Adverse events associated with medium- and long-term use of opioids for chronic non-cancer pain: an overview of Cochrane Reviews

Impact of Informed Consent and Education on Care Engagement After Opioid Initiation in the Veterans Health Administration

Objective

To ensure all patients receiving long-term opioid therapy (LTOT) understand the risks, benefits and treatment alternatives, the Veterans Health Administration (VHA) released a national policy in 2014 to standardize a signature informed consent (SIC) process. We evaluated the impact of this policy on medical follow-up after LTOT initiation, a guideline recommended practice.

Methods

Using VHA administrative data, we identified patients initiating LTOT between May 2013 and May 2016. We used an interrupted time series design to compare the monthly rates of medical follow-up within 30 days and primary care visits within 3 months after LTOT initiation across three periods: 12 months before the policy (Year 1); 12 months after policy release (Year 2); and 12-24 months after policy release, when the SIC process was mandatory (Year 3).

Results

Among the 409,895 patients who experienced 758,416 LTOT initiations, medical follow-up within 30 days and primary care engagement within 3 months increased by 4% between Year 1 and Year 3. Compared to Year 1, patients in Year 3 were 1.12 times more likely to have any medical follow-up (95% CI: 1.10, 1.13) and 1.13 times more likely to have a primary care visit (95% CI: 1.12, 1.15). Facilities with a greater proportion of patients receiving SIC had increased medical follow-up (RR: 1.04, 95% CI: 1.01, 1.07) and primary care engagement (RR: 1.06, 95% CI: 1.03, 1.10).

Conclusion

The VHA's SIC policy is associated with increased medical follow-up among patients initiating LTOT, which may result in improved patient safety and has implications for other healthcare settings.

Time to initiate randomized controlled clinical trials with methadone in cancer patients

Public media coverage has fueled a demand for methadone as potential cure for cancer itself. Because patients have asked for respective prescriptions, clinical societies issued statements warning against the use of methadone as long as preclinical findings have not been supported by clinical evidence. In fact, not all preclinical data clearly support relevant effects. However, strong epidemiologic data suggest beneficial effects of methadone on cancer. Alternative explanations, namely better safety of methadone or hidden selection bias, seem less likely. This uncertainty can only be resolved by randomized controlled clinical trials. This review discusses all relevant data pertinent to methadone and cancer, uncovers supportive epidemiologic data, and suggests possible study designs.

Persistent opioid use after hospital discharge in Australia: a systematic review

ObjectiveThis systematic review identified studies that provided an estimate of persistent opioid use following patient discharge from hospital settings in Australia.MethodsA literature search was performed on 5 December 2020, with no date restrictions to identify studies that reported a rate of persistent opioid use following patient discharge from Australian Hospitals. The search strategy combined all terms relating to the themes 'hospital patients', 'prescribing', 'opioids' and 'Australia'. Studies that dealt solely with cancer, palliative care or addiction medicine were excluded. The databases searched in this review were Embase, PubMed, Scopus, CINAHL, and International Pharmaceutical Abstracts. Studies were assessed for bias using the Newcastle-Ottawa Scale and considered against international literature.ResultsIn total, 13 publications are included for final analysis in this review. Of these, 11 articles relate to post-surgical opioid use. With one exception, studies were of a 'good' quality. Methods of data collection in included studies were a mixture of those conducting follow up of patients directly over time and those utilising dispensing databases. Persistent opioid use among surgical patients generally ranged from 3.9 to 10.5% at between 2 and 4 months after discharge.ConclusionsHow rates of persistent opioid use following hospital encounters in Australia are established, and how long after discharge rates are reported, is heterogeneous. Literature primarily relates to post-surgical patients, with very few studies investigating other settings such as encounters with the emergency department.

Guided self-determination in treatment of chronic pain - a randomized, controlled trial

OBJECTIVES

To test whether Guided Self-Determination (GSD) used in chronic pain management could improve the health-related quality of life, patient activation and sense of coherence (SoC) as a measurement of life skills in patients with chronic pain. The method has been shown to be effective in other chronic conditions, but has not been tested in chronic pain.

METHODS

A three-site randomised, controlled trial at three major multidisciplinary pain centres in Denmark. 200 patients were included and randomised. In the intervention period, both groups had regular visits to the pain centre with both doctors and nurses. The intervention group additionally received the GSD intervention with weekly sessions for eight weeks. Data were collected from February 2013 to July 2016 and consisted of three questionnaires answered before and after the 8-week intervention period, and after six months. The primary outcome was self-reported health related quality of life. Secondary outcomes included self-reported activation and SoC.

RESULTS

We found no clinically relevant difference between the groups for health-related quality of life, patient activation or SoC at either baseline, at three months or at six months. We also analysed data for trends over time using mixed model analysis, and this did not show any significant differences between groups.

CONCLUSIONS

GSD did not improve health-related quality of life, patient activation or SoC when administered to patients with chronic pain treated in a multidisciplinary pain centre. New research is recommended using a combination of self-reported and objective measures and longer follow-up.

How Would You Treat This Patient With Acute and Chronic Pain From Sickle Cell Disease? : Grand Rounds Discussion From Beth Israel Deaconess Medical Center

Sickle cell disease is prevalent in large numbers of patients in the United States and has a significant global impact. Its complications span numerous organs and lead to reduced life expectancy. Acute and chronic sickle cell pain is a common cause of patient suffering. The American Society of Hematology published updated guidelines on management of acute and chronic pain from sickle cell disease in 2019. Several of the recommendations are conditional and leave specific decisions to the treating physician. These include conditional recommendations about the use of ketamine for acute pain and the initiation and discontinuation of long-term opioid therapy for chronic pain. Here, 2 hematologists discuss these guidelines and make contrasting recommendations for the management of acute and chronic pain for a patient with sickle cell disease.

Opioids and older adults: Increasing trends in opioid usage in a dental population compared to a National Database (NHANES)

Aim

To examine self‐reported opioid prevalence at a dental school clinic for patients ≥65 years old as compared to national data, comparing gender, ethnicity/race and older adult age groupings.

Methods and results

Self‐reported prescription opioid medication use was extracted from the medical record for dental patients ≥65 years old who visited the school's general dental clinic (GDC) in 2012 or 2017. This data was compared to the National Health and Nutrition Examination Survey (NHANES) data for 2011–2012 and 2017–18. There was a significant increase in prevalence of opioid use in adults ≥65 between 2012 (4.5%) and 2017 (6.5%) and for ages 65–79 (from 4.7% to 6.3%) and ≥80 (3.4% to 7.9%), women (4.8% to 7.0%), and African Americans (4.7% to 8.4%) in the GDC. Older adults at the GDC reported less opioid use than the NHANES national average for both periods no matter the gender or the age with variable results for race/ethnicity.

Conclusion

The prevalence of older adults taking opioids in our general dental school clinic population increased significantly in 2017 as compared to 2012 but was lower than the national average for the respective periods. Awareness of existing opioid usage in older adult patients and its higher adverse risk potential is critical when prescribing analgesics for dental pain for this age group.

Comparative Efficacy of Pharmacological Therapies for Low Back Pain: A Bayesian Network Analysis

Low back pain (LBP) is a common problem, but the efficacy of pharmacological therapies remains controversial. Therefore, we aimed to comprehensively evaluate and quantitatively rank various pharmacological therapies for patients with low back pain. Two meta-analyses were performed: an initial pair-wise meta-analysis, followed by network meta-analysis using a random-effects Bayesian model. We included randomized controlled trials comparing placebos, non-steroidal anti-inflammatory drugs, opioids, skeletal muscular relaxants, pregabalin (or gabapentin), and some drug combinations. The primary and secondary outcomes were pain intensity and physical function. Eighty-eight eligible trials with 21,377 patients were included. Here, we show that only skeletal muscle relaxants significantly decreased the pain intensity of acute (including subacute) low back pain. Several kinds of drugs significantly decreased the pain of chronic low back pain, but only opioids and cyclo-oxygenase 2-selective non-steroidal anti-inflammatory drugs effectively reduced pain and improved function. Pregabalin (or gabapentin) seemed to be an effective treatment to relieve pain, but it should be used with caution for low back pain.

