Buprenorphine for managing opioid withdrawal

BACKGROUND

Managed withdrawal is a necessary step prior to drug-free treatment or as the endpoint of substitution treatment.

OBJECTIVES

To assess the effects of buprenorphine versus tapered doses of methadone, alpha2-adrenergic agonists, symptomatic medications or placebo, or different buprenorphine regimens for managing opioid withdrawal, in terms of the intensity of the withdrawal syndrome experienced, duration and completion of treatment, and adverse effects.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL, Issue 11, 2016), MEDLINE (1946 to December week 1, 2016), Embase (to 22 December 2016), PsycINFO (1806 to December week 3, 2016), and the Web of Science (to 22 December 2016) and handsearched the reference lists of articles.

SELECTION CRITERIA

Randomised controlled trials of interventions using buprenorphine to modify the signs and symptoms of withdrawal in participants who were primarily opioid dependent. Comparison interventions involved reducing doses of methadone, alpha2-adrenergic agonists (clonidine or lofexidine), symptomatic medications or placebo, and different buprenorphine-based regimens.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

We included 27 studies involving 3048 participants. The main comparators were clonidine or lofexidine (14 studies). Six studies compared buprenorphine versus methadone, and seven compared different rates of buprenorphine dose reduction. We assessed 12 studies as being at high risk of bias in at least one of seven domains of methodological quality. Six of these studies compared buprenorphine with clonidine or lofexidine and two with methadone; the other four studies compared different rates of buprenorphine dose reduction.For the comparison of buprenorphine and methadone in tapered doses, meta-analysis was not possible for the outcomes of intensity of withdrawal or adverse effects. However, information reported by the individual studies was suggestive of buprenorphine and methadone having similar capacity to ameliorate opioid withdrawal, without clinically significant adverse effects. The meta-analyses that were possible support a conclusion of no difference between buprenorphine and methadone in terms of average treatment duration (mean difference (MD) 1.30 days, 95% confidence interval (CI) -8.11 to 10.72; N = 82; studies = 2; low quality) or treatment completion rates (risk ratio (RR) 1.04, 95% CI 0.91 to 1.20; N = 457; studies = 5; moderate quality).Relative to clonidine or lofexidine, buprenorphine was associated with a lower average withdrawal score (indicating less severe withdrawal) during the treatment episode, with an effect size that is considered to be small to moderate (standardised mean difference (SMD) -0.43, 95% CI -0.58 to -0.28; N = 902; studies = 7; moderate quality). Patients receiving buprenorphine stayed in treatment for longer, with an effect size that is considered to be large (SMD 0.92, 95% CI 0.57 to 1.27; N = 558; studies = 5; moderate quality) and were more likely to complete withdrawal treatment (RR 1.59, 95% CI 1.23 to 2.06; N = 1264; studies = 12; moderate quality). At the same time there was no significant difference in the incidence of adverse effects, but dropout due to adverse effects may be more likely with clonidine (RR 0.20, 95% CI 0.04 to 1.15; N = 134; studies = 3; low quality). The difference in treatment completion rates translates to a number needed to treat for an additional beneficial outcome of 4 (95% CI 3 to 6), indicating that for every four people treated with buprenorphine, we can expect that one additional person will complete treatment than with clonidine or lofexidine.For studies comparing different rates of reduction of the buprenorphine dose, meta-analysis was possible only for treatment completion, with separate analyses for inpatient and outpatient settings. The results were diverse, and we assessed the quality of evidence as being very low. It remains very uncertain what effect the rate of dose taper has on treatment outcome.

AUTHORS' CONCLUSIONS

Buprenorphine is more effective than clonidine or lofexidine for managing opioid withdrawal in terms of severity of withdrawal, duration of withdrawal treatment, and the likelihood of treatment completion.Buprenorphine and methadone appear to be equally effective, but data are limited. It remains possible that the pattern of withdrawal experienced may differ and that withdrawal symptoms may resolve more quickly with buprenorphine.It is not possible to draw any conclusions from the available evidence on the relative effectiveness of different rates of tapering the buprenorphine dose. The divergent findings of studies included in this review suggest that there may be multiple factors affecting the response to the rate of dose taper. One such factor could be whether or not the initial treatment plan includes a transition to subsequent relapse prevention treatment with naltrexone. Indeed, the use of buprenorphine to support transition to naltrexone treatment is an aspect worthy of further research.Most participants in the studies included in this review were male. None of the studies reported outcomes on the basis of sex, preventing any exploration of differences related to this variable. Consideration of sex as a factor influencing response to withdrawal treatment would be relevant research for selecting the most appropriate type of intervention for each individual.

