The long-term safety and efficacy of opioids: a survey of 84 selected patients with intractable chronic noncancer pain

Perspectives of pain specialists, patients, and family members on long-term opioid use for chronic non-cancer pain: a qualitative study

BACKGROUND

Opioids are currently prescribed for chronic non-cancer pain (CNCP), and some patients use opioids continuously for long-term treatment. Stakeholders' awareness about long-term opioid therapy is essential for improving the safety and effectiveness of pain treatment. The purpose of this study is to explore the perspectives of pain specialists, patients, and family caregivers about long-term opioid use in CNCP management.

METHODS

This study was a qualitative study and adhered to the COREQ guidelines. Pain specialists (n = 12), patients (n = 14), and family members (n = 9) were recruited to the study by purposive sampling at the Pain Clinic of Ramathibodi Hospital. Semi-structured interviews were recorded, verbatim transcribed, conceptually coded, and analyzed using Atlas.ti 8.0.

RESULTS

All groups of participants described opioids as non-first-line drugs for pain management. Opioids should be prescribed only for severe pain, when non-opioid pharmacotherapy and non-pharmacological therapies are not effective. Patients reported that the benefits of opioids were for pain relief, while physicians and most family members highlighted that opioid use should improve functional outcomes. Physicians and family members expressed concerns about opioid-related side effects, harm, and adverse events, while patients did not. Patients confirmed that they would continue using opioids for pain management under supervision. However, physicians stated that they would taper off or discontinue opioid therapy if patients' pain relief or functional improvement was not achieved. Both patients and family members were willing to consider non-pharmacological therapies if potential benefits existed. Patient education, doctor-patient/family relationships, and opioid prescription policies were proposed to enhance CNCP management.

CONCLUSION

Long-term opioid therapy for CNCP may be beneficial in patients who have established realistic treatment goals (for both pain relief and functional improvement) with their physicians. Regular monitoring and evaluation of the risks and benefits, adverse events, and drug-related aberrant behaviors are necessary. Integrated multimodal multidisciplinary therapies and family member collaborations are also important for improving CNCP management.

Design considerations for a remote randomized multi-site clinical trial evaluating an e-health self-management program for chronic pain patients receiving opioid therapy

Based on the adverse consequences and inadequate evidence of effectiveness for long-term opioid therapy (LOT), the CDC developed recommendations to decrease the use of LOT and morphine equivalent dose (MED) for patients receiving LOT. However, the majority of these patients report that opioid medication is significantly beneficial for pain management and are hesitant to reduce/decrease its use. Compounding the problem is poor access to non-pharmacologic therapies for many patients due to insurance reimbursement structures and limited pain-service availability. EMPOWER is an intent-to-treat, two-arm, open-label, randomized controlled trial evaluating a web-based self-management chronic pain program (E-Health) that has been found to reduce self-reported MED, while also decreasing pain, in two randomized controlled trials. Approximately 400 chronic pain patients receiving LOT at a daily average prescribed MED ≥ 20 mg at one of two U.S. healthcare systems, located in North Carolina and Ohio, will be randomized in a 1:1 ratio to treatment as usual (TAU) or TAU plus E-Health (E-Health+). TAU consists of LOT from a prescribing clinician. E-Health+ participants are provided with a 4-month E-Health subscription (active treatment phase). All participants will complete web-based self-report measures at baseline, the end of the active treatment phase, and 6-months post-active treatment. Opioid prescription information will be collected from the participants' electronic health record (EHR) from baseline through 6 months post-active treatment. This paper describes design considerations for this unique trial which is conducted completely remotely, with no in-person visits, and utilizes the EHR for participant identification and primary outcome collection.

Work Enabling Opioid Management

OBJECTIVE

This study describes the relationship between opioid prescribing and ability to work.

METHODS

The opioid prescription patterns of 4994 claimants were studied. Three groups were constructed: 1) at least 3 consecutive months prescribed (chronic opioid therapy; COT); 2) less than 3 consecutive months prescribed (acute opioid therapy; AOT); and 3) no opioids prescribed. Variables included sex, age, daily morphine equivalent dose (MED), days opioids were prescribed, temporary total days (TTDs), and medical/indemnity/total costs.