Effects of Ultramicronized N-Palmitoylethanolamine Supplementation on Tramadol and Oxycodone Analgesia and Tolerance Prevention

Chronic pain management requires increasing doses of opioids, the milestone of painkillers, which may result in the onset of tolerance with exacerbated side effects. Maintaining stable analgesia with low doses of opioids is thus imperative. N-palmitoylethanolamine (PEA) is an endogenous lipid compound endowed with pain-relieving as well as anti-inflammatory properties. The ultramicronized formulation of PEA was recently demonstrated to be able to modulate morphine’s effects, delaying tolerance and improving efficacy. To evaluate the possible application to other opioids, in this study, we analysed the capacity of ultramicronized PEA to regulate analgesia and tolerance induced by oxycodone and tramadol. Pre-emptive and continuative treatment with ultramicronized PEA (30 mg kg⁻¹, daily, per os) delayed the onset of opioid tolerance and enhanced opioid analgesia when it was acutely administered in association with tramadol (20 mg kg⁻¹, daily, subcutaneously) or oxycodone (0.5 mg kg⁻¹, daily, subcutaneously). Moreover, PEA exerted antinociceptive effects on tolerant rats, suggesting the use of PEA together with opioids for stable, long-lasting analgesia. To that purpose, the oxycodone dose needed to be increased from 0.3 mg kg⁻¹ (day 1) up to 1 mg kg⁻¹ (day 31) in the oxycodone + vehicle group; the tramadol dose was progressively enhanced from 15 mg kg⁻¹ to 50 mg kg⁻¹ in 31 days in the tramadol + vehicle group. Acute oral co-treatment with PEA (120 mg kg⁻¹) achieved the same analgesia without increasing the dose of both opioids. The behavioural effects of PEA on opioid chronic treatment paralleled a decrease in astrocyte activation in the dorsal horn of the spinal cord (a marker of the development of opioid tolerance) and with a modulation of mRNA expression of IL-6 and serpin-A3. In conclusion, pre- and co-administration of ultramicronized PEA delayed the development of tramadol tolerance, potentiating either oxycodone or tramadol analgesia and allowing a long-lasting analgesic effect with a low opioid dose regimen. The use of PEA is suggested for clinical purposes to support the opioid-based management of persistent pain.

Pain Management Strategies After Orthopaedic Trauma: A Mixed-Methods Study with a View to Optimizing Practices

PURPOSE

To examine 1) pain management strategies within the care trajectory of orthopaedic trauma patients and patients' perception of their effectiveness, 2) adverse effects (AEs) associated with pharmacological treatments, particularly opioids and cannabis, and 3) patients' perceptions of strategies that should be applied after an orthopaedic trauma and support that they should obtain from health professionals for their use.

PATIENTS AND METHODS

This study was conducted with orthopaedic trauma patients in a level 1 trauma center. A convergent mixed-methods design was used. Data on pain experience, pain management strategies used and AEs were collected with self-administered questionnaires at hospital discharge (T1) and at 3 months after injury (T2). Patients' preferences about the pain management strategies used, the required support and AEs were further examined through semi-structured individual interviews at the same time measures. Descriptive statistics and thematic analyses were performed.

RESULTS

Seventy-one patients were recruited and 30 individual interviews were undertaken. Pharmacological pain management strategies used at T1 and T2 were mainly opioids (95.8%; 20.8%) and acetaminophen (91.5%; 37.5%). The most frequently applied non-pharmacological strategies were sleep (95.6%) and physical positioning (89.7%) at T1 and massage (46.3%) and relaxation (32.5%) at T2. Findings from quantitative and qualitative analyses highlighted that non-pharmacological strategies, such as comfort, massage, distraction, and physical therapy, were perceived as the most effective by participants. Most common AEs related to opioids were dry mouth (78.8%) and fatigue (66.1%) at T1 and insomnia (30.0%) and fatigue (20.0%) at T2. Dry mouth (28.6%) and drowsiness (14.3%) were the most reported AEs by patients using recreational cannabis. An important need for information at hospital discharge and for a personalized follow-up was identified by participants during interviews.

CONCLUSION

Despite its AEs, we found that opioids are still the leading pain management strategy after an orthopaedic trauma and that more efforts are needed to implement non-pharmacological strategies. Cannabis was taken for recreational purposes but patients also used it for pain relief. Support from health professionals is needed to promote the adequate use of these strategies.

Do Formulation and Dose of Long-Term Opioid Therapy Contribute to Risk of Adverse Events among Older Adults?

BACKGROUND

Chronic non-cancer pain (CNCP) is highly prevalent in older adults and long-term opioid therapy (LTOT) has been used to manage chronic pain. However, the safety of LTOT among older adults with CNCP is not well-established and there is a need to identify therapy-related risk factors of opioid-related adverse events among older adults.

OBJECTIVE

To evaluate the relationship between opioid dose and formulation and the risk of opioid-related adverse events among Medicare-eligible older adults on LTOT.

DESIGN

Nested case-control study.

PARTICIPANTS

Older Medicare beneficiaries (N=35,189) who received > 3 opioid prescriptions with a total days-supply of >45 days within a 90-day period for CNCP between 2012 and 2016.

MAIN MEASURES

This study utilized Medicare 5% medical and prescription claims data. Outcome measures included opioid-induced respiratory depression (OIRD), opioid overdose, all-cause mortality, and a composite outcome, defined as the first occurrence of any of the previous three events. Key independent variables were opioid formulation and opioid dose (measured in morphine milligram equivalents (MME)) prescribed during LTOT.

KEY RESULTS

Seventy-four OIRD, 133 overdose, 982 all-cause mortality, and 1122 composite outcome events were observed during follow-up. In unadjusted analyses, the use of combination opioids (OR: 4.52 [95%CI: 1.51-13.47]) was significantly associated with OIRD compared to short-acting (SA) opioids. In adjusted analyses, opioid-related adverse events were significantly associated with the use of LA (overdose OR: 13.00 [95%CI: 1.30-130.16] and combination opioids (overdose OR: 6.27 [95%CI: 1.91-20.55]; mortality OR: 2.75 [95%CI: 1.87-4.04]; composite OR: 2.82 [95%CI: 2.01-3.96]) when compared to SA opioids. When compared to an average dose of less than 20 MME, outcomes were significantly associated with doses of 20-50 MME (mortality OR: 1.61 [95%CI: 1.24-2.10]; composite OR: 1.59 [95%CI: 1.26-2.01]) and >50 MME (mortality OR: 1.99 [95%CI: 1.28-3.10]; composite OR: 2.09 [95%CI: 1.43-3.04]).

CONCLUSIONS

Older adults receiving medically prescribed opioids at higher doses and those using LA and combination of LA and SA opioids are at increased risks for opioid-related adverse events, highlighting the need for close patient supervision.

Pain after midurethral sling; the underestimated role of mesh removal

Introduction

The primary aim of this study was to evaluate the results of midurethral sling (MUS) removal in women who have pain as their single complication of MUS.

Material and methods

We performed a retrospective chart study supplemented with a cross sectional questionnaire. Women who underwent MUS removal for pain as the solitary reason for removal between 2004 and 2018 were included. Primary outcome was change in pain levels assessed by the visual analogue scale (VAS) pain score (range 0–10). Secondary outcome was the recurrence of stress urinary incontinence (SUI).

Results

Twenty-six of 31 patients returned the questionnaire. Median medical file follow-up was 12 months (range 2–66) and 25 months (range 5–104) regarding questionnaires. VAS pain score dropped from 7.8 (SD 1.9) at baseline to 4.5 (SD 3.2) at follow-up (p <.00). Seven (23%) patients were pain-free. Patients undergoing partial vaginal resection (n = 6) had a VAS pain score decrease of 4.7 (p = .02) versus 2.7 (p = .02) for complete vaginal removal (n = 14). Twenty-three (89%) patients experienced SUI at follow-up, whereof 10 (45%) reported (almost) no incidents of SUI.

Conclusions

MUS removal is a viable and safe option with a significant drop in VAS pain score in patients with chronic pain after MUS placement. A post-operative increase of SUI and a possible renewed wish for SUI treatment have to be considered. This should not be a reason to refrain from information and/or referral for surgical removal.

Describing long-term opioid use utilizing Nordic Prescription Registers - A Norwegian example

Previous studies have defined long-term opioid use in varying ways, decreasing comparability, reproducibility, and clinical applicability of the research. Based on recommendations from recent systematic reviews, we aimed to develop a methodology to estimate the prevalence of use persisting more than three months utilizing one of the Nordic prescription registers. We used the Norwegian Prescription Register (NorPD) to extract data on all opioid dispensations between 1 January 2004 and 31 October 2019. New users of opioids (washout 365 days) were defined as long-term users if they fulfilled two criteria: 1) they had ≥2 dispensations of opioids, 91-180 days apart; 2) days 0-90 included ≥90 dispensed administration units (e.g., tablets) of opioids. Overall, there were 2,543,224 new users of opioids during the study period. Of these, 354,666 (13.9%) fulfilled the criteria for long-term opioid use at least once. Compared with those who did not fulfill the criteria (short-term users), long-term users were older, more likely women, and used tramadol, oxycodone, and buprenorphine more frequently as their first opioid. In conclusion, we found that 1/7 of opioid users continued use longer than 3 months. Future outcome research should identify the clinically most important dose requirements for long-term opioid use criteria.