Strategic Shift to a Diagnostic Model of Care in a Multi-Site Group Dental Practice

Background

Documenting standardized dental diagnostic terms represents an emerging change for how dentistry is practiced. We focused on a mid-sized dental group practice as it shifted to a policy of documenting patients’ diagnoses using standardized terms in the electronic health record.

Methods

Kotter’s change framework was translated into interview questions posed to the senior leadership in a mid-size dental group practice. In addition, quantitative content analyses were conducted on the written policies and forms before and after the implementation of standardized diagnosis documentation to assess the extent to which the forms and policies reflected the shift. Three reviewers analyzed the data individually and reached consensuses where needed.

Results

Kotter’s guiding change framework explained the steps taken to 97 percent utilization rate of the Electronic Health Record and Dental Diagnostic Code. Of the 96 documents included in the forms and policy analysis, 31 documents were officially updated but only two added a diagnostic element.

Conclusion

Change strategies established in the business literature hold utility for dental practices seeking diagnosis-centered care.

Practical Implications

A practice that shifts to a diagnosis-driven care philosophy would be best served by ensuring that the change process follows a leadership framework that is calibrated to the organization’s culture.

A Computerized Procedure for Teaching Letter Formation Skills to Mentally Retarded Individuals

A computerized procedure was used to teach letter formation skills to moderately and severely retarded students. The students' handwriting was detected by a digitized graphics tablet. The tablet was linked to a computer which provided modeling of the letter, corrective feedback, and reinforcement contingent upon accuracy. Nine out of ten students whose initial writing skills were poor learned to write legible letter “q”s after seven sessions of twenty-five trials.

Tetra-porphyrin molecular tweezers: two binding sites linked via a polycyclic scaffold and rotating phenyl diimide core

The synthesis of a tetra-porphyrin molecular tweezer with two binding sites is described. The bis-porphyrin binding sites are aligned by a polycyclic scaffold and linked via a freely rotating phenyl diimide core. Synthesis was achieved using a divergent approach employing a novel coupling method for linking two polycyclic units to construct the core, with a copper(ii)-mediated phenyl boronic acid coupling found to extend to our polycyclic imide derivative. We expect this chemistry to be a powerful tool in accessing functional polycyclic supramolecular architectures in applications where north/south reactivity and/or directional interactions between modules are important. Porphyrin receptor functionalisation was undertaken last, by a four-fold ACE coupling reaction on the tetra-epoxide derivative of the core.

Temporal trends in drug use in Adelaide, South Australia by wastewater analysis

Analysis of municipal wastewater for drug metabolites can reveal the scale of drug use within communities. An Australian city with a population of 1.2million inhabitants was assessed for 4 stimulants: cocaine, methamphetamine, 3.4-methylenedioxymethamphetamine (MDMA) and amphetamine; 6 opioids: codeine, morphine, heroin, fentanyl, oxycodone and methadone; 11 new psychoactive substances (NPS); benzylpiperazine (BZP), trifluoromethylphenylpiperazine (TFMPP), methcathinone, methylone, mephedrone, methylenedioxypyrovalerone (MDPV), alpha pyrrolidinopentiophenone (alpha-PVP), paramethoxyamphetamine (PMA), 25C-NBOMe, 25B-NBOMe, 25I-NBOMe; and cannabis, for up to four years between December 2011 and December 2015. Temporal trends revealed increasing usage rates of methamphetamine, cocaine, oxycodone, and fentanyl, while decreasing rates of use were observed for MDMA, BZP and methylone. Use of other opioids and cannabis was generally stable across years, while use of new psychoactive substances fluctuated without an apparent direction. Opioids and cannabis were used at a consistent level through the course of the week, while use of stimulants and some NPS increased on the weekend. Seasonal differences in use were observed for MDMA and cannabis (p$_amp_$lt;0.05) where, on average, MDMA use was approximately 90% higher in December than in other months and cannabis use was approximately 45% lower in each February. Residual month-to-month variability measures on trend-free data showed NPS use had higher variability than the stimulants and opioids. Frequent wastewater sampling and analysis over prolonged periods has yielded valuable insights into long-term drug use trends, in some instances revealed important within-year trends, and demonstrated the differing patterns of use of drugs on weekends compared to weekdays.

A dynamic landscape of allergen associations in delayed-type cutaneous hypersensitivity

BACKGROUND

Delayed-type hypersensitivity represents a significant clinical and public health challenge. Patients undergoing patch testing may exhibit positive reactions to more than one allergen. It is recognized that reactions to specific pairs of allergens are associated, reflecting a combination of exposure patterns and structural similarity.

