title: Gamma-hydroxybutyrate serum levels and clinical syndrome after severe overdose.
abstract: OBJECTIVE
  We discuss a prospective case series of patients who present with a severe gamma-hydroxybutyrate intoxication with confirmatory serum and urine gamma-hydroxybutyrate levels.
  
  
  METHODS
  Patients with a clinical suspicion of gamma-hydroxybutyrate-like drug overdoses and a Glasgow Coma Scale score of 8 or lower were identified from July 1998 through January 1999. Serial serum specimens and a single urine specimen were collected. The levels of gamma-hydroxybutyrate were performed by gas chromatography-mass spectrometry.
  
  
  RESULTS
  All 16 suspected severe gamma-hydroxybutyrate overdose patients had significant serum or urine levels of gamma-hydroxybutyrate. Serum levels ranged from 45 to 295 mg/L, with a median of 180 mg/L (interquartile range [IQR] 235 to 118 mg/L). Patients who developed a Glasgow Coma Scale score of 3 had serum levels that ranged from 72 to 300 mg/L, with a median of 193 mg/L (IQR 242 to 124 mg/L). The time of awakening ranged from 30 minutes to 190 minutes, with a median of 120 minutes (IQR 150 to 83 minutes). Quantitative serum gamma-hydroxybutyrate levels did not correlate with the degree of coma or the time to awakening. Urine levels ranged from 432 to 2,407 mg/L, with a median of 1,263 mg/L (IQR 1,550 to 796 mg/L). Mild transitory hypoventilation occurred in 5 of the 16 patients.
  
  
  CONCLUSIONS
  All of our patients with clinically suspected severe gamma-hydroxybutyrate overdose were confirmed to have significant serum and urine levels of exogenous gamma-hydroxybutyrate. They presented with severe coma that lasted 1 to 2 hours. Transient hypoventilation occurred in one third of these patients.
authors.affiliation: Department of Emergency Services, San Francisco General Hospital, University of California-San Francisco, 1001 Potrero Avenue, San Francisco, CA 94110, USA. ksporer@itsa.ucsf.edu
authors.forename: Karl A
authors.initials: KA
authors.lastname: Sporer
authors.forename: Rachel L
authors.initials: RL
authors.lastname: Chin
authors.forename: Jo Ellen
authors.initials: JE
authors.lastname: Dyer
authors.forename: Ryan
authors.initials: R
authors.lastname: Lamb
mesh_terms: D000759:Adjuvants, Anesthesia / Q000009:adverse effects* / Q000097:blood / Q000652:urine; D000328:Adult; D062787:Drug Overdose / Q000097:blood / Q000652:urine; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry; D015600:Glasgow Coma Scale; D006801:Humans; D008297:Male; D011446:Prospective Studies; D012978:Sodium Oxybate / Q000009:adverse effects* / Q000097:blood / Q000652:urine
chemical_list: D000759:Adjuvants, Anesthesia; D012978:Sodium Oxybate