Toxicology and characteristics of deaths involving zolpidem in New South Wales, Australia 2001-2010.

All cases presenting to the New South Wales Department of Forensic Medicine between January 1, 2001 and September 31, 2010 in which zolpidem was detected, were retrieved. A total of 91 cases were identified. The mean age was 49.4 years, 65.9% were male, and 61.5% were suicides. Zolpidem was a factor contributing to death in 35 (37.3%) cases, of which 31 (34.1%) involved zolpidem toxicity. The median blood zolpidem concentration was 0.20 mg/L (range 0.05-3.50 mg/L), with no significant gender difference. Drug toxicity cases involving zolpidem had significantly higher median blood zolpidem concentrations than other cases (0.50 vs. 0.10 mg/L). In 83.5% of cases, psychoactive substances other than zolpidem were detected, most commonly antidepressants (46.2%), benzodiazepines (35.2%), opioids (26.4%), and alcohol (39.6%). In summary, zolpidem was a factor contributing to death in a large proportion of cases, predominately involving drug toxicity and suicide.