Concurrent heroin use among methadone maintenance clients in China

Opioid relapse and its predictors among methadone maintenance patients: a multicenter, cross-sectional study in Vietnam

BACKGROUND

Opioid relapse, one of the common and severe problems during methadone maintenance treatment, can give rise to poor treatment outcomes. This study measured the opioid relapse rate and its associated factors among methadone maintenance patients in Vietnam.

METHODS

Information about the demographic characteristics and social support of 655 patients was collected through direct interviews. Medical records were used to gather data on treatment characteristics. Relapse was determined via urine opioid test results.

RESULTS

The overall relapse rate of patients during treatment was 13.1%. According to the multivariate logistic regression model, living in mountainous areas (adjusted odds ratio (aOR) = 3.63, 95% CI 1.90-7.46) and long duration of drug use in the past (aOR = 1.06, 95% CI 1.03-1.09) were associated with an increase in the odds of opioid relapse. By contrast, living with many family members (aOR = 0.69, 95% CI 0.55-0.85), having longer treatment time (aOR = 0.80, 95% CI 0.73-0.87), and completely adhering to treatment (aOR = 0.38, 95% CI 0.23-0.64) were protective for opioid relapse. As per the univariate analyses, the odds of opioid relapse declined by 25% for each increase of one close friend or relative (OR = 0.75, 95% CI 0.66-0.86). Regarding social support (range score: 0-100), each additional increase of one score was associated with a 1% decrease in the odds of opioid relapse (OR = 0.99, 95% CI 0.98-0.99). Patient sex, education level, occupation type, patient's monthly income, family's monthly income, the number of previous treatments, daily methadone dose, comorbidity, and received antiretroviral therapy were not associated with opioid relapse among patients (p > 0.05).

CONCLUSIONS

Residence, the role of family and social support, and treatment adherence should be paid more attention to guarantee and enhance the success of methadone maintenance treatment.

Exploring factors jointly associated with recurrent relapse and dropout of methadone maintenance treatment clients in Guangdong, China: A retrospective cohort study

BACKGROUND

Clients receiving methadone maintenance treatment (MMT) may experience multiple relapses, which may lead to dropout. However, previous studies mostly only explored the influencing factors of relapse or dropout separately. In this study, we investigated the influencing factors jointly associated with both recurrent relapse and dropout.

METHODS

This study was conducted in 16 MMT clinics in Guangdong, China. Data on the clients' demographic characteristics; drug-related behavior; HIV, HCV, and urine morphine test results; and daily methadone doses were collected. The outcomes were time to recurrent relapse and time to dropout. A joint frailty model was used to explore factors jointly associated with recurrent relapse and dropout. The hazard ratios (HRs) of the covariates in the multivariable model were adjusted, with HR > 1 indicating a faster time to recurrent relapse and dropout.

RESULTS

Among 1539 clients, 39.5% had ≥ 2 relapse events, and 90.8% of the clients dropped out. A high attendance rate was protective for recurrent relapse (HR_50-80%=0.63, 95% CI: 0.51, 0.79; HR_>80%=0.35, 95% CI: 0.28, 0.44) and dropout (HR_50-80%=0.56, 95% CI: 0.47, 0.68; HR_>80%=0.27, 95% CI: 0.23, 0.33). Being married (HR=0.80, 95% CI: 0.67, 0.96), having a fair relationship with family (HR=0.79, 95% CI: 0.67, 0.93) and drug injection (HR=0.80, 95% CI: 0.67, 0.96) were also protective for recurrent relapse. Female (HR=0.64, 95% CI: 0.50, 0.82) and a high methadone dose (≥60 ml/day; HR=0.79, 95% CI: 0.65, 0.96) were protective for dropout, and a longer traveling time to the clinic (>60 min; HR=1.59, 95% CI: 1.20, 2.10) was associated with an increased risk of dropout.

CONCLUSIONS

It is common for clients to experience recurrent relapse and dropout. The findings suggest that MMT clinics should provide holistic interventions and appropriate methadone doses for clients to improve treatment compliance.

Social Interaction With Relapsed Partner Facilitates Cocaine Relapse in Rats

Social factors strongly contribute to drug use and relapse, and epidemiological studies have found that members of peer groups influence each other to use drugs. However, previous animal models mostly failed to incorporate social factors and demonstrate the effects of social partners on drug addiction and relapse. In the present study, we investigated the transfer of relapse to cocaine seeking between drug-addicted partners in rats. Male Sprague-Dawley rats were pair-housed and subjected to training and extinction of cocaine self-administration and conditioned place preference (CPP). 24 h after extinction test, the targeted rats interacted with a cocaine-primed (relapsed) partner or stranger, or saline-injected (unrelapsed) partner for 30 min, after which the targeted rats were tested for drug seeking behavior. We found that social interaction with a relapsed partner increased drug seeking behavior in cocaine self-administration and CPP models in rats, while social interaction with an unrelapsed partner or relapsed stranger had no effect on cocaine seeking. Moreover, the effect of social interaction on cocaine seeking could last for at least 1 day. Our findings demonstrate a facilitation effect of relapsed social partners on drug relapse in rats and provide a novel animal model for social transfer of drug relapse.

Altered brain intrinsic functional hubs and connectivity associated with relapse risk in heroin dependents undergoing methadone maintenance treatment: A resting-state fMRI study

BACKGROUND

The neural substrates underlying the relapse behavior of heroin dependents (HD) who received long-term methadone maintenance treatment (MMT) have yet to be thoroughly expounded. This study investigated the relapse-related intrinsic functional hubs of HD and their functional integration feature at whole brain network level.

METHODS

57 male HD receiving MMT and 49 matched healthy controls (HC) were enrolled. All of the subjects received resting-state functional magnetic resonance imaging scan. And the 57 patients were assigned a 26-month follow-up for collecting illegal drug use information. Of them, 11 were non-relapsers and 46 relapsers. We analyzed the voxel-based degree centrality (DC) to reveal the differences in nodule centrality between HD and HC, conducted Pearson partial-correlation analysis to confirm the relationship between relapse frequency and DC value of the nodes with significant intergroup differences, and finally compared the functional connectivity (FC) of the relapse-related hubs between non-relapsers and relapsers.

RESULTS

We found the DC values of right insula and left nucleus accumbens (NAc) were negatively correlated with relapse frequency. Compared with the non-relapsers, the relapsers had a significant decreased FC between left NAc and inhibitory control circuitry, including left dorsolateral prefrontal cortex, left inferior frontal gyrus and motor regions.

