Opioids,stimulants, and depressant drugs in fifteen Mexican Cities: A wastewater-based epidemiological study

BackgroundMonitoring drug use in México is a challenge due to emerging drugs and rapid changes in consumption patterns. The temporal and geographical patterns of cocaine, methamphetamine, amphetamine, MDMA, cannabis, heroin, ketamine, and fentanyl were examined in Mexican cities using wastewater-based epidemiology (WBE).Methods105 daily composite wastewater samples were collected from sewage treatment plants in fifteen Mexican cities. We quantified drug residues using liquid chromatography–high-resolution mass spectrometry, and estimated drug use by back-calculation of drug loads.ResultsWe identified ten drug target residues in at least one sample across cities. Drugs with the highest median levels were cannabis, methamphetamine, and cocaine. The median range of cannabis for one week was between 147 and 20,364 mg/day/1000inhab across cities, whereas methamphetamine ranged between 5 and 3,628 mg/day/1000inhab. Cocaine was found in levels between 2 and 370 mg/day/1000inhab. The highest levels of methamphetamine and amphetamine were observed in the US border cities of Tijuana and San Luis Río Colorado. The presence of heroin, MDMA, ketamine, and fentanyl was stronger during weekends, while cannabis, cocaine, and amphetamine were found throughout the week.ConclusionThis study provides the first report of fentanyl, norfentanyl, and ketamine in wastewater in Mexico. The results indicate an increased presence of drugs on known drug traffic routes, demonstrating that WBE can help identify areas of high drug use and assist governments in developing policies to reduce drug use and harm in the communities.     

The relationship between impulsivity and craving in cocaine- and methamphetamine-dependent volunteers

Impulsivity and craving have been independently hypothesized to contribute to sustained drug use and relapse in addiction. The primary focus of this project was to determine the relationship between impulsivity and craving in 85 cocaine-dependent and 73 methamphetamine-dependent, non-treatment-seeking volunteers. Drug use was assessed with a 14-item, self-report drug and alcohol use questionnaire. Self report instruments utilized included the Barratt Impulsivity Scale (BIS) and the Visual Analog Scale (VAS), which probed “just before your last use of cocaine (for cocaine-dependent participants) or methamphetamine (for methamphetamine-dependent participants), how much craving did you experience?” The groups were similar with respect to recent use of cocaine or methamphetamine, alcohol, nicotine, and marijuana. Analysis of variance (ANOVA) did not reveal significant differences between cocaine and methamphetamine groups for total impulsivity or total craving. Simple linear regression revealed correlations between total impulsivity and total craving in cocaine (r² = 0.05, p ≤ 0.03) and methamphetamine users (r² = 0.09, p ≤ 0.008). Participants were separated into high impulsivity (HIBIS) or low impulsivity (LOBIS) subgroups using a median split. ANOVA revealed significantly higher craving in the HIBIS group versus the LOBIS group in methamphetamine users (p ≤ 0.02), but not in cocaine users. For both cocaine and methamphetamine groups, level of impulsivity and craving were found to be related to some drug use variables including years of alcohol use, severity of withdrawal, and craving level following drug use. Taken together, this study shows a marginal relationship between impulsivity and craving, which may further the understanding of motivational factors contributing to ongoing drug use and addiction in psychostimulant users.     

Associations Between Religiosity,Perceived Social Support,and Stimulant Use in an Untreated Rural Sample in the U.S.A.

Background: Religiosity and perceived social support (SS) may serve as protective factors for more severe substance use in adults. Objectives: This study sought to examine whether aspects of religiosity and SS are associated with longitudinal reductions in stimulant use over three years in an untreated sample of rural drug users. Methods: Respondent-driven sampling was used to recruit stimulant users (N = 710) from Arkansas, Kentucky, and Ohio. Follow-up interviews were conducted at 6-month intervals for 36 months. Results: Our bivariate findings indicate that higher religiosity was associated with lower odds and fewer days of methamphetamine and cocaine use. After controlling for covariates, higher religiosity was associated with fewer days of crack cocaine use, but more days of methamphetamine use among a small sample of users in the two final interviews. Higher SS from drug-users was also associated with higher odds and days of methamphetamine and powder cocaine use, while higher SS from nondrug users was associated with fewer days of methamphetamine use. Conclusions/Importance: Our bivariate findings suggest that higher levels of religiosity may be helpful for some rural individuals in reducing their drug use over time. However, our multivariate findings suggest a need for further exploration of the potential effects of religiosity on longer-term drug use, especially among those who continue to use methamphetamine and/or remain untreated. Our findings also highlight the potential deleterious effect of SS from drug users on the likelihood and frequency of methamphetamine and powder cocaine use over time among untreated rural drug users.     

