Low, nonreinforcing doses of heroin have been shown to shift the dose-response function of cocaine leftward in rhesus monkeys trained under a progressive-ratio schedule of i.v. drug injection. Our study sought to determine 1) whether a reciprocal enhancement of heroin self-administration would be observed when heroin was combined with low, nonreinforcing doses of cocaine, and 2) whether self-ad...

The last decade has seen cocaine establish itself as the most commonly used illicit stimulant drug in Europe, with an estimated 2.5 million young adults (aged 15–34) using the drug in the last year. Overall, powder cocaine is the most common form of the drug used, and high levels of use tend to be concentrated in a relatively small number of western European countries (e.g. Denmark, Spain, Irel...

background: the health risks of crack cocaine smoking on the oral mucosa has not been widely researched and documented. objective: the purpose of this study was to analyze the proliferative activity of oral epithelial cells exposed to crack cocaine smoke using silver nucleolar organizer region (agnor) staining. methods: oral smears were collected from clinically normal-appearing buccal mucosa b...

Many polydrug abusers combine cocaine with heroin in the form of a "speedball." This study investigated the discriminative stimulus (DS) effects of speedballs in rhesus monkeys trained to discriminate either intravenous cocaine or intravenous heroin from vehicle. Initial substitution tests revealed an asymmetry in the generalization profile of dopamine and opioid agonists such that mu agonists ...

BACKGROUND Current drug-control strategies in Canada focus funding and resources predominantly on drug law enforcement, often at the expense of preventive, treatment, and harm reduction efforts. This study aimed to examine the availability of the most commonly used substances in Vancouver, Canada after the implementation of such strategies. METHODS Using data from two large cohorts of drug-us...

BACKGROUND This study examined longitudinal patterns of heroin use, other substance use, health, mental health, employment, criminal involvement, and mortality among heroin addicts. METHODS The sample was composed of 581 male heroin addicts admitted to the California Civil Addict Program (CAP) during the years 1962 through 1964; CAP was a compulsory drug treatment program for heroin-dependent...

This paper examines the effects of cocaine and heroin prices and possession arrests on medical examiner mentions of cocaine and heroin in 37 metropolitan statistical areas (MSAs) over the 1990-1998 period. Using data from DAWN, STRIDE, Uniform Crime Reports, BEA, BLS, and the Census Bureau, OLS regression results show that without the inclusion of MSA dummies, there is a highly significant nega...

US Federal sentencing guidelines punish possession of crack cocaine very differently from powder cocaine, based partially upon the assumption that crack users engage more frequently in criminal behavior to pay for their habit. This article analyzed frequent users (those who have used at least 15 of the last 30 days) of crack with subgroups of less frequent hard drug users in terms of various in...

OBJECTIVE To describe the pattern of co-use of heroin and cocaine in individuals who were not receiving methadone maintenance treatment. DESIGN Structured interviews. SETTING Community hospital. PARTICIPANTS Individuals (n = 1111) selected from a cohort of out-of-treatment injection drug users in Montréal, Que. OUTCOME MEASURE Frequency (injections per day) and quantity (number of days ...

In 2004, a team comprised of researchers and service providers launched the Safer Crack Use, Outreach, Research and Education (SCORE) project in the Downtown Eastside of Vancouver, British Columbia, Canada. The project was aimed at developing a better understanding of the harms associated with crack cocaine smoking and determining the feasibility of introducing specific harm reduction strategie...