CONCLUSIONS

These findings suggest that the neural substrates of relapse vulnerability in HD undergoing MMT are the intrinsic functional hubs of introceptive and reward systems and the latter modulates relapse behavior via interaction with inhibitory control circuit.

Childhood Trauma, Cognitive Emotion Regulation and Motivation for Behavior Change Among Clients of Opioid Substitution Treatment With and Without Past Year Synthetic Cathinone Use During Therapy

Background

With a decrease in heroin's purity and availability in the European drug market, Hungarian opioid dependent patients started to substitute heroin with novel psychoactive substances (NPS) and especially with synthetic cathinones.

Goal

This study aims to assess whether clients of opioid substitution treatment (OST) with and without a history of synthetic cathinone use during therapy differ in (1) the rate and type of experienced childhood trauma, (2) the way they cope with negative life events, (3) their motivation to change substance use behavior, (4) the rate of treatment retention.

Methods

A total of 198 clients of an outpatient centers (Nyírõ Gyula National Institute of Psychiatry and Addictions, Budapest) OST were asked to provide information about their general substance use experiences, including the consumption of NPS during treatment, their childhood traumatic experiences (Childhood Trauma Questionnaire), cognitive emotion regulation strategies (Cognitive Emotion Regulation Questionnaire), their motivation to change substance use behavior (University of Rhode Island Change Assessment Scale) and current psychiatric symptoms (Brief Symptom Inventory). Baseline data was collected in the summer of 2015, while 4 years follow-up data on treatment retention was obtained in the summer of 2019.

Results

The majority of the clients were male (N = 141, 71.2%), receiving methadone as a substitute for opioids (N = 178, 89.9%), while mean age of the full sample was 39.7 (SD = 6.8). Based on a logistic regression model, the odds for past year synthetic cathinone use was higher among clients with more severe psychiatric symptoms (B = 0.8, OR = 2.2, p < 0.01) and among clients who were in treatment for a shorter period of time (B = 0.1, OR = 0.9, p < 0.05). Synthetic cathinone use during treatment was further associated with less adaptive strategies to cope with negative life events. Synthetic cathinone use was also a risk factor for reduced treatment retention (B = -0.8, OR = 0.4, p < 0.05) and was associated with lower odds of being member of a latent class with less severe psychopathological profile (B = -0.9, OR = 0.4, p < 0.05).

Conclusion

Synthetic cathinone use during treatment is associated with poorer treatment outcomes and might be characterized by more severe psychiatric symptoms and amotivation to change substance use among opioid dependent clients.

Evaluation of the treatment failure ratio in individuals receiving methadone maintenance therapy via the network scale up method

BACKGROUND

The network scale up (NSU) method is an indirect size estimation method that has received remarkable attention in estimating the sensitive behaviors. Using methadone maintenance therapy (MMT), which is a treatment for opioid use disorder, is a sensitive topic in many societies. The aim of this manuscript was to estimate the number of MMT users and its failure ratio using the NSU method in the city of Kerman, Iran, in 2016.

METHODS

In this cross-sectional study, 1275 men and 1275 women which were aged >18 years and who had lived in the city of Kerman for at least 5 years were recruited via multistage sampling. Data was collected via face-to-face interviews using a questionnaire that was included questions for estimating the network size of the residents of Kerman as well as the number of MMT users and the existing failure among them.

RESULTS

In total, the average network size of the citizens of Kerman was 235; among them, 97 were men and 138 were women. Overall, the numbers of MMT users and failures were estimated at about 5289 and 2731, respectively, leading to a failure ratio about 52%. The treatment failure ratio in the women and men was equal to 55% and 51%, respectively. Among the men, the failure ratio in all age groups was equal to ˜50%. Among the women, the failure ratio in those who were aged <18 years was equal to 76%.

CONCLUSION

The considerable failure ratio indicates the need for conducting studies on MMT services in order to understand the reasons which exist regarding this failure. This is of particular importance in specific groups, such as in young women. Further, the comparable results with other direct methods indicate that the NSU method could be used in the size estimation of MMT failure ratios.

Review: Sex-Based Differences in Treatment Outcomes for Persons With Opioid Use Disorder

BACKGROUND AND OBJECTIVES

In order to address the current opioid crisis, research on treatment outcomes for persons with opioid use disorder (OUD) should account for biological factors that could influence individual treatment response. Women and men might have clinically meaningful differences in their experience in OUD treatment and might also have unique challenges in achieving successful, long-term recovery. This review summarizes and synthesizes the current literature on sex-based differences in OUD treatment outcomes.

METHODS

Relevant literature was identified via automated and manual searches using the terms "opioid treatment outcome sex [or gender] differences" and "opiate treatment outcome sex [or gender] differences." Search methodology was consistent with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), and were conducted within the PubMed electronic database during March and April of 2018.

RESULTS

The initial PubMed search yielded 241 manuscripts and 31 original research articles that met inclusion/exclusion criteria were synthesized in this review. Several important trends emerged, including findings that women are more likely than men to present to treatment with co-occurring mental health conditions such as depression, and that women might respond particularly well to buprenorphine maintenance.

DISCUSSION AND CONCLUSIONS

While much of the literature on this topic is subject to potential cohort effects, interventions that address co-occurring mental health conditions and psychosocial stress might improve treatment outcomes for women with OUD.

SCIENTIFIC SIGNIFICANCE

Funding agencies and researchers should focus attention toward human laboratory studies and clinical trials that are prospectively designed to assess sex-based differences in OUD recovery. (Am J Addict 2019;28:246-261).

An intervention trial targeting methadone maintenance treatment providers to improve clients' treatment retention in China

BACKGROUND

Service providers including doctors, nurses, and other healthcare professionals play an essential role in methadone maintenance treatment (MMT). This study evaluated the impact of an intervention targeting MMT providers on their clients' treatment retention.

METHODS

This study was conducted in 68 MMT clinics in five provinces of China with 36 clients randomly selected from each clinic. The clinics were randomized to intervention or control condition. The MMT CARE intervention started with group sessions to enhance providers' communication skills. The trained providers were encouraged to conduct individual sessions with clients to promote treatment engagement. The outcomes, which include client retention (main outcome) and their reception of provider-delivered individual sessions (process outcome), were measured over a 24-month period.

