Analysis of zolpidem in postmortem fluids and tissues using ultra-performance liquid chromatography-mass spectrometry.

Zolpidem is a nonbenzodiazepine sedative hypnotic drug used for the short-term treatment of insomnia. While quite effective in producing sedation, zolpidem has potentially hazardous side effects when put in the context of complex tasks. Therefore, to more fully understand the postmortem concentrations of zolpidem, our laboratory has developed a sensitive method for the quantitation of zolpidem in biological specimens. Additionally, we have evaluated the distribution of zolpidem in various postmortem tissues and fluids from 10 aviation fatalities. This method incorporated a modified acetonitrile 'crash and shoot' extraction and a Waters Xevo TQ-S with an Acquity ultra-performance liquid chromatograph. The linear dynamic range was 0.4-800 ng/mL. The extraction efficiencies ranged from 78 to 87%, depending on the concentration. Postmortem blood zolpidem concentrations in these 10 cases ranged from 7.6 to 76.5 ng/mL. The highest concentrations of zolpidem present in each victim were found in the liver, spleen, lung and kidney tissues. Distribution coefficients for zolpidem were determined for each of the specimen types analyzed. These coefficients are expressed relative to the blood concentration in each case. This method proved to be simple, accurate and robust for the identification and quantitation of zolpidem in postmortem fluids and tissues.

Increased cannabinoids concentrations found in specimens from fatal aviation accidents between 1997 and 2006.

The National Institute on Drug Abuse (NIDA) and the Office of National Drug Control Policy (ONDCP) reported a 1.5-fold increase in the delta-9-tetrahydrocannabinol (THC) content of street cannabis seizures from 1997 to 2001 versus 2002 to 2006. This study was conducted to compare the changes, over those years, in blood and urine cannabinoid concentrations with the potency of THC reported in the cannabis plant. Cannabinoids were screened using radioimmunoassay (RIA) for blood and fluorescence polarization immunoassay (FPIA) for urine and confirmed using GC/MS. A total of 95 individuals were found to be using cannabis from a total number of 2769 (3.4%) individuals tested over the period 1997 through 2006. Other impairing drugs were found in 38% of the cannabinoids-positive individuals. The mean concentration of THC in blood for 1997-2001 was 2.7 ng/mL; for 2002-2006, it was 7.2 ng/mL, a 2.7-fold increase in the mean THC concentration of specimens from aviation fatalities, compared to a 1.5-fold increase in cannabis potency reported by the NIDA and ONDCP. The mean age for cannabis users was 40 years (range 18-72) for aviation fatalities. For all blood and urine specimens testing negative for cannabinoids from aviation fatalities, the mean age of the individuals was 50 years (range 14-92). More than half of the fatalities tested were 50 years or older, whereas, 80% of the positive cannabis users were under 50. As indicated by these findings, members of the transportation industry, government regulators, and the general public should be made aware of the increased potential for impairment from the use of high-potency cannabis currently available and being used.