The Cannabis-Dependent Relationship Between Methadone Treatment Dose and Illicit Opioid Use in a Community-Based Cohort of People Who Use Drugs.

Background: Methadone maintenance treatment (MMT) is an effective treatment for opioid use disorder. However, subtherapeutic dosing may lead to continued opioid use by failing to suppress opioid withdrawal and craving. Preclinical and pilot experimental research suggests that cannabinoids may reduce opioid withdrawal and craving. We sought to test whether the association between low methadone dose and illicit opioid use differs according to concurrent cannabis use patterns. Methods: Data for this study were derived from two community-recruited cohorts of people (≥18 years old) who use illicit drugs in Vancouver, Canada. We used generalized estimating equations to estimate the adjusted association between lower daily MMT dose (<90 mg/day) and daily illicit opioid use, testing for interaction between dose and daily cannabis use. Results: Between December 2005 and December 2018, 1389 participants reported MMT enrolment and were included in the study. We observed a significant interaction (p<0.01) between daily cannabis and lower MMT dose on concurrent daily illicit opioid use: lower MMT doses increased the odds of daily illicit opioid use by 86% (adjusted odds ratio [AOR]=1.86, 95% confidence interval [CI]=1.61-2.16) during periods of no or low-frequency cannabis use and by 30% during periods of daily cannabis use (AOR=1.30, 95% CI=1.01-1.67). Discussion: This study provides preliminary observational evidence that cannabis may mitigate some of the negative effects of subtherapeutic MMT dosing, guiding future clinical investigations into the safety and efficacy of cannabis and cannabinoids as adjunct treatment for MMT.

Methadone Dose, Cannabis Use, and Treatment Retention: Findings From a Community-based Sample of People Who Use Unregulated Drugs.

OBJECTIVES: Lower daily methadone dose is negatively associated with retention in methadone maintenance treatment (MMT). Cannabis use during MMT is common, with many patients reporting its use for opioid withdrawal mitigation. We sought to test whether the association between lower MMT dose and treatment retention differs by concurrent high-frequency cannabis use in a community sample of people on MMT. METHODS: We obtained data from participants initiating MMT in 2 community-recruited prospective cohorts of people who use drugs in Vancouver, Canada. We built multivariable Cox frailty models to estimate the relationships between MMT dose (<90 mg/d vs ≥90 mg/d) and time to treatment discontinuation. We included an interaction term to test whether high-frequency (≥daily) cannabis use modified the measured effect of lower treatment dose on treatment retention. RESULTS: Between December 2005 and December 2018, 829 participants (54.1%) initiated at least 1 MMT episode and were included in the analysis. Lower MMT dose was strongly positively associated with treatment discontinuation regardless of concurrent high-frequency cannabis use (interaction P > 0.05). Structural factors including homelessness and incarceration were significantly and positively associated with treatment discontinuation. CONCLUSIONS: Although we previously found the magnitude and strength of the relationship between lower MMT dose and high-frequency unregulated opioid use to be tempered during high-frequency cannabis use periods, this effect measure modification does not appear to translate to time retained in treatment. Cannabis-based interventions to promote retention in MMT are unlikely to produce long-term benefit without addressing external factors that place MMT patients at increased risk of treatment discontinuation.

Suboptimal nonmedical qualities of primary care linked with care avoidance among people who use drugs in a Canadian setting amid an integrated health care reform.

BACKGROUND: People who use unregulated drugs (PWUD) often face significant barriers to-and thereby avoid seeking-health care. In Vancouver, Canada, a neighborhood-wide health care system reform began in 2016 to improve health care delivery and quality. In the wake of this reform, we sought to determine the prevalence of health care avoidance and its association with emergency department use among PWUD in this setting and examine patient-reported nonmedical qualities of health care ("responsiveness"). METHODS: The study derived data from two prospective cohort studies of community-recruited PWUD in Vancouver in 2017-18. Responsiveness was ascertained by the World Health Organizations' standardized measurements and we evaluated seven domains of responsiveness (dignity, autonomy, communication, confidentiality, prompt attention, choice of provider, and quality of basic amenities). The study used Pearson chi-squared test to examine differences in responsiveness between those who did and did not avoid care. The study team used multivariable logistic regression to determine the relationship between care avoidance due to past mistreatment and emergency department use, adjusting for potential confounders. RESULTS: Among 889 participants, 520 (58.5%) were male, 204 (22.9%) reported avoiding health care, most commonly for chronic pain (47.4%). Overall, 6.6% to 36.2% reported suboptimal levels (i.e., not always meeting the expected quality) across all seven measured domain of responsiveness. Proportions reporting suboptimal qualities were significantly higher among those who avoided care than those who did not across all domains, including care as soon as wanted (51.0% vs. 31.8%), listened to carefully (44.1% vs. 20.4%), and involved in health care decision-making (27.9% vs. 12.7%) (all p < 0.05). In multivariable analyses, avoidance of health care was independently associated with self-reported emergency department use (adjusted odds ratio = 1.49; 95% confidence interval:1.01-2.19). CONCLUSION: We found that almost a quarter of our sample of PWUD avoided seeking health care due to past mistreatment, and all seven measured domains of responsiveness were suboptimal and linked with avoidance. Individuals who reported avoidance of health care were significantly more likely to report emergency department use. Multi-level interventions are needed to remedy the suboptimal qualities of health care and thereby reduce care avoidance.

