IMPORTANCE: Opioid analgesics are commonly used for low back pain, however, to our knowledge there has been no systematic evaluation of the effect of opioid dose and use of enrichment study design on estimates of treatment effect.
OBJECTIVE: To evaluate efficacy and tolerability of opioids in the management of back pain; and investigate the effect of opioid dose and use of an enrichment study design on treatment effect.
DATA SOURCES: Medline, EMBASE, CENTRAL, CINAHL, and PsycINFO (inception to September 2015) with citation tracking from eligible randomized clinical trials (RCTs).
STUDY SELECTION: Placebo-controlled RCTs in any language.
DATA EXTRACTION AND SYNTHESIS: Two authors independently extracted data and assessed risk of bias. Data were pooled using a random effects model with strength of evidence assessed using the grading of recommendations assessment, development, and evaluation (GRADE).
MAIN OUTCOMES AND MEASURES: The primary outcome measure was pain. Pain and disability outcomes were converted to a common 0 to 100 scale, with effects greater than 20 points considered clinically important.
RESULTS: Of 20 included RCTs of opioid analgesics (with a total of 7925 participants), 13 trials (3419 participants) evaluated short-term effects on chronic low back pain, and no placebo-controlled trials enrolled patients with acute low back pain. In half of these 13 trials, at least 50% of participants withdrew owing to adverse events or lack of efficacy. There was moderate-quality evidence that opioid analgesics reduce pain in the short term; mean difference (MD), -10.1 (95% CI, -12.8 to -7.4). Meta-regression revealed a 12.0 point greater pain relief for every 1 log unit increase in morphine equivalent dose (P = .046). Clinically important pain relief was not observed within the dose range evaluated (40.0-240.0-mg morphine equivalents per day). There was no significant effect of enrichment study design.
CONCLUSIONS AND RELEVANCE: For people with chronic low back pain who tolerate the medicine, opioid analgesics provide modest short-term pain relief but the effect is not likely to be clinically important within guideline recommended doses. Evidence on long-term efficacy is lacking. The efficacy of opioid analgesics in acute low back pain is unknown.
Back pain affects most adults, causes disability for some, and is a common reason for seeking healthcare. In the United States, opioid prescription for low back pain has increased, and opioids are now the most commonly prescribed drug class. More than half of regular opioid users report back pain. Rates of opioid prescribing in the US and Canada are two to three times higher than in most European countries. The analgesic efficacy of opioids for acute back pain is inferred from evidence in other acute pain conditions. Opioids do not seem to expedite return to work in injured workers or improve functional outcomes of acute back pain in primary care. For chronic back pain, systematic reviews find scant evidence of efficacy. Randomized controlled trials have high dropout rates, brief duration (four months or less), and highly selected patients. Opioids seem to have short term analgesic efficacy for chronic back pain, but benefits for function are less clear. The magnitude of pain relief across chronic non-cancer pain conditions is about 30%. Given the brevity of randomized controlled trials, the long term effectiveness and safety of opioids are unknown. Loss of long term efficacy could result from drug tolerance and emergence of hyperalgesia. Complications of opioid use include addiction and overdose related mortality, which have risen in parallel with prescription rates. Common short term side effects are constipation, nausea, sedation, and increased risk of falls and fractures. Longer term side effects may include depression and sexual dysfunction. Screening for high risk patients, treatment agreements, and urine testing have not reduced overall rates of opioid prescribing, misuse, or overdose. Newer strategies for reducing risks include more selective prescription of opioids and lower doses; use of prescription monitoring programs; avoidance of co-prescription with sedative hypnotics; and reformulations that make drugs more difficult to snort, smoke, or inject.
Background: We updated a systematic review on the comparative efficacy, tolerability and safety of opioids and of their routes of application in chronic noncancer pain (CNCP).
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 CNCP. We included randomized head-to-head comparisons of opioids (opioid of the sponsor of the study versus standard opioid) of at least 4 week’s duration. Using a random effects model, absolute risk differences (RD) were calculated for categorical data and standardized mean differences (SMD) for continuous variables. The quality of evidence was rated by the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach.