Identifying Epidermolysis Bullosa Patient Needs and Perceived Treatment Benefits: An Explorative Study Using the Patient Benefit Index

Epidermolysis bullosa (EB) is a genetic blistering skin condition for which no cure exists. Symptom alleviation and quality of life are therefore central to EB care. This study aimed to gain insight into EB patient needs and benefits from current clinical care. Two questionnaires were administered cross-sectionally to adult EB patients at the Dutch expertise centre for blistering diseases. Patient needs and benefits were analyzed using the patient benefit index survey (PBI-S). Ancillary data were compiled pertaining to self-reported EB severity, pain and pruritus, as well as current and previous treatments. In total, 104 participants were included (response rate 69.8%). Sixty-eight participants comprised the analyzed cohort (n = 36 omitted from analysis). The needs given the highest importance were to get better skin quickly (64.7%) and to be healed of all skin alterations (61.8%). A positive correlation between pain and EB severity and the importance of most needs was observed. Minimal clinically important differences within the PBI-S, relating to reported benefits from clinical care, were reported by 60.3% of the cohort. This study highlights a discrepancy between patient needs and feasible treatment outcomes. Utilizing the PBI-S in conjunction with well-established multidisciplinary care may catalyze the process of tailoring treatments to the needs of individual patients.

Drug-Drug Interactions in Vestibular Diseases, Clinical Problems, and Medico-Legal Implications

Peripheral vestibular disease can be treated with several approaches (e.g., maneuvers, surgery, or medical approach). Comorbidity is common in elderly patients, so polytherapy is used, but it can generate the development of drug-drug interactions (DDIs) that play a role in both adverse drug reactions and reduced adherence. For this reason, they need a complex kind of approach, considering all their individual characteristics. Physicians must be able to prescribe and deprescribe drugs based on a solid knowledge of pharmacokinetics, pharmacodynamics, and clinical indications. Moreover, full information is required to reach a real therapeutic alliance, to improve the safety of care and reduce possible malpractice claims related to drug-drug interactions. In this review, using PubMed, Embase, and Cochrane library, we searched articles published until 30 August 2021, and described both pharmacokinetic and pharmacodynamic DDIs in patients with vestibular disorders, focusing the interest on their clinical implications and on risk management strategies.

Conolidine: A Novel Plant Extract for Chronic Pain

Pain, the most common symptom reported among patients in the primary care setting, is complex to manage. Opioids are among the most potent analgesics agents for managing pain. Since the mid-1990s, the number of opioid prescriptions for the management of chronic non-cancer pain (CNCP) has increased by more than 400%, and this increased availability has significantly contributed to opioid diversion, overdose, tolerance, dependence, and addiction. Despite the questionable effectiveness of opioids in managing CNCP and their high rates of side effects, the absence of available alternative medications and their clinical limitations and slower onset of action has led to an overreliance on opioids. Conolidine is an indole alkaloid derived from the bark of the tropical flowering shrub Tabernaemontana divaricate used in traditional Chinese, Ayurvedic, and Thai medicine. Conolidine could represent the beginning of a new era of chronic pain management. It is now being investigated for its effects on the atypical chemokine receptor (ACK3). In a rat model, it was found that a competitor molecule binding to ACKR3 resulted in inhibition of ACKR3's inhibitory activity, causing an overall increase in opiate receptor activity. Although the identification of conolidine as a potential novel analgesic agent provides an additional avenue to address the opioid crisis and manage CNCP, further studies are necessary to understand its mechanism of action and utility and efficacy in managing CNCP.

Tapentadol and Oxycodone/Naloxone Prescribing Patterns in Primary Health Care in Catalonia, Spain: A Cross-Sectional Study

Objective

To characterize the use of tapentadol and the combination oxycodone/naloxone in primary health care. Data on their use and possible misuse will allow the identification of risk factors and to design protocols to reduce and prevent avoidable harm to patients being treated for pain.

Design

A descriptive, cross-sectional and multicenter study was performed.

Setting

Fifty-three primary health care teams, which provides healthcare for 1,300,000 inhabitants.

Patients

A total of 1840 patients had active prescriptions of tapentadol and 985 of oxycodone/naloxone.

Methods

Demographic (age, sex) and clinical (glomerular filtration rate; active liver disease; dosing and duration of treatment), prescribed daily dose (according to age, sex, length of treatment), concomitant analgesic treatment and diagnosis. Patient information was obtained from medical records.

Results

Most of the patients were women (>74.0% in both cases), and the average age was 69.3 years (women: 70.1±13.2; men: 66.7±13.9 years) in the case of tapentadol and 70.6 years (women: 64.0±13.6; men: 72.6±14.3 years) in the case of oxycodone/naloxone. Only 12.2% of patients taking tapentadol and 12.1% taking oxycodone/naloxone had a normal renal function. In both cases, 4.1% of patients had active liver disease. The average length of treatment was 246.4 days in oxycodone/naloxone and 199.0 days in tapentadol. It was recorded that 85.1% of patients in the case of tapentadol and 89.0% in the oxycodone/naloxone had at least another drug prescribed for pain. About 42.2% of patients treated with tapentadol and 34.4% of patients treated with oxycodone/naloxone had associated neuralgia as a diagnosis.

Conclusion

The pattern of use and profile of patients with tapentadol and oxycodone/naloxone had more similarities than differences, and suggested that prescribing practice, and monitoring should be assessed regularly to ensure patient safety and effective management of pain.

Association of Tramadol vs Codeine Prescription Dispensation With Mortality and Other Adverse Clinical Outcomes

IMPORTANCE

Although tramadol is increasingly used to manage chronic noncancer pain, few safety studies have compared it with other opioids.

OBJECTIVE

To assess the associations of tramadol, compared with codeine, with mortality and other adverse clinical outcomes as used in outpatient settings.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective, population-based, propensity score-matched cohort study using a primary care database with routinely collected medical records and pharmacy dispensations covering more than 80% of the population of Catalonia, Spain (≈6 million people). Patients 18 years or older with 1 or more year of available data and dispensation of tramadol or codeine (2007-2017) were included and followed up to December 31, 2017.

EXPOSURES

New prescription dispensation of tramadol or codeine (no dispensation in the previous year).

MAIN OUTCOMES AND MEASURES

Outcomes studied were all-cause mortality, cardiovascular events, fractures, constipation, delirium, falls, opioid abuse/dependence, and sleep disorders within 1 year after the first dispensation. Absolute rate differences (ARDs) and hazard ratios (HRs) with 95% confidence intervals were calculated using cause-specific Cox models.

RESULTS

Of the 1 093 064 patients with a tramadol or codeine dispensation during the study period (326 921 for tramadol, 762 492 for codeine, 3651 for both drugs concomitantly), a total of 368 960 patients (184 480 propensity score-matched pairs) were included after study exclusions and propensity score matching (mean age, 53.1 [SD, 16.1] years; 57.3% women). Compared with codeine, tramadol dispensation was significantly associated with a higher risk of all-cause mortality (incidence, 13.00 vs 5.61 per 1000 person-years; HR, 2.31 [95% CI, 2.08-2.56]; ARD, 7.37 [95% CI, 6.09-8.78] per 1000 person-years), cardiovascular events (incidence, 10.03 vs 8.67 per 1000 person-years; HR, 1.15 [95% CI, 1.05-1.27]; ARD, 1.36 [95% CI, 0.45-2.36] per 1000 person-years), and fractures (incidence, 12.26 vs 8.13 per 1000 person-years; HR, 1.50 [95% CI, 1.37-1.65]; ARD, 4.10 [95% CI, 3.02-5.29] per 1000 person-years). No significant difference was observed for the risk of falls, delirium, constipation, opioid abuse/dependence, or sleep disorders.

CONCLUSIONS AND RELEVANCE

In this population-based cohort study, a new prescription dispensation of tramadol, compared with codeine, was significantly associated with a higher risk of subsequent all-cause mortality, cardiovascular events, and fractures, but there was no significant difference in the risk of constipation, delirium, falls, opioid abuse/dependence, or sleep disorders. The findings should be interpreted cautiously, given the potential for residual confounding.

Opioid-Related Side Effects and Management

The following areas will be discussed in relation to opioid-related side effects and approaches to their management in the cancer patient.

Evaluation of Buprenorphine Rotation in Patients Receiving Long-term Opioids for Chronic Pain: A Systematic Review

IMPORTANCE

Individuals with chronic pain who use long-term opioid therapy (LTOT) are at risk of opioid use disorder and other harmful outcomes. Rotation to buprenorphine may be considered, but the outcomes of such rotation in this population have not been systematically reviewed.

OBJECTIVE

To synthesize the evidence on rotation to buprenorphine from full μ-opioid receptor agonists among individuals with chronic pain who were receiving LTOT, including the outcomes of precipitated opioid withdrawal, pain intensity, pain interference, treatment success, adverse events or adverse effects, mental health condition, and health care use.

EVIDENCE REVIEW

PubMed, CINAHL, Embase, and PsycInfo were searched from inception through November 3, 2020, for peer-reviewed original English-language research that reported the prespecified outcomes of rotation from prescribed long-term opioids to buprenorphine among individuals with chronic pain. Two independent reviewers extracted data as well as assessed risk of bias and study quality according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guidelines. Quality of evidence was assessed with the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system.