Cannabis use is associated with reduced risk of exposure to fentanyl among people on opioid agonist therapy during a community-wide overdose crisis.

BACKGROUND: The ongoing opioid overdose crisis is driven largely by exposure to illicitly-manufactured fentanyl. Preliminary observational and experimental research suggests that cannabis could potentially play a role in reducing use of prescription opioids among individuals with chronic pain. However, there is limited data on the effects of cannabis on illicit opioid consumption, particularly fentanyl, especially among individuals on opioid agonist therapy (OAT). We sought to assess the longitudinal association between cannabis use and exposure to fentanyl among people on OAT. METHODS: Data were drawn from two community-recruited prospective cohorts of people who use drugs in Vancouver, Canada. We used generalized linear mixed-effects modeling, adjusted by relevant confounders, to investigate the relationship between cannabis use and recent fentanyl exposure (both assessed by urine drug testing) among participants on OAT between 2016 and 2018. RESULTS: Among the 819 participants on OAT who contributed 1989 observations over the study period, fentanyl exposure was common. At the baseline interview, fentanyl was detected in a majority of participants (431, 53 %), with lower prevalence among individuals with urine drug tests positive for tetrahydrocannabinol (47 vs. 56 %, p = 0.028). Over all study interviews, cannabis use was independently associated with reduced likelihood of being recently exposed to fentanyl (Adjusted Prevalence Ratio = 0.91, 95 % Confidence Interval: 0.83 - 0.99). CONCLUSIONS: Participants on OAT using cannabis had significantly lower risk of being exposed to fentanyl. Our findings reinforce the need for experimental trials to investigate the potential benefits and risks of controlled cannabinoid administration for people on OAT.

Longitudinal patterns of illicit drug use, antiretroviral therapy exposure and plasma HIV-1 RNA viral load among HIV-positive people who use illicit drugs.

OBJECTIVES: HIV-positive people who use illicit drugs (PWUD) experience elevated rates of HIV-associated morbidity and mortality compared with members of other key affected populations. Although suboptimal levels of access and adherence to antiretroviral therapy (ART) are common among HIV-positive PWUD, there is a need for studies investigating the possible biological impacts of noninjection illicit drug use among people living with HIV in real-world settings. METHODS: We accessed data from the ACCESS study, an ongoing prospective cohort of illicit drug users with systematic HIV viral load monitoring in a setting with universal care and ART dispensation records. We used multivariable generalized linear mixed models to estimate the longitudinal associations between noninjection use of crack cocaine, powder cocaine, opioids, methamphetamine, cannabis and alcohol on plasma HIV-1 RNA viral load, adjusted for ART exposure and relevant confounders. RESULTS: Between 2005 and 2018, 843 individuals from the ACCESS cohort were included and contributed to 8698 interviews. At baseline, the mean age was 43 years, 566 (67%) reported male sex and 659 (78%) used crack cocaine in the previous 6 months. In multivariable models adjusted for ART exposure, only crack cocaine use in the last 6 months was found to be significantly associated with higher HIV viral load. CONCLUSION: We observed significantly higher HIV viral load during periods of crack cocaine use independent of ART exposure. Our findings support further research to investigate the possible biological mechanisms of this effect.

Changes in substance use in relation to opioid agonist therapy among people who use drugs in a Canadian setting.