Results: We included 13 RCTs with 6748 participants. Median study duration was 15 weeks (range 4–56 weeks). Hydromorphone, morphine, oxymorphone and tapentadol were compared to oxycodone; fentanyl to morphine and buprenorphine to tramadol. In pooled analysis, there were no significant differences between the two groups of opioids in terms of mean pain reduction (low-quality evidence), the patient global impression to be much or very much improved outcome (low-quality evidence), physical function (very low-quality evidence), serious adverse events (moderate-quality evidence) or mortality (moderate-quality evidence). There was no significant difference between transdermal and oral application of opioids in terms of mean pain reduction, physical function, serious adverse events, mortality (all low-quality evidence) or dropout due to adverse events (very low-quality).
Conclusion: Pooled head-to-head comparisons of opioids (opioid of the sponsor of the study versus standard opioid) provide no rational for preferring one opioid and/or administration route over another in the therapy of patients with CNCP.
The English full-text version of this article is freely available at SpringerLink (under “Supplemental”).
BACKGROUND: Chronic musculoskeletal pain is a prevalent condition and a major cause of disability and absence from the workplace worldwide. Opioids are frequently used to treat chronic pain, although adverse effects often restrict their long-term benefits. Tapentadol is an opioid and norepinephrine re-uptake inhibitor, which may cause a lower incidence (and severity) of adverse effects compared to other strong opioids.
OBJECTIVES: To determine the efficacy, safety and tolerability of tapentadol extended release for moderate-to-severe pain for at least three months for any musculoskeletal cause.
SEARCH METHODS: We searched electronic databases (CENTRAL, MEDLINE, EMBASE, Web of Science) to March 2014, unrestricted by language, as well as trials registers and reference lists from retrieved studies. We contacted drug manufacturers for further information.
SELECTION CRITERIA: Randomised controlled trials (RCTs) of tapentadol in people with chronic musculoskeletal pain, compared to placebo or active control.
DATA COLLECTION AND ANALYSIS: Two review authors independently selected trials for inclusion, assessed risk of bias of included studies and extracted data. We performed two meta-analyses for the comparisons tapentadol extended release vs. placebo, and tapentadol extended release vs. active-control (oxycodone). We used random-effects and fixed-effect models according to the presence or not of heterogeneity, respectively. Also, we performed subgroup analyses. The primary efficacy outcome was pain control assessed by change in pain intensity scores and responder's rate (at least 50% pain relief). Primary safety outcome was withdrawal rate due to adverse effects.
MAIN RESULTS: Four parallel-design RCTs of moderate quality including 4094 patients with osteoarthritis or back pain, or both, met the inclusion criteria. Three trials were phase III studies with 12-weeks follow-up and the fourth trial was an open-label safety study of 52-weeks follow-up. All trials were oxycodone-controlled and three were also placebo-controlled. Two trials included patients with knee osteoarthritis, one evaluated patients with low back pain and one enrolled both. All studies reported last-observation-carried-forward (LOCF) as imputation method. We requested baseline-observation-carried-forward (BOCF) imputed analyses and any unpublished data from the manufacturer but the manufacturers denied the request. Two out of the four oxycodone-controlled studies and one out of the three placebo-controlled studies did not provided data on responder's rate. Two studies were considered to be of high risk of bias.In comparison to placebo, tapentadol was associated with a mean reduction of 0.56 points (95% confidence interval (CI) 0.92 to 0.20) in the 11-point numerical rating scale (NRS) at 12 weeks and with a 1.36 increase (95% CI 1.13 to 1.64) in the risk of responding to treatment (number needed to treat for an additional beneficial outcome (NNTB) 16; 95% CI 9 to 57, for 12-weeks). Moderate-to-high heterogeneity was found for the efficacy outcome estimates. Tapentadol was associated with a 2.7 fold increase (95% CI 2.05 to 3.52) in the risk of discontinuing treatment due to adverse effects number needed to treat for an additional harmful outcome (NNTH) 10; 95%CI 7 to 12, for 12 weeks).In comparison to oxycodone, pooled data showed a 0.24 points (95%CI 0.43 to 0.05) reduction in pain intensity from baseline in the 11-point NRS. The two studies that evaluated responder's rate showed a non-significant 1.46 increase (95% CI 0.92 to 2.32) in the risk of responding to treatment among tapentadol treated patients. Tapentadol was associated with a 50% risk reduction (95% CI 42% to 60%) of discontinuing treatment due to adverse effects (NNTB 6; 95% CI 5 to 7, for 12 weeks). Tapentadol was also associated with a 9% reduction (95% CI 4 to 15) in the overall risk of adverse effects (NNTH 18; 95% CI 12 to 35, for 12 weeks) and with a non-significant 43% reduction (95% CI 33 to 76) in the risk of serious adverse effects. Moderate to high heterogeneity was found for most efficacy (except for the primary outcome) and safety outcome estimates. Subgroup analysis showed a higher improvement with tapentadol among patients with knee osteoarthritis and among pooled results from studies of higher quality and shorter follow-up period, although there were no statistical significant differences in the effect size between these subgroups.
