Cannabis recent use in sudden unexpected deaths

Abstract

The aim of this study was to review all sudden unexpected death received in our laboratory over a four years’ period (2018–2021) in order to ascertain the prevalence of recent cannabis consumption. The main cause of death in industrialized countries is ischemic heart disease, and risk factors include smoking, obesity, age, hypercholesterolemia, arterial hypertension, diabetes mellitus and alcohol. The scientific literature now also links cannabis use to cardiovascular accidents. Cannabinoids exert their effects through the activation of two specific membrane receptors, CB1 and CB2 and, at the cardiovascular level, the activation of these receptors is related to increased cardiac output and sinus tachycardia. In total, 7150 cases of sudden unexpected death had been received in our laboratory for toxicological analysis from January 2018 to December 2021, 262 were related to cannabis use and we selected those in which recent cannabis use was demonstrate due to the presence of THC in blood, after having discarded those cases that presented a concomitant consumption of other drugs of abuse, as well as, other psychoactive substances at toxic concentrations. Blood samples were screened for cannabis by CEDIA and Δ9-tetrahydrocannabinol (THC), 11-hydroxy-Δ9-tetrahydrocannabinol (11-OH-THC) and 11-nor-Δ9-tetrahydrocannabinol-9-carboxylic acid (THC-COOH) were confirmed and quantified using solid-phase extraction (SPE) followed by gas chromatography tandem mass spectrometry (GC-MS/MS). The cut-offs applied were 1 ng/mL for THC and 11-OH-THC and 5 ng/mL for THC-COOH. Forty-eight sudden unexpected deaths following recent cannabis use were recorded. THC blood levels have been increasing over the period studied. The mean in 2018 was 1.84 ng/mL, increasing to 8.08 ng/mL in 2021. In terms of sex, 87.5% of cases were male, the age range ranged from 16 to 74 years, with the median being 50 years and the mode 47 years. In 77% of the cases the cause of death was cardiogenic, 6.2% of the cases corresponded to subarachnoid hemorrhage and the rest to other causes. The highest incidence is presented by the population aged between 40–60 years (58.3%), with alcohol and/or tobacco consumption habits in 50% of the cases. In addition, in this group there are cases with different pathological antecedents like arterial hypertension, obesity, epilepsy and congenital heart disease. The lower incidence of sudden unexpected death is in the age group from 16 to 30 years (10.4%). The distribution of the number of deaths was not homogeneous throughout the four years studied. Both, an increase in the number of deaths and in THC blood levels can be seen. This may be directly related to the increase in THC concentrations in the different forms of cannabis presentations in street samples. Despite cannabis being the most consumed drug among young people, the incidence of sudden unexpected death in this age group is lower, which highlights the importance of the existence of previous pathologies. In people with certain pathologies and/or alcohol and tobacco consumption habits cannabis use is a risk factor that can contribute to sudden unexpected death.