An evaluation of the sensitivity of the standardised field sobriety tests to detect the presence of amphetamine.
BACKGROUND
The Standardised Field Sobriety Tests (SFSTs), designed and validated to assess impairment associated with alcohol intoxication, are currently being employed by the Victoria Police (Australia) for the identification of driving impairment associated with drugs other than alcohol.


OBJECTIVE
The aim of this study was to evaluate whether the SFSTs are a sensitive measure for identifying the presence of dexamphetamine and methamphetamine.


METHODS
Three studies each employed a repeated-measures, counterbalanced, double-blind placebo-controlled design. In each study, 20 healthy volunteers completed two treatment conditions: either 0.42 mg/kg d,l-dexamphetamine and placebo, 0.42 mg/kg d,l-methamphetamine and placebo, or 0.42 mg/kg d-methamphetamine and placebo. Performance was assessed using the SFSTs, consisting of the Horizontal Gaze Nystagmus test, the Walk and Turn test, and the One Leg Stand test. Blood and saliva samples were obtained before and immediately after the administration of the SFSTs (120 and 170 min post drug administration).


RESULTS
At 120 and 170 min post drug administration, d,l-dexamphetamine blood levels were 83.16 and 98.42 ng/ml, respectively; d,l-methamphetamine levels were 90 and 95 ng/ml, respectively; and d-methamphetamine blood levels were 72 and 67 ng/ml, respectively. None of the three amphetamine doses impaired performance on the SFSTs. Using the SFSTs, the presence of dexamphetamine was identified in 5% of cases, d-methamphetamine in 5%, and d,l-methamphetamine in 0% of cases.


CONCLUSIONS
Under these conditions, the SFSTs are not a sensitive measure for detecting the presence of low levels of amphetamine.
Silber
Beata Y
BY
Drugs and Driving Research Unit, Centre for Neuropsychology, Swinburne University of Technology, P.O. Box 218 , Hawthorn, Victoria, 3122, Australia. bsilber@swin.edu.au
Papafotiou
Katherine
K
Croft
Rodney J
RJ
Stough
Con K K
CK
D000063:Accidents, Traffic / Q000331:legislation & jurisprudence*; D000328:Adult; D000435:Alcoholic Intoxication / Q000175:diagnosis*; D019969:Amphetamine-Related Disorders / Q000175:diagnosis*; D003913:Dextroamphetamine / Q000097:blood; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D008694:Methamphetamine / Q000097:blood; D009460:Neurologic Examination / Q000187:drug effects / Q000592:standards*; D009760:Nystagmus, Physiologic / Q000187:drug effects; D004856:Postural Balance / Q000187:drug effects; D012016:Reference Values; D012680:Sensitivity and Specificity
D008694:Methamphetamine; D003913:Dextroamphetamine