FINDINGS

A total of 22 studies were analyzed, of which 5 (22.7%) were randomized clinical trials, 7 (31.8%) were case-control or cohort studies, and 10 (45.5%) were uncontrolled pre-post studies, which involved 1616 unique participants (675 female [41.8%] and 941 male [58.2%] individuals). Six of the 22 studies (27.3%) were primary or secondary analyses of a large randomized clinical trial. Participants had diverse pain and opioid use histories. Rationale for buprenorphine rotation included inadequate analgesia, intolerable adverse effects, risky opioid regimens (eg, high dose and/or sedative coprescriptions), and aberrant opioid use. Most protocols were adapted from protocols for initiating treatment in patients with opioid use disorder and used buccal or sublingual buprenorphine. Very low-quality evidence suggested that buprenorphine rotation was associated with maintained or improved analgesia, with a low risk of precipitating opioid withdrawal. Steady-dose buprenorphine was better tolerated than tapered-dose buprenorphine. Adverse effects were manageable, and severe adverse events were rare. Only 2 studies evaluated mental health outcomes, but none evaluated health care use. Limitations included a high risk of bias in most studies.

CONCLUSIONS AND RELEVANCE

In this systematic review, buprenorphine was associated with reduced chronic pain intensity without precipitating opioid withdrawal in individuals with chronic pain who were receiving LTOT. Future studies are necessary to ascertain the ideal starting dose, formulation, and administration frequency of buprenorphine as well as the best approach to buprenorphine rotation.

Beneficial Effects of Opioid Rotation to Buprenorphine/Naloxone on Opioid Misuse, Craving, Mental Health, and Pain Control in Chronic Non-Cancer Pain Patients with Opioid Use Disorder

Patients with chronic non-cancer pain (CNCP) often use opioids for long periods of time. This may lead to opioid use disorder (OUD) and psychiatric symptoms: mainly depression and anxiety. The current study investigated the effect of buprenorphine/naloxone (BuNa) rotation on opioid misuse, craving, psychiatric symptoms and pain in patients with CNCP and OUD. Forty-three participants with CNCP and OUD were converted from a full mu-receptor agonist opioid (mean morphine equivalent dose: 328.3 mg) to BuNa, in an inpatient setting. Opioid misuse, craving, co-occurring psychiatric symptoms, and pain perception were determined at baseline and after a two-month follow-up, using the following self-report questionnaires: Current Opioid Misuse Measurement (COMM), Visual Analog Scale (VAS-craving and VAS-pain) and Depression, Anxiety and Stress Scale (DASS), respectively. VAS-craving and VAS-pain were also determined immediately after conversion. A total of 37 participants completed the protocol. The mean COMM decreased from 17.1 to 6.7 (F = 36.5; p < 0.000), the mean VAS-craving decreased from 39.3 to 5.3 (−86.6%; F = 26.5, p < 0.000), the mean DASS decreased from 12.1 to 6.6 (F = 56.3, p < 0.000), and the mean VAS-pain decreased from 51.3 to 37.2 (−27.4%, F = 3.3; p = 0.043). Rotation to BuNa in patients with CNCP and OUD was accompanied by reductions in (i) opioid misuse, (ii) opioid craving, (iii) the severity of co-occurring psychiatric symptoms, and (iv) self-reported pain. BuNa as opioid agonist treatment may therefore be a beneficial strategy in CNCP patients with OUD. The limited sample size and the observational nature of this study underline the need for the replication of the current findings in large-scale, controlled studies.

Rationalisation of long-term high-dose opioids for chronic pain: development of an intervention and conceptual framework

There has been a large increase in the number of prescriptions for opioid drugs in the United Kingdom over the last 20 years or more and the prescribing of opioids in high doses continues to increase. Much opioid prescribing is for chronic non-cancer pain (CNCP) despite serious doubts about the long-term effectiveness of opioids for this indication. Clinical experience is that there are increasing numbers of patients who are on high dosages of opioid drugs over sustained periods which provide limited or no pain relief while having significant negative effects on functioning and quality of life. The aim of this article is to bring readers' attention to some clinical observations of the CNCP population with high doses and to describe an intervention to reduce these doses. Many of these patients have no clinical features of addiction; we suggest that those who show little or no substance misuse behaviours are best understood as a distinct clinical population who have different treatment needs. In order to understand and treat these patients, a model is required which, rather than seeing the problem as lying solely with the patient, focuses on the interaction between the individual and his or her environment and seeks a change in what the patient does every day, rather than a simple, and largely unattainable, goal of symptom elimination. The clinician authors worked together to develop an intervention based upon approaches taken from both pain management and psychiatric practice. A detailed description of this rapid opioid reduction intervention (RORI) is provided along with some preliminary outcome data.

Tapering of prescribed opioids in patients with long-term non-malignant pain (TOPIO)-efficacy and effects on pain, pain cognitions, and quality of life: a study protocol for a randomized controlled clinical trial with a 12-month follow-up

Background

Opioids are still widely prescribed to long-term pain patients although they are no longer recommended for long-term treatments due to poor evidence for long-term efficacy, risks of serious side effects, and the possibility of inducing opioid hyperalgesia. In a Cochrane study from 2017, the authors identified an urgent need for more randomized controlled trials investigating the efficiency and effects of opioid tapering.

The study aimed to assess (1) the efficiency of a structured intervention in causing stable reductions of opioid consumption in a population with long-term non-malignant pain and (2) effects on pain, pain cognitions, physical and mental health, quality of life, and functioning in response to opioid tapering.

Methods

The study is a randomized controlled trial. The sample size was set to a total of 140 individuals after estimation of power and dropout. Participants will be recruited from a population with long-term non-malignant pain who will be randomly allocated to (1) the start of tapering immediately or (2) the control group who return to usual care and will commence tapering of opioids 4 months later. A 12-month follow-up is included.

When all follow-ups are closed, data from the Swedish drug register of the National Board of Health and Welfare will be collected and individual mean daily opioid dose in morphine equivalents will be calculated at three time points: baseline, 4 months, and 12 months after the start of the intervention. At the same time points, participants fill out the following questionnaires: Numeric Pain Rating Scale (NPRS), Tampa Scale of Kinesiophobia (TSK), Pain Catastrophizing Scale (PCS), Chronic Pain Acceptance Questionnaire (CPAQ-8), Hospital Anxiety and Depression Scale (HADS), and RAND-36. At baseline and follow-up, a clinical assessment of opioid use disorder is performed.

Discussion

A better understanding of the efficiency and effects of opioid tapering could possibly facilitate attempts to taper opioid treatments, which might prove beneficial for both the individual and society.

Trial registration

ClinicalTrials.gov NCT03485430. Retrospectively registered on 26 March 2018, first release date. “Tapering of Long-term Opioid Therapy in Chronic Pain Population. RCT with 12 Months Follow up (TOPIO).” First patient in trial 22 March 2018.

Naldemedine Improves Patient-Reported Outcomes of Opioid-Induced Constipation in Patients with Chronic Non-Cancer Pain in the COMPOSE Phase 3 Studies

Objective

Opioid-induced constipation is among the most common side effects associated with opioid use in patients with chronic non-cancer pain, and it can have a significant negative impact on health-related quality of life (QOL). This analysis evaluated the effect of naldemedine 0.2 mg on patient-reported outcomes in three phase 3 clinical studies.

Methods

COMPOSE-1 and COMPOSE-2 were identical randomized, double-blind, placebo-controlled, parallel-group studies of 12 weeks’ duration, allowing data to be integrated (n=1095). COMPOSE-3 was similar in design, but of 52 weeks’ duration (n=1241). Patients were adults with chronic non-cancer pain who had been treated with opioid analgesics for ≥3 months and experiencing opioid-induced constipation. Patient-reported outcomes included Patient Assessment of Constipation Symptoms (PAC-SYM; 12 questions assessed on a 5-point Likert scale), PAC-QOL (28 questions assessed on a 5-point Likert scale), and Subject Global Satisfaction (measured on a 7-point Likert scale). The proportion of patients achieving a ≥1.5 improvement in PAC-SYM and PAC-QOL was calculated. The correlation between change in PAC-SYM and PAC-QOL scores and frequency of bowel movements was also explored.

Results

The proportion of PAC-SYM and PAC-QOL responders was significantly higher for naldemedine than for placebo at all assessed time points in COMPOSE-1/COMPOSE-2 (p<0.005 for both) and COMPOSE-3 (p<0.005 and p<0.0001, respectively). There was a statistically significant correlation between improvement in PAC-SYM/PAC-QOL and frequency of bowel movements at all time points (p≤0.0002). The majority of patients treated with naldemedine reported markedly or moderately improved satisfaction with constipation and abdominal symptoms on the Subject Global Satisfaction questionnaire.

Discussion

Naldemedine treatment was associated with a rapid and sustained clinically relevant improvement in patient-reported outcomes, indicating improvement in opioid-induced constipation-related symptoms and QOL.