Polydrug Use and HIV Risk Among People Who Inject Heroin in Tijuana,Mexico: A Latent Class Analysis

Background: Although most people who inject drugs (PWID) in Tijuana, Mexico, primarily inject heroin, injection and non-injection use of methamphetamine and cocaine is common. We examined patterns of polydrug use among heroin injectors to inform prevention and treatment of drug use and its health and social consequences. Methods: Participants were PWID residing in Tijuana, aged ≥18 years who reported heroin injection in the past six months and were recruited through respondent-driven sampling (n = 1,025). Latent class analysis was conducted to assign individuals to classes on a probabilistic basis, using four indicators of past six-month polydrug and polyroute use: cocaine injecting, cocaine smoking or snorting, methamphetamine injecting, and methamphetamine smoking or snorting. Latent class membership was regressed onto covariates in a multinomial logistic regression. Results: Latent class analyses testing 1, 2, 3, and 4 classes were fit, with the 3-class solution fitting best. Class 1 was defined by predominantly heroin use (50.2%, n = 515); class 2 by methamphetamine and heroin use (43.7%, n = 448), and class 3 by methamphetamine, cocaine, and heroin use (6.0%, n = 62). Bivariate and multivariate analyses indicated a group of methamphetamine and cocaine users that exhibited higher-risk sexual practices and lower heroin injecting frequency, and a group of methamphetamine users who were younger and more likely to be female. Conclusions: Discrete subtypes of heroin PWID were identified based on methamphetamine and cocaine use patterns. These findings have identified subtypes of heroin injectors who require more tailored interventions to reduce the health and social harms of injecting drug use.     

Patterns of illicit drug use in NSW,Australia following a reduction in heroin supply

Objective:To examine whether a reduction in the availability of heroin in New South Wales (NSW) in 2001 was associated with community level changes in heroin and other drug use.Method:Data from the NSW Alcohol and Drug Information Service (ADIS) on the number of persons calling about different drug types were used to examine NSW trends in calls of concern about heroin and other drugs. ADIS is a 24-h telephone information and counselling service in NSW; data from ADIS has previously been shown to be related to trends in drug use. Data from an inner Sydney needle and syringe program on drugs injected by clients were also used to examine time trends among a sentinel group of injecting drug users (IDU). Time series analysis was used to model the series.Results:There was a significant reduction in calls regarding heroin associated with the reduction in heroin supply. Increases in calls about cocaine and methamphetamine were also associated with the heroin shortage. The reduction in calls about heroin appeared to be sustained, whereas the increases in calls about cocaine and methamphetamine were not.Conclusions:Decreases in heroin supply were associated with sustained decreases in the use of heroin at a community level. Substitution of other drugs probably occurred among some users, such substitution did not appear to be sustained, as the number of calls returned to pre-shortage levels.Implications:Drug supply reduction may lead to increases in use of other drug types. The health implications of such changes need to be borne in mind by law enforcement and health services.     

Measuring Current Drug Use in Female Sex Workers and Their Noncommercial Male Partners in Mexico: Concordance Between Data Collected From Surveys Versus Semi-Structured Interviews

Background: Self-reports are commonly used to assess prevalence and frequency of drug use, but it is unclear whether qualitative methods like semi-structured interviews are as useful at obtaining such information as quantitative surveys. Objectives: This study compared drug use occurrence and frequency using data collected from quantitative surveys and qualitative interviews. We also examined whether combining data from both sources could result in significant increases in percentages of current users and whether the concordance between the two sets of data was associated with the type of drug use, age, gender and socioeconomic status. Methods: Self- reports of recent marijuana, heroin, crack, cocaine, crystal/methamphetamine, inhalant, and tranquilizer use were collected using both methods from a cohort of Mexican female sex workers and their non-commercial male partners (n = 82). Results: Participants were significantly less likely to report marijuana, cocaine and tranquilizer use and frequency of use during the qualitative interviews than during the quantitative surveys. Agreement on frequency of drug use was excellent for crystal/methamphetamine, heroin and inhalant use, and weak for cocaine, tranquilizers and marijuana use. Older participants exhibited significantly higher concordance than younger participants in reports of marijuana and methamphetamine use. Higher monthly income was significantly associated with higher concordance in crack use but lower concordance with marijuana use. Conclusions: Although use of such data can result in an underreporting of drug use, qualitative data can be quantified in certain circumstances to triangulate and confirm the results from quantitative analyses and provide a more comprehensive view of drug use.     