BACKGROUND: Although previous studies have shown that opioid agonist therapy (OAT) is linked to reductions in illicit opioid use, less is known about how OAT impacts the use of other psychoactive substances. We aimed to examine the changes in use of different substances by comparing patterns before and after initiating OAT. METHODS: Data for this study was derived from three ongoing prospective cohorts involving people who use drugs in Vancouver, Canada from 1996 to 2018. We assessed use patterns for heroin, illicit prescription opioid, cocaine, crack cocaine, crystal methamphetamine, cannabis, daily alcohol use, and benzodiazepines. Segmented regression was conducted to compare the trends of substance use between pre-treatment and post-treatment periods. RESULTS: The study included 1107 participants. After OAT engagement, we observed an immediate decline in the proportion as well as a decreasing trend for heroin (Adjusted Odds Ratio (AOR): 0.80, 95% confidence interval (CI): 0.77, 0.83), illicit prescription opioid (AOR: 0.87, 95% CI: 0.83, 0.90), and benzodiazepines (AOR: 0.73, 95 % CI: 0.67, 0.80). There was no significant difference comparing the pre-treatment and post-treatment trends for cocaine, crack cocaine, crystal methamphetamine, and cannabis. However, higher growth slope was noted during the post-treatment period for daily alcohol use (P = 0.016). CONCLUSIONS: We observed significant reduction in illicit opioids use following OAT initiation, but not for stimulant and cannabis. The increasing problematic use of alcohol may pose challenges to the safety and effectiveness of OAT. Development of comprehensive and tailored treatment strategies is needed for poly-substance users accessing OAT.

Frequency of cannabis and illicit opioid use among people who use drugs and report chronic pain: A longitudinal analysis.

BACKGROUND: Ecological research suggests that increased access to cannabis may facilitate reductions in opioid use and harms, and medical cannabis patients describe the substitution of opioids with cannabis for pain management. However, there is a lack of research using individual-level data to explore this question. We aimed to investigate the longitudinal association between frequency of cannabis use and illicit opioid use among people who use drugs (PWUD) experiencing chronic pain. METHODS AND FINDINGS: This study included data from people in 2 prospective cohorts of PWUD in Vancouver, Canada, who reported major or persistent pain from June 1, 2014, to December 1, 2017 (n = 1,152). We used descriptive statistics to examine reasons for cannabis use and a multivariable generalized linear mixed-effects model to estimate the relationship between daily (once or more per day) cannabis use and daily illicit opioid use. There were 424 (36.8%) women in the study, and the median age at baseline was 49.3 years (IQR 42.3-54.9). In total, 455 (40%) reported daily illicit opioid use, and 410 (36%) reported daily cannabis use during at least one 6-month follow-up period. The most commonly reported therapeutic reasons for cannabis use were pain (36%), sleep (35%), stress (31%), and nausea (30%). After adjusting for demographic characteristics, substance use, and health-related factors, daily cannabis use was associated with significantly lower odds of daily illicit opioid use (adjusted odds ratio 0.50, 95% CI 0.34-0.74, p < 0.001). Limitations of the study included self-reported measures of substance use and chronic pain, and a lack of data for cannabis preparations, dosages, and modes of administration. CONCLUSIONS: We observed an independent negative association between frequent cannabis use and frequent illicit opioid use among PWUD with chronic pain. These findings provide longitudinal observational evidence that cannabis may serve as an adjunct to or substitute for illicit opioid use among PWUD with chronic pain.

Engagement in Maximally-Assisted Therapy and Adherence to Antiretroviral Therapy Among a Cohort of Indigenous People Who Use Illicit Drugs.

Throughout the world, Indigenous populations experience a disproportionate burden of HIV infection. Maximally-assisted therapy (MAT) is an interdisciplinary care intervention that includes ART dispensation to support individuals with a history of addiction and homelessness. This study sought to longitudinally evaluate the relationship between engagement in MAT and achieving optimal adherence using data from an ongoing cohort of HIV-positive individuals who use drugs in Vancouver, Canada, where HIV/AIDS treatment is offered at no cost. Between December 2005 and November 2016, 354 HIV-positive Indigenous participants were enrolled and data were analyzed using generalized mixed-effects (GLMM) and marginal structural modeling. In both multivariable analyses, engagement in MAT was independently associated with optimal adherence to ART (GLMM: AOR = 4.92, 95% CI 3.18-7.62; marginal structural model: AOR = 5.76, 95% CI 3.34-9.96). MAT-based programmes could be a part of a renewed evidence-base to elevated levels of preventable HIV/AIDS-associated morbidity, mortality and viral transmission among Indigenous peoples in Canada.