OBJECTIVES

To explore the influence of time of testing, age, sex and atopy status on allergen pair associations in a series of 45 110 consecutive patients tested over 30 years.

METHODS

Patch test records of all patients undergoing testing with a modified European baseline series between 1985 and 2014 were retrieved from a database at St John's Institute of Dermatology. Reactions were read on days 2 and 4. For each allergen it was recorded whether the allergen was tested and whether the result was positive or negative.

RESULTS

This is the largest reported study of patch test allergen pair relationships. Our analysis shows a high degree of variability in allergen pair associations. Rigorous statistical analysis reveals a large number of differences between groups, including a significant increase in the association between formaldehyde and multiple formaldehyde-releasing preservatives over the study period, in addition to pair associations with cobalt and formaldehyde-releasing preservatives. These were present to a significantly greater extent in men than in women.

CONCLUSIONS

These observations extend our understanding of cutaneous allergy, with implications for both clinical practice and mechanisms of cutaneous hypersensitivity.

Alpha₂-adrenergic agonists for the management of opioid withdrawal

BACKGROUND

Withdrawal is a necessary step prior to drug-free treatment or as the endpoint of long-term substitution treatment.

OBJECTIVES

To assess the effectiveness of interventions involving the use of alpha2-adrenergic agonists compared with placebo, reducing doses of methadone, symptomatic medications, or an alpha2-adrenergic agonist regimen different to the experimental intervention, for the management of the acute phase of opioid withdrawal. Outcomes included the withdrawal syndrome experienced, duration of treatment, occurrence of adverse effects, and completion of treatment.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (1946 to November week 2, 2015), EMBASE (January 1985 to November week 2, 2015), PsycINFO (1806 to November week 2, 2015), Web of Science, and reference lists of articles.

SELECTION CRITERIA

Randomised controlled trials comparing alpha2-adrenergic agonists (clonidine, lofexidine, guanfacine, tizanidine) with reducing doses of methadone, symptomatic medications or placebo, or comparing different alpha2-adrenergic agonists to modify the signs and symptoms of withdrawal in participants who were opioid dependent.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by The Cochrane Collaboration.

MAIN RESULTS

We included 26 randomised controlled trials involving 1728 participants. Six studies compared an alpha2-adrenergic agonist with placebo, 12 with reducing doses of methadone, four with symptomatic medications, and five compared different alpha2-adrenergic agonists. We assessed 10 studies as having a high risk of bias in at least one of the methodological domains that were considered.We found moderate-quality evidence that alpha2-adrenergic agonists were more effective than placebo in ameliorating withdrawal in terms of the likelihood of severe withdrawal (risk ratio (RR) 0.32, 95% confidence interval (CI) 0.18 to 0.57; 3 studies; 148 participants). We found moderate-quality evidence that completion of treatment was significantly more likely with alpha2-adrenergic agonists compared with placebo (RR 1.95, 95% CI 1.34 to 2.84; 3 studies; 148 participants).Peak withdrawal severity may be greater with alpha2-adrenergic agonists than with reducing doses of methadone, as measured by the likelihood of severe withdrawal (RR 1.18, 95% CI 0.81 to 1.73; 5 studies; 340 participants; low quality), and peak withdrawal score (standardised mean difference (SMD) 0.22, 95% CI -0.02 to 0.46; 2 studies; 263 participants; moderate quality), but these differences were not significant and there is no significant difference in severity when considered over the entire duration of the withdrawal episode (SMD 0.13, 95% CI -0.24 to 0.49; 3 studies; 119 participants; moderate quality). The signs and symptoms of withdrawal occurred and resolved earlier with alpha2-adrenergic agonists. The duration of treatment was significantly longer with reducing doses of methadone (SMD -1.07, 95% CI -1.31 to -0.83; 3 studies; 310 participants; low quality). Hypotensive or other adverse effects were significantly more likely with alpha2-adrenergic agonists (RR 1.92, 95% CI 1.19 to 3.10; 6 studies; 464 participants; low quality), but there was no significant difference in rates of completion of withdrawal treatment (RR 0.85, 95% CI 0.69 to 1.05; 9 studies; 659 participants; low quality).There were insufficient data for quantitative comparison of different alpha2-adrenergic agonists. Available data suggest that lofexidine does not reduce blood pressure to the same extent as clonidine, but is otherwise similar to clonidine.

