The association between cannabis use and outcome in pharmacological treatment for opioid use disorder

The Role of Medicinal Cannabis as an Emerging Therapy for Opioid Use Disorder

This narrative review explores current insights into the potential use of medicinal cannabis-related products as an emerging therapy for opioid use disorder in the landscape of increasing knowledge about medicinal cannabis-based products, commercialisation and global legalisation. Preclinical studies have provided preliminary insight into the putative neurobiological mechanisms that underpin the potential for medicinal cannabis to be considered a therapeutic in opioid use disorder and addiction. With the progressive legalisation of cannabis in many jurisdictions worldwide, contemporary research has highlighted further evidence that medicinal cannabis may have efficacy in reducing cravings and withdrawal effects, and therefore may be considered as an adjunct or standalone to current medications for opioid use disorder. Despite this potential, the landscape of research in this space draws from a large number of observational studies, with a paucity of rigorous randomised controlled trials to ascertain a true understanding of effect size and safety profile. With current challenges in implementation that arise from political and legal qualms about adopting medicinal cannabis on the background of associated social stigma, significant hurdles remain to be addressed by government, policy-makers, healthcare providers and researchers before medical cannabis can be introduced globally for the treatment of opioid use disorder.

"Everything is kind of the same except my mind is with me": exploring cannabis substitution in a sample of adults in early recovery from an opioid or stimulant addiction

BACKGROUND

Recovery from addiction is frequently equated with abstinence. However, some individuals who resolve an addiction continue to use substances, including via substitution (i.e., increased use of one substance after eliminating/ reducing another). Substitution may play a distinct role during early recovery (≤ 1 year), as this period is marked by dramatic change and adjustment. Cannabis is one of the most used substances and is legal for medical and recreational use in an increasing number of states. Consequently, cannabis an increasingly accessible substitute for substances, like fentanyl, heroin, cocaine and methamphetamine, with higher risk profiles (e.g., associated with risk for withdrawal, overdose, and incarceration).

METHODS

Fourteen participants reported that they had resolved a primary opioid or stimulant addiction and subsequently increased their cannabis use within the previous 12 months. Using grounded theory, the interviewer explored their experiences of cannabis use during early recovery. Data were analyzed in three stages: line by line coding for all text related to cannabis use and recovery, focused coding, and axial coding to generate a theory about recovery with cannabis substitution. The motivational model of substance use provided sensitizing concepts.

RESULTS & DISCUSSION

The final sample included eight men and six women ranging in age from 20 to 50 years old. Three participants resolved an addiction to methamphetamine and the remaining 11, an addiction to opioids. Participants explained that cannabis was appealing because of its less harmful profile (e.g., no overdose risk, safe supply, few side effects). Participants' primary motives for cannabis use included mitigation of psychiatric symptoms, withdrawal/ cravings, and boredom. While cannabis was effective toward these ends, participants also reported some negative side effects (e.g., decreased productivity, social anxiety). All participants described typical benefits of recovery (e.g., improved self-concept, better relationships) while continuing to use cannabis. Their experiences with and beliefs about substitution suggest it can be an effective strategy for some individuals during early recovery.

CONCLUSIONS

Cannabis use may benefit some adults who are reducing their opioid or stimulant use, especially during early recovery. The addiction field's focus on abstinence has limited our knowledge about non-abstinent recovery. Longitudinal studies are needed to understand the nature of substitution and its impact on recovery over time.

Characteristics of Cannabis and Opioid Users Among Older U.S. Veterans and Their Health Outcomes: A Longitudinal Perspective

Medical cannabis use among U.S. Veterans has continued to rise. However, data on cannabis use by older Veterans is generally less available. This study aims to understand the characteristics of older Veterans who enrolled in the Medical Cannabis Patient Program in Illinois and analyze their health outcomes and co-use of cannabis and opioids using longitudinal survey data. Overall, participants reported positive outcomes for pain, sleep, and emotional problems because of cannabis use in two survey periods. Approximately, 62% and 85% respondents reported no change in memory and falls, respectively, with only 3% and 1% reporting a negative outcome for the conditions in both surveys. About 20.4% of those who indicated cannabis use only in the initial survey started to co-use opioids in the follow-up survey, while 44.1% of those who indicated the use of both substances in the initial survey reported no longer using opioids in the follow-up survey. However, these changes were not statistically significant (α = 0.05 ) . The logistic regression showed that both clinical and contextual factors affected co-use. In conclusion, older U.S. Veterans may be using cannabis to alleviate their pain and other chronic conditions. More research is needed to understand the effect of cannabis use on reducing or substituting opioids.