RESULTS

Significantly fewer intervention clients dropped out from MMT than control clients during the study period (31% vs. 41%; p < 0.0001). Dropout hazard was significantly lower in the intervention condition compared to the control condition (HR = 0.71, 95% CI: 0.57, 0.89). More intervention clients had individual sessions than control clients (93% vs. 70%; p < 0.0001). Having individual sessions was associated with a significantly lower dropout hazard (HR = 0.30, 95% CI: 0.23, 0.40). The intervention clients had a significantly lower dropout hazard than the control clients if they started the individual sessions during the first six months (HR = 0.68, 95% CI: 0.51, 0.90).

CONCLUSIONS

The MMT CARE intervention focusing on provider capacity building has demonstrated efficacy in reducing clients' treatment dropout. This study sheds light on MMT service improvement in China and other global community-based harm reduction programs.

Systematic review of sex-based differences in opioid-based effects

There are several biological factors that might play a role in physiological response to opioids and/or the onset of problematic opioid use; however, sex-based differences in non-analgesic opioid-based effects are poorly understood. The goal of this review is to provide a current analysis of the pre-clinical literature on sex-based differences in response to endogenous and exogenous opioids, including the interplay between sex hormones and opioid receptor-mediated neuronal activity and associated behaviours. A systematic search was performed on the following terms within PubMed between March and April 2018: 'opioid oestrogen', 'opioid progesterone', 'opioid oestradiol', and 'opioid testosterone'. Pre-clinical research on the non-analgesic, sex-based effects of opioids is disparate, both in terms of methodology and outcomes, which prohibits a cohesive summary of the results. Themes from the pre-clinical literature suggest that opioid receptor binding, coupling, and density vary as a function of hormone exposure. Findings also suggest that interactions between endogenous opioid and stress systems may differ between males and females as a function of ovarian hormones. Given the current opioid-related public health crisis, there is a pressing need to increase systematic pre-clinical and clinical research on sex-based differences in opioid-effects and opioid use disorder.

Family Related Factors and Concurrent Heroin Use in Methadone Maintenance Treatment in China

BACKGROUND

The use of heroin during Methadone Maintenance Treatment (MMT) is a challenging problem that contributes to poor treatment outcomes. Families may play an important role in addressing concurrent heroin use during MMT, especially in collectivist societies such as China.

OBJECTIVES

In this study, we explored the relationship between family-related factors and concurrent heroin use during MMT in China.

METHODS

This study was conducted at 68 MMT clinics in five provinces of China. There were 2,446 MMT clients in the analysis. Demographic information, MMT dosage, family members' heroin use status, family support of MMT, family problem, and self-reported heroin use were collected in a cross-sectional survey. The most recent urinalysis of opiate use was obtained from clinical records.

RESULTS

Of the 2,446 participants, 533 (21.79%) self-reported heroin use in the previous seven days or had a positive urine morphine test result in the clinic record. Participants whose family member[s] used heroin were 1.59 times (95% CI: 1.17, 2.15) more likely to use concurrently during treatment. Those with family members who totally support them on the MMT were less likely to use (AOR: 0.75, 95% CI: 0.60, 0.94). Having more family problems was positively associated with concurrent heroin use (AOR: 2.01, 95% CI: 1.03, 3.93).

CONCLUSIONS

The results highlight the importance of the family's role in concurrent heroin use during MMT programs. The study's findings may have implications for family-based interventions that address concurrent heroin use.

Influence of social network on drug use among clients of methadone maintenance treatment centers in Kunming, China

AIMS

To examine drug use behavior of clients attending Methadone Maintenance Treatment (MMT) programs and its relationship with the clients' social network characteristics.

DESIGN

Cross-sectional study.

SETTING

Four MMT clinics in Kunming, Yunnan province, China.

PARTICIPANTS

324 consecutive MMT clients.

MEASUREMENTS

A structured, self-completed questionnaire on background characteristics and existing social network. Current drug use was assessed by urine test for opiate metabolites.

ANALYSIS

The association between client's social network characteristics and their own current drug use behavior is analysed using multiple logistic regression adjusting for socio-demographic characteristics. Adjusted odds ratios (AOR) with 95% confidence intervals (CI) are obtained to give the strength of the associations.

FINDINGS

MMT clients were more likely to concurrently use heroin while attending MMT if their social network had any of the following characteristics: more than half of the members were older than them (AOR = 1.03, 95% CI = 1.00,1.06), any member had a high level of influence on them (AOR = 6.47, 95% CI = 2.86,14.65) and any member joined them in using drugs (AOR = 1.94, 95% CI = 1.04,3.63). Having a social network member who could provide emotional support (AOR = 0.11, 95% CI = 0.03,0.35), having a spouse and/or child in their social network (AOR = 0.44, 95% CI = 0.24,0.81) and having a social network member with a high level of closeness (AOR = 0.28, 95% CI = 0.09,0.90) were associated with a decreased odds of heroin use.

CONCLUSION

Social networks who could provide MMT clients with emotional support and a close relationship were significant factors for reducing the risk of concurrent drug use among clients attending MMT clinics in Kunming, China. Behavioral interventions should address the role of family and social network members in providing support to these clients.

Concurrent drug injection during opioid agonist treatment among people who inject drugs in Ukraine

Ongoing drug use during opioid agonist treatment (OAT) negatively affects treatment and health outcomes, and increases treatment dropout. This study aimed to examine correlates of concurrent illicit drug use among OAT patients in Ukraine. A random sample of 434 patients currently on OAT receiving buprenorphine (BMT) or methadone maintenance treatment (MMT) from five cities in Ukraine were assessed for factors associated with self-reported concurrent illicit drug use during OAT using a multivariable logistic regression. Among 434 OAT patients, 100 (23%) reported concurrent drug injecting in the previous 30 days; 28% of these were injecting ≥20 days. While 100 (100%) of these injected opioids, 24 (24%) injected stimulants; 40 (40%) met criteria for polysubstance use disorder that included opioids, stimulants and alcohol. Independent correlates of concurrent drug injection included: being on MMT vs. BMT (aOR = 2.8, 95%CI = 1.4-5.8), lower OAT dosage (aOR = 1.7, 95%CI = 1.1-2.7), more severe addiction severity (aOR = 2.3, 95%CI = 1.4-3.8), younger age of injection initiation (aOR = 2.3, 95%CI = 1.3-3.9), and presence of alcohol use disorder (aOR = 2.1, 95%CI = 1.3-3.5); participants living with parents were negatively associated with concurrent drug injection. Concurrent drug use was prevalent among OAT patients in Ukraine indicating the urgent needs for tailored interventions and changes in OAT program design and implementation. Results highlight the importance of prescribing an adequate OAT dosage, and discrepancies between MMT and BMT programs in Ukraine addressing needs of OAT patients with specific characteristics such as severe opioid and alcohol dependence.

