Self-report of illicit benzodiazepine use on the Addiction Severity Index predicts treatment outcome

Opioid use disorder in two samples of the Lebanese population: scale validation and correlation with sleep and mood disorders

BACKGROUND

The revised Opioid Risk Tool (ORT-OUD) is a brief, self-report scale designed to provide clinicians with a simple, validated method to screen for the risk of developing an Opioid Use Disorder (OUD) in patients without a prior history of substance abuse. This study aimed to translate and validate the Arabic version of ORT-OUD in the Lebanese population and assess its clinical validity in a sample of patients with OUD.

METHODS

This cross-sectional study in the Lebanese population used several validated scales to assess the risk of OUD, including the Alcohol, Smoking, and Substance Involvement Screening Test (ASSIST). Other tools evaluated chronotype and sleep and mood disturbances. Principal component analysis with Varimax rotation was applied to assess ORT-OUD construct validity. Convergent validity with the Arabic version of ASSIST was evaluated. The ORT-OUD criterion validity was then assessed in a clinical sample of patients with OUD.

RESULTS

This study included 581 participants. The prevalence of the OUD risk in the Lebanese population using the ORT-OUD scale and the ASSIST-opioids scale was estimated at 14.5% and 6.54%, respectively. No items of the ORT-OUD were removed; all items converged over a solution of four factors with an eigenvalue > 1, explaining a total of 68.2% of the variance (Cronbach's alpha = 0.648). The correlation coefficients between the ORT-OUD total score and ASSIST subscales were as follows: ASSIST-opioids (r = 0.174; p = < 0.001), ASSIST-sedatives (r = 0.249; p < 0.001), and ASSIST-alcohol (r = 0.161; p = < 0.001). ORT-OUD clinical validation showed a correlation with ASSIST-opioids (r = 0.251; p = 0.093) and ASSIST-sedatives (r = 0.598; p < 0.001). Higher ORT-OUD scores were associated with a family and personal history of alcohol and substance consumption and higher insomnia and anxiety scores.

CONCLUSIONS

This study is the first to validate the Arabic version of ORT-OUD in the Lebanese population, an essential step towards improving the detection and management of OUD in this population.

Predictors of Retention and Drug Use Among Patients With Opioid Use Disorder Transferred to a Specialty "Second Chance" Methadone Program

Background

Many patients in methadone treatment have difficulty achieving or maintaining drug abstinence, and many clinics have policies that lead to discharging these patients. We designed a pilot "Second Chance" (SC) program for patients scheduled to be discharged from other local methadone clinics to be transferred to our clinic.

Aim

Determine whether SC patients' retention and opioid use is related to physical or mental health conditions, non-opioid substance use, or treatment features.

Methods

From December 2012 to December 2014, this program enrolled 70 patients who were discharged from other clinics in the area; we were their last remaining option for methadone treatment. Unlike the clinic's standard policies, the treatment focus for SC patients was retention rather than abstinence. This program focused on connection to care (eg, psychiatric services) and enabled patients to continue receiving services despite ongoing substance use. Each patient was assessed at treatment entry and followed until June 2016 to evaluate outcomes.

Results

SC patients receiving disability benefits (n = 37) vs. non-disabled (n = 33) had significantly (P < .05) higher rates of current DSM-IV Axis I psychiatric diagnosis (97% vs 70%), prescriptions for opioids (84% vs 55%) and benzodiazepines (65% vs 27%), and higher methadone doses at admission (58 vs 46 mg) but did not differ significantly in rates of 6-month or 1-year retention (77% and 56%, respectively) or all-drug use (39% positive urine drug screens). Methadone doses >65 mg predicted significantly longer retention and less opioid use, but these effects were not moderated by baseline characteristics.

Conclusions

Patients in methadone treatment struggling to achieve abstinence may benefit from retention-oriented harm-reduction programs. Higher methadone doses can improve retention and opioid abstinence despite psychiatric comorbidities. Further work is needed to improve program implementation and outcomes in this complex population.