RESULTS

The COT versus AOT claimants had higher opioid costs ($8618 vs $94), longer TTD (636.2 vs 182.3), and average MED (66.8 vs 34.9). Only 2% of the COT cohort were not released to work. Fifty-seven percent of patients in the COT category (64 of 112) were released to work while still receiving opioids.

CONCLUSION

COT does not preclude ability to work when prescribing within established guidelines.

Effectiveness of long-term opioid therapy among chronic non-cancer pain patients attending multidisciplinary pain treatment clinics: A Quebec Pain Registry study

OBJECTIVE

The objective of this study was to investigate in a real-life context the effectiveness of long-term opioid therapy for reducing pain intensity and interference and improving health-related quality of life (QOL) in patients with chronic noncancer pain.

METHODS

Participants were 893 patients (age = 52.4 ± 14.1, female = 62.4%) enrolled in the Quebec Pain Registry (2008-2011) who completed questionnaires before their first visit at one of three multidisciplinary pain management clinics and 6 and 12 months thereafter. Based on their opioid use profile (OUP), patients were categorized as nonusers, non-lasting users, or lasting users. Data were analyzed using generalized estimating equations.

RESULTS

More than 60% of patients newly initiated on opioid therapy stopped their medication mainly because of adverse effects and/or lack of pain relief. OUP significantly predicted pain intensity and interference and physical QOL (pQOL; P values < 0.001). Lasting users of opioids reported higher levels of pain intensity and interference and poorer pQOL than nonusers and/or non-lasting users over the 12-month follow-up (P values < 0.001). However, all effect sizes were small, thus questioning the clinical significance of these group differences. Among lasting users, more than 20% of patients experienced a meaningful amelioration in pain intensity and interference as well as mental QOL (mQOL), whereas only 8% exhibited improved pQOL.

DISCUSSION

A significant subgroup of patients may benefit from long-term opioid therapy in terms of pain severity and mQOL but the majority do not. The challenge facing clinicians is how to identify who the responders will be.

Content analysis of chronic pain content at three undergraduate medical schools in Ontario

Background: It has been well documented that interdisciplinary, comprehensive pain education can foster positive pain beliefs among medical students, in addition to improving students’ abilities to diagnose and treat pain. Though some work has been done to quantify the number of hours of pain education students receive, the content itself has received little attention.

Aims: This study seeks to identify what medical students learn about chronic pain throughout an undergraduate medical degree program in Ontario.

Methods: Three undergraduate medical schools in Ontario were selected on the basis of variety in curricular structure and instructional methods. Written documents comprising the formal curriculum were analyzed through qualitative and quantitative content analysis. These findings were compared with promising practices from the pain education literature.

Results: The three curricula studied here dedicate the bulk of pain education to three topics: pain mechanisms, pain management, and opioids and addiction. The curricula vary considerably in organization of content and hours of pain training. All three curricula were found to contain negative pain beliefs that characterize pain patients as difficult, overwhelming, and unrewarding to work with. Two of the medical schools studied here do not have a pain curriculum.

Conclusions: The results of this study indicate a need for medical schools to develop comprehensive, interdisciplinary pain curricula. Though increasing the number of hours of pain training is crucial, equally imperative is a consideration of what, and how, students learn about pain.

[Long-term opioid therapy in chronic noncancer pain. A systematic review and meta-analysis of efficacy, tolerability and safety in open-label extension trials with study duration of at least 26 weeks]

BACKGROUND

The efficacy and safety of long-term (≥ 6 months) opioid therapy (LtOT) in chronic noncancer pain (CNCP) is under debate. A systematic review with meta-analysis of the efficacy and harms of opioids in open-label extension studies of randomized controlled trials (RCTs) has not been conducted until now.

METHODS

We screened MEDLINE and clinicaltrials.gov (through to December 2013), as well as reference sections of systematic reviews of long-term RCTs of opioids in CNCP. We included open-label extension trials with a study duration ≥ 26 weeks of RCTs of ≥ 2 weeks duration. Using a random effects model, pooled estimates of event rates for categorical data and standardized mean differences (SMD) for continuous variables were calculated.