AUTHORS' CONCLUSIONS: Tapentadol extended release is associated with a reduction in pain intensity in comparison to placebo and oxycodone. However, the clinical significance of the results is uncertain due to the following reasons: modest difference between interventions in efficacy outcomes, high heterogeneity in some comparisons and outcomes, high withdrawals rates, lack of data for the primary outcome in some studies and impossibility to use BOCF as imputation method. Tapentadol is associated with a more favourable safety profile and tolerability than oxycodone.
PURPOSE: The objective of this systematic review was to assess the clinical efficacy, safety, tolerability, and health-related quality of life outcomes associated with management of moderate-to-severe chronic pain with oxycodone/naloxone and tapentadol, focusing on the effect of these treatments on patients' daily functioning.
METHODS: Literature from a wide range of sources, including Embase, MEDLINE, MEDLINE In-Process, and the Cochrane Central Register of Controlled Trials, was searched to identify randomized controlled trials investigating tapentadol or oxycodone/naloxone for the treatment of patients with chronic pain. A network meta-analysis was conducted to determine the relative efficacy and safety profiles of these treatments.
FINDINGS: Oxycodone/naloxone was significantly better than tapentadol with respect to the Patient Assessment of Constipation Symptoms total score (risk ratio = -3.60; 95% credible interval, -5.36 to -2.11) and revealed a significantly lower risk of dizziness (risk ratio = 0.72; 95% credible interval, 0.42-0.98). Oxycodone/naloxone was directionally favored, although not significantly superior to tapentadol for headache, fatigue, dry mouth, dyspepsia, and withdrawals due to lack of efficacy. For the AE outcomes of constipation, nausea, and vomiting, as well as pain efficacy and all-cause withdrawals from studies, tapentadol was directionally favored without any statistical difference from oxycodone/naloxone. However, the two treatments were not wholly comparable for the evaluation of pain efficacy because of differences in on-study rescue medication and a higher baseline pain severity in the tapentadol studies.
IMPLICATIONS: Oxycodone/naloxone offers significant improvements in Patient Assessment of Constipation Symptoms total score and dizziness and was directionally favored for fatigue and headache compared with extended-release tapentadol, which may translate to improved patient daily functioning and health-related quality of life.
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").
BACKGROUND: Low back pain (LBP) is one of the most common health problems in adults. The impact of LBP on the individual can cause loss of health status in the form of symptoms and loss of function related to pain in the back; limitation of daily, leisure, and/or strenuous activities, and disability. LBP also poses an economic burden to society, mainly in terms of one of the most common reasons for seeking medical care (direct treatment costs), and accounts for the large number of work days lost (indirect costs). To reduce the impact of LBP on adults, drug therapy is the most frequently recommended intervention. Over the last decade, a substantial number of randomized clinical trials of drug therapy for LBP have been published.
OBJECTIVE: To determine the effectiveness of drug therapy for the treatment of chronic nonspecific low back pain (CNLBP).
STUDY DESIGN: Systematic review
METHODS: A systematic review and meta-analysis of randomized controlled trials was conducted. Five databases (Medline, CINAHL, Science Direct, CAJ Full-text Database, and Cochrane databases) were searched for articles published from 2002 to 2012. The eligibility criteria were randomized trials and double-blind controlled trials of oral or injection drug therapy for CNLBP in subjects who were aged at least 18 years old, published in English or Chinese. Two independent reviewers extracted the data.
