Substance misuse in patients who have comorbid chronic pain in a clinical population receiving methadone maintenance therapy for the treatment of opioid dependence

Pain in people seeking and receiving opioid agonist treatment: A systematic review and meta-analysis of prevalence and correlates

BACKGROUND AND AIMS

People with opioid use disorder (OUD) commonly experience pain including chronic pain. Despite the high prevalence, few studies have systematically examined the prevalence and correlates of pain among people seeking or receiving opioid agonist treatment (OAT) for OUD. This review aimed to determine the prevalence of pain in this population globally, and estimate the association between chronic pain and other demographic and clinical characteristics.

METHODS

Electronic searches were conducted in three databases (Medline, Embase and PsycINFO) from the inception until October 2022. Eligible studies reported prevalence rates of current and/or chronic pain. Meta-analyses examining the main prevalence estimates were conducted by Stata SE 18.0, and comorbid clinical conditions were analysed by Review Manager 5.4.

RESULTS

Fifty-six studies (n participants = 35 267) from sixty-seven publications were included. Prevalence estimates of current and chronic pain were reported in 27 (48.2%) and 40 studies (71.4%), respectively. Most studies were conducted in North America (71.4%, n = 40) and used cross-sectional designs (64.3%, n = 36). Meta-analyses revealed a pooled prevalence of 60.0% (95% confidence interval [CI]: 52.0-68.0) for current pain and 44.0% [95% CI: 40.0-49.0] for chronic pain. Chronic pain was positively associated with older age (mean deviation of mean age: 2.39 years, 95% CI: 1.40-3.37; I2 = 43%), unemployment (odds ratio [OR] = 0.57, 95% CI: 0.42-0.76; I2 = 78%), more severe mental health symptoms (e.g. more severe depression (standardised mean difference [SMD] of mean scores: 0.45, 95% CI: 0.20-0.70; I2 = 48%) and anxiety symptoms (SMD: 0.52, 95% CI: 0.17-0.88; I2 = 67%), and hepatitis C (OR = 1.41, 95% CI: 1.03-1.94; I2 = 0%). No association was observed between chronic pain and the onset and type of OAT, geographic location, study design, survey year, participant age or use of specific pain assessment tools.

CONCLUSIONS

There appears to be a high prevalence of pain among people seeking or receiving opioid agonist treatment for opioid use disorder compared with the general population, with positive associations for older age, unemployment, hepatitis C and the severity of some mental health symptoms.

Stepped Care for Patients to Optimize Whole Recovery (SC-POWR): An Effectiveness Trial Evaluating a Stepped Care Model for Individuals With Opioid Use Disorder and Chronic Pain

Many patients who receive treatment for opioid use disorder (OUD) report experiencing chronic pain (CP), which is associated with high levels of ongoing nonmedical opioid use and low retention in OUD treatment. In pilot studies of patients with OUD receiving buprenorphine or methadone who had CP, cognitive behavioral therapy (CBT) attenuated nonmedical opioid use compared with treatment-as-usual (TAU), but patients in both treatment arms exhibited similar pain improvements. Adding exercise and stress reduction to this model may augment pain-related outcomes. With funding from National Institutes of Health, we plan to conduct a randomized clinical trial of 316 patients with OUD and CP to test the effectiveness of TAU compared with Stepped Care for Patients to Optimize Whole Recovery (SC-POWR) to reduce nonmedical opioid use and pain (primary outcomes) (Aim 1) and decrease pain intensity and interference, alcohol use, anxiety, depression and stress, and improve sleep (secondary outcomes) (Aim 2). Eligible participants will be randomized to receive TAU (buprenorphine or methadone and at least once a month individual or group counseling) or SC-POWR (ie, TAU and up to 12 CBT sessions) for 24 weeks. Based on prespecified nonresponse criteria, SC-POWR may be stepped up at week 6 to receive onsite weekly group sessions of exercise (Wii Fit, Tai Chi) and "stepped up" again at week 15 to receive weekly group sessions of stress reduction (relaxation training, auricular acupuncture). They will be followed for another 24 weeks to evaluate durability of treatment response for illicit opioid use, alcohol use, pain, anxiety, depression, stress, sleep, and retention in medications for OUD (Aim 3).