The impact of cannabis on non-medical opioid use among individuals receiving pharmacotherapies for opioid use disorder: a systematic review and meta-analysis of longitudinal studies

Background: The relationship between cannabis use and the risk of returning to using opioids non-medically during treatment for opioid use disorder (OUD) remains unclear.Objective: We sought to quantify the impact of cannabis use on the risk of non-medical opioid use among people receiving pharmacotherapies for OUD.Methods: A comprehensive search was performed using multiple databases from March 1 to April 5 of 2023. Eligible studies longitudinally assessed the association between cannabis use and non-medical opioid use among people with OUD receiving treatment with buprenorphine, methadone, or naltrexone. We utilized a random-effects model employing the restricted maximum likelihood method. A sensitivity analysis was conducted to understand potential differences between each OUD treatment modality.Results: A total of 10 studies were included in the final meta-analysis. There were 8,367 participants (38% female). The average follow-up time across these studies was 9.7 months (SD = 3.77), ranging from 4 to 15 months. The pharmacotherapies involved were methadone (76.3%) buprenorphine (21.3%), and naltrexone (2.4%). The pooled odds ratio did not indicate that cannabis use significantly influenced non-medical opioid use (OR: 1.00, 95% CI: 0.97-1.04, p = .98). There is evidence of moderate heterogeneity and publication bias.Conclusion: There was no significant association between cannabis use and non-medical opioid use among patients receiving pharmacotherapies for OUD. These findings neither confirm concerns about cannabis increasing non-medical opioid use during MOUD, nor do they endorse its efficacy in decreasing non-medical opioid use with MOUD. This indicates a need for individualized approaches for cannabis use and challenges the requirement of cannabis abstinence to maintain OUD pharmacotherapies.

The Therapeutic Potential of Cannabidiol in Revolutionising Opioid Use Disorder Management

Opioid use disorder (OUD) is a significant cause of morbidity and mortality worldwide and is linked to a complex interplay of biopsychosocial factors as well as the increasing overprescription and availability of opioid medications. Current OUD management relies on the controlled provision of opioid medications, such as methadone or buprenorphine, known as opioid replacement therapy. There is variable evidence regarding the long-term efficacy of these medications in improving the management of OUD, thereby necessitating an exploration into innovative approaches to complement, or even take the place of, existing treatment paradigms. Cannabidiol (CBD), a non-psychoactive compound derived from the cannabis plant, has garnered attention for its diverse pharmacological properties, including anti-inflammatory, analgesic, and anxiolytic effects. Preliminary studies suggest that CBD may target opioid withdrawal pathways that make CBD a potential therapeutic option for OUD. This narrative review synthesises current literature surrounding OUD and offers a nuanced review of the current and future role of CBD in managing this condition. In doing so, we highlight the potential avenues to explore with respect to CBD research for the guidance and development of further research opportunities, framework and policy development, and clinical considerations before medicinal CBD can be integrated into evidence-based clinical guidelines.

Risks of returning to opioid use at treatment entry and early in opioid use disorder treatment: Role of non-opioid substances

OBJECTIVE

Patients in treatment with medications for opioid use disorder (MOUD) often report use of other substances in addition to opioids. Few studies exist that examine the relationship between use at treatment entry and early non-opioid use in opioid treatment outcome.

METHODOLOGY

We combined and harmonized three randomized, controlled MOUD clinical trials from the National Institutes of Drug Abuse (NIDA) Clinical Trials Network (CTN) (N=2197) and investigated the association of non-opioid substance use at treatment entry and during early treatment with a return to opioid use. The trials compared MOUD treatment (buprenorphine, methadone, extended-release naltrexone) in populations with opioid use disorder (OUD). Non-opioid substances were identified through harmonizing self-reported use. The primary outcomes were markers of return to opioid use by 12 weeks.

RESULTS

When treatment cohorts were adjusted, no association between self-reported treatment entry use of non-opioid substances and week-12 opioid use was detected. During the first month of treatment, higher use of cocaine (OR 1.41 [1.18-1.69]) and amphetamine (OR 1.70 [1.27-2.26]) was found to be associated with higher likelihood of illicit opioid use by week 12. Exploratory analyses of potential treatment cohort-by-predictor interactions showed that those with heavier cocaine use had a lower rate of returning to opioid use in the extended-release naltrexone group than in the methadone group.

CONCLUSION

Substance use other than opioids at treatment entry is not associated with relapse. Use of cocaine or amphetamines during the first few weeks of MOUD treatment may signal a worse outcome, suggesting a need for additional interventions.