Comparing Injection and Non-Injection Routes of Administration for Heroin,Methamphetamine, and Cocaine Users in the United States

ABSTRACT

Research examining the demographic and substance use characteristics of illicit drug use in the United States has typically failed to consider differences in routes of administration or has exclusively focused on a single route of administration—injection drug use. Data from National Survey on Drug Use and Health were used to compare past-year injection drug users and non-injection drug users' routes of administration of those who use the three drugs most commonly injected in the United States: heroin, methamphetamine, and cocaine. Injection drug users were more likely than those using drugs via other routes to be older (aged 35 and older), unemployed, possess less than a high school education, and reside in rural areas. IDUs also exhibited higher rates of abuse/dependence, perceived need for substance abuse treatment, and co-occurring physical and psychological problems. Fewer differences between IDUs and non-IDUs were observed for heroin users compared with methamphetamine or cocaine users.     

Patterns of cocaine and opioid co-use and polyroutes of administration among street-based cocaine users in Montréal,Canada

BackgroundEffective public health programs aimed at problematic cocaine users are challenged by the fact that they can have complex patterns of drug use with respect to polysubstance use and routes of drug administration. This study was carried out to explore the presence of subgroups of cocaine users on the basis of their concurrent use of opioids and their routes of cocaine and opioid administration, and to determine if subgroups could be differentiated in terms of sociodemographic factors and risk behaviours.MethodsRegular cocaine users (≥1 per week) were recruited in low-threshold services located in the Montréal downtown area. The following variables were examined: demographic characteristics, types of drug used, routes of drug administration, and condom use with occasional or commercial sexual partners. Latent class analysis and multinomial logistic regression modeling were carried out.Results886 cocaine users were recruited (83.5% male: mean age 35.38 years). A 5-class model was identified: (1) “cocaine smokers” (CSs) (n = 161; membership probability (MP) = 0.183); (2) “cocaine smokers/sniffers” (CSSs) (n = 201; MP = 0.218); (3) “cocaine injectors” (CIs) (n = 207; MP = 0.231); (4) “cocaine-opioid injectors” (COIs) (n = 277; MP = 0.291); (5) “cocaine-opioid polyroute users” (COPs) (n = 40; MP = 0.077). Compared with COIs, other subtypes were significantly different in terms of either age, duration of cocaine use, ethnic background, homelessness, polydrug use or condom use.ConclusionThe heterogeneity of consumption patterns supports the importance of offering an array of interventions aimed at problematic cocaine users. These should include the provision of clean injecting and smoking material, the promotion of safe sexual behaviours and the prevention of initiation to drug injection. In the absence of specific treatment, cocaine users should have access to primary health care services and addiction treatment based on innovative behavioural and pharmacological approaches.     

Trends in production, trafficking, and consumption of methamphetamine and cocaine in Mexico

Over the past decade, Mexico has experienced a significant increase in trafficking of cocaine and trafficking and production of methamphetamine. An estimated 70% of United States cocaine originating in South America passes through the Central America-Mexico corridor. Mexico-based groups are now believed to control 70%-90% of methamphetamine production and distribution in the United States. Increased availability of these drugs at reduced prices has led to a parallel rise in local drug consumption. Methamphetamine abuse is now the primary reason for seeking drug abuse treatment in a number of cities, primarily in northwestern Mexico. Although cocaine and methamphetamine use have been linked with the sex trade and high-risk behaviors, such as shooting gallery attendance and unprotected sex in other settings, comparatively little is known about the risk behaviors associated with use of these drugs in Mexico, especially for methamphetamines. We review historical aspects and current trends in cocaine and methamphetamine production, trafficking, and consumption in Mexico, with special emphasis on the border cities of Ciudad Juarez and Tijuana. Additionally, we discuss the potential public health consequences of cocaine use and the recent increase in methamphetamine use, especially in regards to the spread of bloodborne and other infections, in an effort to inform appropriate public health interventions.     

Trends in Production,Trafficking, and Consumption of Methamphetamine and Cocaine in Mexico

Over the past decade, Mexico has experienced a significant increase in trafficking of cocaine and trafficking and production of methamphetamine. An estimated 70% of United States cocaine originating in South America passes through the Central America–Mexico corridor. Mexico-based groups are now believed to control 70%–90% of methamphetamine production and distribution in the United States. Increased availability of these drugs at reduced prices has led to a parallel rise in local drug consumption. Methamphetamine abuse is now the primary reason for seeking drug abuse treatment in a number of cities, primarily in northwestern Mexico. Although cocaine and methamphetamine use have been linked with the sex trade and high-risk behaviors, such as shooting gallery attendance and unprotected sex in other settings, comparatively little is known about the risk behaviors associated with use of these drugs in Mexico, especially for methamphetamines. We review historical aspects and current trends in cocaine and methamphetamine production, trafficking, and consumption in Mexico, with special emphasis on the border cities of Ciudad Juarez and Tijuana. Additionally, we discuss the potential public health consequences of cocaine use and the recent increase in methamphetamine use, especially in regards to the spread of bloodborne and other infections, in an effort to inform appropriate public health interventions.     