Concurrent drug use among methadone maintenance patients in mountainous areas in northern Vietnam

OBJECTIVES

With the rise in methadone maintenance therapy (MMT) for drug users in Vietnam, there has been growing interest in understanding if and how often MMT patients engage in concurrent illicit drug use while on methadone therapy in various settings. This study examined factors associated with concurrent opioid use among patients on MMT in a mountainous area in Vietnam.

SETTING

One urban and one rural MMT clinics in Tuyen Quang province.

PARTICIPANTS

Survey participants consisted of patients who were taking MMT at the selected study sites. A convenience sampling approach was used to recruit the participants.

PRIMARY AND SECONDARY OUTCOME MEASURES

Participants were asked a series of questions about their socioeconomic status, current alcohol and tobacco use, health problems (measured by the EuroQol-Five Dimension-Five Level instrument), psychological distress (measured by Kessler score), and factors associated with current and/or previous drug use. Regression models were used to determine factors associated with concurrent drug use among MMT patients.

RESULTS

Among the 241 male MMT patients included in the study, 13.4% reported concurrent opioid use. On average, the longer patients had been enrolled in MMT, the less likely they were to concurrently use drugs. Conversely, patients with higher levels of psychological distress were more likely to engage in concurrent drug use while on MMT.

CONCLUSION

Longer duration of MMT was significantly correlated with reduced illicit drug use among participants. Higher levels of psychological distress were associated with increased use of illicit drugs among MMT patients. Regardless of distance, long-term MMT is still effective and should be expanded in mountainous areas.

Comparison Between Urinalysis Results and Self-Reported Heroin Use Among Patients Undergoing Methadone Maintenance Treatment in China

BACKGROUND

The validity and concordance of two main measures of drug use behavior, self-report and urinalysis, has long been discussed. More understanding is needed about the underlying factors associated with discordance between these two methods.

OBJECTIVES

Describe the pattern and associated factors of discordance between self-reported heroin use and the urinalysis results of opiate use among methadone maintenance therapy (MMT) patients in China.

METHODS

A total of 2,448 MMT patients from 68 clinics in five provinces of China participated in a survey, which collected information on demographics, drug use and MMT-related factors, depressive symptoms, and drug avoidance self-efficacy. The most recent urine morphine test result was obtained from medical records and compared with self-reported heroin use. Participants who had urinalysis within 14 days of the survey were included in the analysis.

RESULTS

Among the 1,092 participants, 70 (6.4%) self-reported heroin use and 195 (17.9%) had positive urinalysis results. The over-reporters group had significantly higher education, and the under-reporters had significantly higher level of drug-avoidance self-efficacy and lower level of depressive symptoms. Among the participants who either self-reported heroin use or had positive urinalysis results, being young, having higher education, and having lower level of depressive symptoms were associated with discordance between self-reports and urinalysis results.

CONCLUSION

The combination of both measures in assessing drug use behavior seems necessary. The validity of self-report should be considered differently based on demographic and psychosocial characteristics.

Evaluation of a community-based integrated heroin addiction treatment model in Chinese patients

In this study, we analyzed the efficacy and feasibility of a community-based integrated heroin addiction treatment model in Chinese patients. The 210 heroin addicts belonging to six Chinese communities received an integrated biopsychosocial intervention that included pharmacological treatment, counseling and social assistance. High proportions of study participants were retained at the 12-month (91.9%; 193/210) and 24-month (88.1%; 185/210) follow-up visits. The number of morphine-positive subjects declined from 61.4% at baseline to 36.2% and 30.5% (Q=52.01; P<0.001) after 12 and 24 months, respectively. The crime rate decreased from 32.4% at baseline to 2.2% and 1.6% (Q=7.84; P<0.001) after 12 and 24 months, respectively. The number of patients that were employed increased from 24.3% at baseline to 37.8% and 50.8% after 12 and 24 months, respectively (Q=41.68; P<0.001). Addiction-related issues and mental health status improved according to Addiction Severity Index (ASI) and Symptom Checklist-90 (SCL-90). We therefore conclude that this community-based, integrated heroin addiction treatment model is highly feasible with high treatment retention, reduced drug use, a lower crime rate, improved health and increased employment.

Positive percentages of urine morphine tests among methadone maintenance treatment clients with HIV/AIDS: a 12-month follow-up study in Guangdong Province, China

OBJECTIVE

We aimed to assess the positive percentages of urine morphine tests and correlates among methadone maintenance treatment (MMT) clients with HIV/AIDS in Guangdong, China.

SETTING

Fourteen MMT clinics located in nine cities of Guangdong were chosen as study sites.

PARTICIPANTS

In this study, we reviewed 293 clients with opioid dependence, who were HIV seropositive, 18 years or older, provided informed consent and had at least 10 records of urine morphine tests during the study period.

PRIMARY AND SECONDARY OUTCOME MEASURES

The positive percentages of urine morphine tests were calculated and underlying predictors were estimated.

RESULTS

The highest positive percentage (95.9%) was observed in the first month. After excluding the highest percentage in the first month, the average positive percentage was 40.9% for month 2 to month 12. Positive percentages of urine morphine tests that were <20%, 20-60% and >80% were 25.4%, 36.1% and 38.5% respectively. Lower percentages of continued heroin use were associated with being young (OR≤30=0.31, 95% CI 0.12 to 0.78; OR31-=0.44, 95% CI 0.20 to 1.00), and financial sources depending on family or friends (OR=0.55, 95% CI 0.32 to 0.93). Higher percentages of continued heroin use were associated with being unemployed (OR=1.99, 95% CI 1.13 to 3.49) and poor MMT attendance (OR<20%=3.60, 95% CI 1.55 to 8.33; OR20%-=2.80, 95% CI 1.48 to 5.33).