AUTHORS' CONCLUSIONS

Clonidine and lofexidine are more effective than placebo for the management of withdrawal from heroin or methadone. We detected no significant difference in efficacy between treatment regimens based on clonidine or lofexidine and those based on reducing doses of methadone over a period of around 10 days, but methadone was associated with fewer adverse effects than clonidine, and lofexidine has a better safety profile than clonidine.

Adults with a history of illicit amphetamine use exhibit abnormal substantia nigra morphology and parkinsonism

INTRODUCTION

The sonographic appearance of the substantia nigra is abnormally bright and enlarged (hyperechogenic) in young adults with a history of illicit stimulant use. The abnormality is a risk factor for Parkinson's disease. The aim of the current study was to identify the type of illicit stimulant drug associated with substantia nigra hyperechogenicity and to determine if individuals with a history of illicit stimulant use exhibit clinical signs of parkinsonism. We hypothesised that use of amphetamines (primarily methamphetamine) is associated with substantia nigra hyperechogenicity and clinical signs of parkinsonism.

METHODS

The area of echogenic signal in the substantia nigra was measured in abstinent human amphetamine users (n = 27; 33 ± 8 years) and in three control groups comprising a) 'ecstasy' users (n = 19; 23 ± 3 years), b) cannabis users (n = 30; 26 ± 8 years), and c) non-drug users (n = 37; 25 ± 7 years). A subset of subjects (n = 55) also underwent a neurological examination comprising the third and fifth part of the Unified Parkinson's Disease Rating Scale.

RESULTS

Area of substantia nigra echogenicity was significantly larger in the amphetamine group (0.276 ± 0.080 cm(2)) than in the control groups (0.200 ± 0.075, 0.190 ± 0.049, 0.191 ± 0.055 cm(2), respectively; P < 0.002). The score on the clinical rating scale was also significantly higher in the amphetamine group (8.4 ± 8.1) than in pooled controls (3.3 ± 2.8; P = 0.002).

CONCLUSION

Illicit use of amphetamines is associated with abnormal substantia nigra morphology and subtle clinical signs of parkinsonism. The results support epidemiological findings linking use of amphetamines, particularly methamphetamine, with increased risk of developing Parkinson's disease later in life.

Trends in stimulant use in Australia: A comparison of wastewater analysis and population surveys

Levels of community drug use are usually described by national surveys; data relied upon by decision makers in health and law enforcement. In recent years the analysis of wastewater for drugs and their metabolites has become prominent. Both methods convey unique drug use information. This paper demonstrates differences arising from the two approaches, using methamphetamine, 3,4-methylenedioxymethamphetamine (MDMA) and cocaine data from the state of South Australia. The proportion of people using each drug, obtained from three prominent drug surveys, was compared with estimates of total community drug use derived by wastewater analysis. Temporal trends were compared for available years of the surveys and wastewater analysis from 2010 to 2013. Wastewater results showed methamphetamine to be the most prevalent stimulant in Adelaide, South Australia, with an average of 24.4±1.7 doses per day per 1000 inhabitants for 2013, while consumption of MDMA and cocaine were much lower at 0.52±0.12 and 0.42±0.06 doses per day per 1000 inhabitants, respectively. Survey data typically had MDMA as the most used stimulant on a proportion of the population basis. The difference in magnitude of drug use between MDMA and methamphetamine was also less apparent. Temporal trends of the proportion of the population using a drug by surveys did not generally reflect total use within the community which was observed by wastewater analysis. Survey data are excellent for describing users demographically. However, discrepancies between the proportion of the population who are users and the magnitude of drug use can lead to misrepresentation of the overall scale of use. The results from this study indicate methamphetamine was used to a much greater extent than suggested by the surveys. Together, wastewater analysis and survey data give a comprehensive view of the drug problem enabling more informed decisions on drug policy.

Acute opioid administration induces hypothalamic-pituitary-adrenal activation and is mediated by genetic variation in interleukin (Il)1B