ClinicalTrials.gov Registration

NCT01965158, NCT01993940, NCT01965652.

Validity of Current Assessment Tools Aiming to Measure the Affective Component of Pain: A Systematic Review

The objective of this study was to identify patient-reported outcome measures (PROMs), which aim to measure the affective component of pain and to assess their content validity, unidimensionality, measurement invariance, and Internal consistency in patients with chronic pain. The study was reported according to the PRISMA guidelines. A protocol of the review was submitted to PROSPERO before data extraction. Eligible studies were any type of study that investigated at least one of the domains: PROM development, content validity, dimensionality, internal consistency, or measurement invariance of any type of scale that claimed to measure the affective component of pain among patients with chronic pain. The databases Medline, Embase, PsycINFO, and the Cochrane Library were searched for eligible studies. The database search was supplemented by looking for relevant articles in the reference list of included studies, ie backtracking. All included studies were assessed independently by two authors according to the “COSMIN methodology on Systematic Reviews of Patient-Reported Outcome Measures”. Descriptive data synthesis of the identified PROMs was conducted. The search yielded 11,242 titles of which 283 were assessed at the full-text level. Full-text screening led to the inclusion of 11 studies and an additional 28 studies were identified via backtracking, leading to the inclusion of 39 studies in total in the review. Included studies described the development and validity of 10 unique PROMs, all of which we assessed to have potentially inadequate content validity and doubtful psychometric properties. No studies reported whether the PROMs possessed invariant measurement properties. The existing PROMs measuring affective components of chronic pain potentially lack content validity and have inadequate psychometric measurement properties. There is a need for new PROMs measuring the affective component of chronic pain that possess high content validity and adequate psychometric measurement properties.

Trajectories of Opioid Coverage After Long-Term Opioid Therapy Initiation Among a National Cohort of US Veterans

PURPOSE

The objective of this study was to identify the trajectories that patients take after initiating long-term opioid therapy (LTOT).

MATERIALS AND METHODS

Using a retrospective cohort design, veterans with chronic non-cancer pain (CNCP) initiating LTOT were identified. Group-based trajectory models were used to identify opioid therapy trajectories based on days of opioid supply (primary outcome) and average daily morphine milligram equivalent dose (AMME; secondary outcome) in each 180-day period following initiation of LTOT.

RESULTS

A total of 438,398 veterans with CNCP initiated LTOT. Nine trajectories were identified: 33.7% with persistent, high days covered, 17.7% with persistent, moderate days covered, 16.6% with slow, persistent days-covered reduction, 2.4% with days-covered reduction followed by increase, 4.6% with delayed days-covered reduction, 4.1% with rapid days-covered reduction, 10.9% with moderate-paced discontinuation, 3.4% with delayed discontinuation, and 6.5% with rapid discontinuation. Patients following discontinuation trajectories were more likely to be younger, persons of color, use more supportive services (eg, physical therapy), and received less opioid days' supply and lower doses prior to initiating LTOT as compared to patients following persistent opioid days-covered trajectories. AMME trajectories were similar to days-covered trajectories.

CONCLUSION

Among persons initiating LTOT, nine opioid trajectories emerged which can be broadly characterized into three main trajectory groups: persistent opioid therapy (2 trajectories), reductions in opioid therapy (4 trajectories), and discontinuation (3 trajectories). A majority of patients (51.4%) maintained persistent opioid therapy. Further research is needed to assess the risks of opioid-related adverse outcomes among the identified trajectories.

Early Detection of Exposure to Toxic Chemicals Using Continuously Recorded Multi-Sensor Physiology

Early detection of exposure to a toxic chemical, e.g., in a military context, can be life-saving. We propose to use machine learning techniques and multiple continuously measured physiological signals to detect exposure, and to identify the chemical agent. Such detection and identification could be used to alert individuals to take appropriate medical counter measures in time. As a first step, we evaluated whether exposure to an opioid (fentanyl) or a nerve agent (VX) could be detected in freely moving guinea pigs using features from respiration, electrocardiography (ECG) and electroencephalography (EEG), where machine learning models were trained and tested on different sets (across subject classification). Results showed this to be possible with close to perfect accuracy, where respiratory features were most relevant. Exposure detection accuracy rose steeply to over 95% correct during the first five minutes after exposure. Additional models were trained to correctly classify an exposed state as being induced either by fentanyl or VX. This was possible with an accuracy of almost 95%, where EEG features proved to be most relevant. Exposure detection models that were trained on subsets of animals generalized to subsets of animals that were exposed to other dosages of different chemicals. While future work is required to validate the principle in other species and to assess the robustness of the approach under different, realistic circumstances, our results indicate that utilizing different continuously measured physiological signals for early detection and identification of toxic agents is promising.

Cognition and Pain: A Review

Cognition is defined as the brain's ability to acquire, process, store, and retrieve information. Pain has been described as an unpleasant sensory or emotional experience, and for experiencing pain consciously, cognitive processing becomes imperative. Moreover, evaluation of pain strongly depends on cognition as it requires learning and recall of previous experiences. There could be a possible close link between neural systems involved in cognition and pain processing, and studies have reported an association between pain and cognitive impairment. In this narrative review, we explore the available evidence that has investigated cognitive changes associated with pain. We also examine the anatomical, biochemical, and molecular association of pain and neuro-cognition. Additionally, we focus on the cognitive impairment caused by analgesic medications. There is a need to improve our understanding of pathophysiology and cognitive impairment mechanisms associated with chronic pain and its treatment. This area provides a diverse opportunity for grounding future research, aiding institution of timely interventions to prevent chronic pain and associated cognitive decline, ultimately improving patient care.

Predictive variables of prescription opioid misuse in patients with chronic noncancer pain. Development of a risk detection scale: A registered report protocol

BACKGROUND

Opioid therapy is utilized for a broad range of chronic pain conditions. Several studies have highlighted the adverse effects of opioid medication due to the misuse of these drugs. The gradual increase in the use of opioids has become a global phenomenon and is generating social concern. Several treatment guidelines have strongly recommended assessing the risks and benefits of pharmacological treatment with opioids. These guidelines also recommend the psychological assessment of patients with chronic noncancer pain in order to make informed decisions on the advisability of intervention with opioids. Some authors have emphasized the relevance of assessing the risk of opioid misuse in patients with noncancer chronic pain before initiating treatment.

METHODS AND ANALYSIS

Two studies will be conducted, each with a different primary objective. The primary objective of the first study (Study 1) will be to conduct a comprehensive investigation to identify the factors most closely associated with subsequent opioid misuse; and based on the results of Study 1, the primary objective of the second study (Study 2) will be to develop a brief, reliable, valid, and useful instrument that would enable health care providers to make decisions on opioid prescription and on the required level of monitoring and follow-up. These decisions would have positive consequences for patient wellbeing. Study 1 will include a logistic regression analysis to test the hypothetical model. Study 2 will have a longitudinal design and include three assessment sessions in order to develop a measure to assess the risk of prescribed opioid misuse and to analyse its reliability and validity. Participants will be individuals with chronic noncancer pain attending three Pain Units. These individuals will either be undergoing pharmacological treatment that includes opioid analgesics (Study 1, N = 400) or are going to commence such treatment (Study 2, N = 250).

Association of Opioid Consumption Profiles After Hospitalization With Risk of Adverse Health Care Events

IMPORTANCE

Although better pain management has guided policies for opioid use over the past few decades, evidence is limited regarding how patterns of use are associated with the risk of potentially avoidable opioid-related adverse events.

OBJECTIVE

To estimate the risk of harms associated with opioid dose and duration of use, and to ascertain whether the risk is modified by treatment indication and age.

DESIGN, SETTING, AND PARTICIPANTS

This ad hoc cohort study followed up patients who were enrolled in a cluster randomized trial of medication reconciliation between October 1, 2014, and November 30, 2016, 12 months after they were discharged from the McGill University Health Centre in Montreal, Quebec, Canada. To be eligible for this study, patients needed to have filled at least 1 opioid prescription 3 months after discharge. Patients with a history of using methadone or buprenorphine were excluded. Data analyses were performed between February 1, 2019, and February 28, 2020.

EXPOSURES

Time-varying measures of opioid use included current use, daily morphine milligram equivalent (MME) dose, cumulative and continuous use duration, and type of ingredients in prescription opioids used. Hospitalization records, dispensed prescriptions records, and postdischarge interviews were used to evaluate adherence to the opioid prescriptions after discharge.

MAIN OUTCOMES AND MEASURES

Opioid-related emergency department visits, hospital readmissions, or all-cause death. Outcomes were ascertained using provincial medical services claims and hospitalization databases.

