Withdrawal from gamma-hydroxybutyrate, 1,4-butanediol and gamma-butyrolactone: a case report and systematic review. CJEM 2008; 10:69–74
  6. Cappetta M, Murnion BP. Inpatient management of gamma-hydroxybutyrate withdrawal. Australas Psychiatry. 2019 Jun;27(3):284-287. doi: 10.1177/1039856218822748. Epub 2019 Jan 17. PMID: 30652947.
  7. Sewell, Janey et al. Poly drug use, chemsex drug use, and associations with sexual risk behaviour in HIV-negative men who have sex with men attending sexual health clinics. International Journal of Drug Policy 43, 33–43, 2017
  8. Pufall, EL et al. Sexualized drug use (‘chemsex’) and high-risk sexual behaviours in HIV-positive men who have sex with men, HIV medicine 19.4, pp. 261–270, 2018
Cite this article as: Francesco Adami, Italy, "GHB/GBL overdose in Recreational Settings," in International Emergency Medicine Education Project, April 12, 2021,, date accessed: May 9, 2021

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