Incidence of drugs and alcohol in fatally injured motor vehicle drivers.

All motor vehicle accident fatalities occuring in Dallas County during a 1 1/2-year period were studied to determine drug usage at the time of death. Blood samples obtained at autopsy or at the time of hospital admission were analyzed for the presence of drugs and alcohol. Of the drivers, 70% were positive for alcohol or drugs. Ethyl alcohol alone was detected in 52%, drugs in 9%, and both drugs and alcohol in another 9%. Seventy-six percent of the drivers determined to be at fault in their respective accidents had alcohol or drugs detected compared to 41% for not-at-fault drivers. The minor tranquilizer diazepam accounted for over half of all positive drug findings, while barbiturates, antihistamines, methaqualone, propoxyphene, and pentazocine were each detected in more than one instance.