An index of fatal toxicity for new psychoactive substances

Alpha-methyltryptamine and 5-(2-methylaminopropyl)-benzofuran (5-MAPB) fatal co-intoxication: case report and review of literature

The scientific literature contains little reliable data regarding new psychoactive substances and designer drugs, making it difficult to assess toxic blood levels and potentially lethal threshold. Here, we report a fatal co-intoxication involving two uncommon drugs ‒ alpha-methyltryptamine (AMT) and 5-(2-methylaminopropyl)-benzofuran (5-MAPB) ‒ combined with exposure to benzodiazepines, ephedrine, and norephedrine. AMT and 5-MAPB were quantified using ultra-high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC/MS-MS), revealing concentrations of AMT 4690 ng/mL and 5-MAPB 101 ng/mL in postmortem peripheral blood. We additionally reviewed the literature to help interpret the likely roles of these molecules in the occurrence of death.

Measuring The Harms Caused by Illicit Drugs. A New Methodology for Estimating Drug Harm Index

BACKGROUND

Substance use carries a wide range of negative consequences, impacting both the individual using the substances and others. In recent years, there have been multiple efforts to assess the harm caused by drugs and to rank them, with each taking a distinctive approach to the matter. Objectives: This study seeks to introduce a new model for assessing the harm index and ranking of drugs. Methods: This prospective study involved the evaluation of 277 male drug users, assessing substance use harm on four separate occasions throughout the span of 1 year. Various aspects of harm were quantified through the utilization of the Duke Health Profile (DUKE) and the Addiction Severity Index (ASI) questionnaire. The pharmaceutical properties of each drug were incorporated into the study. The relationship between the combined variables in a mixed statistical model was determined at a significance level of .05 using the Rsoftware. This procedure facilitated the establishment of models and the definition of harm index ranges for each substance. Result: The results indicated that heroin had the highest harm index at 71.2 (95% CI69.6-72.8), while pure methadone scored the lowest at 36.5 (95% CI31.7-41.7), along with methadone combined with methamphetamine, which scored 35 (95% CI33-37.1). Conclusion: The variables utilized in this study can help estimate the approximate harm index range for both traditional and novel substances. Furthermore, the harm model designed in this study has the capability to predict the extent of harm to a drug user.

Alprazolam-related deaths in Scotland, 2004-2020

BACKGROUND

The benzodiazepine drug alprazolam, a fast-acting tranquiliser, cannot be prescribed on the National Health Service in the United Kingdom. Illicit alprazolam supply and consumption have increased. Concern about increasing numbers of alprazolam-related fatalities started circulating in 2018. However, statistics on this issue are very limited. This study examined patterns in such mortality in Scotland.

METHODS

Statistics on deaths where alprazolam was mentioned in the 'cause of death' were obtained from official mortality registers. Anonymised Scottish case-level data were obtained. Data were examined in respect of the characteristics of decedents and deaths using descriptive statistics.

RESULTS

Scotland registered 370 deaths in 2004-2020; 366 of these occurred in 2015-2020: most involved males (77.1%); mean age 39.0 (SD 12.6) years. The principal underlying cause of death was accidental poisoning: opiates/opioids (77.9%); sedatives/hypnotics (15.0%). Two deaths involved alprazolam alone. Main drug groups implicated: opiates/opioids (94.8%), 'other benzodiazepines' (67.2%), gabapentinoids (42.9%), stimulants (30.1%), antidepressants (15.0%). Two-thirds (64.2%) involved combinations of central nervous system (CNS) depressants.

DISCUSSION

Alprazolam-related deaths are likely due to an increasing illicit supply. The fall in deaths in 2019-2020 is partially due to increased use of designer benzodiazepines. Treatment for alprazolam dependence is growing. Clinicians need to be aware of continuing recreational alprazolam use. When such consumption occurs with CNS depressants, overdose and death risks increase.

CONCLUSIONS

More awareness of alprazolam contributing to deaths, especially in conjunction with other CNS depressants, is needed by consumers and clinicians. Improved monitoring of illicit supplies could identify emerging issues of medicines' abuse.

Comparative Neuropharmacology and Pharmacokinetics of Methamphetamine and Its Thiophene Analog Methiopropamine in Rodents

Methiopropamine is a novel psychoactive substance (NPS) that is associated with several cases of clinical toxicity, yet little information is available regarding its neuropharmacological properties. Here, we employed in vitro and in vivo methods to compare the pharmacokinetics and neurobiological effects of methiopropamine and its structural analog methamphetamine. Methiopropamine was rapidly distributed to the blood and brain after injection in C57BL/6 mice, with a pharmacokinetic profile similar to that of methamphetamine. Methiopropamine induced psychomotor activity, but higher doses were needed (E_max 12.5 mg/kg; i.p.) compared to methamphetamine (E_max 3.75 mg/kg; i.p.). A steep increase in locomotor activity was seen after a modest increase in the methiopropamine dose from 10 to 12.5 mg/kg, suggesting that a small increase in dosage may engender unexpectedly strong effects and heighten the risk of unintended overdose in NPS users. In vitro studies revealed that methiopropamine mediates its effects through inhibition of norepinephrine and dopamine uptake into presynaptic nerve terminals (IC₅₀ = 0.47 and 0.74 µM, respectively), while the plasmalemmal serotonin uptake and vesicular uptake are affected only at high concentrations (IC₅₀ > 25 µM). In summary, methiopropamine closely resembles methamphetamine with regard to its pharmacokinetics, pharmacodynamic effects and mechanism of action, with a potency that is approximately five times lower than that of methamphetamine.