A comparative analysis of methamphetamine use: black gay and bisexual men in relation to men of other races

We investigated the patterns and correlates of methamphetamine use among Black gay and bisexual men who participated in a large-scale study of club drug use, and sexual behavior in combination with club drug use in New York City. Almost half of the Black men (49%) in the sample indicated use of methamphetamine in the 4 months prior to assessment, a proportion somewhat lower than their White counterparts. In terms of the overall sample, the proportion of the Black men in the study was equivalent to the proportion of methamphetamine users who identified as Black. Black methamphetamine users tended not to reside in neighborhoods considered traditionally gay, were more likely to be HIV-positive, have lower educational attainment, and have lower levels of income than other methamphetamine users. In terms of frequency and reasons for use, Black methamphetamine users did not differ in any substantive way compared to other races and ethnicities. In addition, they did not differ along any key demographic lines from Black non-methamphetamine users. Poly-drug use was common among all Black men in the sample, with almost all methamphetamine users also reporting use of cocaine, but cocaine users not necessarily reporting methamphetamine use. Once a drug that was considered popular only among White gay men, methamphetamine use has been shown to transcend racial and ethnic lines. Because of the synergy that exists between use of the drug, the concentrated levels of HIV in the Black gay population, and the sexual disinhibition engendered with methamphetamine use, this drug presents a potentially mounting public health challenge.     

Bath salts components mephedrone and methylenedioxypyrovalerone (MDPV) act synergistically at the human dopamine transporter

Background and Purpose

Bath salts is the street name for drug combinations that contain synthetic cathinone analogues, among them possibly mephedrone (MEPH) and certainly methylenedioxypyrovalerone (MDPV). In animal studies, cathinone and certain cathinone analogues release dopamine (DA), similar to the action of amphetamine (AMPH) and methamphetamine (METH). AMPH and METH act on the human DA transporter (hDAT); thus, we investigated MEPH and MDPV acting at hDAT.

Experimental Approach

We recorded electrical currents mediated by hDAT expressed in Xenopus laevis oocytes and exposed to: DA, METH, a known hDAT stimulant and DA releaser, MEPH, MDPV, MEPH + MDPV, or cocaine, a known hDAT inhibitor.

Key Results

DA, METH and MEPH induce an inward current (depolarizing) when the oocyte is held near the resting potential (–60 mV), therefore acting as excitatory hDAT substrates. Structurally analogous MDPV induces an outward (hyperpolarizing) current similar to cocaine, therefore acting as an inhibitory non-substrate blocker.

Conclusions and Implications

Two components of bath salts, MEPH and MDPV, produce opposite effects at hDAT that are comparable with METH and cocaine, respectively. In our assay, MEPH is nearly as potent as METH; however, MDPV is much more potent than cocaine and its effect is longer lasting. When applied in combination, MEPH exhibits faster kinetics than MDPV, viz., the MEPH depolarizing current occurs seconds before the slower MDPV hyperpolarizing current. Bath salts containing MEPH (or a similar drug) and MDPV might then be expected initially to release DA and subsequently prevent its reuptake via hDAT. Such combined action possibly underlies some of the reported effects of bath salts abuse.     

The Stimulant Selective Severity Assessment: A replication and exploratory extension of the Cocaine Selective Severity Assessment

Background: Cocaine and methamphetamine have similar withdrawal symptoms and many individuals concurrently use both substances; however, no measures concurrently assess withdrawal from multiple stimulants. Objectives: This study’s aim was to explore the Stimulant Selective Severity Assessment (SSSA), a modified version of the Cocaine Selective Severity Assessment (CSSA), in a sample of stimulant users to determine if it can assess withdrawal symptoms in users of one or more stimulants. Methods: Baseline data were analyzed from the STimulant Reduction Intervention using Dosed Exercise trial, a multisite randomized clinical trial that evaluated exercise versus health education on drug use outcomes in individuals with stimulant use disorders. Data were analyzed for internal consistency, construct validity, and scale dimensionality. Results: Internal consistency for the full sample was good (α?=?0.81; N?=?302), with similar alphas in Cocaine (0.81; n?=?177) and Cocaine/Other Stimulant (0.82; n?=?92) groups, but with much lower alpha for the group without cocaine use (Other Stimulant, i.e., primarily methamphetamine, α?=?0.66; n?=?32). Support for construct validity was evidenced by significant positive correlations (r?=?0.17 to 0.67) with measures of stimulant craving, depressive symptoms, and pain. Four factors were revealed. Conclusions/Importance: The Stimulant Selective Severity Assessment is a new measure that can be used to assess withdrawal symptoms in users of cocaine or cocaine plus methamphetamine, but it should not be administered to users of methamphetamine only.     