RESULTS

We included 11 open-label extension studies with 2445 participants with nociceptive (low back, osteoarthritis) and neuropathic (radicular, polyneuropathy) pain. Median study duration was 26 (range 26-108) weeks. Four studies tested oxycodone, two studies tramadol and buprenorphine; hydromorphone, morphine, oxymorphone and tapentadol were each tested in one study. Of the patients randomized at baseline, 28.5 % (95 % confidence interval, CI, 17.9-39.2 %) finished the open-label period; 53.5 % (95 % CI 38.1-68.2 %) of patients entering the open-label period finished the open-label period. In sum, the total loss was 71.5 % (95 % CI 60.9-83.1 %) of all patients primarily included into the RCT. A total of 4.9 % (95 % CI 2.9-8.2 %) of patients dropped out due lack of efficacy; 16.8 % (95 % CI 11.0-24.8 %) dropped out to due adverse events (AE) in the open-label period and 0.08 % (95 % CI 0.001-0.05 %) of patients died during the open-label period. Only one study systematically assessed aberrant drug behavior of the patients: 5.7 % (95 % CI 3.4-9.6 %) showed aberrant drug behavior in the opinion of the investigators and 2.6 % (95 % CI 1.2-5.8 %) were judged to show aberrant drug behavior by independent expert assessment. There was no significant change (p = 0.50) in pain intensity between the end of the randomized period and the end of open-label phase (SMD 0.19 [- 0.03, 0.41]; six studies with 1360 participants).

CONCLUSION

Only a minority of patients selected for opioid therapy at randomization finished the long-term open-label study. However, sustained effects of pain reduction could be demonstrated in these patients. LtOT can be considered in carefully selected and monitored CNCP patients who experience clinically meaningful pain reduction with at least tolerable AE in short-term opioid therapy. The English full-text version of this article is freely available at SpringerLink (under "Supplementary Material").

[Opioids in chronic low back pain. A systematic review and meta-analysis of efficacy, tolerability and safety in randomized placebo-controlled studies of at least 4 weeks duration]

BACKGROUND

The efficacy and safety of opioid therapy in chronic low back pain (CLBP) is under debate. We updated a recent systematic review on the efficacy and safety of opioids in CLBP.

METHODS

We screened MEDLINE, Scopus and the Cochrane Central Register of Controlled Trials (CENTRAL) up until October 2013, as well as reference sections of original studies and systematic reviews of randomized controlled trials (RCTs) of opioids in CLBP. We included double-blind randomized placebo-controlled studies of at least 4 weeks duration. Using a random effects model, absolute risk differences (RD) were calculated for categorical data and standardized mean differences (SMD) for continuous variables.

RESULTS

We included 12 RCTs with 17 treatment arms and 4375 participants. Median study duration was 12 (4-16) weeks. Of the 17 treatment arms, seven (41.2 %) used oxycodone; four (23.6 %) tramadol; buprenorphine and oxymorphone were each used in two (11.8 %) and hydromorphone and tapentadol each in one (5.8 %). The results for studies with parallel/cross-over design were as follows (with 95 % confidence interval, CI): opioids were superior to placebo in reducing pain intensity (SMD - 0.29 [- 0.37, - 0.21], p < 0.0001; six studies with 2896 participants). Opioids were superior to placebo in 50 % pain reduction (RD 0.05 [0.01, 0.10], p = 0.01; two studies with 1492 participants; number needed to benefit (NNTB) 19 [95 % CI 10-107]). Opioids were not superior to placebo in reports of much or very much improved pain (RD 0.16 [- 0.01, 0.34], p = 0.07; two studies with 1153 participants). Opioids were superior to placebo in improving physical functioning (SMD - 0.22 [- 0.31, - 0.12], p < 0.0001; four studies with 1895 participants). Patients dropped out less frequently with opioids than with placebo due to lack of efficacy (RD - 0.10 [- 0.16, - 0.04], p = 0.001; five studies with 3168 participants; NNTB 10 [8-13]). Patients dropped out more frequently with opioids than with placebo due to adverse events (RD 0.12 [0.05, 0.19], p = 0.0007; six studies with 2910 participants; number needed to harm (NNTH) 7 [95 % CI 6-8]). There was no significant difference between opioids and placebo in terms of the frequency of serious adverse events or deaths.