There is a complex relationship between drug dependence and stress, with alcohol and other drugs of abuse both relieving stress and potentially inducing physiological stress responses in the user. Opioid drugs have been shown to modulate hypothalamic-pituitary-adrenal (HPA) activity in animal models and individual response to this modulation may play a role in continuation of drug use. Healthy young Caucasian adults were administered a single dose of immediate release oxycodone (20mg, n=30) or assigned to a control group (n=19) that was not administered the drug. At 0, 1, 2, 4 and 6h post-administration, blood and saliva samples were collected along with assessment of pupil diameter. The HPA response was determined by measurement of salivary cortisol through a commercially available enzyme-linked immunosorbent assay (ELISA). The results were compared to genotype at the -511 and -31 positions in the interleukin1B (IL1B) gene. No difference in cortisol production was initially observed between the two groups, however, when participants were separated based on their genotype for two single nucleotide polymorphisms in the promoter of the IL1B gene, which have been shown to occur at a higher frequency in opioid-dependent populations, individuals carrying the -511T and -31 C alleles (-511 C/T, -31 C/T or -511 T/T, -31 C/C) had a significantly (p<0.05) higher cortisol levels compared to individuals homozygous for the -511 C and -31T alleles. These results suggest that individuals carrying the -511T and -31 C alleles experience HPA activation in response to opioid administration and therefore may be less likely to undertake subsequent self-administration.

Hand function is altered in individuals with a history of illicit stimulant use

Use of illicit stimulant drugs such as methamphetamine, cocaine, and ecstasy are a significant worldwide problem. However, little is known about the effect of these drugs on movement. The aim of the current study was to investigate hand function in adults with a history of illicit stimulant use. We hypothesized that prior use of illicit stimulant drugs is associated with abnormal manipulation of objects. The study involved 22 subjects with a history of illicit stimulant use (aged 29±8 yrs; time since last use: 1.8±4.0 yrs) and two control groups comprising 27 non-drug users (aged 25±8 yrs) and 17 cannabis users with no history of stimulant use (aged 22±5 yrs). Each subject completed screening tests (neuropsychological assessment, medical history questionnaire, lifetime drug history questionnaire, and urine drug screen) prior to gripping and lifting a light-weight object with the dominant right hand. Horizontal grip force, vertical lift force, acceleration, and first dorsal interosseus electromyographic (EMG) activity were recorded during three trials. In trial one, peak grip force was significantly greater in the stimulant group (12.8±3.9 N) than in the control groups (non-drug: 10.3±4.6 N; cannabis: 9.4±2.9 N, P<0.022). However, peak grip force did not differ between groups in trials two and three. The results suggest that individuals with a history of stimulant use overestimate the grip force required to manipulate a novel object but, are able to adapt grip force in subsequent lifts. The results suggest that movement dysfunction may be an unrecognized consequence of illicit stimulant use.

Towards finding a population biomarker for wastewater epidemiology studies

Wastewater analysis has the potential to provide objective information on community drug use. Introducing a population biomarker (PB) in the sample analysis may significantly reduce errors in the back-calculation associated with population estimation and wastewater volume measurement. A number of potential PBs have been suggested but no systematic evaluation has been conducted so far. This study evaluated the eligibility of the previously suggested PB candidates (creatinine, cholesterol, coprostanol and cotinine) as well as three new ones (cortisol, androstenedione and 5-hydroxyindoleacetic acid (5-HIAA)) using five criteria. We assessed the quantification method, affinity to particulate matter and stability of candidates in wastewater, as well as the constancy of inter-day excretion and correlation between excretion and census population. All PB candidates were quantifiable in wastewater. Cholesterol and coprostanol were eliminated from further consideration due to affinity to particulate matters in the wastewater. Creatinine, cortisol and androstenedione were disqualified for stability reasons. On a population scale, both cotinine and 5-HIAA were excreted (RSD=8.01 ± 1.13% and 10.20 ± 0.89%, respectively) at a constant rate and concentrations of each correlated well with the census population (r=0.9809 and 0.9442, respectively). Overall, both cotinine and 5-HIAA are eligible PBs, but the neurotransmitter metabolite 5-HIAA may be more suitable for international comparisons.

Energy transfer in PPV-based conjugated polymers: a defocused widefield fluorescence microscopy study

Both pendant and main chain conjugated MEH-PPV based polymers have been studied at the level of single chains using confocal and widefield fluorescence microscopy techniques. In particular, defocused widefield fluorescence is applied to reveal the extent of energy transfer in these polymers by identifying whether they act as single emitters. For main chain conjugated MEH-PPV, molecular weight and the surrounding matrix play a primary role in determining energy transport processes and whether single emitter behaviour is observed. Surprisingly in polymers with a saturated backbone but containing the same pendant MEH-PPV oligomer on each repeating unit, intra-chain energy transfer to a single emitter is also apparent. The results imply there is chromophore heterogeneity that can facilitate energy funneling to the emitting site. Both main chain conjugated and pendant MEH-PPV polymers exhibit changes in orientation of the emission dipole during a fluorescence trajectory of many seconds, whereas a model MEH-PPV oligomer does not. The results suggest that, in the polymers, the nature of the emitting chromophores can change during the time trajectory.