High-intensity cannabis use is associated with retention in opioid agonist treatment: a longitudinal analysis.

BACKGROUND AND AIMS: Cannabis use is common among people on opioid agonist treatment (OAT), causing concern for some care providers. However, there is limited and conflicting evidence on the impact of cannabis use on OAT outcomes. Given the critical role of retention in OAT in reducing opioid-related morbidity and mortality, we aimed to estimate the association of at least daily cannabis use on the likelihood of retention in treatment among people initiating OAT. As a secondary aim we tested the impacts of less frequent cannabis use. DESIGN: Data were drawn from two community-recruited prospective cohorts of people who use illicit drugs (PWUD). Participants were followed for a median of 81 months (interquartile range = 37-130). SETTING: Vancouver, Canada. PARTICIPANTS: This study comprised a total of 820 PWUD (57.8% men, 59.4% of Caucasian ethnicity, 32.2% HIV-positive) initiating OAT between December 1996 and May 2016. The proportion of women was higher among HIV-negative participants, with no other significant differences. MEASUREMENTS: The primary outcome was retention in OAT, defined as remaining in OAT (methadone or buprenorphine/naloxone-based) for two consecutive 6-month follow-up periods. The primary explanatory variable was cannabis use (at least daily versus less than daily) during the same 6-month period. Confounders assessed included: socio-demographic characteristics, substance use patterns and social-structural exposures. FINDINGS: In adjusted analysis, at least daily cannabis use was positively associated with retention in OAT [adjusted odds ratio (aOR) = 1.21, 95% confidence interval (CI) = 1.04-1.41]. Our secondary analysis showed that compared with non-cannabis users, at least daily users had increased odds of retention in OAT (aOR = 1.20, 95% CI = 1.02-1.43), but not less than daily users (aOR = 1.00, 95% CI = 0.87-1.14). CONCLUSIONS: Among people who use illicit drugs initiating opioid agonist treatment in Vancouver, at least daily cannabis use was associated with approximately 21% greater odds of retention in treatment compared with less than daily consumption.

Substance Use and Adherence to Antiretroviral Therapy: What Is Known and What Is Unknown.

PURPOSE OF REVIEW: People who use drugs face multiple challenges to achieve optimal HIV treatment outcomes. This review discusses the current knowledge in substance use and antiretroviral therapy adherence, highlighting recent findings and potential interventions. RECENT FINDINGS: Studies continue to demonstrate the negative impacts of substance use and related disorders on antiretroviral therapy adherence, with the exception of cannabis. Evidence-based addiction treatment, in particular, opioid agonist therapy, appears to improve adherence levels. Most individual-level adherence specific interventions did not provide sustained effects, and no studies evaluating structural-level interventions were found. Findings suggest the urgent need to scale-up opioid agonist therapy, as well as to simultaneously address multiple structural barriers to care to optimize HIV treatment outcomes among people who use drugs.

Intentional cannabis use to reduce crack cocaine use in a Canadian setting: A longitudinal analysis.

BACKGROUND: No effective pharmacotherapies exist for the treatment of crack cocaine use disorders. Emerging data suggests that cannabinoids may play a role in reducing cocaine-related craving symptoms. This study investigated the intentional use of cannabis to reduce crack use among people who use illicit drugs (PWUD). METHODS: Data were drawn from three prospective cohorts of PWUD in Vancouver, Canada. Using data from participants reporting intentional cannabis use to control crack use, we used generalized linear mixed-effects modeling to estimate the independent effect of three pre-defined intentional cannabis use periods (i.e., before, during and after first reported intentional use to reduce crack use) on frequency of crack use. RESULTS: Between 2012 and 2015, 122 participants reported using cannabis to reduce crack use, contributing a total of 620 observations. In adjusted analyses, compared to before periods, after periods were associated with reduced frequency of crack use (Adjusted Odds Ratio [AOR]=1.89, 95% Confidence Interval [CI]: 1.02-3.45), but not the intentional use periods (AOR=0.85, 95% CI: 0.51-1.41). Frequency of cannabis use in after periods was higher than in before periods (AOR=4.72, 95% CI: 2.47-8.99), and showed a tendency to lower frequency than in intentional cannabis use periods (AOR=0.56, 95% CI: 0.32-1.01). CONCLUSIONS: A period of intentional cannabis use to reduce crack use was associated with decreased frequency of crack use in subsequent periods among PWUD. Further clinical research to assess the potential of cannabinoids for the treatment of crack use disorders is warranted.