Factors affecting addiction severity index (ASI) among clients enrolled in methadone maintenance treatment (MMT) program in Myanmar

BACKGROUND

Opioid substitution with methadone maintenance treatment (MMT) is shown to reduce illicit opioid use and renew social functioning. Understanding factors that undermine clients' social functioning during MMT treatment is vital for improving treatment compliance and quality of life.

METHOD

A total of 210 respondents who were already enrolled in a formal MMT program in Myanmar were recruited from five cities through stratified random sampling for this cross-sectional study. The addiction severity index (ASI) was used to objectively assess respondents social functioning in the last 30 days. Higher ASI scores denote poorer social functioning.

RESULT

Respondents total ASI scores in the respective domains were: employment (47.4%), alcohol (44.4%), drug use (7.2%), legal (49.2%) and social-family relationship (10.7%). Those reported to have never injected drugs in the last 30 days had lower ASI total scores than those who reported injection drug use (p = 0.01). After identifying the differences in ASI total scores, we found there were significant associations in the clients' hepatitis C status, age category, frequency of heroin injection, quality of life score, marital status, current leisure status with family/friend, current history of injection in the last 30 days, income status, satisfaction with current marital status, as well as reported drug and alcohol use (p < 0.05). Stepwise binary logistic regression showed that alcohol and higher frequency of heroin injection were associated with higher ASI scores. Meanwhile, older age, respondents those who had leisure time with family, and satisfied with current marital status had lower ASI scores (p < 0.05).

CONCLUSION

Our results indicate that those enrolled in the MMT program in Myanmar faced many challenges in their daily social functioning. Treatment providers must take heed of these apparent impediment to ensure clients chequered social functioning does not undermine their treatment compliance.

TRIAL REGISTRATION

NA.

The epidemiology of benzodiazepine misuse: A systematic review

BACKGROUND

Benzodiazepine misuse is a growing public health problem, with increases in benzodiazepine-related overdose deaths and emergency room visits in recent years. However, relatively little attention has been paid to this emergent problem. We systematically reviewed epidemiological studies on benzodiazepine misuse to identify key findings, limitations, and future directions for research.

METHODS

PubMed and PsychINFO databases were searched through February 2019 for peer-reviewed publications on benzodiazepine misuse (e.g., use without a prescription; at a higher frequency or dose than prescribed). Eligibility criteria included human studies that focused on the prevalence, trends, correlates, motives, patterns, sources, and consequences of benzodiazepine misuse.

RESULTS

The search identified 1970 publications, and 351 articles were eligible for data extraction and inclusion. In 2017, benzodiazepines and other tranquilizers were the third most commonly misused illicit or prescription drug in the U.S. (approximately 2.2% of the population). Worldwide rates of misuse appear to be similar to those reported in the U.S. Factors associated with misuse include other substance use, receipt of a benzodiazepine prescription, and psychiatric symptoms and disorders. Benzodiazepine misuse encompasses heterogeneous presentations of motives, patterns, and sources. Moreover, misuse is associated with myriad poor outcomes, including mortality, HIV/HCV risk behaviors, poor self-reported quality of life, criminality, and continued substance use during treatment.

CONCLUSIONS

Benzodiazepine misuse is a worldwide public health concern that is associated with a number of concerning consequences. Findings from the present review have implications for identifying subgroups who could benefit from prevention and treatment efforts, critical points for intervention, and treatment targets.