Genetics of cannabis use in opioid use disorder: A genome-wide association and polygenic risk score study

BACKGROUND

Individuals with an Opioid Use Disorder (OUD) have increased rates of cannabis use in comparison to the general population. Research on the short- and long-term impacts of cannabis use in OUD patients has been inconclusive. A genetic component may contribute to cannabis cravings.

AIMS

Identify genetic variants associated with cannabis use through Genome-wide Association Study (GWAS) methods and investigate a Polygenic Risk Score (PRS). In addition, we aim to identify any sex differences in effect size for genetic variants reaching or nearing genome-wide significance in the GWAS.

METHODS

The study outcomes of interest were: regular cannabis use (yes/no) (n = 2616), heaviness of cannabis use (n = 1293) and cannabis cravings (n = 836). Logistic and linear regressions were preformed, respectively, to test the association between genetic variants and each outcome, regular cannabis use and heaviness of cannabis use. GWAS summary statistics from a recent large meta-GWAS investigating cannabis use disorder were used to conduct PRS's. Findings are limited to a European ancestry sample.

RESULTS

No genome-wide significant associations were found. Rs1813412 (chromosome 17) for regular cannabis use and rs62378502 (chromosome 5) for heaviness of cannabis use were approaching genome-wide significance. Both these SNPs were nominally significant (p<0.05) within males and females, however sex did not modify the association. The PRS identified statistically significant association with cannabis cravings. The variance explained by all PRSs were less than 1.02x10-2.

CONCLUSION

This study provides promising results in understanding the genetic contribution to cannabis use in individuals living with OUD.

Different Tokes for Different Folks: Use of Cannabis Products Among a Longitudinal Cohort of People with Heroin Dependence

Co-occurring cannabis use is common among those with opioid use disorder (OUD), but the extent to which it is harmful may be due to its preparation and concentration of various cannabinoids. The current study aimed to examine the prevalence of, and long-term associations with, the use of varying cannabis products among a naturalistic longitudinal cohort of people with heroin dependence. A total of 615 people, most of whom were entering treatment, were recruited to the Australian Treatment Outcome Study (ATOS) in 2001-2002. This analysis focuses on the 401 participants followed up at 18-20 years post baseline. Structured interviews assessed the use of cannabis products, as well as demographic and health covariates. High-potency/indoor-grown cannabis was the most common type ever used (68.8%), and in the past 12 months (80.4%), followed by low potency/outdoor grown (22.4%; 14.4%), and less so for other types of cannabis. After controlling for covariates, older age at baseline was associated with lower odds of high-potency cannabis being used as the primary type in the past 12 months. In contrast to studies of non-opioid dependent populations, common use of high-potency cannabis was not associated with more severe health outcomes.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11469-023-01071-5.

Psychosocial Correlates of Opioid Use Profiles among Young Adults in a Longitudinal Study across 6 US Metropolitan Areas

Background: Examining opioid use profiles over time and related factors among young adults is crucial to informing prevention efforts. Objectives: This study analyzed baseline data (Fall 2018) and one-year follow-up data from a cohort of 2,975 US young adults (Mage=24.55, 42.1% male; 71.7% White; 11.4% Hispanic). Multinomial logistic regression was used to examine: 1) psychosocial correlates (i.e. adverse childhood experiences [ACEs], depressive symptoms, parental substance use) of lifetime opioid use (i.e. prescription use vs. nonuse, nonmedical prescription [NMPO] use, and heroin use, respectively); and 2) psychosocial correlates and baseline lifetime use in relation to past 6-month use at one-year follow-up (i.e. prescription use vs. nonuse and NMPO/heroin use, respectively). Results: At baseline, lifetime use prevalence was: 30.2% prescription, 9.7% NMPO, and 3.1% heroin; past 6-month use prevalence was: 7.6% prescription, 2.5% NMPO, and 0.9% heroin. Compared to prescription users, nonusers reported fewer ACEs and having parents more likely to use tobacco, but less likely alcohol; NMPO users did not differ; and heroin users reported more ACEs and having parents more likely to use cannabis but less likely alcohol. At one-year follow-up, past 6-month use prevalence was: 4.3% prescription, 1.3% NMPO, and 1.4% heroin; relative to prescription users, nonusers were less likely to report baseline lifetime opioid use and reported fewer ACEs, and NMPO/heroin users were less likely to report baseline prescription opioid use but more likely heroin use. Conclusions: Psychosocial factors differentially correlate with young adult opioid use profiles, and thus may inform targeted interventions addressing different use patterns and psychosocial risk factors.

