Drug Preference in Humans: Lorazepam

A drug’s capacity to reinforce behavior in a laboratory setting usually correlates with its dependence potential in the general population. In laboratory tests, diazepam is not an effective positive reinforcer, either in laboratory animals using drug self-administration tests () or in normal human volunteer subjects using a choice test (). The failure to find evidence for a positive reinforcing effect of diazepam in these experimental tests is inconsistent with clinical reports that diazepam is used excessively by some people. The failure to demonstrate the positive reinforcing efficacy of diazepam in an experimental situation may be due in part to the drug’s long duration of action (half-life = 24 – 48 hours). In animal self-administration studies that test the reinforcing efficacy of drugs, it has been found that benzodiazepines that have shorter durations of action are also more effective reinforcers (). In the present study, human subjects were tested for preference for lorazepam, a benzodiazepine with effects similar to diazepam but with a shorter half-life than diazepam (half-life = 12-15 hours). Method Subjects. Twelve normal healthy volunteers, aged 21 to 27 (4 males, 8 females) participated in this study. Read more […]

Measuring the Developmental Nature of Multiple Drug Use

There have been a number of studies in which attempts have been made to measure or assess multiple drug use. Some of these are from general populations while others are focused on specific subpopulations of users. The studies are grouped more on the basis of the approach taken to assessing multiple drug use than on the patterns uncovered. There are at least four different groupings of studies and some studies fit into more than one grouping. Developmental Patterns of Onset of Use One of the most influential attempts to describe patterns of multiple drug use is the “stages of drug use” model developed by Kandel. Kandel posited that persons proceed from licit to illicit drugs and from use of less to more serious drugs. The stages of drug use involvement that she identified were: (1) no use of any drugs; (2) use of beer or wine; (3) use of cigarettes and/or hard liquor; (4) use of marijuana; and (5) use of illicit drugs other than marijuana. Although it is not made explicit by Kandel, there is an implication that the drugs from the earlier stages of development are “carried forward” into the later stages of drug involvement. Thus, a marijuana user is likely to continue his or her use of cigarettes/hard liquor and beer Read more […]

Internal Stimulus Control and Subjective Effects of Drugs

For many years psychotropic drugs have been characterized and classified using methods designed to measure their subjective effects in humans (). This research approach has two principal purposes: 1) to investigate the efficacy of a drug in attenuating unwanted subjective states in patients (e.g., pain, anxiety, depression), 2) to investigate the abuse potential of new drugs by comparing their subjective effects in experienced drug abusers to those produced by known drugs of abuse. In regard to the latter, such methods have been used to determine whether there are any common subjective states produced by all drugs of abuse (e.g., euphoria). Systematic studies of subjective methods for drug classification have been conducted at the Addiction Research Center (ARC) in Lexington, Kentucky, now part of the National Institute on Drug Abuse. A major mission of the ARC has been to evaluate new analgesic compounds to determine whether they produced morphine-like effects. The subjective effects of morphine and related compounds were an important aspect of this evaluation. The research demonstrated that morphine and related narcotic analgesics produced a unique spectrum of subjective effects that can be reliably discriminated Read more […]

A Review of Drug Abuse Data Bases: the National Survey

The data base which appears to provide the most consistent source of drug use data on youth and young adults is the National Survey co2nducted between 1971 and 1977. There are five studies in this series. The first two surveys were conducted for the National Commission on Marihuana and Drug Abuse. The most recent three were conducted for the National Institute on Drug Abuse. The five studies are entitled: 1) 1971 study: Public Attitudes Toward Marihuana. 2) 1972 study: Drug Experience, Attitudes and Related Behavior Among Adolescents and Adults. 3) 1974 study: Public Experience with Psychoactive Substances. 4) 1976 study: Nonmedical Use of Psychoactive Substances. () 5) 1977 study: National Survey on Drug Abuse. () These surveys share several critical characteristics which contribute to their utility for estimating drug use: Data collection on the “at risk” 18-25 year age bracket; Adequate and consistent sampling methodology; Comparability of drugs investigated; Comparability of question formats; and Accessibility of detailed tabular data. Each of the five studies is discussed below to demonstrate its adequacy as a data base for projecting the number of drug users in the United States Read more […]

A Review of Drug Abuse Data Bases: Treatment-Oriented Data Systems

Six treatment-oriented data systems were studied: 1. Drug Abuse Warning Network (DAWN) Purpose. Project DAWN is a Federal program jointly funded by the Drug Enforcement Administration (DEA) and the National Institute on Drug Abuse (NIDA). DAWN has been in existence since 1972 and was established to monitor the consequences of drug abuse using two indicators, emergency room visits and deaths. Respondents and Sampling. DAWN collects its information through episode reports provided by selected hospital emergency rooms, crisis centers, and medical examiners. In order to be eligible, emergency rooms must: Be open 24 hours per day; Be located in non-Federal short-term general hospitals (specialty hospitals, hospital units of institutions, and pediatric hospitals are excluded); and Have at least 1,000 patient visits to the emergency room per year. At the end of 1978, over 900 facilities were supplying data to the program. Reporting facilities are concentrated in 24 Standard Metropolitan Statistical Areas (SMSA’S) which are not randomly selected but are chosen to account for approximately 30 percent of the population of the U.S. in geographically diverse locations. Drugs Investigated. DAWN distinguishes Read more […]