CONCLUSIONS

High positive percentages of urine morphine tests remain prevalent among MMT clients with HIV/AIDS in Guangdong. The present findings have implications for taking effective measures to facilitate attendance in order to decrease heroin use and ultimately improve the effectiveness among these sub-group MMT clients.

Psychoactive Substance Use among Methadone Maintenance Therapy Clients in China

A proportion of methadone maintenance therapy (MMT) clients in China shifted their substance use habit from opiate to psychoactive substances. The objective of this study was to examine the pattern and associated factors of psychoactive substance use among MMT clients. The study was conducted among 2,448 clients from 68 MMT clinics of China. The type and frequency of psychoactive substance use were self-reported. About 38.1% (N=933) of the participants reported psychoactive substance use in lifetime, and 6.5% (N=158) in the previous 30 days. The most commonly used psychoactive substances were sedative/hypnotic/antidiarrheal agent and amphetamine. Psychoactive substance use in the past 30 days was correlated with younger age, recent heroin use, having psychoactive substance using friend(s), and depressive symptoms. The finding suggested that urinalysis of psychoactive substances should be routinely administered in the MMT clinics. Young clients, concurrent heroin users, and clients with depressive symptoms deserve more screening and intervention efforts.

Factors related to client satisfaction with methadone maintenance treatment in China

BACKGROUND

This study examined clients' treatment satisfaction with the services provided by methadone maintenance treatment (MMT) in China and explored relevant factors that are directly or indirectly associated with treatment satisfaction.

METHODS

The study used baseline data from a randomized controlled trial conducted among 2,448 clients from 68 MMT clinics in five provinces of China. The participants reported their demographic characteristics, treatment-related factors, depressive symptoms, treatment progression, counseling rapport, and treatment satisfaction. Structural equation modeling (SEM) was used to test the direct and indirect relationships among various factors and treatment satisfaction.

RESULTS

Clients' demographic characteristics, such as older age, had both a direct effect on treatment satisfaction and an indirect effect mediated by counseling rapport. Depressive symptoms and a lack of social support had a direct negative impact on treatment satisfaction and an indirect effect mediated by treatment progression and counseling rapport. Both mediators: treatment progression (estimate=0.227, p<0.01) and counseling rapport (estimate=0.229, p<0.01), showed positive associations with treatment satisfaction.

CONCLUSION

The findings reiterate the complex nature of MMT clients' treatment satisfaction and its interrelationship with multidimensional factors. The study has implications for evaluating the quality of care provided by MMT programs and suggests several strategies that can potentially improve MMT clients' level of treatment satisfaction.

Mortality and virological failure among HIV-infected people who inject drugs on antiretroviral treatment in China: An observational cohort study

OBJECTIVE

HIV-infected people who inject drugs (PWID) have a disproportionally low rate of access to antiretroviral therapy (ART). We aimed to assess the impact of ART on 12-month mortality and virological failure of HIV-infected PWID in China, stratified by methadone maintenance treatment (MMT) and active drug use status.

METHODS

HIV-infected PWID who initiated ART at 29 clinics in 2011 were enrolled and followed in this prospective cohort study. Kaplan-Meier curves and log-rank tests were used to compare the survival probability. Risk factors for mortality and virological failure were evaluated by Cox proportional hazards models and logistic regression analyses.

RESULTS

A total of 1,633 participants initiated ART. At the time of initiation, 324 were on MMT, 625 were engaged in active drug use, and 684 had discontinued drug use but were not on MMT. At the 12-month follow-up, 80.3% remained on ART, 13.5% had discontinued ART, and 6.2% had died. Among the MMT group, active drug use group, and drug abstinent group, we observed all-cause mortality of 4.9%, 12.0%, and 1.5% and virological suppression of 51.9%, 41.1%, and 68.7%, respectively. Factors associated with both mortality and virological failure were drug use status, unemployment, and treatment facility type.

CONCLUSION

For HIV-infected PWID receiving ART, engagement in MMT and discontinuation of drug use were more likely to be associated with lower mortality and virological failure compared with active drug use. In order to maximize the clinical impact of ART, HIV treatment programs in China should be further integrated with MMT and social services.

Factors associated with illicit opioid use in methadone maintenance treatment clients in 5 Provinces, China

OBJECTIVES

To investigate factors associated with illicit opioid use among methadone maintenance treatment (MMT) population.

METHODS

Participants were recruited from Beijing (2 clinics), Shanghai (2 clinics), Guangdong (2 clinics), Chongqing (2 clinics) and Gansu (1 clinic) provinces. Information about heroin use and MMT was obtained from a self-reported questionnaire, illicit opioid use was obtained from monthly medical records. Binary logistic regression was used to investigate factors associated with illicit opioid use.

RESULTS

Five hundred ninety-eight eligible MMT participants were used for data analysis. Variables such as age, gender, route of heroin use and daily MMT dosages were associated with illicit opioid use. Compared with MMT participants aged <40 years, participants aged 40-44 years (P = 0.027, OR = 0.57, 95 % CI 0.35-0.94), 45-49 years (P < 0.001, OR = 0.41, 95 % CI 0.24-0.67) and ≥50 years (P = 0.008, OR = 0.52, 95 % CI 0.33-0.85) were more likely not to have illicit opioid use. Compared with male participants, females were more likely to have illicit opioid use (P = 0.044, OR = 1.53, 95 % CI 1.01-2.32). Compared with inhalation heroin abusers, abusers with route of inhalation + injection heroin use were more likely to have illicit opioid use (P = 0.009, OR = 2.00, 95 % CI 1.19-3.36). Compared with daily MMT dosages <60 mg participants, participants with daily MMT dosages >80 mg were more likely to have illicit opioid use (P = 0.003, OR = 2.37, 95 % CI 1.35-4.15).

CONCLUSIONS

Age, gender, route of heroin use and daily MMT dosages were associated with illicit opioid use. A tailored intervention is needed for a promotion of MMT.

HIV seroconversion and risk factors among drug users receiving methadone maintenance treatment in China: A qualitative study

OBJECTIVE

We sought to explore the experiences of drug users in China who were recently diagnosed with HIV infection while engaged in methadone maintenance treatment (MMT) and to better understand their perceptions of MMT, HIV risk, and HIV prevention.

METHODS

We recruited clients of MMT clinics in Chongqing and Kunming who had a baseline HIV-negative test result upon entry to MMT and had been diagnosed with HIV within the past 12 months. We conducted semi-structured qualitative interviews and thematic data analysis to identify situations and factors that increased HIV risk.

