Gamma-Hydroxybutyrate Toxicity Clinical Presentation

Updated: May 12, 2022
  • Author: Theodore I Benzer, MD, PhD; Chief Editor: Sage W Wiener, MD  more...
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Patients with gamma-hydroxybutyric acid (GHB) toxicity typically present with altered mental status, making it difficult or impossible to obtain reliable history. Prehospital personnel frequently have valuable information from the scene implicating GHB as the cause of the patient's complaint. History may also be obtained from bystanders or friends since patients frequently ingest GHB in the presence of others at the gym, nightclubs, or parties. The history may include agitation and confusion as well as myoclonus and seizurelike activity. [15]

Many patients present after taking multiple drugs, and efforts should be made to identify everything the patient has ingested. In contrast, patients given GHB surreptitiously as part of a drug-facilitated rape may have no history at all of drug ingestion. 

A history that the GHB was manufactured in a home lab is important since homemade GHB can be contaminated with sodium hydroxide (lye). 

Cultural sensitivity may be needed to elicit history from patients or others.  Among MSM, increased high-risk sexual behaviors and non-consensual sexual activity have been associated with GHB use in the context of chemsex. [16]  


Physical Examination

After GHB ingestion, the patient may have a period of euphoria that is rapidly followed by a period of profoundly depressed level of consciousness. This may progress to coma with a Glasgow Coma Scale of 3. GHB intoxication characteristically produces episodes of agitated delirium that can precede or follow the period of stupor or coma. Seizurelike movements and myoclonus are common during the course of the intoxication. These findings may reverse rapidly, leaving the patient awake, alert, and oriented within minutes after several hours of altered mentation.

Bradycardia occurs in approximately 30-35% of GHB ingestions. Hypotension occurs in approximately 10% of ingestions and is usually mild. More profound cardiovascular changes can be seen with multidrug ingestions.

Respiratory depression leading to frank apnea can occur and is exacerbated by multidrug ingestion. Decreased breath sounds or rales may indicate aspiration of gastric contents. Pulmonary edema is not a finding that is usually associated with GHB.

Nausea and vomiting are common in GHB ingestions, especially during reemergence. Alkali burns to the lips, mouth, and GI tract can be seen when the GHB is contaminated by sodium hydroxide during the manufacturing process. Mild hypothermia is a common finding in these cases.

Signs and symptoms of GHB withdrawal syndrome appear 4  hours after the last dose of GHB. In the initial period of abstinence, these include the following:

  • Tremors
  • Miosis
  • Sweating
  • Tachycardia
  • Palpitations
  • Dyspnea
  • Nausea
  • Vomiting
  • Diarrhea
  • Abdominal painAnxiety-related behaviors

In more severe cases of withdrawal, patients experience hypertension and symptoms such as the following [17] :

  • Insomnia
  • Agitation
  • Paranoia
  • Disorientation
  • Confusion
  • Aggression
  • Auditory and visual hallucinations