"I's" on the prize: A systematic review of individual differences in Contingency Management treatment response

Contingency Management is an evidence-based treatment for substance use disorders with strong potential for measurement-based customization. Previous work has examined individual difference factors in Contingency Management treatment response of potential relevance to treatment targeting and adaptive implementation; however, a systematic review of such factors has not yet been conducted. Here, we summarize and evaluate the existing literature on patient-level predictors, mediators, and moderators of Contingency Management treatment response in stimulant and/or opioid using outpatients - clinical populations most frequently targeted in Contingency Management research and clinical practice. Our search strategy identified 648 unique, peer-reviewed publications, of which 39 met full inclusion criteria for the current review. These publications considered a variety of individual difference factors, including (1) motivation to change and substance use before and during treatment (8/39 publications), (2) substance use comorbidity and chronicity (8/39 publications), (3) psychiatric comorbidity and severity (8/39 publications), (4) medical, legal, and sociodemographic considerations (15/39 publications), and (5) cognitive-behavioral variables (1/39 publications). Contingency Management was generally associated with improved treatment outcomes (e.g., longer periods of continuous abstinence, better retention), regardless of individual difference factors; however, specific patient-level characteristics were associated with either an enhanced (e.g., more previous treatment attempts, history of sexual abuse, diagnosis of antisocial personality disorder) or diminished (e.g., complex post-traumatic stress symptoms, pretreatment benzodiazepine use) response to Contingency Management. Overall, the current literature is limited but existing evidence generally supports greater benefits of Contingency Management in patients who would otherwise have a poorer prognosis in standard outpatient care. It was also identified that the majority of previous work represents a posteriori analysis of pre-existing clinical samples and has therefore rarely considered pre-specified, hypothesis-driven individual difference factors. We therefore additionally highlight patient-level factors that are currently understudied, as well as promising future directions for measurement-based treatment adaptations that may directly respond to patient traits and states to improve Contingency Management effectiveness across individuals and over time.

Nonmedical prescription sedative/tranquilizer use in alcohol and opioid use disorders

AIMS

Nonmedical prescription sedative/tranquilizer (e.g., benzodiazepines) use (NMSTU) increases risk of overdose when combined with opioids and/or alcohol. Yet, little is known about NMSTU among those with alcohol and opioid use disorders. We aimed to characterize NMSTU and sedative/tranquilizer use disorder among adults with alcohol use disorder (AUD) and/or opioid use disorder (OUD) in a general population sample.

METHODS

We conducted analyses of 2008-2014 National Survey on Drug Use and Health data; adults with past-year AUD-only (n = 27,416), OUD-only (n = 2142), and co-occurring AUD and OUD (n = 1483) were included (total N = 31,041). Multivariable logistic regression models were utilized to examine correlates of past-month NMSTU and past-year sedative/tranquilizer use disorder. Focal independent variables were polysubstance use (i.e., number of substances used in the previous year) and psychiatric distress.

RESULTS

Among those with AUD-only, 27.1% reported lifetime NMSTU, 7.6% reported past-year NMSTU, 2.7% reported past-month NMSTU, and 0.6% met criteria for past-year sedative/tranquilizer use disorder. Corresponding prevalence rates among those with OUD-only were 69.5%, 43.0%, 22.6%, and 11.3%. Those with co-occurring AUD and OUD displayed the highest rates of NMSTU (e.g., 27.5% with past-month NMSTU) and sedative/tranquilizer use disorder (20.2%). Across groups, more severe polysubstance use and psychiatric distress were associated with increased risk of NMSTU and sedative/tranquilizer use disorder.

CONCLUSIONS

Results of this analysis indicate that >25% of adults with AUD and approximately 70% of those with OUD report lifetime NMSTU. Among these populations, individuals with more polysubstance use and greater psychiatric distress might benefit from targeted interventions to reduce NMSTU.

Conditional probabilities of substance use disorders and associated risk factors: Progression from first use to use disorder on alcohol, cannabis, stimulants, sedatives and opioids

BACKGROUND

Relatively little is known about factors that may lead to the development of a substance use disorder (SUD), across a range of drug classes. This study aimed to identify factors that predict the likelihood of transition from use to SUD and the speed with which this may occur at the population level, with a focus on the impact of pre-existing mental disorders.