RESULTS: A total of 25 drug therapy trials were included. cyclo-oxygenase-2 (COX-2) nonsteroidal anti-inflammatory drugs (NSAIDs), tramadol, and opioids were commonly used. Only 5 trials studied the efficacy of adjuvant analgesics of antiepileptics (n = 1) and antidepressants (n = 4) for CNLBP. The standardized mean difference (SMD) for COX-2 NSAIDs in pain relief was -12.03 (95% confidence interval [CI]: -15.00 to -9.06). The SMD for tramadol in pain relief was -1.72 (95% CI: -3.45 to 0.01). As the 95% CI crossed 0, this effect size was not considered statistically significant. The SMD for the overall effects of opioids in pain relief was -5.18 (95% CI: -8.30 to -2.05). The SMD for the partial opioid agonist drug in pain relief was -7.46 (95% CI: -11.87 to -3.04).
LIMITATIONS: The follow-up periods of these included trials in the meta-analysis ranged from 4 to 24 weeks. The difference of follow-up periods influenced how study outcomes were recorded. These included trials also had significant differences in patient selections. Some trials may actually include CNLBP patients with neuropathic pain, as not having focal neurological findings or signs does not mean that the pain is not neuropathic. Consequently, different pain conditions may influence patients who responded to the same drug and then influence pooled estimates of treatment effect size.
CONCLUSION: This review endorses the use of COX-2 NSAIDs as the first-line drugs for CNLBP. Tramadol shows no statistically significant effect on pain relief, but has small effect sizes in improving functioning. Among included opioid therapy studies, the overall effects of opioids and the partial opioids agonist drug had statistically significant treatment effects in pain relief for CNLBP patients.
BACKGROUND: The use of opioids in the long-term management of chronic low-back pain (CLBP) has increased dramatically. Despite this trend, the benefits and risks of these medications remain unclear. This review is an update of a Cochrane review first published in 2007.
OBJECTIVES: To determine the efficacy of opioids in adults with CLBP.
SEARCH METHODS: We electronically searched the Cochrane Back Review Group's Specialized Register, CENTRAL, CINAHL and PsycINFO, MEDLINE, and EMBASE from January 2006 to October 2012. We checked the reference lists of these trials and other relevant systematic reviews for potential trials for inclusion.
SELECTION CRITERIA: We included randomized controlled trials (RCTs) that assessed the use of opioids (as monotherapy or in combination with other therapies) in adults with CLBP that were at least four weeks in duration. We included trials that compared non-injectable opioids to placebo or other treatments. We excluded trials that compared different opioids only.
DATA COLLECTION AND ANALYSIS: Two authors independently assessed the risk of bias and extracted data onto a pre-designed form. We pooled results using Review Manager (RevMan) 5.2. We reported on pain and function outcomes using standardized mean difference (SMD) or risk ratios with 95% confidence intervals (95% CI). We used absolute risk difference (RD) with 95% CI to report adverse effects.
MAIN RESULTS: We included 15 trials (5540 participants). Tramadol was examined in five trials (1378 participants); it was found to be better than placebo for pain (SMD -0.55, 95% CI -0.66 to -0.44; low quality evidence) and function (SMD -0.18, 95% CI -0.29 to -0.07; moderate quality evidence). Transdermal buprenorphine (two trials, 653 participants) may make little difference for pain (SMD -2.47, 95%CI -2.69 to -2.25; very low quality evidence), but no difference compared to placebo for function (SMD -0.14, 95%CI -0.53 to 0.25; very low quality evidence). Strong opioids (morphine, hydromorphone, oxycodone, oxymorphone, and tapentadol), examined in six trials (1887 participants), were better than placebo for pain (SMD -0.43, 95%CI -0.52 to -0.33; moderate quality evidence) and function (SMD -0.26, 95% CI -0.37 to -0.15; moderate quality evidence). One trial (1583 participants) demonstrated that tramadol may make little difference compared to celecoxib (RR 0.82, 95% CI 0.76 to 0.90; very low quality evidence) for pain relief. Two trials (272 participants) found no difference between opioids and antidepressants for either pain (SMD 0.21, 95% CI -0.03 to 0.45; very low quality evidence), or function (SMD -0.11, 95% -0.63 to 0.42; very low quality evidence). The included trials in this review had high drop-out rates, were of short duration, and had limited interpretability of functional improvement. They did not report any serious adverse effects, risks (addiction or overdose), or complications (sleep apnea, opioid-induced hyperalgesia, hypogonadism). In general, the effect sizes were medium for pain and small for function.