CONCLUSION

Opioids were superior to placebo in terms of efficacy and inferior in terms of tolerability. Opioids and placebo did not differ in terms of safety during the study period. The conclusion on the safety of opioids compared to placebo is limited by the low number of serious adverse events and deaths. Short-term and intermediate-term opioid therapy may be considered in selected CLBP patients. The English full-text version of this article is freely available at SpringerLink (under "Supplemental").

[Opioids in chronic neuropathic pain. A systematic review and meta-analysis of efficacy, tolerability and safety in randomized placebo-controlled studies of at least 4 weeks duration]

BACKGROUND

The efficacy and safety of opioid therapy in chronic neuropathic pain (CNP) is under debate. We updated a recent Cochrane systematic review on the efficacy, tolerability and safety of opioids in CNP.

METHODS

We screened MEDLINE, Scopus and the Cochrane Central Register of Controlled Trials (CENTRAL) up until October 2013, as well as the reference sections of original studies and systematic reviews of randomized controlled trials (RCTs) of opioids in CNP. We included double-blind randomized placebo-controlled studies of at least 4 weeks duration. Using a random effects model, absolute risk differences (RD) were calculated for categorical data and standardized mean differences (SMD) for continuous variables.

RESULTS

We included 12 RCTs with 1192 participants. The included diagnostic entities were painful diabetic neuropathy (four studies), postherpetic neuralgia (three studies), mixed polyneuropathic pain (two studies), and lumbar root, spinal cord injury and postamputation pain (one study each). Mean study duration was 6 (4-12) weeks. Four studies tested morphine, three studies tramadol, two studies oxycodone and one study tapentadol. These are the pooled results of studies with a parallel or cross-over design: opioids were superior to placebo in reducing pain intensity (SMD - 0.64 [95 % confidence interval, CI - 0.81, - 0.46], p < 0.0001; 11 studies with 1040 participants). Opioids were not superior to placebo in 50 % pain reduction (RD 0.16 [95 % CI - 0.04, 0.35], p = 0.11; one study with 93 participants). Opioids were not superior to placebo in reports of much or very much improved pain (RD 0.17 [95 % CI - 0.01, 0.36], p = 0.07; one study with 53 participants). Opioids were superior to placebo in improving physical functioning (SMD - 0.28 [95 % CI - 0.43, - 0.13], p < 0.0001; seven studies with 680 participants). Patients dropped out less frequently due to lack of efficacy with opioids than with placebo (RD - 0.07 [95 % CI - 0.13, - 0.02], p = 0.008; six studies with 656 participants). Patients dropped out due to adverse events more frequently with opioids than with placebo (RD 0.08 [95 % CI 0.05, 0.12], p < 0.0001; ten studies with 1018 participants; number needed to harm 11 [95 % CI 8-17]). There was no significant difference between opioids and placebo in terms of the frequency of serious adverse events (SAE) or deaths.

CONCLUSION

In short-term studies (4-12 weeks) in CNP, opioids were superior to placebo in terms of efficacy and inferior in terms of tolerability. Opioids and placebo did not differ in terms of safety. The conclusion relating to the safety of opioids compared to placebo in CNP is limited by the low number of SAE and deaths. Short-term opioid therapy may be considered in selected CNP patients. The English full-text version of this article is freely available at SpringerLink (under "Supplementary Material").

Attitudes and Beliefs of Working and Work-Disabled People with Chronic Pain Prescribed Long-Term Opioids

OBJECTIVE

This study was designed to gain insight into the apparent contradiction between the perspectives of researchers and policy makers, who have questioned the efficacy and safety of chronic opioid therapy for non-cancer pain patients, and the patients themselves, who often indicate that the therapy has value.

SUBJECTS

A convenience sample of 54 patients on chronic opioid therapy was studied.

METHODS

Participants completed a questionnaire specifically designed for the study, and also several standard instruments that addressed functional interference, emotional functioning, and possible misuse of opioids. Their treating physicians rated the participants on the severity of their disability and the success of their opioid therapy.

