METHODS: The three hundred participants comprised 152 opioid naive subjects and 148 opioid dependent patients. Opioid naive subjects had not taken any opioids including morphine and methadone to their best knowledge and were presumed so after two consecutive negative urine screenings for drugs. All opioid dependent patients were stabilized in treatment, defined as having been enrolled in the program for more than one month with no change of methadone dosage over the past one month. Excluded from the study were individuals with chronic or ongoing acute pain and individuals with a history of analgesics ingestion within 3 d before the cold pressor test (CPT). Pain tolerance to CPT was evaluated at 0 h, and at 2, 4, 8, 12, and 24 h post-methadone dose.
RESULTS: Patients exhibited a significantly shorter mean pain tolerance time of 34.17 s (95% CI 24.86, 43.49) versus 61.36 (52.23, 70.48) [p < 0.001] compared with opioid naive subjects. Time-dependent mean pain tolerance was also significantly different when naive subjects were compared to patients (p = 0.016).
CONCLUSIONS: This study revealed hyperalgesia amongst patients on MMT, as manifested by their quicker hand withdrawal. The complaints of pain in this population should not be underestimated and the pain should be evaluated seriously and managed aggressively.
METHODS: The cold pressor pain responses of 148 opioid dependent patients receiving MMT were evaluated using the cold pressor test (CPT). DNA was extracted from whole blood and subjected to polymerase chain reaction (PCR)-genotyping.
RESULTS: Of the 148 subjects, 77 (52.0%) were carriers of CYP2B6*6 allele. CYP2B6*6 allele carriers had shorter cold pain threshold and pain tolerance times than non-carriers of CYP2B6*6 allele (21.05s vs 33.69s, p=0.036 and 27.15s vs 44.51s, p=0.020, respectively). Pain intensity scores of the CYP2B6*6 allele carriers was 67.55, whereas that of the CYP2B6*6 allele non-carriers was 64.86 (p=0.352).
CONCLUSION: Our study indicates that the CYP2B6*6 allele is associated with a lower pain threshold and lower pain tolerance among males with opioid dependence on MMT. The CYP2B6*6 allele may provide a mechanistic explanation for clinical observations of heightened pain sensitivity among opioid dependent patients receiving MMT.
METHODS: Clinical records of active opioid dependents who underwent MMT between 1 January 2007 and 31 March 2021 in Hospital Tuanku Fauziah, Perlis, Malaysia were retrospectively reviewed. Data collected included baseline demographics, history of illicit drug use, temporal trend in methadone dosage modulation, and co-use of illicit drugs during the MMT.
RESULTS: A total of 87 patients (mean age, 43.9 ± 8.33 years) were included. Their mean duration of involvement in MMT was 7.8 ± 3.69 years. The most commonly used drug was heroin (88.5%), followed by kratom (51.7%). Between 2019 and 2021, 61 (70.1%) patients had ceased abusing opioid, but 51 (58.6%) patients continued using any of the illicit drugs. Methamphetamine and amphetamine co-use was most common (n = 12, 37.5%). Hepatitis C status was not associated with the current methadone dose (U = 539.5, p = 0.186) or the highest dose required (t = -0.291, df = 74, p = 0.772). No predictor for illicit drug abstinence during MMT was identified. Methadone dose positively correlated with frequency of defaulting treatments (r = 0.22, p = 0.042).
CONCLUSION: Among our patients, MMT for opioid dependents cannot sufficiently curb illicit drug use, and there is a shift toward stimulants abuse.
METHODS: We did a parallel, two-arm, prospective observational study of opioid-dependent individuals aged 18 years and older who were treated in Malaysia in the Klang Valley in two settings: CDDCs and VTCs. We used sequential sampling to recruit individuals. Assessed individuals in CDDCs were required to participate in services such as counselling sessions and manual labour. Assessed individuals in VTCs could voluntarily access many of the components available in CDDCs, in addition to methadone therapy. We undertook urinary drug tests and behavioural interviews to assess individuals at baseline and at 1, 3, 6, 9, and 12 months post-release. The primary outcome was time to opioid relapse post-release in the community confirmed by urinary drug testing in individuals who had undergone baseline interviewing and at least one urine drug test (our analytic sample). Relapse rates between the groups were compared using time-to-event methods. This study is registered at ClinicalTrials.gov (NCT02698098).
FINDINGS: Between July 17, 2012, and August 21, 2014, we screened 168 CDDC attendees and 113 VTC inpatients; of these, 89 from CDDCs and 95 from VTCs were included in our analytic sample. The baseline characteristics of the two groups were similar. In unadjusted analyses, CDDC participants had significantly more rapid relapse to opioid use post-release compared with VTC participants (median time to relapse 31 days [IQR 26-32] vs 352 days [256-unestimable], log rank test, p<0·0001). VTC participants had an 84% (95% CI 75-90) decreased risk of opioid relapse after adjustment for control variables and inverse propensity of treatment weights. Time-varying effect modelling revealed the largest hazard ratio reduction, at 91% (95% CI 83-96), occurs during the first 50 days in the community.