METHODS

Data were collected as part of the 2007 Australian National Survey of Mental Health and Wellbeing, a nationally representative survey of 8841 Australian adults. A series of discrete time survival analyses were undertaken on data pertaining to the age of onset of use and symptoms of use disorder, for alcohol, cannabis, sedatives, stimulants, and opioids, as well as the impact of pre-existing mood and anxiety disorders on the likelihood of developing a SUD.

RESULTS

Lifetime cumulative probability estimates indicated that 50.4% of stimulant, 46.6% of opioid, 39% of sedative, 37.5% of alcohol, and 34.1% of cannabis users would develop a SUD on those substances, within an estimated 14, 12, 8, 30, and 23 years after onset respectively. Pre-existing mental disorders were significantly associated with increased risk of developing a SUD for alcohol, cannabis and stimulant use disorder.

CONCLUSION

The relative speed associated with the transition from use to SUD emphasizes the narrow window of time available to intervene, underscoring the urgency of early identification of mental health conditions and the timely provision of appropriate evidence-based interventions, which could potentially prevent the development of secondary SUDs.

Factors associated with sedative use and misuse among heroin users

BACKGROUND

Rates of both opioid and sedative use and misuse are rising. Comorbid opioid and sedative use is associated with especially severe consequences (e.g., overdose and poor health outcomes). Heroin users report multiple motivations for sedative use, including self-medication. We aimed to understand differences in lifetime substance use characteristics between heroin users with different sedative use histories.

METHODS

Substance use data were collected from 385 non-treatment seeking heroin users. Subjects were divided into four lifetime sedative-use groups: no use, medical use only, non-medical use only, and mixed medical and non-medical use. We examined patterns of use of various substances of abuse (tobacco, alcohol, marijuana, cocaine, heroin, and sedatives) and individual characteristics associated with each.

RESULTS

Non-medical sedative use (alone or in addition to medical use) was associated with more negative consequences from using all substances. Medical sedative use alone was not related to increased overdose or emergency room visits associated with heroin use. Non-medical sedative use was associated with increases in 15 of the 21 measured heroin consequences and only one of those - health problems - was also associated with medical sedative use.

CONCLUSIONS

Concomitant non-medical sedative use and heroin use is associated with significantly greater negative outcomes than those experienced by heroin users who report use of sedatives only as prescribed. Understanding these differences offers insight into risks related to using both substances and may help treatment providers create targeted harm reduction interventions for this population.

High enhancer, downer, withdrawal helper: Multifunctional nonmedical benzodiazepine use among young adult opioid users in New York City

BACKGROUND

Benzodiazepines are a widely prescribed psychoactive drug; in the U.S., both medical and nonmedical use of benzodiazepines has increased markedly in the past 15 years. Long-term use can lead to tolerance and dependence, and abrupt withdrawal can cause seizures or other life-threatening symptoms. Benzodiazepines are often used nonmedically in conjunction with other drugs, and with opioids in particular-a combination that can increase the risk for fatal and non-fatal overdose. This mixed-methods study examines nonmedical use of benzodiazepines among young adults in New York City and its relationship with opioid use.

METHODS

For qualitative analysis, 46 90-minute semi-structured interviews were conducted with young adult opioid users (ages 18-32). Interviews were transcribed and coded for key themes. For quantitative analysis, 464 young adult opioid users (ages 18-29) were recruited using Respondent-Driven Sampling and completed structured interviews. Benzodiazepine use was assessed via a self-report questionnaire that included measures related to nonmedical benzodiazepine and opioid use.