Differential effect of cannabis use on opioid agonist treatment outcomes: Exploratory analyses from the OPTIMA study

INTRODUCTION

Conflictual evidence exists regarding the effects of cannabis use on the outcomes of opioid agonist therapy (OAT). In this exploratory analysis, we examined the effect of recent cannabis use on opioid use, craving, and withdrawal symptoms, in individuals participating in a trial comparing flexible buprenorphine/naloxone (BUP/NX) take-home dosing model to witnessed ingestion of methadone.

METHODS

We analyzed data from a multi-centric, pragmatic, 24-week, open label, randomized controlled trial in individuals with prescription-type opioid use disorder (n = 272), randomly assigned to BUP/NX (n = 138) or methadone (n = 134). The study measured last week cannabis and opioid use via timeline-follow back, recorded at baseline and every two weeks during the study. Craving symptoms were measured using the Brief Substance Craving Scale at baseline, and weeks 2, 6, 10, 14, 18 and 22. The study measured opioid withdrawal symptoms via Clinical Opiate Withdrawal Scale at treatment initiation and weeks 2, 4, and 6.

RESULTS

The mean maximum dose taken during the study was 17.3 mg/day (range = 0.5-32 mg/day) for BUP/NX group and 67.7 mg/day (range = 10-170 mg/day) in the methadone group. Repeated measures generalized linear mixed models demonstrated that cannabis use in the last week (mean of 2.3 days) was not significantly associated with last week opioid use (aβ ± standard error (SE) = -0.06 ± 0.04; p = 0.15), craving (aβ ± SE = -0.05 ± 0.08, p = 0.49), or withdrawal symptoms (aβ ± SE = 0.09 ± 0.1, p = 0.36). Bayes factor (BF) for each of the tested models supported the null hypothesis (BF < 0.3).

CONCLUSIONS

The current study did not demonstrate a statistically significant effect of cannabis use on outcomes of interest in the context of a pragmatic randomized-controlled trial. These findings replicated previous results reporting no effect of cannabis use on opioid-related outcomes.

Endogenous opiates and behavior: 2021

This paper is the forty-fourth consecutive installment of the annual anthological review of research concerning the endogenous opioid system, summarizing articles published during 2021 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides and receptors as well as effects of opioid/opiate agonizts and antagonists. The review is subdivided into the following specific topics: molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors (1), the roles of these opioid peptides and receptors in pain and analgesia in animals (2) and humans (3), opioid-sensitive and opioid-insensitive effects of nonopioid analgesics (4), opioid peptide and receptor involvement in tolerance and dependence (5), stress and social status (6), learning and memory (7), eating and drinking (8), drug abuse and alcohol (9), sexual activity and hormones, pregnancy, development and endocrinology (10), mental illness and mood (11), seizures and neurologic disorders (12), electrical-related activity and neurophysiology (13), general activity and locomotion (14), gastrointestinal, renal and hepatic functions (15), cardiovascular responses (16), respiration and thermoregulation (17), and immunological responses (18).

Alleviation of opioid withdrawal by cannabis and delta-9-tetrahydrocannabinol: A systematic review of observational and experimental human studies

BACKGROUND

While six U.S. states have already officially authorized cannabinoids to substitute opioids and treat opioid use disorder, the therapeutic benefits of cannabinoids remain unclear, especially when weighted against their adverse effects.

METHODS

We conducted a systematic review of studies examining the association between opioid withdrawal and cannabis use or delta-9-tetrahydrocannabinol (THC) administration. We searched multiple databases from inception to July 30, 2022, and assessed study quality.

RESULTS

Eleven studies were identified, with a total of 5330 participants, of whom 64 % were male. Nine observational studies examined the association between cannabis use and opioid withdrawal. Two randomized, placebo-controlled clinical trials (RCTs) investigated the withdrawal-alleviating effects of dronabinol, a synthetic form of THC. Four observational studies found an association between cannabis use and the alleviation of opioid withdrawal; one reported exacerbation of opioid withdrawal symptoms; and four reported no association. RCTs reported that THC alleviated opioid withdrawal, albeit with dose-dependent increases in measures of abuse liability, dysphoria, and tachycardia. There was high heterogeneity in measurements of opioid withdrawal and the type and dose of opioid at baseline.

