The described procedure provides a rapid technique for the detection and semi-quantitation of a large number of drugs in blood. This procedure uses a minimal sample volume and employs a one-step liquid extraction and automated data processing to yield rapid turnaround times. 327 of the most commonly used medicinal and illicit drugs in Australia were selected including various amphetamines, anesthetics, anti-depressants, anti-psychotics, anti-convulsants, benzodiazepines, beta blockers, opioid and non-opioid analgesics, stimulants, THC and a large number of synthetic cannabinoids and other novel psychoactive substances. The extracts were subject to 5-minute chromatography using a Kinetex C18 50 x 4.6 mm 2.6 μm solid-core analytical column and analyzed using a Sciex 3200 Q-TRAP MS-MS (+ ESI, MRM mode, two transitions per analyte). The method was fully validated in accordance with international guidelines. Matrix effects and extraction efficiencies were acceptable with most analytes showing > 80% response and low variation (within 25%RSD). Cannabinoids were most affected by the matrix and yielded poorest recovery values but were still detectable. Precision, accuracy, repeatability and multipoint linearity were assessed for all analytes. The method has been used in routine practice in the forensic toxicology service at the Victorian Institute of Forensic Medicine in over 6000 coronial investigations using both post-mortem and clinical blood specimens. This technique has greatly increased throughput, reduced turnaround times and allowed for rapid same-day analysis of results when needed. The method is routinely used in routine overnight testing with results reported to pathologists within 4 hours of data acquisition. This rapid toxicological technique is used in conjunction with other investigative processes such as full-body CT imaging, review of case circumstances and medical histories to provide an efficient death investigation process.

Postmortem drug redistribution (PMR) is a well-known phenomenon in forensic toxicology with implications for medico-legal death investigations. Paired antemortem (AM) specimen and postmortem (PM) mortuary admission femoral blood drug concentrations from 811 coronial cases were used to construct a retrospective compilation of PM/AM drug concentration ratios for 42 parent drugs and metabolites. The median PM/AM ratios for all antidepressants were > 1 and consistent with PMR. In contrast, the median PM/AM ratios of most benzodiazepines were < 1. The antipsychotics were varied (0.63–3.3) and suggest the mixed effects of PMR and drug instability. Amphetamines exhibited no trends (0.90–0.95) and is likely confounded by many factors. The PM/AM ratios of cardiovascular drugs, opioids and other drugs are also reported. This research represents an expansive retrospective compilation of paired AM and PM drug concentrations for many toxicologically-relevant drugs. While the median PM/AM ratios demonstrate some drug-dependent trends, there was no obvious relationship between AM specimens and PM femoral blood taken at mortuary admission.

Abstract Changes in the concentrations of Δ9-tetrahydrocannabinol (THC) in the postmortem period were investigated in a series of cases by comparing concentrations in blood taken on receipt of the body in the mortuary (admission specimen, AD) with the concentrations obtained in blood taken at autopsy some time later and also from blood specimens taken antemortem. Overall, the median THC concentration in AD blood was 13.7 ng/mL (n = 239, range LOQ–220), while the median concentration at autopsy was 13.8 ng/mL (n = 106, range LOQ–810) and 1.9 ng/mL (n = 147, range LOQ–48) antemortem. Fourteen cases had all three specimens taken from the same decedent. The corresponding AM, AD and PM median concentrations were 4.0 (range LOQ–48), 15.5 (range 4.0–176) and 4.4 ng/mL (LOQ–56), respectively. The median elapsed times from AM to AD and AD to PM were 33 and 97.5 h, respectively. In contrast, acetaminophen showed no change in blood concentration from AM to AD (6.8 and 6.0 mg/L, respectively). These data show large increases in THC concentration in the early postmortem period, followed by a decline, although the median blood concentrations at autopsy were similar to that obtained antemortem. In contrast, when blood was taken from the femoral region, subclavian and heart ventricles sites, in the same case, the THC concentrations, while variable, showed overall no significant difference. These dynamic changes reflect complex phenomenon occurring in deceased persons and will further serve to increase the uncertainty over any interpretation of postmortem THC concentrations.

No abstract