Characteristics of poisonings involving ketamine in the United States, 2019-2021

Antinociceptive and adverse effects of morphine:ketamine mixtures in rats

Prescription opioids are the gold standard for treating moderate to severe pain despite their well-documented adverse effects. Of all prescription medications, opioids are abused most widely, and fatal overdoses have reached epidemic levels. One strategy for improving the margin of safety of opioids is combining them with non-opioid drugs to decrease the opioid dose needed for pain relief, thereby reducing adverse effects that occur with larger doses. The N-methyl-D-aspartate receptor antagonist ketamine has been used safely as an analgesic but only under a very limited range of conditions. The current studies characterized the antinociceptive, behavioral suppressant, and gastrointestinal effects of morphine and ketamine alone and in mixtures to determine their interaction in 24 adult male Sprague-Dawley rats (n = 8 per assay). Given alone, both morphine and ketamine produced antinociception, decreased responding for food, and reduced gastrointestinal transit (i.e. produced constipation). The effects of morphine:ketamine mixtures generally were additive, except for the antinociceptive effects of 1:1 mixtures for which the difference in slope (i.e. non-parallel shift) between the observed and predicted effects suggested synergy at smaller doses and additivity at larger doses. The potency of morphine to produce constipation was not enhanced by administration of morphine:ketamine mixtures with antinociceptive effects. The nature of the interaction between morphine and ketamine for adverse effects such as dependence, withdrawal, abuse, or respiratory depression remains unknown but also might be related to the ratio of each drug in mixtures. It will be important to identify conditions that produce the largest potential therapeutic window in humans.

The Rapidly Shifting Ketamine Landscape in the US

This Viewpoint discusses changes in the use of ketamine as a medical therapeutic and a recreational substance, the potential risks of use, and the need for increased research and surveillance.

Trends in reported and biologically confirmed drug use among people who use ecstasy in the nightclub/festival-attending population, 2016-2022

Background

Nightclub/festival attendees are a population with high rates of party drug use, but research is needed to determine whether there have been shifts in unintended drug exposure in this population (e.g., via adulterants) to inform prevention and harm reduction efforts.

Methods

Adults entering nightclubs and festivals in New York City were asked about past-year drug use in 2016 through 2022, with a subset providing a hair sample for testing. We focused on the 1943 who reported ecstasy use (of which 247 had a hair sample analyzed) and compared trends in self-reported drug use, drug positivity, and adjusted prevalence (adjusting for unreported use).

Results

MDMA positivity decreased from 74.4 % to 42.3 %, and decreases occurred regarding detection of synthetic cathinones ("bath salts"; a 100.0 % decrease), MDA (a 76.9 % decrease), amphetamine (an 81.3 % decrease), methamphetamine (a 64.2 % decrease), and ketamine (a 33.4 % decrease) (ps < .05). Although prevalence of MDA and synthetic cathinone use was comparable between self-report and adjusted report in 2022, gaps in prevalence were wider in 2016 (ps < .01). Adjusted prevalence of synthetic cathinone use decreased more across time than prevalence based on self-report (a 79.4 % vs. 69.1 % decrease) and adjusted report for MDA use decreased more than prevalence based on self-report (a 50.6 % vs. 38.9 % decrease).

Conclusions

Combining self-report and toxicology tests helped us determine that decreases in drug use/exposure were steeper regarding adjusted prevalence. Underreported drug exposure-possibly due to exposure to adulterants-appears to have had less of an effect on prevalence in 2022 than it did in 2016.

Trends in Illicit Ketamine Seizures in the US From 2017 to 2022

This cross-sectional study evaluates trends in the number and weight of illicit ketamine seizures in the US from 2017 to 2022.

Prevalence of self-reported adverse effects associated with drug use among nightclub and festival attendees, 2019-2022

BACKGROUND

Research investigating adverse effects from drug use has focused extensively on poisonings and mortality. This study focuses on drug-related adverse effects not necessarily resulting in hospitalization or death among a population known for high prevalence of party drug use-electronic dance music (EDM) nightclub and festival attendees.

METHODS

Adults entering EDM venues were surveyed in 2019-2022 (n = 1952). Those reporting past-month use of a drug were asked whether they had experienced a harmful or very unpleasant effect after use. We examined 20 drugs and drug classes with a particular focus on alcohol, cannabis, cocaine, and ecstasy. Prevalence and correlates of adverse effects were estimated.

RESULTS

Almost half (47.6%) of adverse effects involved alcohol and 19.0% involved cannabis. 27.6% of those using alcohol reported an adverse effect, while 19.5%, 15.0%, and 14.9% of participants reported an effect from use of cocaine, ecstasy, and cannabis, respectively. Use of less prevalent drugs, such as NBOMe, methamphetamine, fentanyls, and synthetic cathinones, tended to be associated with higher prevalence of adverse effects. The most consistent risk factor was younger age, while past-month use of a greater number of drugs was often a protective factor against adverse effects. For most drugs, taking too much was the most common perceived reason for the adverse effect, and visiting a hospital after use was most prevalent among those experiencing an adverse effect from cocaine (11.0%).

CONCLUSIONS

Adverse drug effects are common in this population and results can inform prevention and harm reduction in this population and the general population.

Trends in drug use among nightclub and festival attendees in New York City, 2017-2022

BACKGROUND

Drug use is prevalent among people who attend electronic dance music (EDM) parties at nightclubs or festivals. This population can serve as a sentinel population to monitor trends in use of party drugs and new psychoactive substances (NPS) that may diffuse through larger segments of the population.

METHODS

We surveyed adults entering randomly selected EDM parties at nightclubs and dance festivals in New York City about their drug use in 2017 (n=954), 2018 (n=1,029), 2019 (n=606), 2021 (n=229), and 2022 (n=419). We estimated trends in past-year and past-month use of 22 drugs or drug classes based on self-report from 2017-2022 and examined whether there were shifts pre- vs. post-COVID (2017-2019 vs. 2021-2022).

RESULTS

Between 2017 and 2022, there were increases in past-year and past-month use of shrooms (psilocybin), ketamine, poppers (amyl/butyl nitrites), synthetic cathinones ("bath salts"), and novel psychedelics (lysergamides and DOx series), increases in past-year cannabis use, and increases in past-month use of 2C series drugs. Between 2017 and 2022, there were decreases in past-year heroin use and decreases in past-month cocaine use, novel stimulant use, and nonmedical benzodiazepine use. The odds of use of shrooms, poppers, and 2C series drugs significantly increased after COVID, and the odds of use of cocaine, ecstasy, heroin, methamphetamine, novel stimulants, and prescription opioids (nonmedical use) decreased post-COVID.

CONCLUSIONS

We estimate shifts in prevalence of various drugs among this sentinel population, which can inform ongoing surveillance efforts and public health response in this and the general populations.