RESULTS

Of 3486 participants in the cluster randomized trial (mean [SD] age of 69.6 [14.9] years; 2010 men [57.7%]), 1511 patients were included in this ad hoc cohort study. Among those with at least 1 opioid dispensation, 241 patients (15.9%) experienced an opioid-related emergency department visit, hospital readmission, or death. Results from marginal structural Cox proportional hazards regression models showed more than a 2-fold increase in the risk of opioid-related adverse events associated with a cumulative use duration of more than 90 days (adjusted hazard ratio, 2.56; 95% CI, 1.25-5.27) compared with 1 to 30 days. A 3-fold risk increase was found with a mean daily dose higher than 90 MME (adjusted hazard ratio, 3.51; 95% CI, 1.58-7.82) compared with 90 MME or lower.

CONCLUSIONS AND RELEVANCE

This study found an association between risk of adverse health care events and higher opioid doses and longer treatment duration. This finding can inform policies for limiting opioid duration and dose to attenuate the risk of avoidable morbidity.

Subjective symptoms and serum methadone concentrations: what should guide dose adjustments in methadone maintenance treatment? A naturalistic cohort study from Norway

BACKGROUND

There is little evidence-based guidance on how to optimize methadone dosages among patients with opioid addiction undergoing methadone maintenance treatment (MMT). This study aims to investigate whether self-perceived opioid withdrawal symptoms, adverse effects, and self-reported substance use in patients on MMT are related to serum methadone concentrations and the role that these variables could play in clinical decisions on dose adjustments.

METHODS

This naturalistic prospective cohort study included clinical and laboratory measurements from 83 patients undergoing MMT in outpatient clinics in Bergen, Norway, from May 2017 to January 2020. Information on age, gender, methadone daily doses and serum concentrations, subjective opioid withdrawal symptoms using 16 items Subjective Opioid Withdrawal Scale (SOWS) questionnaire, self-reported adverse effects, and substance use was obtained. Linear mixed modelling was used for analyzing the data.

RESULTS

The mean age of the participants was 45 years, and 33% were women. Almost half reported mild to moderate subjective opioid withdrawal symptoms, and all had experienced at least one subjective adverse effect. The use of at least one substance was reported by 88% of the participants. Serum concentration-to-dose ratios were lower among those who had reported subjective opioid withdrawal symptoms (p) = 0.039). The total SOWS score (p < 0.001); the specific subjective withdrawal symptoms of anxiety (p = 0.004), bone and muscle aches (p = 0.003), restlessness (p = 0.017), and (slightly) shaking (p = 0.046), also use of heroin (p = 0.015) and alcohol (p = 0.011) were associated with lower methadone concentrations. Cannabis use was slightly related to higher methadone concentrations (p = 0.049).

CONCLUSIONS

The findings suggest that the patient's self-perceived symptoms and current clinical condition are related to the serum concentrations of methadone. This interpretation supports dose adjustments based on patient-reported symptoms. In some aberrant cases, measurement of serum concentrations together with other individual assessments may be considered to support the clinical decision.

Opioid prescribing and risks among commercially insured women undergoing pelvic organ prolapse repair

PURPOSE

Opioid use after surgical repair for pelvic organ prolapse (POP) is intended for short-term post-operative pain. This study compared the incidence of opioid prescribing in women undergoing POP transabdominal repair with mesh and transvaginal native tissue repair.

METHODS

A retrospective cohort of women undergoing POP transabdominal repair with mesh or transvaginal native tissue repair, was derived from a 10% random sample of enrollees from 2007 to 2015 within the IQVIA PharMetrics® Plus Database. Primary outcomes were any prescription of opioids and cumulative days of opioids prescribed in the 14- 180 days following surgical intervention. Inverse probability of treatment weights controlled for observed baseline confounders. Any opioid prescription was estimated using logistic regression and generalized linear regression for cumulative days of opioids prescribed.

RESULTS

The cohort of 49 052 women who underwent POP surgical repair included 46 813 women with transvaginal native tissue repair and 2239 women with transabdominal repair with mesh. Women with a transabdominal repair with mesh had a 1.19 (95%CI: 1.09-1.31) significantly higher odds of receiving an opioid prescription than women with transvaginal native tissue repair. Post-operatively, over 29% of women received opioid prescriptions. Mean cumulative days of post-surgical opioid prescribing was 32.2 (SD = 43.1), and was not statistically different between groups. Thirteen percent of women were prescribed opioids for 90 days or more.

CONCLUSIONS

Women undergoing POP with transabdominal mesh are more likely to receive prescriptions for opioids after surgery compared to transvaginal native tissue repair. Treatment plans that address pain while mitigating the risks associated with prolonged opioid prescribing should be employed.

Pain Acceptance Creates an Emotional Context That Protects against the Misuse of Prescription Opioids: A Study in a Sample of Patients with Chronic Noncancer Pain

There is solid evidence of an association between several psychological flexibility processes, particularly pain acceptance, and adaptation to chronic pain. However, there are relatively few studies on the relationship between pain acceptance and opioid misuse in chronic pain patients. Thus, the aim of the present study was to test a hypothetical model in which pain acceptance would regulate pain sensations and pain-related thoughts and emotions, which would be related to opioid misuse. The sample comprised 140 chronic pain patients attending two hospitals. All patients were receiving pharmacological treatment, including opioid analgesics. Structural equation modelling analyses showed a significant association between higher pain acceptance and lower pain intensity and catastrophizing, and lower levels of anxiety and depression. Only higher anxiety and depression were significantly associated with increased opioid misuse. The results suggest that levels of anxiety, depression, and pain acceptance must be assessed before opioids are prescribed. Pain acceptance implies a relationship with internal events that protects against anxiety and depression and thus against opioid misuse. Acceptance and Commitment Therapy appears to be particularly appropriate for these patients.

Impact of Opioid Consumption in Patients With Functional Gastrointestinal Disorders

Objective: We aimed to determine the burden of opioid consumption in a cohort of patients with functional gastrointestinal disorders.

Methods: All patients diagnosed with functional gastrointestinal disorders and referred to our university hospital were evaluated from 2013 to the beginning of 2019. Irritable bowel syndrome and functional dyspepsia diagnoses were determined according to Rome criteria and severity according to irritable bowel syndrome severity scoring system. Vomiting was quantified using a 5-point Likert scale, and constipation severity was measured using the Knowles-Eccersley-Scott-Symptom questionnaires. Quality of life was quantified by the GastroIntestinal Quality of Life Index. Patients were categorized as being treated on a chronic basis with either tramadol, step II opioids, step III opioids or as being opioid-free.

Results: 2933 consecutive patients were included. In our cohort, 12.5% had only irritable bowel syndrome, 39.3% had only functional dyspepsia, 24.9% had a combination of both, and 23.4% had other functional gastrointestinal disorders. Among them, the consumption of tramadol, step II (tramadol excluded) and step III opioids was 1.8, 1.3 and 0.3 % respectively in 2013 and 4.3, 3.4 and 1.9% in 2018 (p < 0.03). Opioid consumption was associated with increased vomiting (p = 0.0168), constipation (p < 0.0001), symptom severity (p < 0.001), more altered quality of life (p < 0.0001) and higher depression score (p = 0.0045).

Conclusion: In functional gastrointestinal disorders, opioid consumption has increased in the last years and is associated with more GI symptoms (vomiting, constipation and GI severity), higher depression and more altered quality of life.

Cognitive Function During Opioid Tapering in Patients with Chronic Pain: A Prospective Cohort Study

Purpose

Evidence for efficacy and safety lacks for long-term opioid therapy in patients with chronic non-cancer pain and adverse effects, including affection of cognitive function and quality of life, is of concern. We aimed to investigate cognitive function and health-related quality of life in patients with chronic non-cancer pain during opioid reduction.

Patients and Methods

At two multidisciplinary pain centers, all patients with planned opioid reduction were screened for eligibility. Cognitive function was assessed using the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) and Trail Making Test A and B. Health-related quality of life was assessed using Short Form-36 (SF36) and Hospital Anxiety and Depression Scale (HADS).

Results

We included 51 participants and 40 participants attended follow-up of median 254 (IQR 106–357) days. Baseline RBANS score was 82 (IQR 65–93) with reference population norm value of 100 (SD±15). Daily opioid consumption was reduced from median 80 (IQR 45–161) oral morphine milligram equivalents to 19 (IQR 0–60) mg. RBANS score estimate increased by 6.2 (95% CI 3.1–9.3, p=0.0004) points after tapering. No differences were observed for Trail Making Test times, HADS or SF36 scores.

Conclusion

Generally, cognitive function showed minor improvement after opioid tapering with stationary health-related quality of life, depression and anxiety scores. The clinical significance is unclear, as no minimal clinically important difference in RBANS score is available.

Protocol for an economic analysis of the randomised controlled trial of Improving the Well-being of people with Opioid Treated CHronic pain: I-WOTCH Study

INTRODUCTION

Over the last two decades, the use of opioids for the treatment of chronic pain in England has steadily increased despite lack of evidence of both long-term effectiveness in pain relief and significant, well-documented physical and mental adverse events. Guidelines recommend tapering when harms outweigh benefits, but the addictive nature of opioids hinders simple dose-reduction strategies. Improving the Well-being of people with Opioid Treated CHronic pain (I-WOTCH) trial tests a multicomponent self-management intervention aimed to help patients with chronic non-malignant pain taper opioid doses. This paper outlines the methods to be used for the economic analysis of the I-WOTCH intervention compared with the best usual care.