Epidemiology of Drug Use Among Adolescents

This review of the epidemiology of adolescent drug use focuses on typical stages of the drug use career and assesses the diversity of experience that my characterize special subgroups of youth. As shown by earlier longitudinal studies (), drug use during the adolescent years is a dynamic, multistage phenomenon which my best be understood by a conceptualization of progressive stages of involvement. The most recent data on dominant patterns of drug use in the 12 to 21 age group are provided by two series of nationwide surveys: the national survey of high school seniors () and the national survey of household population aged 12 and older (). Both of these surveys are cross-sectional, but because many of the data consist of retrospective drug use histories, nationwide patterns of use in 1979 can be described in terms of sequential stages of drug experience. As Kandel has noted, the study of stages of adolescent drug use does not imply “that the use of a drug causes the progression to the next level. Nor can we assume that once started adolescents will progress through the entire sequence” (). Rather, during the adolescent years, each stage of the drug use career represents a risk factor with regard to more serious stages Read more […]

Adolescence and Drug Abuse: Biomedical Consequences

Many facets of the biomedical aspects of substance abuse in adolescents have not yet been adequately researched. Little is known about the biological elements, if any, that contribute to the genesis of substance abuse. In the instance of alcoholism a genetic vulnerability appears to be established from the studies of identical twins, one raised by the natural parent and the other placed at an early age in the home of nonalcoholic foster parents. In the studies conducted both in this country () and in Denmark () the incidence of problem drinking of both groups of twins was similar. It is well established that among people of Mongolian descent, a widespread sensitivity to alcohol, based upon the rapid accumulation of acetaldehyde, is observed (). Facial flushing and more upsetting symptoms, including asthma and hypotension, can be present. In those with marked discomfort after drinking small amounts of ethanol, a certain preventive role is probably played by this inborn racial change in the ability to metabolize alcohol. Such genetic factors have not yet been uncovered for other psychoactive drugs. With the recent identification of opiate () and benzodiazepine () receptor sites, and the hint that other drug-specific Read more […]

The Diagnosis and Treatment of the Phencyclidine Abuse Syndrome

David E. Smith, M.D., Donald R. Wesson, M.D., Millicent E. Buxton, Richard Seymour, M.A., and Honey M. Kramer Our first exposure to Phencyclidine occurred during the summer of 1967 in the Haight-Ashbury District of San Francisco in which the drug was first introduced as the “PeaCe Pill” during a rock concert. We saw that day between twenty-five and thirty acute Phencyclidine toxic reactions. In some respects, these reactions were like the bad LSD trips we were used to treating, but in other respects quite different, with greater physical toxicity and paranoid thinking. We had samples of the “PeaCe Pill” analyzed through a local Bay Area toxicology laboratory and found that the psychoactive drug was PCP. The “PeaCe Pill” was not well received by the majority of individuals in Haight-Ashbury at that time, although Phencyclidine became the drug of choice for a small number of users who continued to use it on a chronic basis. For them most part, Phencyclidine was a drug of deception, usually marketed as “THC” or as one of the psychedelics which were more in demand. Within the past five years, however, Phencyclidine has become increasingly visible as a primary drug of abuse under a variety of street names, including “hog,” Read more […]

Survey of Methamphetamine Cases Evaluated in a Court Clinic

Although assessment and treatment options in the county from which the below cases were reviewed are better than many, they are generally available only to defendants for whom a mandatory prison sentence is not involved. The general inclination of judges at this court is to refer whenever they perceive questions about treatment-related issues. It is the impression of the court psychologist that defendants referred for a pre-sentence psychological evaluation often are seen as having greater potential for treatment than incarceration. The focus for psychological evaluations as the psychologist reported it is to develop information relevant to the mitigation and sentencing issues and to the risk of violation of probation where a treatment package is recommended. In his opinion, further evaluation of the substance-related and other treatment aspects of referred defendants should be a component of any ongoing treatment facility. The major sources of referral are the judges on their own initiatives, motions by defense counsel, or the request of the probation department where initial psychosocial history leads to a question of psychological status. The majority of referred persons with substance-related issues attend Read more […]

Drug-Drug Interactions of Cannabinoids

Alcohol Additive psychoactive effects sought by users may be achieved by combinations of cannabis and alcohol, but at the same time the ability of THC to induce microsomal enzymes will increase the rate of metabolism of alcohol and so reduce the additive effects. Anticholinergic drugs The anticholinergic effects of cannabis may result in interactions with other drugs with anticholinergic effects, such as some antidysrhythmic drugs. Barbiturates, short-acting Additive psychoactive effects sought by users may be achieved by combinations of cannabis and short-acting barbiturates, but at the same time the ability of THC to induce microsomal enzymes will increase the rate of metabolism of barbiturates and so reduce the additive effects. Disulfiram Concurrent administration with disulfiram is associated with hypomania. Indinavir The effects of smoked marijuana (3.95% tetrahydrocan-nabinol; up to three cigarettes per day) and oral dronabi-nol (2.5 mg tds) on the pharmacokinetics of indinavir 800 mg 8-hourly (n =28) have been evaluated in a randomized, placebo-controlled study in HIV-infected patients. On day 14, marijuana reduced the 8-hour AUC of indinavir by 15%, the Cmax by 14%, and the Cmin by 34%. However, only Read more […]