Evaluation of intervention components to maximize yoga practice among people with chronic pain taking opioid agonist therapy: A factorial experiment using the multiphase optimization strategy framework

BACKGROUND

Chronic pain affects up to half of individuals taking opioid agonist therapy (OAT; i.e., methadone and buprenorphine) for opioid use disorder (OUD), and yoga-based interventions may be useful for decreasing pain-related disability. Whereas more yoga practice (i.e., higher "dosage") may improve pain-related outcomes, it can be challenging for people with chronic pain taking OAT to attend class regularly and sustain a regular personal yoga practice. Therefore, we plan to optimize a yoga-based intervention (YBI) package in order to support class attendance and personal practice, thus maximizing the yoga dose received.

STUDY DESIGN

Using the Multiphase Optimization Strategy (MOST) framework, we will conduct a factorial experiment to examine four intervention components that may be added to a weekly yoga class as part of a YBI. Components include: 1) personal practice videos featuring study yoga teachers, 2) two private sessions with a yoga teacher, 3) daily text messages to inspire personal practice, and 4) monetary incentives for class attendance. The primary outcome will be minutes per week engaged in yoga (including class attendance and personal practice). We plan to enroll 192 adults with chronic pain who are taking OAT for OUD in this 2x2x2x2 factorial experiment.

CONCLUSION

Results of the study will guide development of an optimized yoga-based intervention package that maximizes dosage of yoga received. The final treatment package can be tested in a multisite efficacy trial of yoga to reduce pain interference in daily functioning in people with chronic pain who are taking OAT.

TRIAL REGISTRATION

Pre-registration of the study was completed on ClinicalTrials.gov (identifier: NCT04641221).

Polymorphisms in the A118G SNP of the OPRM1 gene produce different experiences of opioids: A human laboratory phenotype-genotype assessment

Allelic variations in the A118G SNP of the OPRM1 gene change opioid signaling; however, evaluations of how allelic differences may influence opioid effects are lacking. This human laboratory paradigm examined whether the AA versus AG/GG genotypes determined opioid response profiles. Individuals with limited opioid exposure (N = 100) completed a five-day within-subject, double-blind, placebo-controlled, residential study. Participants were admitted (Day 1), received 4 mg hydromorphone (Day 2) and 0 mg, 2 mg and 8 mg hydromorphone in randomized order (Days 3-5) and completed self-reported visual analog scale (VAS) ratings and Likert scales, observed VAS, and physiological responses at baseline and for 6.5 h post-dose. Outcomes were analysed as peak/nadir effects over time as a function of genotype (available for N = 96 individuals; AG/GG = 13.5%, AA = 86.4%). Participants with AG/GG rated low and moderate doses of hydromorphone as significantly more positive (e.g., Good Effects VAS, coasting, drive, friendly, talkative, stimulation) with fewer negative effects (e.g., itchy skin, nausea, sleepiness), and were also observed as being more talkative and energetic relative to persons with AA. Persons with AG/GG were less physiologically reactive as determined by diastolic blood pressure and heart rate, but had more changes in core temperature compared with those with AA. Persons with AA also demonstrated more prototypic agonist effects across doses; persons with AG/GG showed limited response to 2 mg and 4 mg. Data suggest persons with AG/GG genotype experienced more pleasant and fewer unpleasant responses to hydromorphone relative to persons with AA. Future studies should replicate these laboratory findings in clinical populations to support a precision medicine approach to opioid prescribing.

Systematic Review and Meta-Analysis of the Prevalence of Chronic Pain Among Patients With Opioid Use Disorder and Receiving Opioid Substitution Therapy

To assess studies examining the prevalence of chronic pain (CP) in patients treated with Opioid Substitution Treatment (OST - buprenorphine or methadone) for Opioid Used Disorder (OUD), we conducted a systematic review and meta-analysis of the literature between the years 2000 and 2020. We searched EMBASE, PsycINFO, Cochrane, and MEDLINE databases and included studies assessing the prevalence of CP in OUD adults treated with OST. The studies were assessed for risk of bias and overall quality and the results were pooled using a random-effects model. Subgroup analyses and meta-regressions were used to identify possible factors associated with CP. Twenty-three studies reported data on the prevalence of CP in patients treated with OST were evaluated. The prevalence obtained was 45.3% (CI95% [38.7; 52.1]). Overall, 78.3% of the studies had a low risk of bias. Subgroup analysis estimates did not vary according to gender, OST, and CP duration. However, it appeared that the clinical settings was associated with a lower CP prevalence when assessed in primary care sites. Our study provided an estimate regarding the prevalence of CP among OST patients. These patients deserve specific attention from health professionals and health authorities. Thus, the real challenge in OST patients is the implementation of a multidisciplinary approach to manage CP. PERSPECTIVE: Our meta-analysis provided an estimate of CP prevalence, reaching almost 50% of OUD patients with OST. Thus, the urgent challenge in OST patients is to pay systematic attention to chronic pain diagnosis, along with the implementation of a multidisciplinary patient-focused approach for an appropriate management of CP. REGISTRATION: PROSPERO (CRD42021284790).

