. 2013 Mar 2;9(2):163–171. doi: 10.1007/s13181-013-0294-y

Table 2.

Z-drug blood concentration (ng/mL) in driving impairment

Z-drug	Therapeutic C_max (dose)	Legal limit^a	Driving impairment^b	Driving impairment^c
Zolpidem	100–200 (10 mg)	31	77	184
Zopiclone	60–90 (7.5 mg)	12	23	58

Blood/plasma ratio for zopiclone is 1.0. References: [58, 73, 74, 80]

C_max maximal plasma concentration at therapeutic doses (in brackets)

^aLegal limit in Norway

^bDriving impairment lower threshold (whole blood concentration) for graded sanctions in Norway, comparable to BAC 0.05 %

^cDriving impairment higher threshold (whole blood concentration) for graded sanctions in Norway, comparable to BAC 0.12 %