Alpha2-adrenergic agonists for the management of opioid withdrawal

BACKGROUND

Withdrawal is a necessary step prior to drug-free treatment or as the endpoint of long-term substitution treatment.

OBJECTIVES

To assess the effectiveness of interventions involving the use of alpha2-adrenergic agonists compared with placebo, reducing doses of methadone, symptomatic medications or with comparison of different alpha2-adrenergic agonists, for the management of the acute phase of opioid withdrawal. Outcomes included the intensity of signs and symptoms and overall withdrawal syndrome experienced, duration of treatment, occurrence of adverse effects and completion of treatment.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (Issue 7, 2013), MEDLINE (1946 to July week 4, 2013), EMBASE (January 1985 to August week 1, 2013), PsycINFO (1806 to July week 5, 2013) and reference lists of articles. We also contacted manufacturers in the field.

SELECTION CRITERIA

Randomised controlled trials comparing alpha2-adrenergic agonists (clonidine, lofexidine, guanfacine, tizanidine) with reducing doses of methadone, symptomatic medications or placebo, or comparing different alpha2-adrenergic agonists to modify the signs and symptoms of withdrawal in participants who were opioid dependent.

DATA COLLECTION AND ANALYSIS

One review author assessed studies for inclusion and undertook data extraction. All review authors decided on inclusion and confirmed the overall process.

MAIN RESULTS

We included 25 randomised controlled trials, involving 1668 participants. Five studies compared a treatment regimen based on an alpha2-adrenergic agonist with placebo, 12 with a regimen based on reducing doses of methadone, four with symptomatic medications and five compared different alpha2-adrenergic agonists.Alpha2-adrenergic agonists were more effective than placebo in ameliorating withdrawal in terms of the likelihood of severe withdrawal (risk ratio (RR) 0.32, 95% confidence interval (CI) 0.18 to 0.57, 3 studies, 148 participants). Completion of treatment was significantly more likely with alpha2-adrenergic agonists compared with placebo (RR 1.95, 95% CI 1.34 to 2.84, 3 studies, 148 participants).Alpha2-adrenergic agonists were somewhat less effective than reducing doses of methadone in ameliorating withdrawal symptoms, as measured by the likelihood of severe withdrawal (RR 1.18, 95% CI 0.81 to 1.73, 5 studies, 340 participants), peak withdrawal score (standardised mean difference (SMD) 0.22, 95% CI -0.02 to 0.46, 2 studies, 263 participants) and overall withdrawal severity (SMD 0.13, 95% CI -0.24 to 0.49, 3 studies, 119 participants). These differences were not statistically significant. The signs and symptoms of withdrawal occurred and resolved earlier with alpha2-adrenergic agonists. The duration of treatment was significantly longer with reducing doses of methadone (SMD -1.07, 95% CI -1.31 to -0.83, 3 studies, 310 participants). Hypotensive or other adverse effects were significantly more likely with alpha2-adrenergic agonists (RR 1.92, 95% CI 1.19 to 3.10, 6 studies, 464 participants) but there was no significant difference in rates of completion of withdrawal treatment (RR 0.85, 95% CI 0.69 to 1.05, 9 studies, 659 participants).There were insufficient data for quantitative comparison of different alpha2-adrenergic agonists. Available data suggest that lofexidine does not reduce blood pressure to the same extent as clonidine, but is otherwise similar to clonidine.

AUTHORS' CONCLUSIONS

Clonidine and lofexidine are more effective than placebo for the management of withdrawal from heroin or methadone. No significant difference in efficacy was detected for treatment regimens based on clonidine or lofexidine, and those based on reducing doses of methadone over a period of around 10 days but methadone is associated with fewer adverse effects than clonidine, and lofexidine has a better safety profile than clonidine.

Abnormal maximal finger tapping in abstinent cannabis users

OBJECTIVE

To investigate movement speed and rhythmicity in abstinent cannabis users, we hypothesized that abstinent cannabis users exhibit decreased maximal finger tapping frequency and increased variability of tapping compared with non-drug users.

METHODS

The study involved 10 healthy adult cannabis users and 10 age-matched and gender-matched controls with no history of illicit drug use. Subjects underwent a series of screening tests prior to participation. Subjects were then asked to tap a strain gauge as fast as possible with the index finger of their dominant hand (duration 5 s).

RESULTS

The average intertap interval did not significantly differ between groups, but the coefficient of variation of the intertap interval was significantly greater in the cannabis group than in controls (p=0.011). The cannabis group also exhibited a slow tapping frequency at the beginning of the task.