Continuity of illicit drug use among Malay patients attending methadone clinics in Kelantan, Malaysia

The study aimed to determine the prevalence of continuity of illicit drug use and its associated factors among Malay opioid users receiving methadone treatment in Kelantan, Malaysia. This cross-sectional study involved a total of 150 respondents. Sociodemographic characteristic of participants, level of religiosity, and quality of life were collected using the self-administered questionnaires. The prevalence of continuity illicit drug use was 38.7% (n = 58) by self-report and 40.7% (n = 61) by positive urine test result for drugs. Positive hepatitis C status and high quality of life in the psychological health domain were associated with low continuity of illicit drug use by self-reported data and urine drug test results. In conclusion, the continuity of illicit drug use among methadone program users is still high, especially among those on methadone therapy for less than 2 years.

Differential Experience of Interdose Withdrawal During Long-Term Opioid Therapy and its Association With Patient and Treatment Characteristics: A Latent Class Analysis in Chronic Pain Population

Opioid withdrawal is characterized by a set of physical and psychological symptoms that depend on both opioid and patient specific characteristics. The present study aims to identify different latent classes of chronic pain patients according to the type of opioid withdrawal symptoms experienced, and to analyze the relationships between the classes and demographic, opioid therapy, psychological and substance use variables. This cross-sectional descriptive study included 391 chronic pain patients on long-term opioid therapy. A Latent Class Analysis (LCA) identified 3 classes (BIC = 7051.89, entropy = .87, LRTs P < .01). The mild withdrawal class showed low probabilities of presenting physical and psychological symptoms, the moderate withdrawal class was characterized by experiencing psychological symptoms, and the severe withdrawal class stood out for high probabilities of presenting both types of symptoms. The classes differed from each other, with higher rates of moderate-severe POUD, opioid misuse, anxiety, depression, and greater pain intensity and interference in more severe withdrawal classes (P < .05). The multinomial logistic regression showed that moderate-severe POUD and anxiety were the strongest variables related to moderate (OR_POUD = 3.34, OR_Anxiety = 2.58) and severe withdrawal classes (OR_POUD = 4.26, OR_Anxiety = 5.15). Considering that POUD and anxiety were strongly related to a more severe withdrawal syndrome, the inclusion of psychological interventions in pain management seems critical in this population. PERSPECTIVE: Although interdose opioid withdrawal is common in chronic pain patients, this study shows 3 different patterns in its experience (mild, moderate, and severe withdrawal). A more severe withdrawal may result in reduced effectiveness of opioids in relieving pain and increased negative consequences, such as higher risk of POUD. Findings that could help improve chronic pain management.

Opioid dependence disorder and comorbid chronic pain: comparison of groups based on patient-attributed direction of the causal relationship between the two conditions

Background:

Chronic pain is highly prevalent in treatment-seeking opioid-dependent patients; therefore, this comorbid presentation is an important clinical consideration for both addiction and pain specialists. The objectives of the present study were to examine whether the direction of causal attribution of opioid dependence disorder and chronic pain resulted in two distinct clinical populations, and, if so, to compare treatment received during the 5-year follow-up period.

Methods:

Participants comprised opioid-dependent patients with chronic pain who reported a perceived causal relationship, in either direction, between the development of these two conditions (n = 252). A range of health- and addiction-related instruments were used at study inception. Treatment characteristics were obtained for the follow-up period from national health registers.

Results:

Those reporting that pain caused opioid dependence disorder (n = 174; 69%) were characterised by poorer pain-related health, more illicit cannabinoid use (p = 0.031), more frequent illicit use of opioid analgesics (p = 0.025) and they were in receipt of higher doses of prescribed opioid analgesics. Those reporting that opioid dependence disorder caused pain (n = 78; 31%) were characterised by poorer overall physical health (p = 0.002), more severe psychiatric symptoms and more overall drug use (p = 0.001).