Initiation into methamphetamine use for young gay and bisexual men

Research over the past 10 years has suggested that methamphetamine use has become a significant problem and is associated with risky sexual behaviors among gay and bisexual men. In order to better understand initiation into methamphetamine use among gay and bisexual men, qualitative analyses were performed on a sample of young gay and bisexual men (ages 18–29) in New York City. Participants were recruited as part of a larger study which used time–space sampling to enroll club-going young adults who indicated recent club drug (ecstasy, ketamine, GHB, methamphetamine, cocaine, and/or LSD) use. The data for this paper are derived from the qualitative interviews of 54 gay and bisexual male methamphetamine users. At initiation (1) methamphetamine was used in a social, non-sexual setting for a majority of the participants; (2) participants expressed limited knowledge of methamphetamine; and (3) many participants used cocaine as a basis for comparison when describing various effects of the drug. The understanding that at initiation methamphetamine was not solely used as a sexual enhancement for members of this community may enable health workers to more accurately target potential users when putting forth intervention efforts. Future research should aim to gain a better understanding into the role that methamphetamine plays in non-sexual contexts, particularly among gay and bisexual men who may not be part of the club “scene.” The relationship between attitudes towards methamphetamine and other drugs, particularly cocaine, among gay and bisexual men should be explored.     

Barriers and Pathways to Diffusion of Methamphetamine Use Among African Americans in the Rural South

Abstract

There are no studies of African Americans', methamphetamine use in the South where it is widespread among whites. We describe factors that inhibit or facilitate the diffusion of methamphetamine use among African Americans based on qualitative interviews with 86 drug users in rural Arkansas and Kentucky. Results suggest low prevalence of methamphetamine use among African Americans, and interviewees cited several barriers to its diffusion which were linked to the drug's ingredients, psychoactive and physiological effects, difficulty in accessing distribution networks, and established African-American preference for cocaine. Fourteen African Americans reported methamphetamine use and discussed pathways to it. Possible increases in African-American methamphetamine use merits further investigation.     

Polydrug use and its association with drug treatment outcomes among primary heroin,methamphetamine, and cocaine users

BackgroundPolydrug use may challenge effective treatment for substance use disorders. We evaluate whether secondary substance use modifies the association between treatment and primary drug use among primary heroin, cocaine and methamphetamine (MA) users.MethodsData were obtained from prospective cohort studies on people who use illicit drugs (PWUD) in California, USA. Using repeated monthly data on self-reported secondary substance use (heroin, cocaine, MA, alcohol or marijuana; ≥1 day in a month), primary drug use (≥1 day in a month), and treatment participation, collected via timeline follow-back, we fitted generalized linear mixed multiple regression models controlling for potential confounders to examine the interactions between treatment and secondary substance use on the odds of primary heroin, cocaine and MA use, respectively.ResultsIncluded in our study were 587 primary heroin, 444 primary MA, and 501 primary cocaine users, with a median of 32.4, 13.3 and 18.9 years of follow-up, respectively. In the absence of secondary substance use, treatment was strongly associated with decreased odds of primary drug use (adjusted odds ratios (aORs): 0.25, 95% CI: 0.24, 0.27, 0.07 (0.06, 0.08), and 0.07 (0.07, 0.09)) for primary heroin, MA, and cocaine users, respectively. Secondary substance use of any kind moderated these associations (0.82 (0.78, 0.87), 0.25 (0.21, 0.30) and 0.53 (0.45, 0.61), respectively), and these findings were consistent for each type of secondary substance considered. Moreover, we observed different associations in terms of direction and magnitude between secondary substance use and primary drug use during off-treatment periods across substance types.ConclusionThis study demonstrates secondary substance use moderates the temporal associations between treatment and primary drug use among primary heroin, MA and cocaine users. Disparate patterns of polydrug use require careful measurement and analysis to inform targeted treatment for polydrug users.