CONCLUSIONS

Rhythmicity of finger tapping is abnormal in individuals with a history of cannabis use. The abnormality appears to be long lasting and adds to the list of functional changes present in abstinent cannabis users.

Dysregulated STAT1-SOCS1 control of JAK2 promotes mammary luminal progenitor cell survival and drives ERα(+) tumorigenesis

We previously reported that STAT1 expression is frequently abrogated in human estrogen receptor-α-positive (ERα(+)) breast cancers and mice lacking STAT1 spontaneously develop ERα(+) mammary tumors. However, the precise mechanism by which STAT1 suppresses mammary gland tumorigenesis has not been fully elucidated. Here we show that STAT1-deficient mammary epithelial cells (MECs) display persistent prolactin receptor (PrlR) signaling, resulting in activation of JAK2, STAT3 and STAT5A/5B, expansion of CD61(+) luminal progenitor cells and development of ERα(+) mammary tumors. A failure to upregulate SOCS1, a STAT1-induced inhibitor of JAK2, leads to unopposed oncogenic PrlR signaling in STAT1(-/-) MECs. Prophylactic use of a pharmacological JAK2 inhibitor restrains the proportion of luminal progenitors and prevents disease induction. Systemic inhibition of activated JAK2 induces tumor cell death and produces therapeutic regression of pre-existing endocrine-sensitive and refractory mammary tumors. Thus, STAT1 suppresses tumor formation in mammary glands by preventing the natural developmental function of a growth factor signaling pathway from becoming pro-oncogenic. In addition, targeted inhibition of JAK2 may have significant therapeutic potential in controlling ERα(+) breast cancer in humans.

Inhibition of CYP2D6-mediated tramadol O-demethylation in methadone but not buprenorphine maintenance patients

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

Management of pain in opioid dependent individuals is problematic due to numerous issues including cross-tolerance to opioids. Hence there is a need to find alternative analgesics to classical opioids and tramadol is potentially one such alternative. Methadone inhibits CYP2D6 in vivo and in vitro. We aimed to investigate the effect of methadone on the pathways of tramadol metabolism: O-demethylation (CYP2D6) to the opioid-active metabolite M1 and N-demethylation (CYP3A4) to M2 in subjects maintained on methadone or buprenorphine as a control.

WHAT THIS STUDY ADDS

Compared with subjects on buprenorphine, methadone reduced the clearance of tramadol to active O-desmethyl-tramadol (M1) but had no effect on N-desmethyltramadol (M2) formation. Similar to other analgesics whose active metabolites are formed by CYP2D6 such as codeine, reduced formation of O-desmethyltramadol (M1) is likely to result in reduced analgesia for subjects maintained on methadone. Hence alternative analgesics whose metabolism is independent of CYP2D6 should be utilized in this patient population.

AIMS

To compare the O- (CYP2D6 mediated) and N- (CYP3A4 mediated) demethylation metabolism of tramadol between methadone and buprenorphine maintained CYP2D6 extensive metabolizer subjects. METHODS Nine methadone and seven buprenorphine maintained subjects received a single 100 mg dose of tramadol hydrochloride. Blood was collected at 4 h and assayed for tramadol, methadone, buprenorphine and norbuprenorphine (where appropriate) and all urine over 4 h was assayed for tramadol and its M1 and M2 metabolites.

RESULTS

The urinary metabolic ratio [median (range)] for O-demethylation (M1) was significantly lower (P= 0.0002, probability score 1.0) in the subjects taking methadone [0.071 (0.012-0.103)] compared with those taking buprenorphine [0.192 (0.108-0.392)], but there was no significant difference (P= 0.21, probability score 0.69) in N-demethylation (M2). The percentage of dose [median (range)] recovered as M1 was significantly lower in subjects taking methadone compared with buprenorphine (0.069 (0.044-0.093) and 0.126 (0.069-0.187), respectively, P= 0.04, probability score 0.19), M2 was significantly higher in subjects taking methadone compared with buprenorphine (0.048 (0.033-0.085) and 0.033 (0.014-0.049), respectively, P= 0.04, probability score 0.81). Tramadol was similar (0.901 (0.635-1.30) and 0.685 (0.347-1.04), respectively, P= 0.35, probability score 0.65).

CONCLUSIONS

Methadone inhibited the CYP2D6-mediated metabolism of tramadol to M1. Hence, as the degree of opioid analgesia is largely dependent on M1 formation, methadone maintenance patients may not receive adequate analgesia from oral tramadol.

