Table 7b Observations on the occurrence of ..

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).