Conclusion:

Two distinct clinical populations were identified, determined by how participants perceive the causal relationship between opioid dependence disorder and chronic pain. These two populations have differing clinical profiles and treatment requirements: those reporting that pain caused opioid dependence disorder were characterised by poorer pain-related health and more illicit use of drugs with analgesic properties; and those reporting that opioid dependence disorder caused pain were characterised by more overall use of substances, multiple substance use and more intravenous substance use and poorer general health. Identifying the causal direction, where such a relationship exists, could help addiction and pain services to develop more effective, individualised treatment strategies.

Clinical and psychological factors associated with interdose opioid withdrawal in chronic pain population

BACKGROUND

The DSM-5 diagnostic criteria for Prescription Opioid-Use Disorder (POUD) have undergone some significant changes. One of the most controversial changes has been the elimination of the withdrawal symptoms criterion when opioid use is under appropriate medical supervision. For this reason, the goal of this study was to analyze factors associated with opioid withdrawal in patients with chronic non-cancer pain (CNCP).

METHODS

This cross-sectional descriptive study involved 404 patients who use prescription opioids for long-term treatment (≥90 days) of CNCP. Measures included sociodemographic and clinical characteristics, POUD, withdrawal symptoms, craving, anxiety-depressive symptoms, and pain intensity and interference.

RESULTS

Forty-seven percent (n = 193) of the sample reported moderate-severe withdrawal symptoms, which were associated with lower age, higher daily morphine dose and duration of treatment with opioids, moderate-severe POUD, use of psychotropic drugs, higher anxiety-depressive symptoms, and greater pain intensity and interference (p < .05). Binary logistic regression analysis showed that moderate-severe POUD (OR = 2.82), anxiety (OR = 2.21), depression (OR = 1.81), higher pain interference (OR = 1.05), and longer duration of treatment with opioids were the strongest factors associated with moderate-severe withdrawal symptoms (p < .05).

CONCLUSION

Psychological factors seem to play a key role in the severity of withdrawal symptoms. Since greater intensity of these symptoms increases the risk of developing POUD, knowing the factors associated with withdrawal may be useful in developing preventive psychological interventions.

Dispensations of benzodiazepines, z-hypnotics, and gabapentinoids to patients receiving opioid agonist therapy; a prospective cohort study in Norway from 2013 to 2017

Background

Dispensations of benzodiazepines, z-hypnotics, and gabapentinoids to patients on opioid agonist therapy (OAT) are common and have pros and cons. The objectives of the current study are to define the dispensation rates of these potentially addictive drugs, and whether the number and the mean daily doses of dispensed OAT opioids and discontinuing OAT, are associated with being dispensed benzodiazepines, z-hypnotics and gabapentinoids among patients on OAT in Norway in the period 2013 to 2017.

Methods

Information about all dispensed opioids, benzodiazepines, z-hypnotics and gabapentinoids were recorded from the Norwegian Prescription Database (NorPD). A total of 10,371 OAT patients were included in the study period. The dispensation rates were defined as the number of patients who were dispensed at least one of the potentially addictive drugs divided among the number of patients who have dispensed an OAT opioid per calendar year. Mean daily doses were calculated, and for benzodiazepines and z-hypnotics, stated in diazepam equivalents. The association between dispensed potentially addictive drugs, and the number and the type of dispensed OAT opioids were calculated by using logistic regression models.

Results

Half of the OAT patients received at least one dispensation of a benzodiazepine or z-hypnotic, and 11% were dispensed at least a gabapentinoid in 2017. For dispensed benzodiazepines or z-hypnotics, the mean daily dose was reduced from 21 mg (95% confidence interval (CI): 20–23) diazepam equivalents in 2013 to 17 mg (95% CI: 16–17) in 2017. The mean daily dose of pregabalin increased from 365 mg (95% CI: 309–421) in 2013 to 386 mg (95% CI: 349–423) in 2017. Being dispensed a gabapentinoid (adjusted odds ratio (aOR) = 2.5, 95% CI: 2.1–3.0) or a non-OAT opioid (aOR = 3.0, 95% CI: 2.6–3.5) was associated with being dispensed a benzodiazepine or z-hypnotic. Discontinuing OAT did not affect the number of dispensations and the doses of potentially addictive drugs.

