BACKGROUND: A 2007 American College of Physicians guideline addressed pharmacologic options for low back pain. New evidence and medications have now become available.
PURPOSE: To review the current evidence on systemic pharmacologic therapies for acute or chronic nonradicular or radicular low back pain.
DATA SOURCES: Ovid MEDLINE (January 2008 through November 2016), Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and reference lists.
STUDY SELECTION: Randomized trials that reported pain, function, or harms of systemic medications versus placebo or another intervention.
DATA EXTRACTION: One investigator abstracted data, and a second verified accuracy; 2 investigators independently assessed study quality.
DATA SYNTHESIS: The number of trials ranged from 9 (benzodiazepines) to 70 (nonsteroidal anti-inflammatory drugs). New evidence found that acetaminophen was ineffective for acute low back pain, nonsteroidal anti-inflammatory drugs had smaller benefits for chronic low back pain than previously observed, duloxetine was effective for chronic low back pain, and benzodiazepines were ineffective for radiculopathy. For opioids, evidence remains limited to short-term trials showing modest effects for chronic low back pain; trials were not designed to assess serious harms. Skeletal muscle relaxants are effective for short-term pain relief in acute low back pain but caused sedation. Systemic corticosteroids do not seem to be effective. For effective interventions, pain relief was small to moderate and generally short-term; improvements in function were generally smaller. Evidence is insufficient to determine the effects of antiseizure medications.
LIMITATIONS: Qualitatively synthesized new trials with prior meta-analyses. Only English-language studies were included, many of which had methodological shortcomings. Medications injected for local effects were not addressed.
CONCLUSION: Several systemic medications for low back pain are associated with small to moderate, primarily short-term effects on pain. New evidence suggests that acetaminophen is ineffective for acute low back pain, and duloxetine is associated with modest effects for chronic low back pain.
PRIMARY FUNDING SOURCE: Agency for Healthcare Research and Quality. (PROSPERO: CRD42014014735).
BACKGROUND: Opioid drugs, including hydromorphone, are commonly used to treat neuropathic pain, and are considered effective by some professionals. Most reviews have examined all opioids together. This review sought evidence specifically for hydromorphone, at any dose, and by any route of administration. Other opioids are considered in separate reviews.This review is part of an update of a previous review, Hydromorphone for acute and chronic pain that was withdrawn in 2013 because it needed updating and splitting to be more specific for different pain conditions. This review focuses only on neuropathic pain.
OBJECTIVES: To assess the analgesic efficacy of hydromorphone for chronic neuropathic pain in adults, and the adverse events associated with its use in clinical trials.
SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL), via the CRSO; MEDLINE via Ovid; and EMBASE via Ovid from inception to 17 November 2015, together with reference lists of retrieved papers and reviews, and two online study registries.
SELECTION CRITERIA: We included randomised, double-blind studies of two weeks' duration or longer, comparing hydromorphone (at any dose, by any route of administration, or in any formulation) with placebo or another active treatment in chronic neuropathic pain.
DATA COLLECTION AND ANALYSIS: Two review authors independently searched for studies, extracted efficacy and adverse event data, and examined issues of study quality. We did not carry out any pooled analyses. We assessed the quality of the evidence using GRADE (Grading of Recommendations Assessment, Development and Evaluation).