RESULTS

Participants reported using benzodiazepines nonmedically for a wide variety of reasons, including: to increase the high of other drugs; to lessen withdrawal symptoms; and to come down from other drugs. Benzodiazepines were described as readily available and cheap. There was a high prevalence (93%) of nonmedical benzodiazepine use among nonmedical opioid users, with 57% reporting regular nonmedical use. In bivariate analyses, drug-related risk behaviours such as polysubstance use, drug binging, heroin injection and overdose were strongly associated with regular nonmedical benzodiazepine use. In multivariate analysis, growing up in a middle-income household (earning between $51,000 and $100,000 annually), lifetime overdose experience, having ever used cocaine regularly, having ever been prescribed benzodiazepines, recent drug binging, and encouraging fellow drug users to use benzodiazepines to cope with opioid withdrawal were consistently strong predictors of regular nonmedical benzodiazepine use.

CONCLUSION

Nonmedical benzodiazepine use may be common among nonmedical opioid users due to its drug-related multi-functionality. Harm reduction messages should account for the multiple functions benzodiazepines serve in a drug-using context, and encourage drug users to tailor their endorsement of benzodiazepines to peers to include safer alternatives.

Preference for an Opioid/Benzodiazepine Mixture over an Opioid Alone Using a Concurrent Choice Procedure in Rhesus Monkeys

Increased abuse of opioids is contributing to an escalation in overdose deaths. Benzodiazepines are frequently abused with opioids, possibly because they increase the potency and/or effectiveness of opioids to produce reinforcing effects. This study used a concurrent-choice procedure to determine whether monkeys would choose to self-administer a mixture of the opioid remifentanil and the benzodiazepine midazolam over remifentanil alone. Initially, three monkeys could respond on one lever for saline and on a second lever for either remifentanil alone or midazolam alone. Thereafter, monkeys chose between a dose of remifentanil (0.32 µg/kg/infusion) that did not change and a dose of remifentanil that varied across sessions; for some sessions, midazolam was combined with varying doses of remifentanil. All monkeys received more infusions of remifentanil (0.0032-0.32 µg/kg/infusion) than saline, whereas only two monkeys responded more for midazolam than for saline. When 0.32 µg/kg/infusion remifentanil was available on one lever and a dose of remifentanil that varied across sessions (0.1-1 µg/kg/infusion) was available on the other lever, monkeys chose the larger dose. Combining 3.2 µg/kg/infusion midazolam with 0.32 µg/kg/infusion remifentanil increased responding for the mixture over 0.32 µg/kg/infusion remifentanil alone, although monkeys chose remifentanil alone over mixtures containing smaller doses of remifentanil. When 10 µg/kg/infusion midazolam was combined with 0.1 µg/kg/infusion remifentanil, monkeys chose the mixture over 0.32 µg/kg/infusion remifentanil alone. Thus, monkeys prefer some opioid/benzodiazepine mixtures to larger doses of the opioid alone, suggesting that opioid/benzodiazepine coabuse might be due to increased potency (and possibly effectiveness) of opioids to produce reinforcing effects.

Psychosocial interventions for benzodiazepine harmful use, abuse or dependence

BACKGROUND

Benzodiazepines (BZDs) have a sedative and hypnotic effect upon people. Short term use can be beneficial but long term BZD use is common, with several risks in addition to the potential for dependence in both opiate and non-opiate dependent patients.

OBJECTIVES

To evaluate the effectiveness of psychosocial interventions for treating BZD harmful use, abuse or dependence compared to pharmacological interventions, no intervention, placebo or a different psychosocial intervention on reducing the use of BZDs in opiate dependent and non-opiate dependent groups.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL- the Cochrane Library issue 12, 2014) which includes the Cochrane Drugs and Alcohol Group Specialized Register; PubMed (from 1966 to December 2014); EMBASE (from 1988 to December 2014); CINAHL Cumulative Index to Nursing and AlliedHealth Literature (1982 to September 2013); PsychINFO (1872 to December 2014); ERIC (Education Resources Information Centre, (January 1966 to September 2013); All EBM Reviews (1991 to September 2013, Ovid Interface); AMED (Allied & Alternative Medicine) 1985 to September 2013); ASSIA (Applied Social Sciences Index & Abstracts (1960 to September 2013); LILACS (January 1982 to September 2013);Web of Science (1900 to December 2014);Electronic Grey Literature Databases: Dissertation Abstract; Index to Theses.