Illicit stimulant use in humans is associated with a long-term increase in tremor

Use of illicit stimulants such as methamphetamine, cocaine, and ecstasy is a significant health problem. The United Nations Office on Drugs and Crime estimates that 14-57 million people use stimulants each year. Chronic use of illicit stimulants can cause neurotoxicity in animals and humans but the long-term functional consequences are not well understood. Stimulant users self-report problems with tremor whilst abstinent. Thus, the aim of the current study was to investigate the long-term effect of stimulant use on human tremor during rest and movement. We hypothesized that individuals with a history of stimulant use would exhibit abnormally large tremor during rest and movement. Tremor was assessed in abstinent ecstasy users (n = 9; 22 ± 3 yrs) and abstinent users of amphetamine-like drugs (n = 7; 33 ± 9 yrs) and in two control groups: non-drug users (n = 23; 27 ± 8 yrs) and cannabis users (n = 12; 24 ± 7 yrs). Tremor was measured with an accelerometer attached to the index finger at rest (30 s) and during flexion and extension of the index finger (30 s). Acceleration traces were analyzed with fast-Fourier transform. During movement, tremor amplitude was significantly greater in ecstasy users than in non-drug users (frequency range 3.9-13.3 Hz; P<0.05), but was unaffected in cannabis users or users of amphetamine-like drugs. The peak frequency of tremor did not significantly differ between groups nor did resting tremor. In conclusion, abstinent ecstasy users exhibit an abnormally large tremor during movement. Further work is required to determine if the abnormality translates to increased risk of movement disorders in this population.

Dose-related effects of alcohol on cognitive functioning

We assessed the suitability of six applied tests of cognitive functioning to provide a single marker for dose-related alcohol intoxication. Numerous studies have demonstrated that alcohol has a deleterious effect on specific areas of cognitive processing but few have compared the effects of alcohol across a wide range of different cognitive processes. Adult participants (N = 56, 32 males, 24 females aged 18–45 years) were randomized to control or alcohol treatments within a mixed design experiment involving multiple-dosages at approximately one hour intervals (attained mean blood alcohol concentrations (BACs) of 0.00, 0.048, 0.082 and 0.10%), employing a battery of six psychometric tests; the Useful Field of View test (UFOV; processing speed together with directed attention); the Self-Ordered Pointing Task (SOPT; working memory); Inspection Time (IT; speed of processing independent from motor responding); the Traveling Salesperson Problem (TSP; strategic optimization); the Sustained Attention to Response Task (SART; vigilance, response inhibition and psychomotor function); and the Trail-Making Test (TMT; cognitive flexibility and psychomotor function). Results demonstrated that impairment is not uniform across different domains of cognitive processing and that both the size of the alcohol effect and the magnitude of effect change across different dose levels are quantitatively different for different cognitive processes. Only IT met the criteria for a marker for wide-spread application: reliable dose-related decline in a basic process as a function of rising BAC level and easy to use non-invasive task properties.

Antidepressant-like effects of ecstasy in subjects with a predisposition to depression

INTRODUCTION

Positive effects of ecstasy on mood and self-esteem due to increased synaptic serotonin levels may indicate a potential antidepressant-like action. This effect may be more prominent in subjects with a pre-existing mood disturbance who may use ecstasy more frequently as a 'self-medication'. This study compared depressive symptoms and the immediate effects of ecstasy on mood in subjects with (WP) and without (NP) a predisposition to depression.

METHODS

Current ecstasy users were assessed using the profile of mood states (POMS) and beck depression inventory (BDI) when drug-free, and during social gathering, when 20 subjects voluntarily consumed ecstasy (ecstasy group) and 20 abstained from ecstasy (control group). Predisposition to depression was determined using the Brief Symptom Inventory. During social gathering, POMS and BDI were administered 60 min after ecstasy consumption, or at matched time for controls. 3,4-Methylenedioxymethamphetamine (MDMA) exposure was confirmed using saliva samples collected 60 min after pill ingestion.

RESULTS

There was no difference in ecstasy use patterns between the groups. When drug-free, the WP subjects had greater mood disturbance and depressive symptoms than the NP group (POMS: NP 5.85±1.63, WP 14.5±2.81, p<0.05, BDI: NP 4.9±0.86, WP 11.2±1.65, p<0.01). During social gathering, WP subjects who consumed ecstasy reported a significant decrease in depressive symptoms (F(1,35)=5.47, p<0.05).

CONCLUSIONS

A decrease in depressive symptoms was observed in subjects predisposed to depression. This antidepressant-like action of MDMA may contribute to its use, particularly among people with an existing or latent depressive disorder.