Cannabinoids in Postmortem Toxicology

Abstract

Cannabinoids are often excluded from postmortem toxicology screens due to their ubiquitous nature, interpretative difficulties and unanswered questions regarding their postmortem redistribution. In this study, we review 30 postmortem cases where a drug screen gave a positive cannabinoids result and a confirmation identified Δ⁹-tetrahydrocannabinol (THC), 11-hydroxy-Δ⁹-tetrahydrocannabinol (11-OH-THC), and/or 11-nor-9-carboxy-Δ⁹-tetrahydrocannabinol (THC-COOH) in peripheral (BL-P) or cardiac/central blood (BL-C) and/or urine (UR). Had cannabinoids not been included in these toxicologic evaluations, incomplete or erroneous inferences would have been drawn in a substantial number of cases regarding cause/manner of death. THC was detected in 28 BL-C and in all 30 BL-P. THC and THC-COOH were confirmed present in 2 and 23 UR, respectively. 11-OH-THC was detected in 4 BL-C, 6 BL-P, and 0 UR. The mean THC concentrations in BL-C and BL-P were 8.0 and 15.8 ng/mL, respectively. The mean THC-COOH concentrations in BL-C and BL-P were 55.2 and 60.6 ng/mL, respectively. The mean 11-OH-THC concentrations in BL-C and BL-P were 17.0 and 12.5 ng/mL, respectively. Postmortem interval (PMI) for each case was determined and evaluated in relation to BL-C/BL-P concentration ratios with THC-COOH exhibiting a possible trend. This study is the first of its kind and demonstrates the usefulness of cannabinoid analyses as part of death investigations. Furthermore, it provides distribution data that will improve the ability of toxicologists and pathologists to evaluate cannabinoid concentrations in human postmortem specimens.

Novel associations between FAAH genetic variants and postoperative central opioid-related adverse effects

“…33 Our finding of association of respiratory depression with FAAH gene (especially AA genotype of rs324420) may have potential significance for millions of patients prescribed and individuals abusing opioid agonists and/or cannabinoids (e.g. marijuana, synthetic cannabinoids) 22 , 34 – 39 every year, for both the abuse potential and the potential for life-threatening respiratory depression.…”

Distribution of ∆9‐Tetrahydrocannabinol and 11‐Nor‐9‐Carboxy‐∆9‐Tetrahydrocannabinol Acid in Postmortem Biological Fluids and Tissues From Pilots Fatally Injured in Aviation Accidents

“… reported a mean age of 33 years (range 15–66 years) for their study investigating the frequency of THC in driving under the influence of drugs (DUID) cases in Sweden. Mean and median ages were 38.2 and 35 years, respectively, in a study of postmortem cannabinoid concentrations from 30 autopsy cases .…”

“…By comparison, the Office of the Chief Medical Examiner of San Francisco, California reported that, of 1338 postmortem toxicology cases from July 1, 2010 to June 30, 2011, cannabinoids were confirmed in 30 (2.2%) accidental deaths (27). The Florida Department of Law Enforcement reported a 4.3% positive rate in postmortem cases in 2012 (28). Positive rates for cannabinoids in automobile drivers in three recent roadside studies were 7.7% in Spain, 8.5% in California (USA), and 9.8% in Australia (29)(30)(31).…”

Reply to Beckson et al. (2019): Cannabis, crashes, and blood: challenges for observational research

“…People may survive for hours following a collision and there will be ongoing distribution and metabolism of THC during that time. In the Vancouver region, where many of our cases came from, 50% of trauma deaths occur more than 6 hours after injury . Beckson cites a postmortem study by Drummer et al .…”