Table 3 Concomitant substance use

 GHB monointoxication (no other illicit drugs or alcohol reported)

27 (35)

 GHB polyintoxication (reported co-use of other drugs and/or alcohol)

51 (65)

 Reported co-use of alcohol

26 (33)

 Reported and/or laboratory-confirmed co-use of alcohol

31 (40)

Co-use of other illicit drugs (according to patient self-report)

36 (46)

 Cannabis

14 (18)

 Cocaine

13 (17)

 Sedatives

12 (15)

 Opiates

8 (10)

 Amphetamine

4 (5)

 MDMA (ecstasy)

4 (5)

 Ketamine

1 (1)

Laboratory test data

70 (90)

 Ethanol test performed

66 (85)

 Positive ethanol test

23 (29)

 Drug test performed

67 (86)

  Positive for benzodiazepines

15 (19)

  Positive for cannabis

13 (17)

  Positive for cocaine

10 (13)

  Positive for methadone

4 (5)

  Positive for opiates

2 (3)

  Positive for amphetamines

1 (1)