Conclusion

The dispensation rates of potentially addictive drugs are high in the OAT population. Treatment indications, as well as requirements for prescription authority, need to be debated and made explicit. Randomized controlled trials evaluating the benefits and risks of such co-prescription are required.

Dispensation of attention deficit hyperactivity disorder (ADHD) medications in patients receiving opioid agonist therapy; a national prospective cohort study in Norway from 2015 to 2017

BACKGROUND

It is estimated that up to a third of patients on opioid agonist therapy (OAT) have attention deficit hyperactivity disorder (ADHD). Treatment by ADHD medication, including a centrally acting stimulant (CAS) or atomoxetine is one of the essential approaches. This study evaluates the use of dispensed ADHD medications in the Norwegian OAT population in the period from 2015 to 2017. Types and doses of ADHD medications, co-dispensations of other potentially addictive drugs like benzodiazepines, z-hypnotics, gabapentinoids, and non-OAT opioids, as well as direct-acting antivirals (DAA) against hepatitis C infection, are investigated.

METHODS

Information about all dispensed ADHD medication, OAT opioids, and the defined potentially addictive drugs were recorded from the Norwegian Prescription Database. Dispensation rates, the types, and the doses of dispensed ADHD medications were estimated by summarizing the number of dispensations, and the dispensed doses. Logistic regression analyses were employed to assess the associations between ADHD medication, and OAT opioid use, and dispensations of other potentially addictive drugs and DAAs against hepatitis C infection.

RESULTS

A total of 9235 OAT patients were included. The proportion of patients who were dispensed ADHD medication increased from 3.5 to 4.6% throughout the study period. The three most dispensed CAS were short- and intermediate-acting methylphenidate (55%), lisdexamphetamine (24%), and dexamphetamine (17%) in 2017. Buprenorphine, rather than methadone, as OAT opioid (adjusted odds ratio: 1.6, CI: 1.2-2.1) was associated with being dispensed ADHD medication. Among patients who received CAS and OAT opioids each calendar year, the dispensed doses of methylphenidate increased from 63 mg/day in 2015 to 76 mg/day in 2017 (p = 0.01). Sixty percent of patients receiving ADHD medications were also dispensed other addictive drugs concomitantly in 2017. Similar results were found in 2015 and 2016.

CONCLUSION

Co-prescription of ADHD medications was low among patients on OAT in Norway, considering a high prevalence of ADHD in this patient group. On the other hand, concurrent dispensations of multiple addictive drugs were common in this population. Understanding the underlying reasons for such prescribing is essential, and research on how to optimize ADHD medication of patients with ADHD receiving OAT is needed.

Comparison of psychiatric comorbidity in treatment-seeking, opioid-dependent patients with versus without chronic pain

AIM

To compare psychiatric morbidity in treatment-seeking, opioid-dependent patients with versus without chronic pain.

DESIGN

A retrospective comparative cohort design was used involving record linkage from routinely collected, nationally held data sets. Data were managed within a Scottish Government-certified Safe Haven.

SETTING AND PARTICIPANTS

Participants comprised all patients of an NHS Substance Misuse Service in the East of Scotland (n = 467) who were in treatment during 2005 and had been in treatment for varying lengths of time. Their mean age at study inception was 35.0 years in the chronic pain group and 32.1 years; 68% of the chronic pain group and 74% of the no pain group were male.

MEASUREMENTS

The outcomes were (a) psychiatric comorbidity assessed at study inception using the 28-item General Health Questionnaire and the Clinical Outcomes in Routine Evaluation-Outcome Measure and (b) receipt of at least one prescription for a psychiatric condition during a 5-year period following study inception. The independent variable was chronic pain measured at study inception using the Brief Pain Inventory-Short Form.

FINDINGS

A total of 246 (52.7%) reported chronic pain and 221 (47.3%) did not. A higher proportion of patients with chronic pain had at least one psychiatric morbidity (62.4 versus 46.3%, P < 0.001). At the study inception, a higher proportion of patients with chronic pain were prescribed anxiolytics (49.0 versus 39.1%, P = 0.015) and antimanic drugs (9.9 compared with 4.9%, P = 0.015).

CONCLUSIONS

Patients of opioid treatment services in Scotland who report chronic pain may have a higher prevalence of psychiatric comorbidity than those who do not.