METHODS AND ANALYSIS

Economic evaluation alongside the I-WOTCH study, prospectively designed to identify, measure and value key healthcare resource use and outcomes arising from the treatment strategies being compared. A within-trial cost-consequences analysis and a model-based long-term cost-effectiveness analysis will be conducted from the National Health Service and Personal Social Service perspective in England. The former will quantify key parameters to populate a Markov model designed to estimate the long-term cost and quality-adjusted life years of the I-WOTCH intervention against best usual care. Regression equations will be used to estimate parameters such as transition probabilities, utilities, and costs associated with the model's states and events. Probabilistic sensitivity analysis will be used to assess the impact of parameter uncertainty onto the predicted costs and health outcomes, and the resulting value for money assessment of the I-WOTCH intervention.

ETHICS AND DISSEMINATION

Full ethics approval was granted by Yorkshire & The Humber-South Yorkshire Research Ethics Committee on 13 September 2016 (16/YH/0325). Current protocol: V.1.7, date 31 July 2019. Findings will be disseminated in peer-reviewed journals, scientific conferences, newsletters and websites.

TRIAL REGISTRATION NUMBER

International Standard Randomised Controlled Trial Number (49 470 934); Pre-result.

Examining opioid prescribing trends for non-cancer pain using an estimated oral morphine equivalence measure: a retrospective cohort study between 2005 and 2015

Background

Over the past 20 years prescription of opioid medicines has markedly increased in the UK, despite a lack of supporting evidence for use in commonly occurring, painful conditions. Prescribing is often monitored by counting numbers of prescriptions dispensed, but this may not provide an accurate picture of clinical practice.

Aim

To use an estimated oral morphine equivalent (OMEQ_e) dose to describe trends in opioid prescribing in non-cancer pain, and explore if opioid burden differed by deprivation status.

Design & setting

A retrospective cohort study using cross-sectional and longitudinal trend analyses of opioid prescribing data from Welsh Primary Care General Practices (PCGP) took place. Data were used from the Secure Anonymised Information Linkage (SAIL) databank.

Method

An OMEQ_e measure was developed and used to describe trends in opioid burden over the study period. OMEQ_e burden was stratified by eight drug groups, which was based on usage and deprivation.

Results

An estimated 643 436 843 milligrams (mg) OMEQ_e was issued during the study. Annual number of prescriptions increased 44% between 2005 and 2015, while total daily OMEQ_e per 1000 population increased by 95%. The most deprived areas of Wales had 100 711 696 mg more OMEQ_e prescribed than the least deprived over the study period.

Conclusion

Over the study period, OMEQ_e burden nearly doubled, with disproportionate OMEQ_e prescribed in the most deprived communities. Using OMEQ_e provides an alternative measure of prescribing and allows easier comparison of the contribution different drugs make to the overall opioid burden.

Mechanism and Management of Fentanyl-Induced Cough

Fentanyl-induced cough (FIC) often occurs after intravenous bolus administration of fentanyl analogs during induction of general anesthesia and analgesia procedure. The cough is generally benign, but sometimes it causes undesirable side effects, including elevated intra-abdominal, intracranial or intraocular pressure. Therefore, understanding the related mechanisms and influencing factors are of great significance to prevent and treat the cough. This paper reviews the molecular mechanism, influencing factors and preventive administration of FIC, focusing on the efficacy and side effects of various drugs in inhibiting FIC to provide some medical reference for anesthesiologists.

Incident Reporting System in an Italian University Hospital: A New Tool for Improving Patient Safety

Clinical risk management constitutes a central element in the healthcare systems in relation to the reverberation that it establishes, and as regards the optimization of clinical outcomes for the patient. The starting point for a right clinical risk management is represented by the identification of non-conforming results. The aim of the study is to carry out a systematic analysis of all data received in the first three years of adoption of a reporting system, revealing the strengths and weaknesses. The results emerged showed an increasing trend in the number of total records. Notably, 86.0% of the records came from the medical category. Moreover, 41.0% of the records reported the possible preventive measures that could have averted the event and in 30% of the reports are hints to be put in place to avoid the repetition of the events. The second experimental phase is categorizing the events reported. Implementing the reporting system, it would guarantee a virtuous cycle of learning, training and reallocation of resources. By sensitizing health workers to a correct use of the incident reporting system, it could become a virtuous error learning system. All this would lead to a reduction in litigation and an implementation of the therapeutic doctor–patient alliance.

The Microbiome and the Gut-Liver-Brain Axis for Central Nervous System Clinical Pharmacology: Challenges in Specifying and Integrating In Vitro and In Silico Models

The complexity of integrating microbiota into clinical pharmacology, environmental toxicology, and opioid studies arises from bidirectional and multiscale interactions between humans and their many microbiota, notably those of the gut. Hosts and each microbiota are governed by distinct central dogmas, with genetics influencing transcriptomics, proteomics, and metabolomics. Each microbiota's metabolome differentially modulates its own and the host's multi‐omics. Exogenous compounds (e.g., drugs and toxins), often affect host multi‐omics differently than microbiota multi‐omics, shifting the balance between drug efficacy and toxicity. The complexity of the host‐microbiota connection has been informed by current methods of in vitro bacterial cultures and in vivo mouse models, but they fail to elucidate mechanistic details. Together, in vitro organ‐on‐chip microphysiological models, multi‐omics, and in silico computational models have the potential to supplement the established methods to help clinical pharmacologists and environmental toxicologists unravel the myriad of connections between the gut microbiota and host health and disease.

Magnesium Salt, a Simple Strategy to Improve Methadone Analgesia in Chronic Pain: An Isobolographic Preclinical Study in Neuropathic Mice

Analgesic efficacy of methadone in cancer and chronic non-cancer pains is greater than that of other opioids, probably because of its unique pharmacokinetics properties and also because it targets glutamatergic receptors in addition to µ-opioid receptors. However, methadone has drawbacks which are clearly related to dosing and treatment duration. The authors hypothesized that the antinociceptive efficacy of methadone could be synergistically potentiated by magnesium and copper salts in a preclinical mouse model of chronic pain, using the intraplantar formalin test as algesimetric tool. The spared nerve injury mice model was used to generate mononeuropathy. A low dose (0.25%) formalin was injected in the neuropathic limb in order to give rise only to Phase I response, resulting from direct activation by formalin of nociceptive primary afferents. Licking/biting of the formalin-injected limb was evaluated as nociceptive behavior during a 35-min observation period. Dose-response curves for intraperitoneal magnesium sulfate (10, 30, 100, and 300 mg/kg i.p.), copper sulfate (0.1, 0.3, 1, and 3 mg/kg i.p.) and methadone (0.1, 0.3, 1, and 3 mg/kg i.p.) allowed to combine them in equieffective doses and to determine their interaction by isobolographic analysis. Magnesium sulfate, copper sulfate and methadone dose-dependently decreased the nociceptive response evoked by formalin injection, the respective ED₅₀ being 76.38, 1.18, and 0.50 mg/kg i.p. Isobolographic analysis showed a superadditive interaction for magnesium and methadone. Indeed, despite that both ED₅₀ are obviously equieffective, the ED₅₀ for the MgSO4/methadone combination contained less than one third of the methadone having the ED₅₀ for methadone alone. For the CuSO₄/methadone combination, the interaction was only additive. Extrapolated to clinical settings, the results suggest that magnesium salts might be used to improve synergistically the efficacy of methadone in neuropathy, which would allow to reduce the dose of methadone and its associated side effects.

Perioperative Multimodal Analgesia Reduces Opioid Use Following Skin Grafting in Nonintubated Burn Patients

Hundreds of patients are treated for burn injuries each year at University of Wisconsin School of Medicine and Public Health. Pain management is particularly challenging during dressing changes and following skin grafting procedures. We performed a retrospective chart review from January 2011 through June 2018 to evaluate the effect of nonopioid analgesic medications on opioid use in nonintubated patients. Our primary outcome was the change in opioid use following the procedure. We found that most patients (69%) report severe pain (Numeric Rating Scale ≥7) immediately after autologous skin grafting. On average, patients required an additional 52 mg of oral morphine equivalents (ME) in the 24 h after the procedure compared with the 24 h before. The use of perioperative nonopioid analgesia varied between patients (acetaminophen 29%, gabapentin 29%, ketamine 35%, and all three 8%). Patients who received either gabapentin or a combination of acetaminophen, gabapentin, and ketamine had a smaller increase in their opioid use than patients who did not receive the medications (-25 ME, 95% confidence interval [-46, -4]; P = .018 and -47 ME, [-81, -11]; P = .010, respectively). These results support using a combination of acetaminophen, gabapentin, and ketamine for perioperative analgesia in burn patients undergoing autologous skin grafting.