RESULTS

Although participants reported significant ongoing pain, they gave positive global ratings to their opioid therapy, and reported little concern about addiction or side effects of opioids. They strongly endorsed the beliefs that opioids helped them control their pain and allowed them to participate in important activities such as work. They expressed the belief that their pain would be severe if they did not have access to opioids, and reported negative experiences with tapering or discontinuing opioids in the past. Work-disabled participants reported higher levels of affective distress, catastrophizing, and functional interference than working participants, and were judged by their physicians to be relatively less successful in managing their pain.

CONCLUSION

The results of this study suggest several tentative hypotheses about why patients on chronic opioid therapy value opioids, and identified several areas for systematic investigation in the future.

Methadone for chronic non-cancer pain in adults

BACKGROUND

Methadone belongs to a class of analgesics known as opioids, that are considered the cornerstone of therapy for moderate-to-severe pain due to life-threatening illnesses; however, their use in chronic non-cancer pain (CNCP) is controversial. Methadone has many characteristics that differentiate it from other opioids, which suggests that it may have a different efficacy and safety profile.

OBJECTIVES

To assess the analgesic effectiveness and safety of methadone in the treatment of CNCP.

SEARCH METHODS

We identified both randomized controlled trials (RCTs) and non-randomized studies of methadone use in chronic pain by searching the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library 2011, issue 11, MEDLINE (1950 to November 2011), and EMBASE (1980 to November 2011), together with reference lists of retrieved papers and reviews.

SELECTION CRITERIA

We included RCTs with pain assessment as either the primary or secondary outcome. Quasi-randomized studies, cohorts and case-control trials were also considered for inclusion because we suspected that the beneficial and harmful effects of methadone in CNCP may not be adequately addressed in RCTs.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted efficacy and adverse event data and assessed risk of bias.

MAIN RESULTS

We included two RCTs and one non-randomized study, involving a total of 181 participants. Both RCTs were cross-over studies, one involving 19 participants with diverse neuropathic pain syndromes, the other involving 76 participants with postherpetic neuralgia. Study phases were 20 days and approximately eight weeks, respectively. The non-randomized study retrospectively evaluated 86 outpatients over an average of 8.8 ± 6.3 months.One RCT reported average pain intensity and pain relief, and found statistically significant improvements versus placebo for both outcomes, with 10 mg and 20 mg daily doses of methadone. The second RCT reported differences in pain reduction between methadone and morphine and found morphine to be statistically superior. The non-randomized study found that in patients initially prescribed methadone it was effective in fewer participants than in those initially prescribed other long-acting opioids (28% versus 42%, 33% and 50% for morphine, oxycodone and transdermal fentanyl, respectively).One RCT compared incidences for several individual adverse events, but found a difference between methadone and placebo for only one event, dizziness (P = 0.041).

AUTHORS' CONCLUSIONS

The three studies provide very limited evidence of the efficacy of methadone for CNCP, and there were too few data for pooled analysis of efficacy or harm, or to have confidence in the results of the individual studies. No conclusions can be made regarding differences in efficacy or safety between methadone and placebo, other opioids, or other treatments.

Opioids in chronic noncancer pain: more faces from the crowd

BACKGROUND

The use of opioids for chronic noncancer pain (CNCP) remains very controversial. There are several randomized controlled trials, mostly in neuropathic pain, reporting efficacy and safety in the short term, but more long-term data are needed. Randomized controlled trials may be limited in providing data about the patients who benefit from often high-dose opioids over the long term. The present article provides details of these patients and adds to a previous case series.