RESULTS

Among the 27 participants who were interviewed, 15 believed their infection was due to injection drug use, 7 attributed their infection to sexual contact, and 5 were unsure as to how they became infected. High risk behaviors were common; 18 participants continued to use drugs during treatment, and 10 engaged in unprotected sex. Common themes were the difficulty of drug abstinence despite receiving MMT, social pressure to continue using drugs, and low knowledge of effective HIV prevention measures.

CONCLUSION

While MMT is effective in reducing drug usage and needle sharing, many clients remain at risk of HIV infection due to continued injection drug use and unprotected sex. Clients may benefit from additional counseling on HIV prevention methods as well as structural interventions to increase the availability of clean injection equipment.

Concurrent Heroin Use and Correlates among Methadone Maintenance Treatment Clients: A 12-Month Follow-up Study in Guangdong Province, China

Objective: To assess concurrent heroin use and correlates among Methadone Maintenance Treatment (MMT) clients in Guangdong Province, China. Method: Demographic and drug use data were collected with a structured questionnaire, and MMT information was obtained from the MMT clinic registration system in Guangdong. Human immunodeficiency virus (HIV-) and hepatitis C virus (HCV) infected status and urine morphine results were obtained from laboratory tests. Logistic regressions were employed to investigate the factors associated with concurrent heroin use. Results: Among the 6848 participants, 75% continued using heroin more than once during the first 12 months after treatment initiation. Concurrent heroin use was associated with inharmonious family relationship (OR (odds ratio) = 1.49, 95% CI (confidence intervals): 1.24–1.78), HIV positivity (OR = 1.25, 95% CI: 1.01–1.55), having multiple sex partners (OR = 1.34, 95% CI: 1.07–1.69), having ever taken intravenous drugs (OR = 0.81, 95% CI: 0.69–0.95), higher maintenance dose (OR = 1.13, 95% CI: 1.01–1.28) and poorer MMT attendance (OR_<20% = 1.32, 95% CI: 1.13–1.53; OR_20%– = 1.33, 95% CI: 1.14–1.54; OR_50%– = 1.69, 95% CI: 1.44–2.00). Among those who used heroin concurrently, the same factors, and additionally being older (OR_35– = 1.26, 95% CI: 1.11–1.43; OR_≥45 = 1.63, 95% CI: 1.30–2.05) and female (OR = 1.60, 95% CI: 1.28–2.00), contribute to a greater frequency of heroin use. Conclusions: Concurrent heroin use was prevalent among MMT participants in Guangdong, underscoring the urgent needs for tailored interventions and health education programs for this population.

Baseline HCV Antibody Prevalence and Risk Factors among Drug Users in China's National Methadone Maintenance Treatment Program

BACKGROUND

Hepatitis C virus (HCV) is the most common viral infection among injecting drug users worldwide. We aimed to assess HCV antibody prevalence and associated risk factors among clients in the Chinese national methadone maintenance treatment (MMT) program.

METHODS

Data from 296,209 clients who enrolled in the national MMT program between March 2004 and December 2012 were analyzed to assess HCV antibody prevalence, associated risk factors, and geographical distribution.

RESULTS

Anti-HCV screening was positive for 54.6% of clients upon MMT entry between 2004 and 2012. HCV antibody prevalence at entry declined from 66.8% in 2005 to 45.9% in 2012. The most significant predictors of HCV seropositivity were injecting drug use (adjusted odds ratio [AOR]: 8.34, 95% confidence interval [CI]: 8.17-8.52, p<0.0001) and a history of drug use ≥9 years (AOR: 2.01, 95% CI: 1.96-2.06, p<0.0001). Being female, of Uyghur or Zhuang ethnicity, and unmarried were identified as demographic risk factors (all p-values<0.0001). Of the 28 provincial-level divisions included in the study, we found that 5 divisions had HCV antibody prevalence above 70% and 20 divisions above 50%. The HCV screening rate within 6 months after MMT entry greatly increased from 30.4% in 2004 to 93.1% in 2012.

CONCLUSIONS

The current HCV antibody prevalence remains alarmingly high among MMT clients throughout most provincial-level divisions in China, particularly among injecting drug users and females. A comprehensive prevention strategy is needed to control the HCV epidemic among MMT clients in China.

Factors Associated with Relapse among Heroin Addicts: Evidence from a Two-Year Community-Based Follow-Up Study in China

Background: Many countries including China are facing a serious opiate dependence problem. Anti-drug work effectiveness was affected by the high relapse rate all over the world. This study aims to analyze the factors influencing heroin addict relapse, and to provide evidence for generating relapse prevention strategies. Methods: A community-based follow-up study was conducted in China between October 2010 and September 2012. A total of 554 heroin addicts in accordance with the inclusion criteria from 81 streets in 12 districts of Shanghai, China were divided into 4 groups: group 1—daily dosage taken orally of 60 mL of methadone or under combined with psychological counseling and social supports (n = 130); group 2—daily dosage taken orally of over 60 mL of methadone combined with psychological counseling and social supports (n = 50); group 3—JTT (Jitai tablets) combined with psychological counseling and social supports (n = 206); group 4—JTT combined with social supports (n = 168). Results: Log-rank test results showed that the cumulative relapse rate differences among four groups during the two-year follow-up period were not statistically significant (χ² = 5.889, p = 0.117). Multivariate Cox regression analysis results showed that only three independent variables were still statistically significant, including compliance with participation in psychological counseling (OR = 3.563, p = 0.000), the years of drug use (OR = 1.078, p = 0.001)and intervention model. Conclusions: Using the detoxification medications combined with appropriate psychological counseling and social support measures will help improve the effectiveness of relapse prevention, which is a kind of alternative community detoxification pattern. Appropriate and standard psychological counseling is very important for anti-drug treatment. The longer the drug addiction lasts, the longer the anti-drug treatment takes.

Illicit Heroin and Methamphetamine Use among Methadone Maintenance Treatment Patients in Dehong Prefecture of Yunnan Province, China

Objective

Methadone maintenance treatment (MMT) was introduced to China in 2004 to reduce the harm of injecting drug users (IDUs). However, little is known about continued drug use, especially methamphetamine (MAMP), among MMT patients.

Methods

A survey was conducted among patients attending five major MMT clinics in Dehong Prefecture in 2014 to investigate the heroin and MAMP use and their associated risk factors. Participants were administered with face-to-face interviews, and urine tests for morphine and MAMP.

