title: Prevalence and concentrations of drugs in older suspected drugged drivers.
abstract: Older drivers are somewhat more likely to be involved in car crashes than middle-aged drivers but less likely to be involved than younger drivers. This study aimed to assess the extent of drug use in older suspected drunk and drugged drivers, with respect to which drugs were detected and at which concentrations.
  
  
  
  Blood samples from older suspected drunk and drugged drivers taken between February 1, 2012, and May 22, 2013, were identified from the database at the Norwegian Institute of Public Health and were retrospectively analyzed for a broad repertoire of drugs relevant for impairment. The prevalence of different drugs among the suspected drunk and drugged drivers was studied. Regarding drug concentrations, the findings in older drivers (>65 years) were compared to a reference group of apprehended drivers aged 20-40 years.
  
  
  
  Four hundred and ten older suspected drunk and drugged drivers were included. Any drug (including ethanol) was detected in 92% of blood samples, and ethanol was detected in 81%. Benzodiazepines were found in 15% of the older drivers and z-hypnotics (zopiclone or zolpidem) were detected in 13%. The most frequent single legal drugs found in blood samples taken from older impaired drivers were zopiclone (9.8%) and diazepam (9.3%). Regarding drug combinations, older drivers used a mean number of 1.4 drugs, and 20% of ethanol-positive cases showed at least one other drug. High drug concentrations of clonazepam and diazepam were more frequently seen in the younger group.
  
  
  
  This study showed that drugs were detected in the vast majority of older drivers suspected for drunk or drugged driving. Ethanol was the most frequent drug detected, followed by zopiclone and diazepam. Older drivers combine drugs to a lesser degree than younger drivers, but their combination of ethanol and other drugs represents a considerable traffic risk. Lower concentrations of benzodiazepines are seen in older compared to younger drivers.
authors.affiliation: a Norwegian Institute of Public Health, Division of Forensic Sciences , Oslo , Norway.|b Diakonhjemmet Hospital , Center for Psychopharmacology , Oslo , Norway.
authors.forename: Gudrun
authors.initials: G
authors.lastname: Høiseth
authors.affiliation: a Norwegian Institute of Public Health, Division of Forensic Sciences , Oslo , Norway.
authors.forename: Linn Engeset
authors.initials: LE
authors.lastname: Austdal
authors.affiliation: a Norwegian Institute of Public Health, Division of Forensic Sciences , Oslo , Norway.
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Wiik
authors.affiliation: a Norwegian Institute of Public Health, Division of Forensic Sciences , Oslo , Norway.|c Lovisenberg University College , Oslo , Norway.
authors.forename: Stig Tore
authors.initials: ST
authors.lastname: Bogstrand
authors.affiliation: a Norwegian Institute of Public Health, Division of Forensic Sciences , Oslo , Norway.|d Institute of Clinical Medicine, University of Oslo , Oslo , Norway.
authors.forename: Jørg
authors.initials: J
authors.lastname: Mørland
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D000435:Alcoholic Intoxication / Q000097:blood* / Q000453:epidemiology*; D000661:Amphetamine / Q000097:blood; D001334:Automobile Driving / Q000706:statistics & numerical data*; D001569:Benzodiazepines / Q000097:blood; D016208:Databases, Factual; D000431:Ethanol / Q000097:blood; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009664:Norway / Q000453:epidemiology; D015995:Prevalence; D012189:Retrospective Studies; D019966:Substance-Related Disorders / Q000453:epidemiology
chemical_list: D001569:Benzodiazepines; D000431:Ethanol; D000661:Amphetamine
keywords: Drugs; elderly drivers; impairment; medicines