METHODS

The present article contains 17 case reports of 11 CNCP conditions (followed to 2011) selected to illustrate specific issues from a survey of 84 patients with intractable CNCP treated with opioids and followed every three months for a median of 11 years. The previous published survey of this group reported outcomes of pain severity, adverse effects, pain relief, satisfaction, mood, problematic opioid use, tolerance, physical dependency, functional status, health-related quality of life (HRQL), immune status and sexual function. The outcome measures for that study included a numerical rating scale for pain, the Hospital Anxiety and Depression Scale, the Brief Pain Inventory Interference Scale, the Pain Disability Index and, for HRQL, the Short-Form Health Survey 12 version 2. Most patients in the total sample reported 50% or greater relief and a moderate improvement in disability. Scores for functional status and HRQL were not severely affected. Problematic use, tolerance and serious adverse effects, including constipation, were not major issues. These selected patient reports were chosen, not to illustrate optimal results, but rather important aspects of the diagnoses, opioids and doses, the paucity of intolerable adverse effects, particular issues (concurrent addiction history, bipolar disorder and combination therapy), disease-specific and other outcomes and duration of follow-up with complex pain problems.

RESULTS

Opioids were found to be safe and useful in the long term for these particular patients, as well as in the larger group from which they originated.

INTERPRETATION

These 17 reports of patients with intractable CNCP treated with opioids with some success over many years puts a face on more of the participants in the larger survey of 84 subjects, suggesting that this approach is effective and safe for some patients over many years.

Chronic non-cancer pain and the long-term efficacy and safety of opioids: Some blind men and an elephant?

Background

The use of opioids for chronic non-cancer pain (CNCP) remains very controversial. There are a number of randomized controlled trials (RCTs) showing efficacy and safety in the short-term, but long-term data are limited.

Methods

This article contains 10 case reports (followed to 2011) that were selected from a survey of 84 patients with intractable CNCP treated with opioids and followed every 3 months now for a median of 10 years. The previous published survey of this group reported outcomes of pain severity, adverse effects, pain relief, satisfaction, mood, problematic opioid use, tolerance, physical dependency, functional status, health-related quality of life (HRQL), immune status and sexual function. The outcome measures for that study included a numerical rating scale (NRS) for pain, Hospital Anxiety and Depression Scale (HADS), the Brief Pain Inventory Interference Scale (BPI-I), the Pain Disability Index (PDI), and for Health Related Quality of Life (HRQL) the Short Form Health Survey 12 version 2 (SF12v2). These selected patient reports were chosen to illustrate some important aspects of the diagnostic categories of CNCP, the opioids and doses used, particular issues (concurrent addiction history, bipolar disorder, and combination therapy), disease-specific and other outcomes (pain severity and relief, adverse effects, mood, function) and duration of follow-up with complex pain problems.

Results

Opioids were found to be safe and effective in the long-term for these particular patients, as well as in the larger group from which they originate. Most patients in the total sample reported 50% or greater relief and a moderate improvement in disability. Scores for functional status and HRQL were not severely affected (PDI and BPI-I ratings moderate or less and SF12v2 slightly below normative values for age). Problematic use, tolerance, and serious adverse effects including constipation were not major issues.

Conclusion

These 10 reports of patients with intractable CNCP treated with opioids with some success over many years put a face on some of the participants in the larger survey of 84 suggesting that this approach is effective and safe for some patients over many years.

Implications

These data may not be generalizable to a larger population of patients with CNCP because of the probable selection of patients who benefit and who do not have intolerable adverse effects.

A qualitative systematic review of head-to-head randomized controlled trials of oral analgesics in neuropathic pain

BACKGROUND

Neuropathic pain (NP) encompasses many difficult-to-treat disorders. There are few head-to-head, comparative, randomized controlled trials (RCTs) of drugs for NP in different analgesic categories, or of different drugs within a category, despite many placebo-controlled RCTs for individual agents. Well-designed head-to-head comparative trials are an effective way to determine the relative efficacy and safety of a new drug.

OBJECTIVE

To perform a systematic review of head-to-head RCTs of oral analgesics in NP.

METHODS

A systematic review of RCTs involving NP patients was performed, of which head-to-head comparative trials were selected. Reference lists from published systematic reviews were searched. These studies were rated according to the Jadad scale for quality.

RESULTS AND CONCLUSIONS

Twenty-seven such trials were identified. Seventeen were comparisons of different analgesics, and 10 were of different drugs within an analgesic class. Important information was obtained about the relative efficacy and safety of drugs in different categories and within a category. Some significant differences between active treatments were reported. Trial inadequacies were identified. More and improved head-to-head RCTs are needed to inform clinical choices.