SELECTION CRITERIA

Randomised controlled trials examining the use of a psychosocial intervention to treat BZDs versus pharmacological interventions,no intervention, placebo or a different psychosocial intervention on reducing the use of BZDs in opiate dependent and non-opiate dependent groups.

DATA COLLECTION AND ANALYSIS

We used the standard methodological procedures outlined in Cochrane Guidelines.

MAIN RESULTS

Twenty-five studies including 1666 people met the inclusion criteria. The studies tested many different psychosocial interventions including cognitive behavioural therapy (CBT) (some studies with taper, other studies with no taper), motivational interviewing (MI),letters to patients advising them to reduce or quit BZD use, relaxation studies, counselling delivered electronically and advice provided by a general practitioner (GP). Based on the data obtained, we performed two meta-analyses in this Cochrane review: one assessing the effectiveness of CBT plus taper versus taper only (575 participants), and one assessing MI versus treatment as usual (TAU) (80 participants).There was moderate quality of evidence that CBT plus taper was more likely to result in successful discontinuation of BZDs within four weeks post treatment compared to taper only (Risk ratio (RR) 1.40, 95% confidence interval (CI) 1.05 to 1.86; nine trials, 423 participants) and moderate quality of evidence at three month follow-up (RR 1.51, 95% CI 1.15 to 1.98) in favour of CBT (taper)for 575 participants. The effects were less certain at 6, 11, 12, 15 and 24 months follow-up. The effect of CBT on reducing BZDs by> 50% was uncertain for all time points examined due to the low quality evidence. There was very low quality evidence for the effect on drop-outs at any of the time intervals; post-treatment (RR 1.05, 95% CI 0.66 to 1.66), three month follow-up (RR 1.71, 95% CI0.16 to 17.98) and six month follow-up (RR 0.70, 95% CI 0.17 to 2.88).Based on the very low quality of evidence available, the effect of MI versus TAU for all the time intervals is unclear; post treatment(RR 4.43, 95% CI 0.16 to 125.35; two trials, 34 participants), at three month follow-up (RR 3.46, 95% CI 0.53 to 22.45; four trials,80 participants), six month follow-up (RR 0.14, 95% CI 0.01 to 1.89) and 12 month follow-up (RR 1.25, 95% CI 0.63 to 2.47).There was very low quality of evidence to determine the effect of MI on reducing BZDs by > 50% at three month follow-up (RR 1.52,95% CI 0.60 to 3.83) and 12 month follow-up (RR 0.87, 95% CI 0.52 to 1.47). The effects on drop-outs from treatment at any of e time intervals between the two groups were uncertain due to the wide CIs; post-treatment (RR 0.50, 95% CI 0.04 to 7.10), three month follow-up (RR 0.46, 95% CI 0.06 to 3.28), six month follow-up (RR 8.75, 95% CI 0.61 to 124.53) and 12 month follow-up(RR 0.42, 95% CI 0.02 to 7.71).The following interventions reduced BZD use - tailored GP letter versus generic GP letter at 12 month follow-up (RR 1.70, 95%CI 1.07 to 2.70; one trial, 322 participants), standardised interview versus TAU at six month follow-up (RR 13.11, 95% CI 3.25 to 52.83; one trial, 139 participants) and 12 month follow-up (RR 4.97, 95% CI 2.23 to 11.11), and relaxation versus TAU at three month follow-up (RR 2.20, 95% CI 1.23 to 3.94).There was insufficient supporting evidence for the remaining interventions.We performed a 'Risk of bias' assessment on all included studies. We assessed the quality of the evidence as high quality for random sequence generation, attrition bias and reporting bias; moderate quality for allocation concealment, performance bias for objective outcomes, and detection bias for objective outcomes; and low quality for performance bias for subjective outcomes and detection bias for subjective outcomes. Few studies had manualised sessions or independent tests of treatment fidelity; most follow-up periods were less than 12 months.Based on decisions made during the implementation of protocol methods to present a manageable summary of the evidence we did not collect data on quality of life, self-harm or adverse events.