High-intensity cannabis use and HIV clinical outcomes among HIV-positive people who use illicit drugs in Vancouver, Canada.

BACKGROUND: Reforms to the legal status of medical and non-medical cannabis are underway in many jurisdictions, including Canada, as are renewed efforts to scale-up HIV treatment-as-prevention (TasP) initiatives. It has been suggested that high-intensity cannabis use may be associated with sub-optimal HIV treatment outcomes. Thus, using data from a setting with a community-wide treatment-as-prevention (TasP) initiative coinciding with increasing access to medical cannabis, we sought to investigate the possible impact of high-intensity cannabis use on HIV clinical outcomes. METHODS: Data was derived from the ACCESS study, a prospective cohort of HIV-positive people who use illicit drugs (PWUD) in Vancouver, Canada. Cohort data was confidentially linked to comprehensive clinical profiles, including records of all antiretroviral therapy (ART) dispensations and longitudinal plasma HIV-1 RNA viral load (VL) monitoring. We used generalized estimating equations (GEEs) to estimate the longitudinal bivariable and multivariable relationships between at least daily cannabis use and two key clinical outcomes: overall engagement in ART care, and achieving a non-detectable VL among ART-exposed participants. RESULTS: Between December 2005 and June 2015, 874 HIV-positive PWUD (304 [35%] non-male) were included in this study. In total, 788 (90%) were engaged in HIV care at least once over the study period, of whom 670 (85%) achieved non-detectable VL at least once. In multivariable analyses, ≥ daily cannabis use did not predict lower odds of ART care (Adjusted Odds Ratio [AOR]: 1.02, 95% confidence interval [CI]: 0.77-1.36) or VL non-detectability among ART-exposed (AOR: 0.96, 95% CI: 0.75-1.21). Upon testing for potential interactions, ≥ daily cannabis use was found to be negatively associated with ART engagement during periods of binge alcohol use (p<0.05). CONCLUSION: With the exception of frequent cannabis use during periods of binge alcohol use, our results showed no statistically significant impact of daily cannabis use on the likelihood of ART care or VL non-detectability among ART-exposed HIV-positive PWUD. These findings are reassuring in light of the impending legalization of cannabis in Canada and ongoing efforts to expand TasP initiatives.

The effect of engagement in an HIV/AIDS integrated health programme on plasma HIV-1 RNA suppression among HIV-positive people who use illicit drugs: a marginal structural modelling analysis.

OBJECTIVES: HIV treatment-as-prevention campaigns emphasize early diagnosis and immediate access to care and antiretroviral therapy for HIV-positive individuals in order to increase levels of plasma HIV RNA viral load (VL) suppression. However, the possible role of harm reduction-based programmes in this objective has not yet been well evaluated. The objective of the study was to examine the relationship between being a client of the Dr. Peter Centre (DPC; an HIV/AIDS-focused adult integrated health programme) and VL suppression among highly active antiretroviral therapy (HAART)-exposed HIV-positive people who use illicit drugs (PWUD) in Vancouver, Canada. METHODS: Data were derived from the AIDS Care Cohort to Evaluate Exposure to Survival Services (ACCESS) study, a study of a community-recruited cohort of HIV-positive PWUD. A marginal structural model using inverse probability of treatment weights was used to estimate the longitudinal relationship between being a DPC client and exhibiting a VL < 50 HIV-1 RNA copies/mL plasma. RESULTS: Between 2005 and 2014, 746 HAART-exposed participants were included in the study, of whom 269 (36.1%) reported being a DPC client at some time during the study period. A marginal structural model estimated a 1.54 greater odds of achieving VL suppression (95% confidence interval 1.20-1.99) among DPC clients. CONCLUSIONS: Our findings demonstrate that participating in an innovative HIV/AIDS-focused adult integrated health programme that provides a broad range of clinical, harm reduction, and support services may contribute to optimizing the benefits of HAART in terms of morbidity, mortality and viral transmission among PWUD, and as a result help to fulfill the goals of the treatment-as-prevention strategy.

The impact of an HIV/AIDS adult integrated health program on leaving hospital against medical advice among HIV-positive people who use illicit drugs.