Patterns of Prescription Opioid Use in Women With Endometriosis: Evaluating Prolonged Use, Daily Dose, and Concomitant Use With Benzodiazepines

OBJECTIVE

To examine opioid use, opioid prescribing patterns, and timing of the first opioid prescription in endometriosis patients compared with matched women in the control group without endometriosis.

METHODS

We conducted a retrospective analysis of the Clinformatics Datamart database. Women diagnosed with endometriosis from January 2006 through December 2016 and aged 18-49 years were compared with women in the control group matched on age, region, race, insurance payer, and plan type. Key outcomes included: filled prescription for an opioid, multiple opioid prescriptions, number of days' supply, daily dose (morphine milligram equivalents), and concomitant opioid and benzodiazepine prescriptions. Cohorts were descriptively analyzed using t- and χ statistics and multivariable regression analyses yielded adjusted relative risk (RR) ratios and 95% CI.

RESULTS

The study sample included 53,847 endometriosis patients and 107,694 patients in the control group. The mean age was 38 years, 62.4% of patients were white, and 51.6% lived in the South. Women in the endometriosis case group, compared with women in the control group, were more likely to fill an opioid prescription (42,705 [79.3%] women in the case group vs 26,106 [24.2%] women in the control group; adjusted RR ratio 2.91; 2.87-2.94), had higher likelihood of filling prescriptions with a dose of 50 morphine milligram equivalents or more (24,544 [45.6%] vs 10,463 [9.7%]; adjusted RR ratio 4.07; 3.98-4.16) or 100 morphine milligram equivalents or more (8,013 [14.9%] vs 3,582 [3.3%]; adjusted RR ratio 3.56; 3.43-3.70). Women in the case group were more likely to have concomitant opioid and benzodiazepine prescriptions (5,453 [10.1%] vs 3,711 [3.5%]; adjusted RR ratio 1.95; 1.88-2.03) and to have used these drugs concurrently for at least 30 days (1,596 [3.0%] vs 1,265 [1.2%]; adjusted RR ratio 1.43; 1.34-1.52) or at least 90 days (875 [1.6%] vs 777 [0.7%]; adjusted RR ratio 1.27; 1.17-1.37). Similar results were obtained after excluding opioid prescriptions received during a 30-day postsurgery window.

CONCLUSION

Women with endometriosis had higher probabilities of prolonged use of opioids and concomitant use with benzodiazepines compared with women without this condition.

FUNDING SOURCE

This study was funded by AbbVie, Inc.

The Surgeon's Role in the Opioid Crisis: A Narrative Review and Call to Action

Over the past two decades, there has been a sharp rise in the use of prescription opioids. In several countries, most notably the United States, opioid-related harm has been deemed a public health crisis. As surgeons are among the most prolific prescribers of opioids, growing attention is now being paid to the role that opioids play in surgical care. While opioids may sometimes be necessary to provide patients with adequate relief from acute pain after major surgery, the impact of opioids on the quality and safety of surgical care calls for greater scrutiny. This narrative review summarizes the available evidence on rates of persistent postsurgical opioid use and highlights the need to target known risk factors for persistent postoperative use before patients present for surgery. We draw attention to the mounting evidence that preoperative opioid exposure places patients at risk of persistent postoperative use, while also contributing to an increased risk of several other adverse clinical outcomes. By discussing the prevalence of excess opioid prescribing following surgery and highlighting significant variations in prescribing practices between countries, we note that there is a pressing need to optimize postoperative prescribing practices. Guided by the available evidence, we call for specific actions to be taken to address important research gaps and alleviate the harms associated with opioid use among surgical patients.

Experiences of people taking opioid medication for chronic non-malignant pain: a qualitative evidence synthesis using meta-ethnography

OBJECTIVE

To review qualitative studies on the experience of taking opioid medication for chronic non-malignant pain (CNMP) or coming off them.

DESIGN

This is a qualitative evidence synthesis using a seven-step approach from the methods of meta-ethnography.

DATA SOURCES AND ELIGIBILITY CRITERIA

We searched selected databases-Medline, Embase, AMED, Cumulative Index to Nursing and Allied Health Literature, PsycINFO, Web of Science and Scopus (Science Citation Index and Social Science Citation Index)-for qualitative studies which provide patients' views of taking opioid medication for CNMP or of coming off them (June 2017, updated September 2018).

DATA EXTRACTION AND SYNTHESIS

Papers were quality appraised using the Critical Appraisal Skills Programme tool, and the GRADE-CERQual (Grading of Recommendations Assessment, Development and Evaluation working group - Confidence in Evidence from Reviews of Qualitative research) guidelines were applied. We identified concepts and iteratively abstracted these concepts into a line of argument.

RESULTS

We screened 2994 unique citations and checked 153 full texts, and 31 met our review criteria. We identified five themes: (1) reluctant users with little choice; (2) understanding opioids: the good and the bad; (3) a therapeutic alliance: not always on the same page; (4) stigma: feeling scared and secretive but needing support; and (5) the challenge of tapering or withdrawal. A new overarching theme of 'constantly balancing' emerged from the data.

CONCLUSIONS

People taking opioids were constantly balancing tensions, not always wanting to take opioids, and weighing the pros and cons of opioids but feeling they had no choice because of the pain. They frequently felt stigmatised, were not always 'on the same page' as their healthcare professional and felt changes in opioid use were often challenging.

TRIAL REGISTRATION NUMBER

49470934; Pre-results.

Acceptability of a primary care-based opioid and pain review service: a mixed-methods evaluation in England

BACKGROUND

Primary care opioid prescribing to treat chronic non-cancer pain (CNCP) has progressively increased despite a lack of evidence for long-term safety and effectiveness. Developing primary care interventions to reduce opioid dependence in patients with CNCP is a public health priority.

AIM

To report the acceptability of the South Gloucestershire pain and opioid review service for patients with CNCP, which aimed to help patients understand their relationship with prescribed opioids and support non-drug-based pain management strategies.

DESIGN AND SETTING

A mixed-methods evaluation was performed on the service, which was based in two GP practices in South Gloucestershire, England, and delivered by project workers.

METHOD

Descriptive data were collected on delivered-within-service and community-based interventions. Twenty-five semi-structured interviews (n = 18 patients, n = 7 service providers) explored experiences of the service.

RESULTS

The enrolment process, person-centred primary care-based delivery, and service content focused on psychological issues underlying CNCP were found to be acceptable to patients and service providers. Patients welcomed having time to discuss their pain, its management, and related psychological issues. Maintaining a long-term approach was desired as CNCP is a complex issue that takes time to address. GPs recommended that funding was needed to ensure they have dedicated time to support a similar service and to ensure that project workers received adequate clinical supervision.

CONCLUSION

This service model was acceptable and may be a useful means to manage patients with CNCP who develop opioid dependence after long-term use of opioids. A randomised controlled trial is needed to formally test the effectiveness of the service.

Antinociceptive effects of green synthesized copper nanoparticles alone or in combination with morphine

Objective

The aim of this study was to evaluate the antinociceptive effect of biosynthetic copper nanoparticles from aqueous extract of Capparis spinosa fruit.

Methods

In this study, green synthesis of copper nanoparticles (CuNPs) was performed using C. spinosa extract according to the method described previously. The synthesized CuNPs were characterized using the UV–vis spectroscopy, Fourier transforms of infrared (FTIR), scanning electron microscopy (SEM), and energy-dispersive X-ray (EDX). The antinociceptive effect of CuNPs was evaluated by tail-flick, hot-plate, and rotarod tests following the oral administration of mice with CuNPs at the concentrations of 25, 50, and 75 mg/kg for two weeks.

Results

The obtained maximum peak at the wavelength of 414 nm demonstrated the biosynthesis of the copper nanoparticles. SEM approved the particle size of CuNPs between 17 and 41 nm. The statistical analyses of the data of hot plate and tail-flick tests showed the potent analgesic effect of biosynthetic CuNPs. In this regard, the antinociceptive effect of at the doses of 75 mg/kg and 25 mg/kg plus morphine was significantly higher in comparison with the control group receiving morphine alone (P < 0.05). No significant (p > 0.05) difference was observed after the administration of CuNPs at the doses of 25, 50, and 75 mg/kg in the sensory-motor test.

Conclusion

The present investigation demonstrated the analgesic effects of CuNPs especially in combination with morphine. These findings can provide a new strategy for producing new antinociceptive medications in the future.

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We evaluated the antinociceptive effects of green synthesized copper nanoparticles.

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The antinociceptive effect of CuNPs was evaluated by tail-flick, hot-plate and rotarod test.

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Hot plate and tail flick tests showed the potent analgesic effect of biosynthetic CuNPs.

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No significant difference was observed after administration of CuNPs in sensory motor test.

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The results showed the analgesic effects of CuNPs especially in combination with morphine.