AUTHORS' CONCLUSIONS

CBT plus taper is effective in the short term (three month time period) in reducing BZD use. However, this is not sustained at six months and subsequently. Currently there is insufficient evidence to support the use of MI to reduce BZD use. There is emerging evidence to suggest that a tailored GP letter versus a generic GP letter, a standardised interview versus TAU, and relaxation versus TAU could be effective for BZD reduction. There is currently insufficient evidence for other approaches to reduce BZD use.

Clinically relevant characteristics associated with early treatment drug use versus abstinence

Background

This study describes early treatment drug use status and associated clinical characteristics in a diverse sample of patients entering outpatient substance abuse psychosocial counseling treatment. The goal is to more fully characterize those entering treatment with and without active use of their primary drug in order to better understand associated treatment needs and resilience factors.

Methods

We examined baseline data from a NIDA Clinical Trials Network (CTN) study (Web-delivery of Treatment for Substance Use) with an all-comers sample of patients (N = 494) entering 10 outpatient treatment centers. Patients were categorized according to self-identified primary drug of abuse (alcohol, cocaine/stimulants, opioids, marijuana) and by baseline drug use status (positive/negative) based on urine testing or self-reports of recent use (alcohol). Characteristics were examined by primary drug and early use status.

Results

Classified as drug-negative were 84%, 76%, 62%, and 33% of primary opioid, stimulant, alcohol, and marijuana users; respectively. Drug-positive versus -negative patients did not differ on demographics or rates of substance abuse/dependence diagnoses. However, those negative for active use had better physical and mental health profiles, were less likely to be using a secondary drug, and were more likely to be attending 12-step self-help meetings.

Conclusions

Early treatment drug abstinence is common among substance users entering outpatient psychosocial counseling programs, regardless of primary abused drug. Abstinence (by negative UA) is associated with better health and mental health profiles, less secondary drug use, and more days of 12-step attendance. These data highlight differential treatment needs and resiliencies associated with early treatment drug use status.

Trial registration

NCT01104805.

The discriminative stimulus effects of midazolam are resistant to modulation by morphine, amphetamine, dizocilpine, and γ-butyrolactone in rhesus monkeys

RATIONALE

Although abuse of benzodiazepines alone is uncommon, it is high in polydrug abusers, including those who primarily use opioids or stimulants.

OBJECTIVES

This study investigated whether drugs that are abused (e.g., amphetamine) or drugs that have mechanisms of action similar to abused drugs (e.g., morphine) alter the discriminative stimulus effects of the benzodiazepine midazolam.

METHODS

Three rhesus monkeys discriminated 0.56 mg/kg of midazolam while responding under a fixed-ratio 10 schedule of food presentation. Dose-effect curves were determined for midazolam alone and in the presence of morphine (opioid receptor agonist), amphetamine (dopamine receptor indirect agonist), dizocilpine (N-methyl-D: -aspartic acid receptor antagonist), or γ-butyrolactone (prodrug of γ-hydroxybutyrate, which acts primarily at GABA(B) receptors).

RESULTS

Doses of midazolam larger than 0.32 mg/kg produced ≥80% midazolam-lever responding. When administered alone, morphine, amphetamine, dizocilpine, and γ-butyrolactone did not produce midazolam-lever responding, although large doses of each drug eliminated responding; when administered in combination with midazolam, they did not alter the discriminative stimulus effects of midazolam up to doses that markedly decreased response rates.