Background: Leaving hospital against medical advice (AMA) is a major source of avoidable morbidity, mortality and healthcare expenditure. The objective of this study was to assess the impact of an innovative HIV/AIDS adult integrated health program on leaving hospital AMA among HIV-positive people who use illicit drugs (PWUD). Methods: Using generalized estimating equations, we examined the relationship between being a participant of the Dr. Peter Centre (DPC), a specialty HIV/AIDS-focused adult integrated health program, and leaving hospital AMA among a cohort of HIV-positive PWUD patients. Results: Between July 2005 and July 2011, 181 HIV-positive PWUD who experienced ≥1 hospitalization were recruited into the study. Of the 406 hospital admissions among these individuals, 73 (39.9%) participants left the hospital AMA. In a multivariable model adjusted for confounders, being a participant of the DPC was independently associated with lower odds of leaving hospital AMA (adjusted odds ratio = 0.42; 95% confidence interval: 0.19-0.89). Conclusions: Our findings suggest that the provision of a broad range of clinical, harm reduction and support services through an innovative HIV/AIDS-focused adult integrated health program operating in proximity to a hospital may curb the rate at which individuals leave hospital prematurely.

Pain Among High-Risk Patients on Methadone Maintenance Treatment.

The complexity of treating concurrent pain and opioid dependence among many methadone-maintained individuals presents a major challenge in many clinical settings. Furthermore, recent expert guidelines have called for increased research on the safety of methadone in the context of chronic pain. This study explores the prevalence and correlates of pain among a prospective cohort of people who use illicit drugs in Vancouver, British Columbia, Canada, who reported enrollment in methadone maintenance treatment (MMT) between 2011 and 2014. Among the 823 participants eligible for this analysis, 338 (40.9%) reported moderate pain and 91 (11.1%) reported extreme pain at the first study visit. In multivariable, generalized, linear mixed model analyses, higher pain severity was positively and independently associated with self-managing pain (adjusted odds ratio [AOR] 2.15, 95% confidence interval [CI] 1.77-2.60), patient perception of methadone dose being too low (AOR 1.82, 95% CI 1.41-2.34), older age (AOR 1.31, 95% CI 1.13-1.51), having a physical disability (AOR 4.59, 95% CI 3.73-5.64), having ever been diagnosed with a mental illness (AOR 1.44, 95% CI 1.13-1.84), white ethnicity (AOR 1.42, 95% CI 1.10-1.83), and marijuana use (AOR 1.25, 95% CI 1.02-1.52). These findings suggest several areas for clinical intervention, particularly related to patient education and alternative analgesic approaches for MMT patients experiencing pain. Perspective: To better understand the complexity of concurrent pain and opioid dependency among individuals on methadone maintenance treatment, this article describes the prevalence and correlates of higher pain severity among methadone-maintained people who use illicit drugs. Patients on methadone with comorbid pain may benefit from education and alternative analgesic approaches.

High-intensity cannabis use and adherence to antiretroviral therapy among people who use illicit drugs in a Canadian setting.

Cannabis is increasingly prescribed clinically and utilized by people living with HIV/AIDS (PLWHA) to address symptoms of HIV disease and to manage side effects of antiretroviral therapy (ART). In light of concerns about the possibly deleterious effect of psychoactive drug use on adherence to ART, we sought to determine the relationship between high-intensity cannabis use and adherence to ART among a community-recruited cohort of HIV-positive illicit drug users. We used data from the ACCESS study, an ongoing prospective cohort study of HIV-seropositive illicit drug users linked to comprehensive ART dispensation records in a setting of universal no-cost HIV care. We estimated the relationship between at least daily cannabis use in the last 6 months, measured longitudinally, and the likelihood of optimal adherence to ART during the same period, using a multivariate linear mixed-effects model accounting for relevant socio-demographic, behavioral, clinical and structural factors. From May 2005 to May 2012, 523 HIV-positive illicit drug users were recruited and contributed 2,430 interviews. At baseline, 121 (23.1 %) participants reported at least daily cannabis use. In bivariate and multivariate analyses we did not observe an association between using cannabis at least daily and optimal adherence to prescribed HAART (Adjusted Odds Ratio = 1.12, 95 % Confidence Interval [95 % CI]: 0.76-1.64, p value = 0.555.) High-intensity cannabis use was not associated with adherence to ART. These findings suggest cannabis may be utilized by PLWHA for medicinal and recreational purposes without compromising effective adherence to ART.