CONCLUSIONS

Although there is preliminary evidence that cannabis and its main psychoactive constituent, THC, may alleviate opioid withdrawal, these effects are likely to have a narrow therapeutic window. Further, the potential of cannabinoids to alleviate opioid withdrawal is determined by complex interactions between patient characteristics and pharmacological factors. Collectively, these findings have clinical, methodological, and mechanistic implications for treating opioid withdrawal during cannabinoid use, and for efforts to alleviate opioid withdrawal using non-opioid therapeutics.

"I got a bunch of weed to help me through the withdrawals": Naturalistic cannabis use reported in online opioid and opioid recovery community discussion forums

A growing body of research has reported on the potential opioid-sparing effects of cannabis and cannabinoids, but less is known about specific mechanisms. The present research examines cannabis-related posts in two large online communities on the Reddit platform (“subreddits”) to compare mentions of naturalistic cannabis use by persons self-identifying as actively using opioids versus persons in recovery. We extracted all posts mentioning cannabis-related keywords (e.g., “weed”, “cannabis”, “marijuana”) from December 2015 through August 2019 from an opioid use subreddit and an opioid recovery subreddit. To investigate how cannabis is discussed at-scale, we identified and compared the most frequent phrases in cannabis-related posts in each subreddit using term-frequency-inverse document frequency (TF-IDF) weighting. To contextualize these findings, we also conducted a qualitative content analysis of 200 random posts (100 from each subreddit). Cannabis-related posts were about twice as prevalent in the recovery subreddit (n = 908; 5.4% of 16,791 posts) than in the active opioid use subreddit (n = 4,224; 2.6% of 159,994 posts, p < .001). The most frequent phrases from the recovery subreddit referred to time without using opioids and the possibility of using cannabis as a “treatment.” The most frequent phrases from the opioid subreddit referred to concurrent use of cannabis and opioids. The most common motivations for using cannabis were to manage opioid withdrawal symptoms in the recovery subreddit, often in conjunction with anti-anxiety and GI-distress “comfort meds,” and to enhance the “high” when used in combination with opioids in the opioid subreddit. Despite limitations in generalizability from pseudonymous online posts, this examination of reports of naturalistic cannabis use in relation to opioid use identified withdrawal symptom management as a common motivation. Future research is warranted with more structured assessments that examines the role of cannabis and cannabinoids in addressing both somatic and affective symptoms of opioid withdrawal.

Cannabis use and opioid relapse: An exploratory survival analysis of prospectively collected data

IMPORTANCE

It is known that only minority of patients with opioid use disorder (OUD) receive treatment, of which only a fraction successfully complete treatment as intended. Factors associated with poor treatment outcomes remain unclear, and there is emerging but conflicting evidence that cannabis use may mitigate opioid use.

OBJECTIVE

To analyze predictors of relapse amongst patients receiving buprenorphine-naloxone for OUD and identify the association between cannabis use and time to relapse.

DESIGN

Data were prospectively collected between May 2018 and October 2020, and patients were followed for 12 months.

SETTING

Thirty-one outpatient opioid agonist treatment clinics across Ontario, Canada.

PARTICIPANTS

All patients 16 years of age or older receiving buprenorphine-naloxone for OUD who had a urine toxicology screen negative for opioids at baseline were eligible for inclusion. Of the 488 patients consecutively sampled, 466 were included.

EXPOSURE

Cannabis use.

MAIN OUTCOME AND MEASURE

Relapse to opioid use assessed using urine toxicology screens. We employed a multivariable Cox-proportional hazard model for our analyses.

RESULTS

We found that cannabis use was not protective against relapse [hazard ratio (HR) = 1.03, 95% confidence interval (CI): 0.78, 1.36, p = 0.84]. We found that participants who have been in treatment for at least two years had a 44% decrease in the hazard of relapse compared to those in treatment for less than a year (HR = 0.56, 95% CI: 0.34, 0.92, p = 0.021). We also found that the hazard of relapse was 2.6 times higher for participants who were intravenous drug users (HR = 2.61, 95% CI: 1.74, 3.91, p < 0.001), and that for every 1mg increase in the participants' buprenorphine-naloxone dose, the hazard of relapse is 2% greater (HR = 1.02, 95% CI: 1.01, 1.03, p < 0.001).

CONCLUSION

Our analysis failed to show cannabis to be protective against relapse to opioid use in patients receiving buprenorphine-naloxone for OUD. We identified that individuals who inject drugs, are on higher doses of buprenorphine-naloxone, or have been in treatment for less than two years have a higher hazard for relapse. The presence of such factors may thus warrant closer patient follow-up and more stringent treatment protocols to mitigate risk of relapse and potential overdose.