Metabolite

LC-MS/MS Cutoff (ng/mL)

Substance

LC-MS/MS Cutoff (ng/mL)

Positive Metabolite Count

Number of Times Metabolite Found With Parent Medication

Number of Times Metabolite Found Without Parent Medication

Median Metabolite Concentration With Parent Medication

Median Metabolite Concentration Without Parent Medication

Percent Metabolite Without Parent

EDDP

50

Methadone

50

810

781

29

3,960

96

3.5

Norbuprenorphine

20

Buprenorphine

10

131

105

26

323

58

20

Norfentanyl

8

Fentanyl

2

752

698

54

304

18

7.1

Meprobamate

50

Carisoprodol

50

993

588

405

24,448

3,815

40.7

Table 7b: Observations on the occurrence of metabolite without parent medication (concentration in ng/mL).