Results

A total of 2,121 were eligible and participated in the study. Among them, 220 (10.4%) were only positive for morphine, 12.9% were only positive for MAMP, and 196 (9.2%) were positive for both morphine and MAMP. Compared with neither use of heroin nor MAMP during MMT, heroin use (not using MAMP) was associated with ethnicity, shorter duration of MMT, lower dose of methadone, and having had no more than two sex partners in the past year; MAMP use (not using heroin) was associated with ethnicity, longer duration of MMT, higher dose of methadone and being aged <30 years (vs. ≥50 years); use of both heroin and MAMP was associated with being Dai minority (vs. Han), a marital status of divorced or widowed, having used drugs for ≥10 years and shorter duration of MMT.

Conclusion

These findings indicate the complexity in the treatment of heroin users and underscore the importance in prescribing appropriate methadone dosages in order to reduce both heroin and MAMP use.

Factors associated with depression and anxiety among patients attending community-based methadone maintenance treatment in China

AIM

To estimate the prevalence of, and identify factors associated with, depression and anxiety among community-based methadone maintenance treatment (MMT) clients in China.

DESIGN

A cross-sectional survey.

SETTING

Nine MMT clinics, three each from three Chinese provinces (Yunnan, Anhui and Jiangsu) between October 2008 and February 2009.

PARTICIPANTS

A total of 1301 MMT clients.

MEASUREMENTS

A questionnaire, including the Zung Self-Rating Depression Scale (SDS) and Zung Self-Rating Anxiety Scale (SAS), and on-site urine drug testing.

FINDINGS

The prevalence of depression (SDS score≥53) and anxiety (SAS score≥50) in our sample was 38.3% [95% confidence interval (CI)=35.7, 40.9] and 18.4% (95% CI=16.3, 20.5), respectively, with 14.2% (95% CI=12.3, 16.1) displaying symptoms of both. Sample prevalence rates for depression [mean=49.69, standard deviation (SD)=10.34] and anxiety (mean=40.98, SD=10.66) were higher than the national average for each (t(0.05/2, 1300)=19.2, P<0.001 and t(0.05/2, 1300)=8.0, P<0.001, respectively). Employing multi-level modelling techniques, gender (P=0.03) and employment status (P<0.001) were found to be associated significantly with depression in a single-level model; however, in a multi-level mixed model, only employment status (P<0.001) was associated with depression. Gender (P=0.03), education level (P=0.02), marital status (P=0.04), employment status (P<0.001), positive urine drug test results (P=0.02) and daily methadone dose (P<0.001) were found to be associated significantly with anxiety in a single-level model, while only employment status (P<0.01) and positive results for the urine drug test (P=0.04) were associated with anxiety in a multi-level mixed model.

CONCLUSIONS

A considerable proportion of methadone maintenance treatment clients in China have experienced depression and anxiety during treatment. There is a need to provide tailored mental health interventions for this high-risk population.

Predictors of accessing antiretroviral therapy among HIV-positive drug users in China's National Methadone Maintenance Treatment Programme

AIMS

The objective of this study was to examine factors that predict antiretroviral therapy (ART) access among eligible, HIV-positive methadone maintenance treatment (MMT) clients. We also tested the hypothesis that sustained MMT participation increases the likelihood of accessing ART.

DESIGN

A nation-wide cohort study conducted from 1 March 2004 to 31 December 2011.

SETTING

MMT clients were followed from the time of their enrolment in China's national MMT programme until their death or the study end date.

PARTICIPANTS

Our cohort comprised 7111 ART-eligible, HIV-positive MMT clients, 49.2% of whom remained ART-naive and 50.8% of whom received ART.

MEASUREMENTS

Demographic variables, drug use history, MMT programme participation and HIV-related clinical characteristics of study participants who remained naive to ART and those who accessed ART were compared by univariate and multivariable analysis.

FINDINGS

Predictors of accessing ART among this cohort included being retained in MMT at the time of first meeting ART eligibility [adjusted odds ratio (AOR)=1.84, confidence interval (CI)=1.54-2.21, P<0.001] compared to meeting ART eligibility before entering MMT (AOR=0.98, CI=0.80-1.21, P=0.849) or previously entering MMT and dropping out before meeting ART eligibility. Additional predictors were CD4≤200 cells/μl when ART-eligibility requirement was first met (AOR=1.81, CI=1.61-2.05, P<0.001 compared to CD4=201-350 cells/μl), and being in a stable partner relationship (married/cohabitating: AOR=1.14, CI=1.01-1.28, P=0.030).

CONCLUSIONS

Retained participation in methadone maintenance treatment increases the likelihood that eligible clients will access antiretroviral therapy. These results highlight the potential benefit of colocalization of methadone maintenance treatment and antiretroviral therapy services in a 'one-stop-shop' model.

Endogenous opiates and behavior: 2013

This paper is the thirty-sixth consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2013 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior, and the roles of these opioid peptides and receptors in pain and analgesia; stress and social status; tolerance and dependence; learning and memory; eating and drinking; alcohol and drugs of abuse; sexual activity and hormones, pregnancy, development and endocrinology; mental illness and mood; seizures and neurologic disorders; electrical-related activity and neurophysiology; general activity and locomotion; gastrointestinal, renal and hepatic functions; cardiovascular responses; respiration and thermoregulation; and immunological responses.

Predictors of non-prescribed opioid use after one year of methadone treatment: an attributable-risk approach (ANRS-Methaville trial)

BACKGROUND

The effectiveness of methadone as an opioid maintenance treatment (OMT) for opioid dependence has been widely demonstrated. However many patients continue to use other opioids while on methadone treatment. Studies assessing avoidable cases of continued non-prescribed opioid use during methadone treatment are sparse.

METHODS

At 12 months of treatment (M12), 158 subjects had available data on opioid use, measured using the Opiate Treatment Index. We identified variables associated with non-prescribed opioid use at M12, using a univariate logistic regression and two multivariate models, one incorporating only pre-treatment variables, the second adding the in-treatment variables. We also calculated attributable fractions for risk factors.