INTERPRETATION: Opioid-dependent individuals in CDDCs are significantly more likely to relapse to opioid use after release, and sooner, than those treated with evidence-based treatments such as methadone, suggesting that CDDCs have no role in the treatment of opioid-use disorders.
FUNDING: The World Bank Group, Doris Duke Charitable Foundation, National Institute on Drug Abuse, Australian National Health & Medical Research Council, National Institute of Mental Health, and the University of Malaya-Malaysian Ministry of Higher Education High Impact Research Grant.
METHODS: We used data from the AIDS Care Cohort to Evaluate Exposure to Survival Services (ACCESS) study, a long-running study of a community-recruited cohort of HIV-positive PWUD, linked to comprehensive HIV clinical records in Vancouver, Canada, a setting of no-cost, universal access to HIV care. The longitudinal relationship between MMT-ART dispensation at the same facility and the odds of ≥ 95% ART adherence was analysed using multivariable generalized linear mixed-effects modelling. We conducted a further analysis using a marginal structural mode with inverse probability of treatment weights as a sensitivity analysis.
RESULTS: This study included data on 1690 interviews of 345 ART- and MMT-exposed participants carried out between June 2012 and December 2017. In the final multivariable model, MMT-ART dispensation, compared with nondispensation at the same facility, was associated with greater odds of achieving ≥ 95% adherence [adjusted odds ratio (AOR) 1.56; 95% confidence interval (CI) 1.26-1.96]. A marginal structural model estimated a 1.48 (95% CI 1.15-1.80) greater odds of ≥ 95% adherence among participants who reported MMT-ART dispensation at the same facility compared with those who did not.
CONCLUSIONS: The odds of achieving optimal adherence to ART were 56% higher during periods in which MMT and ART medications were dispensed at the same facility, in a low-barrier setting. Our findings highlight the need to consider a simpler integrated approach with medication dispensation at the same facility in low-threshold settings.
AIM: We conducted a meta-analysis to evaluate the prevalence of sexual dysfunction among male patients on methadone and buprenorphine treatments.
METHODS: Relevant studies published from inception until December 2012 were identified by searching PubMed, OVID, and Embase. Studies were selected using prior defined criteria. Heterogeneity, publication bias, and odds ratio were assessed thoroughly.
MAIN OUTCOME MEASURES: To examine the prevalence and odds ratio of sexual dysfunctions among the methadone and buprenorphine groups.
RESULTS: A total of 1,570 participants from 16 eligible studies were identified in this meta-analysis. The studies provided prevalence estimates for sexual dysfunction among methadone users with a meta-analytical pooled prevalence of 52% (95% confidence interval [CI], 0.39-0.65). Only four studies compared sexual dysfunction between the two groups, with a significantly higher combined odds ratio in the methadone group (OR = 4.01, 95% CI, 1.52-10.55, P = 0.0049).
CONCLUSIONS: Evidence showed that the prevalence of sexual dysfunction was higher among the users of methadone compared with buprenorphine. Patients with sexual difficulty while on methadone treatment were advised to switch to buprenorphine.
METHODS: Two hundred thirty-eight men participated in this cross-sectional study. Four questionnaires were used, the Mini International Neuropsychiatric Interview, Opiate Treatment Index, Malay version of the International Index of Erectile Function 15 (Mal-IIEF-15), and World Health Organization Quality of Life-BREF Scale. Multivariate analysis of covariance was used to examine the relationship between MMT and BMT and the Mal-IIEF 15 scores while controlling for all the possible confounders.
RESULTS: The study population consisted of 171 patients (71.8%) on MMT and 67 (28.2%) on BMT. Patients in the MMT group who had a sexual partner scored significantly lower in the sexual desire domain (p < 0.012) and overall satisfaction (p = 0.043) domain compared with their counterparts in the BMT group. Similarly, patients in the MMT group without a sexual partner scored significantly lower in the orgasmic function domain (p = 0.008) compared with those in the BMT group without a partner. Intercourse satisfaction (p = 0.026) and overall satisfaction (p = 0.039) were significantly associated with the social relationships domain after adjusting for significantly correlated sociodemographic variables.
CONCLUSIONS: Sexual functioning is critical for improving the quality of life in patients in an opioid rehabilitation program. Our study showed that buprenorphine causes less sexual dysfunction than methadone. Thus, clinicians may consider the former when treating heroin dependents who have concerns about sexual function.