Recreational ketamine-related deaths notified to the National Programme on Substance Abuse Deaths, England, 1997-2019

BACKGROUND

Ketamine is a phencyclidine derivative with dissociative anaesthetic properties. Increasing numbers of individuals in England take ketamine recreationally. Information on deaths arising from such use in England is presented.

METHODS

Cases were extracted on 31 January 2020 from the National Programme on Substance Abuse Deaths database, based on text searches of the cause of death, coroner's verdict and positive toxicology results for the terms 'ketamine' or 'norketamine'.

FINDINGS

During 1997-2005, there were <5 deaths p.a. in which ketamine was implicated. Numbers increased until 2009 (21), plateauing until 2016; thereafter, deaths have risen to about 30 p.a. Decedents' characteristics (N = 283): male 84.1%, mean age 31.2 (SD 10.0) years, employed 56.5%, drug use history 79.6% and living with others 60.3%. Ketamine was detected with other substances in most cases. Main (74.6%) underlying cause of death was accidental poisoning. Ketamine may have impaired judgement in other cases.

CONCLUSIONS

Although controlled, recreational ketamine use and related fatalities continue to increase. Consumers need to be more aware of the potentially fatal risks they face.

Fatal and non-fatal health incidents related to recreational ecstasy use

BACKGROUND

The recreational drug ecstasy (3,4-methylenedioxymethamphetamine) is currently used world-wide. Severe (including fatal) health incidents related to ecstasy have been reported but a risk assessment of acute non-fatal and fatal ecstasy-related health incidents has never been performed.

METHODS

In the current risk assessment review, national data of non-fatal health incidents collected in the Netherlands were combined with the nationwide exposure to ecstasy, that is, last-year prevalence of ecstasy use. In addition, the annual number of ecstasy-related deaths in Great Britain (Scotland, Wales and England) was used to assess the risk of fatal ecstasy-related cases.

RESULTS

In the Netherlands, the estimated risk of a moderate to severe acute health incident following the use of ecstasy is one in 900 pills (0.11%), whereas for cocaine it is one in 1600 doses (0.06%) and for gamma-hydroxybutyrate one in 95 doses (1.05%). With respect to ecstasy-related deaths in Great Britain, the estimated risk of ecstasy alone per user is 0.01-0.06%, which is close to the range of the fatality risk in chronic alcohol users (0.01-0.02%), amphetamine users (0.005%) and cocaine users (0.05%), but much lower than that of opiate use (heroin and morphine: 0.35%).

CONCLUSION

The current review shows that almost no data are available on the health risks of ecstasy use. The few data that are available show that ecstasy is not a safe substance. However, compared to opiates (heroin, morphine), the risk of acute ecstasy-related adverse health incidents per ecstasy user and per ecstasy use session is relatively low.

How deaths can help clinicians and policy-makers understand the risks of novel psychoactive substances

Novel psychoactive substances (NPS), especially those newly created, are largely an unknown quantity, particularly in terms of their potential serious adverse effects. This means that policy-makers and clinicians are under-informed about appropriate responses. Collation of detailed information on deaths related to NPS use can help in providing knowledge and understanding these aspects of the NPS phenomenon. The purpose of this review is to outline the role(s) which such evidence-based data can play in this respect. UK NPS-related cases demonstrate differences in definitions used by the General Mortality Registers, and differences between countries, not only in terms of the type of NPS implicated in deaths, but the number and extent of such deaths over time. NPS deaths are continuing to increase numerically and as a proportion of all drug-poisoning deaths. In order to better understand how specific molecules contribute to and/or cause death, detailed information collected by Special Mortality Registers can provide examples of substances' modes of action, adverse effects, symptomatology, treatment interventions, mechanisms of death, etc. This information can provide clinicians and policy-makers with objective information on the serious harms from such emerging molecules. Such evidence-based advice informs public health interventions, service provision and policy decisions on regulation and control of NPS. However, without reliable, accurate and complete information that is correctly collated, scientifically analysed and disseminated in a timely manner, an understanding of the phenomenon of what deaths can be ascribed to NPS, their characteristics and nature will remain unachieved, and thus limit what can be done to reduce them.

Characteristics of deaths associated with kratom use

BACKGROUND

Kratom (Mitragyna speciosa Korth) use has increased in Western countries, with a rising number of associated deaths. There is growing debate about the involvement of kratom in these events.