AUTHORS' CONCLUSIONS: There is some evidence (very low to moderate quality) for short-term efficacy (for both pain and function) of opioids to treat CLBP compared to placebo. The very few trials that compared opioids to non-steroidal anti-inflammatory drugs (NSAIDs) or antidepressants did not show any differences regarding pain and function. The initiation of a trial of opioids for long-term management should be done with extreme caution, especially after a comprehensive assessment of potential risks. There are no placebo-RCTs supporting the effectiveness and safety of long-term opioid therapy for treatment of CLBP.
Journal»European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society
INTRODUCTION: The objective of this study was to obtain parameter estimates for the efficacy of duloxetine versus alternative oral therapies for the treatment of chronic low back pain.
MATERIALS AND METHODS: Electronic databases were searched to identify randomised, double-blind placebo-controlled trials. Studies reporting pain intensity, with parallel-group design of oral treatments with length of treatment of more than 8 weeks were included. A Bayesian approach to indirect comparisons was applied, using standardised mean difference as a measure of relative treatment effect.
RESULTS: Fifteen studies were identified comparing duloxetine with the following oral drug classes: non-scheduled opioids, cyclooxygenase-2 inhibitors, scheduled opioids, selective serotonin reuptake inhibitors, and 'other' (i.e. glucosamine). The primary analysis found scheduled opioids to be more effective than duloxetine for the fixed effects model. However, the estimate of the treatment difference reflected a less than small magnitude of effect (|standardised mean difference| <0.2), and there was no difference for the random effects model. No differences were found in sensitivity analyses involving the subset of patients not receiving concomitant non-steroidal anti-inflammatory medication.
CONCLUSION: The available evidence shows that there does not seem to be any difference in efficacy between duloxetine and other oral pharmacological therapies, providing a valuable alternative for this disabling condition.
Opioid analgesics are commonly used for low back pain, however, to our knowledge there has been no systematic evaluation of the effect of opioid dose and use of enrichment study design on estimates of treatment effect.
OBJECTIVE:
To evaluate efficacy and tolerability of opioids in the management of back pain; and investigate the effect of opioid dose and use of an enrichment study design on treatment effect.
DATA SOURCES:
Medline, EMBASE, CENTRAL, CINAHL, and PsycINFO (inception to September 2015) with citation tracking from eligible randomized clinical trials (RCTs).
STUDY SELECTION:
Placebo-controlled RCTs in any language.
DATA EXTRACTION AND SYNTHESIS:
Two authors independently extracted data and assessed risk of bias. Data were pooled using a random effects model with strength of evidence assessed using the grading of recommendations assessment, development, and evaluation (GRADE).
MAIN OUTCOMES AND MEASURES:
The primary outcome measure was pain. Pain and disability outcomes were converted to a common 0 to 100 scale, with effects greater than 20 points considered clinically important.
RESULTS:
Of 20 included RCTs of opioid analgesics (with a total of 7925 participants), 13 trials (3419 participants) evaluated short-term effects on chronic low back pain, and no placebo-controlled trials enrolled patients with acute low back pain. In half of these 13 trials, at least 50% of participants withdrew owing to adverse events or lack of efficacy. There was moderate-quality evidence that opioid analgesics reduce pain in the short term; mean difference (MD), -10.1 (95% CI, -12.8 to -7.4). Meta-regression revealed a 12.0 point greater pain relief for every 1 log unit increase in morphine equivalent dose (P = .046). Clinically important pain relief was not observed within the dose range evaluated (40.0-240.0-mg morphine equivalents per day). There was no significant effect of enrichment study design.
CONCLUSIONS AND RELEVANCE:
For people with chronic low back pain who tolerate the medicine, opioid analgesics provide modest short-term pain relief but the effect is not likely to be clinically important within guideline recommended doses. Evidence on long-term efficacy is lacking. The efficacy of opioid analgesics in acute low back pain is unknown.