RESULTS

At M12, 32.3% of the patients had used non-prescribed opioids during the previous month. A good patient-physician relationship was the most influential factor associated with not using non-prescribed opioids after one year. Living with a heroin user after one year of treatment, using cocaine during treatment and hazardous alcohol consumption at enrolment were all associated with an increased risk of non-prescribed opioid use at M12. Analysis of attributable fractions indicated that living with a heroin user at M12 accounted for 21% of patients reporting non-prescribed opioid use at M12, while the lack of a good relationship with the physician accounted for 26%.

CONCLUSIONS

The attributable risk approach suggests that continued non-prescribed opioid use by a considerable proportion of individuals could potentially be reduced by improving patient-physician relationships, enhancing care for co-dependent patients and encouraging patients to modify their social network.

Methadone maintenance treatment and mortality in HIV-positive people who inject opioids in China

OBJECTIVE

To examine the effect of methadone maintenance treatment (MMT) on mortality in people injecting opioids who receive antiretroviral therapy (ART) for the treatment of human immunodeficiency virus (HIV) infection in China.

METHODS

The study involved a nationwide cohort of 23 813 HIV-positive (HIV+) people injecting opioids who received ART between 31 December 2002 and 31 December 2011. Mortality rates and demographic, disease and treatment characteristics were compared in patients who received either ART and MMT or ART only. Factors associated with mortality were identified by univariate and multivariate analysis.

FINDINGS

Overall, 3057 deaths occurred during 41 959 person-years of follow-up (mortality: 7.3 per 100 person-years; 95% confidence interval, CI: 7.0-7.5). Mortality 6 months after starting ART was significantly lower with ART and MMT than with ART only (6.6 versus 16.9 per 100 person-years, respectively; P < 0.001). After 12 months, mortality was 3.7 and 7.4 per 100 person-years in the two groups, respectively (P < 0.001). Not having received MMT was an independent predictor of death (adjusted hazard ratio: 1.4; 95% CI: 1.3-1.6). Other predictors were a low haemoglobin level and a low CD4+ T-lymphocyte count at ART initiation and treatment at facilities other than infectious disease hospitals.

CONCLUSION

Patients would benefit more from both MMT and HIV treatment programmes and would face fewer barriers to care if cross-referrals between programmes were promoted and ART and MMT services were located together.

Mortality among methadone maintenance clients in China: a six-year cohort study

Objective

To assess the overall mortality of methadone maintenance treatment (MMT) clients in China and its associated factors.

Methods

A total of 1,511 MMT clients, all of whom enrolled in China's first eight MMT clinics between March and December 2004, were included in this cohort study and followed for approximately six years, until June 2010. Mortality and its predictors were examined using Cox proportional hazards regression models.

Results

A total of 154 deaths were observed within 5,391 person-years (PY) of follow-up for an all-cause mortality rate of 28.6 per 1,000 PY. The leading causes of death were drug overdose (33.8%), HIV/AIDS-unrelated disease (21.4%), and HIV/AIDS (16.9%). The all-cause mortality rate of clients engaged in MMT for one year or less was roughly three times that of clients who stayed in MMT for four years or more (14.0 vs. 4.6, p<0.0001), HIV-positive subjects was nearly four times mortality rate than that of HIV-negative individuals (28.1 vs.6.8, p<0.0001). ART-naive HIV-positive subjects had approximately two times higher mortality rate than those receiving ART (31.2 vs. 17.3, <0.0001). After adjusting for confounding variables, we found that being male (HR = 1.63, CI: 1.03–2.57, p = 0.0355) and being HIV-positive (HR = 5.16, CI: 3.70–7.10, p<0.0001) were both associated with higher risk of death whereas increased durations of methadone treatment were associated with a lower risk of death (HR = 0.26, CI: 0.18–0.38, p<0.0001 for two to three years, HR = 0.08, CI: 0.05–0.14, p<0.0001 for four or more years).

Conclusion

Overall mortality was high among MMT clients in China. Specific interventions aimed at decreasing mortality among MMT clients are needed. Our study supports the need for keeping client at MMT longer and for expanding ART coverage and suggests the potential benefits of integrated MMT and ART services for drug users in China.

Is opioid substitution treatment beneficial if injecting behaviour continues?

BACKGROUND

Opioid substitution treatment (OST) is recognised as an effective treatment for opioid dependence. Still, a subgroup of OST users continues to inject drugs. This study examines health risks and criminal activity in a population of needle exchange programme (NEP) participants by comparing those identified as current OST users to (i) those identified as former OST users and (ii) those with no OST experience.

METHODS

This was a semi-annual cross-sectional study conducted from 2002 to 2011. NEP participants were interviewed in Oslo, Norway (n=1760); 341 were identified as current OST users, 356 as former OST users and 1063 had no OST experience. The associations between OST status and health risk and criminal activity were assessed through univariate and multiple logistic regression analyses.

RESULTS

Among NEP participants, those currently in OST had fewer non-fatal overdoses (OR=0.5 [95% CI 0.3, 0.9]) compared to former OST users and those never in OST. Additionally, they were less likely to have injected frequently (OR=0.4 [95% CI 0.3, 06]), to have used heroin daily or almost daily (OR=0.3 [95% CI 0.2, 0.4]), and to have committed theft (OR=0.6 [95% CI 0.4, 1.0]) and engaged in drug dealing (OR=0.7 [95% CI 0.5, 0.9]) in the past month. Overall, there was a high level of polysubstance use and no group differences on this measure.

CONCLUSIONS

NEP participants who are currently in OST have substantially reduced health risks and criminal activity than other NEP participants. The high level of polysubstance use nevertheless poses a public health challenge.

UGT2B7 genetic polymorphisms are associated with the withdrawal symptoms in methadone maintenance patients

AIM

To test whether the genetic polymorphisms within the gene encoding the UGT2B7 gene may have an impact on methadone treatment.

MATERIALS & METHODS

Twelve SNPs in UGT2B7 were selected. 366 methadone maintenance treatment patients in Taiwan were recruited and genotyped.

RESULTS

In a genotype recessive model, rs6600879, rs6600880, rs4554144, rs11940316, rs7438135, rs7662029, rs7668258, rs7439366, rs4292394 and rs6600893 showed significant associations with severity of withdrawal symptoms (permutation p < 0.002), pupil size (permutation p < 0.048) and tremor (permutation p < 0.008). Haplotypes of GATCAGCCGC and CTCTGATTCT were significantly associated with pupil size score and tremor score (p < 0.034).

CONCLUSION

These results suggest that SNPs of the UGT2B7 gene may play important roles in opiate withdrawal symptoms.