AIMS

This study details the characteristics of such fatalities and provides a 'state-of-the-art' review.

METHODS

UK cases were identified from mortality registers by searching with the terms 'kratom', 'mitragynine', etc. Databases and online media were searched using these terms and 'death', 'fatal*', 'overdose', 'poisoning', etc. to identify additional cases; details were obtained from relevant officials. Case characteristics were extracted into an Excel spreadsheet, and analysed employing descriptive statistics and thematic analysis.

RESULTS

Typical case characteristics (n = 156): male (80%), mean age 32.3 years, White (100%), drug abuse history (95%); reasons for use included self-medication, recreation, relaxation, bodybuilding, and avoiding positive drug tests. Mitragynine alone was identified/implicated in 23% of cases. Poly substance use was common (87%), typically controlled/recreational drugs, therapeutic drugs, and alcohol. Death cause(s) included toxic effects of kratom ± other substances; underlying health issues.

CONCLUSIONS

These findings add substantially to the knowledge base on kratom-associated deaths; these need systematic, accurate recording. Kratom's safety profile remains only partially understood; toxic and fatal levels require quantification.

The relative lethal toxicity of pharmaceutical and illicit substances: A 16-year study of the Greater Newcastle Hunter Area, Australia

AIMS

We aim to calculate 2 metrics of relative lethal toxicity; the fatal toxicity index (FTI; number of deaths per year of a daily dose) and the case fatality (CF; number of deaths per overdose) with a focus on opioids, antidepressants, antipsychotics, benzodiazepines and illicit drugs.

METHODS

This descriptive cohort study used the Australian National Coronial Information System (NCIS) to identify a population of individuals with drug-associated deaths in the Greater Newcastle Hunter Area between January 2002 and December 2016. This was combined with Australian medicine dispensing data and corresponding data from the Hunter Area Toxicology Service to calculate FTI and CF.

RESULTS

There were 444 drug-related deaths and 21,296 overdoses during the study period. FTI and CF were well correlated (Spearman's rho 0.64, P < .001). Of the classes of interest, opioids had the highest FTI (40.3 95% confidence interval [CI] 35.2-45.4 deaths per 100 years of use at the defined daily dose or deaths/DDD/100 years) and CF (12.4% 95%CI 11.0-13.9). Fentanyl, methadone and morphine had the highest relative fatal toxicity within this class. Tricyclic antidepressants had the highest relative fatal toxicity of all antidepressants (FTI 14.5 95%CI 9.7-19.3 deaths/DDD/100 years and CF 7.1% [95%CI 4.8-9.3]) and benzodiazepines appeared to be more associated with multiple agent deaths than single. Of the illicit drugs, heroin had the highest CF (26.4%, 95%CI 19.1-33.7).

CONCLUSION

Knowledge of relative lethal toxicity is useful to prescribers and medicines and public health policy makers in restricting access to more toxic drugs and may also assist coroners in determining cause of death.

Structure-activity relationships of bath salt components: substituted cathinones and benzofurans at biogenic amine transporters

RATIONALE

New psychoactive substances (NPSs), including substituted cathinones and other stimulants, are synthesized, sold on the Internet, and ingested without knowledge of their pharmacological activity and/or toxicity. In vitro pharmacology plays a role in therapeutic drug development, drug-protein in silico interaction modeling, and drug scheduling.

OBJECTIVES

The goal of this research was to determine mechanisms of action that may indicate NPS abuse liability.

METHODS

Affinities to displace the radioligand [¹²⁵I]RTI-55 and potencies to inhibit [³H]neurotransmitter uptake for 22 cathinones, 6 benzofurans and another stimulant were characterized using human embryonic kidney cells stably expressing recombinant human transporters for dopamine, norepinephrine, or serotonin (hDAT, hNET, or hSERT, respectively). Selected compounds were tested for potencies and efficacies at inducing [³H]neurotransmitter release via the transporters. Computational modeling was conducted to explain plausible molecular interactions established by NPS and transporters.

RESULTS

Most α-pyrrolidinophenones had high hDAT potencies and selectivities in uptake assays, with hDAT/hSERT uptake selectivity ratios of 83-360. Other substituted cathinones varied in their potencies and selectivities, with N-ethyl-hexedrone and N-ethyl-pentylone having highest hDAT potencies and N-propyl-pentedrone having highest hDAT selectivity. 4-Cl-ethcathinone and 3,4-methylenedioxy-N-propylcathinone had higher hSERT selectivity. Benzofurans generally had low hDAT selectivity, especially 1-(2,3-dihydrobenzofuran-5-yl)-N-methylpropan-2-amine, with 25-fold higher hSERT potency. Consistent with this selectivity, the benzofurans were releasers at hSERT. Modeling indicated key amino acids in the transporters' binding pockets that influence drug affinities.

CONCLUSIONS

The α-pyrrolidinophenones, with high hDAT selectivity, have high abuse potential. Lower hDAT selectivity among benzofurans suggests similarity to methylenedioxymethamphetamine, entactogens with lower stimulant activity.