Journal Published Online: 01 January 2001
Volume 46, Issue 1

Zolpidem and Driving Impairment



Zolpidem, a non-benzodiazepine hypnotic, was identified in the blood of 29 subjects arrested for impaired driving. Zolpidem concentrations ranged from 0.05 to 1.4 mg/L (mean 0.29 mg/L, median 0.19 mg/L). In the subjects whose cases we reviewed where zolpidem was present with other drugs and/or alcohol, symptoms reported were generally those of CNS depression. Symptoms included slow movements and reactions, slow and slurred speech, poor coordination, lack of balance, flaccid muscle tone, and horizontal and vertical gaze nystagmus. In five separate cases, where zolpidem was the only drug detected (0.08–1.40 mg/L, mean 0.65 mg/L, median 0.47 mg/L), signs of impairment included slow and slurred speech, slow reflexes, disorientation, lack of balance and co-ordination, and “blacking out.” Although no quantitative relationship between blood concentrations and degree of driving impairment is currently possible, it is reasonable to conclude that because of its specific activity as a sleep inducer, blood concentrations consistent with therapeutic doses of zolpidem have the potential to affect driving in a negative way, and that concentrations above the normal therapeutic range would further impair a person's level of consciousness and driving ability.

Author Information

Logan, BK
Bureau of Forensic Laboratory Services, Washington State Patrol, Seattle, WA Washington State Toxicology Laboratory, University of Washington, Seattle, WA
Couper, FJ
Washington State Toxicology Laboratory, University of Washington, Seattle, WA
Pages: 6
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Stock #: JFS14919J
ISSN: 0022-1198
DOI: 10.1520/JFS14919J