CONCLUSIONS

The current study demonstrates a lack of modulation of the discriminative stimulus effects of midazolam by morphine, amphetamine, dizocilpine, and γ-butyrolactone. Other effects of benzodiazepines, such as their reinforcing effects, might be altered by these other drugs, or benzodiazepines might modulate the discriminative stimulus or reinforcing effects of the other drugs, which might contribute to the relatively high incidence of benzodiazepine abuse among polydrug abusers.

Effects of acute and chronic flunitrazepam on delay discounting in pigeons

Delay to delivery of a reinforcer can decrease responding for that reinforcer and increase responding for smaller reinforcers that are available concurrently and delivered without delay; acute administration of drugs can alter responding for large, delayed reinforcers, although the impact of chronic treatment on delay discounting is not well understood. In this experiment, the effects of repeated administration of the benzodiazepine flunitrazepam were studied in 6 pigeons responding on one key to receive food that was delivered immediately and on a second key to receive a larger amount of food that was delivered following delays which increased across a single session. Pigeons responded predominantly for the large reinforcer when there were no delays and when delays were short; however, as delays increased, responding for the large reinforcer decreased. Acutely, flunitrazepam (0.32, 1.0 and 3.2 mg/kg) dose-dependently increased responding for the large reinforcer, shifting the discounting curve rightward and upward. Repeated administration of flunitrazepam (0.32, 1.0 and 3.2 mg/kg, each for six sessions, separated by one session during which vehicle was administered) did not markedly alter its effects on responding for the large reinforcer, indicating that the development of tolerance to this effect of flunitrazepam is modest under these conditions.

Benzodiazepine use among heroin users: baseline use, current use and clinical outcome

INTRODUCTION AND AIMS

Benzodiazepine use is associated with elevated levels of harm. The current study aimed to ascertain the long-term nature of the relationship between benzodiazepine use and clinical profile among heroin users.

DESIGN AND METHODS

Longitudinal cohort, with follow-up at 3, 12, 24 and 36 months. Participants were 615 heroin users recruited for the Australian Treatment Outcome Study.

RESULTS

At baseline, current benzodiazepine users were more likely to be committing crime, had poorer psychological health and poorer physical health. Baseline benzodiazepine use was not associated with the likelihood across follow-up of heroin use (P = 0.44), committing crime (P = 0.17), poorer psychological health (P = 0.31) or poorer physical health (P = 0.48). Current benzodiazepine use was, however, associated with a greater likelihood of concurrent heroin use (OR 2.77), crime (OR 2.04), poorer psychological health (beta = -4.47) and poorer physical health (beta = -2.33).

DISCUSSION AND CONCLUSIONS

Clinicians should be aware that reductions in benzodiazepine use are associated with reductions in harm, and that baseline benzodiazepine status does not equate to poor long-term outcome.

Clinical Characteristics of Central European and North American Samples of Pregnant Women Screened for Opioid Agonist Treatment

BACKGROUND

Little comparable information is available regarding clinical characteristics of opioid-dependent women from different countries. In the present study, women from the USA, Canada and a Central European country, Austria, screened for participation in the Maternal Opioid Treatment Human Experimental Research study, were compared with respect to their demographic and addiction histories.

METHODS

Pregnant women (n = 1,074) were screened for study participation using uniformed clinical criteria and instruments. The screening results were compared with regard to exclusion, demographics, drug use, and psychosocial and treatment histories.

RESULTS

Compared to the screened US and Canadian women, Austrian women were more likely to be younger (p < 0.001), white (p < 0.001), had significantly lower levels of educational attainment (p < 0.001), were less likely to use opioids daily (p < 0.001) and more likely to have been prescribed buprenorphine (p < 0.001). Compared to both rural and urban US groups, the Austrian group was less likely to have legal issues (p < 0.001) and was younger when first prescribed agonist medication (p < 0.001).

CONCLUSION

The differences between North American and European groups may offer unique insights concerning treatment and pregnancy outcomes for opioid-dependent pregnant women.