Latent polydrug use patterns and the provision of injection initiation assistance among people who inject drugs in three North American settings

Longitudinal patterns of use of stimulants and opioids in the AIDS linked to the IntraVenous experience cohort, 2005-2019

BACKGROUND

Overdoses involving opioids and stimulants are on the rise, yet few studies have examined longitudinal trends in use of both substances. We sought to describe use and co-use of opioids and stimulants, 2005-2019, in the AIDS Linked to the Intravenous Experience (ALIVE) cohort - a community-based cohort of people with a history of injection drug use living in or near Baltimore, MD.

METHODS

We included 2083 ALIVE participants, who had at least two visits during the study period. Our outcome was based on self-reported use of opioids and stimulants in the prior 6 months. We estimated prevalence of 4 categories of use (neither stimulants nor opioids, only stimulants, only opioids, stimulants and opioids), using a non-parametric multi-state model, accounting for the competing event of death and weighting for informative loss to follow-up. All analyses were stratified by enrollment cohort, with the main analysis including participants who enrolled prior to 2015 and a sub-analysis including participants who enrolled 2015-2018.

RESULTS

In the main analysis, prevalence of using stimulants and opioids decreased from 38 % in 2005 to 12 % 2013 but stabilized from 2014 onwards (13-19 %). The prevalence of using only stimulants (7-11 %) and only opioids (5-10 %) was stable across time. Participants who reported using both were more likely to report homelessness, depression, and other substance use (e.g., marijuana and heavy alcohol use) than participants in the other use categories. On average, 65 % of visits with use of both were followed by a subsequent visit with use of both; of participants transitioning out of using both, 13% transitioned to using neither.

CONCLUSIONS

While use of stimulants and opioids declined in the cohort through 2013, a meaningful proportion of participants persistently used both. More research is needed to understand and develop strategies to mitigate harms associated with persistent use of both stimulants and opioids.

Detection of fentanyl, synthetic opioids, and ketamine in hair specimens from purposive samples of American and Italian populations

With the current crisis related to the diffusion of fentanyl and other novel opioids in several countries and populations, new and effective approaches are needed to better elucidate the phenomenon. In this context, hair testing offers a unique perspective in the investigation of drug consumption, producing useful information in terms of exposure to psychoactive substances. In this research, we applied targeted ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) analytical methods to detect novel synthetic and prescription opioids and other common controlled psychoactive drugs in the keratin matrix. A total of 120 hair samples were analyzed from the United States (US) and Italy, segmented when longer than 6 cm, and then analyzed. In the 60 samples (83 segments in total) analyzed from a purposive sample of data collected in the US, fentanyl was detected in 14 cases (16.9%), with no detection of nitazens or brorphine. We also detected fentanyl metabolites, despropionyl-p-fluorofentanyl, and prescription opioids. In the 60 samples collected in Italy (91 segments in total), ketamine was the most prevalent compound detected (in 41 cases; 45.1%), with ketamine demonstrating a strong correlation with detection of amphetamines and MDMA, likely due to co-use of these substances in recreational contexts. Several common drugs were also detected but no exposure to fentanyl or its analogs were detected. Results of this retrospective exploration of drug use add to increasing evidence that hair testing can serve as a useful adjunct to epidemiology studies that seek to determine biologically confirmed use and exposure in high-risk populations.

Cross-border Activities Associated With Pattern of Amphetamine-type Stimulants Usage Among Drug Users in Southwest of China

Cross-border activities are possibly associated with the use of amphetamine-type stimulants (ATS), this study was to explore poly-substance of ATS use and influencing factors among ATS use populations in southwest China. A cross-sectional study was conducted by response driven and continuous samplings from January to July 2021. Descriptive, univariate and logistic regression were carried out. ATS users accounted for 95.6% of the target population, of whom one-third had cross-border experiences with 4.1% of the cross-border purchase of drugs. ATS users were mainly over 31 years old (53.9%), male (98.7%), minority (79.1%), and unmarried (72.7%). Cross-border users consumed more ketamine (8%) and methamphetamine (40%) (P < .05). After adjusting for socioeconomic-demographic factors, cross-border activity [OR: 0.336 (0.141, 0.799)], occupation [OR: 0.273 (0.080, 0.929)], injecting drug behavior [OR: 6.239 (1. 087, 35.811)], frequency [OR: 0.251 (0.073, 0.859)], and ATS use location [OR: 2.915 (1.040, 8.168)] were possible factors influencing ATS use patterns (P < .05). Cross-border activity may be associated with polydrug use, especially predominantly methamphetamine use, among ATS users along the Southwest border. It implied that the focus of drug prevention and control in border areas should be on cross-border populations.