MAIN RESULTS: Searches identified seven publications relating to four studies. We excluded three studies. One post hoc (secondary) analysis of a study published in four reports assessed the efficacy of hydromorphone in neuropathic pain, satisfied our inclusion criteria, and was included in the review. The single included study had an enriched enrolment, randomised withdrawal design with 94 participants who were successfully switched from oral morphine to oral hydromorphone extended release (about 60% of those enrolled). These participants were then randomised to continuing hydromorphone for 12 weeks or tapering down the hydromorphone dose to placebo. The methodological quality of the study was generally good, but we judged the risk of bias for incomplete outcome data as unclear, and for study size as high.Since we identified only one study for inclusion, we were unable to carry out any analyses. The included study did not report any of our prespecified primary outcomes, which relate to the number of participants achieving moderate or substantial levels of pain relief. It did report a slightly larger increase in average pain intensity for placebo in the randomised withdrawal phase than for continuing with hydromorphone. It also reported the number of participants who withdrew due to lack of efficacy in the randomised withdrawal phase, which may be an indicator of efficacy. However, in addition to using an enriched enrolment, randomised withdrawal study design, there was an unusual choice of imputation methods for withdrawals (about 50% of participants); the evidence was of very low quality and inadequate to make a judgement on efficacy. Adverse events occurred in about half of participants with hydromorphone, the most common being constipation and nausea. A similar proportion of participants experienced adverse events with placebo, the most common being opioid withdrawal syndrome (very low quality evidence). Most adverse events were mild or moderate in intensity. One in eight participants withdrew while taking hydromorphone during the conversion and titration phase, despite participants being opioid-tolerant (very low quality evidence).We downgraded the quality of the evidence to very low because there was only one study with few participants, it did not report clinically useful efficacy outcomes, and it was a post hoc analysis.
AUTHORS' CONCLUSIONS: There was insufficient evidence to support or refute the suggestion that hydromorphone has any efficacy in any neuropathic pain condition.
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.
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").
A large percentage of patients with chronic pain on around-the-clock (ATC) opioids may experience increased pain occurring at the end of a scheduled dose, also known as end-of-dose pain. Despite the significant prevalence and impact of end-of-dose pain in patients using extended-release (ER) opioids, there are no detailed analyses examining how the frequency of end-of-dose pain is linked to the formulations of long-acting opioids. Consequently, we performed a systematic review to evaluate how many published studies on patients with chronic cancer or noncancer pain identified end-of-dose pain. As only a few studies mentioned end-of-dose pain explicitly, we used breakthrough pain (BTP) as a surrogate parameter. We determined if any opioid formulation had a greater association with the frequency of BTP, the use of rescue medication for BTP, and the frequency of end-of-dose pain. Of the 39 studies entered in the final analysis, 14 studies across different formulations showed that ER opioids were effective in the prevention of BTP. The opioids most frequently studied were hydromorphone (26%), followed by morphine (23%), and transdermal buprenorphine (23%). Only 5% of the studies used immediate-release preparations. Overall, most studies showed that patients using ER preparations experienced fewer episodes of BTP compared with patients on placebo or an active comparator. This could reflect the favorable duration of action of these opioids compared with short-acting formulations. Future studies should examine the incidence of end-of-dose pain and use of rescue medicine in a longitudinal manner in patients with chronic pain taking short- vs. long-acting ATC opioids.
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.
A 2007 American College of Physicians guideline addressed pharmacologic options for low back pain. New evidence and medications have now become available.
PURPOSE:
To review the current evidence on systemic pharmacologic therapies for acute or chronic nonradicular or radicular low back pain.
DATA SOURCES:
Ovid MEDLINE (January 2008 through November 2016), Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and reference lists.
STUDY SELECTION:
Randomized trials that reported pain, function, or harms of systemic medications versus placebo or another intervention.
DATA EXTRACTION:
One investigator abstracted data, and a second verified accuracy; 2 investigators independently assessed study quality.
DATA SYNTHESIS:
The number of trials ranged from 9 (benzodiazepines) to 70 (nonsteroidal anti-inflammatory drugs). New evidence found that acetaminophen was ineffective for acute low back pain, nonsteroidal anti-inflammatory drugs had smaller benefits for chronic low back pain than previously observed, duloxetine was effective for chronic low back pain, and benzodiazepines were ineffective for radiculopathy. For opioids, evidence remains limited to short-term trials showing modest effects for chronic low back pain; trials were not designed to assess serious harms. Skeletal muscle relaxants are effective for short-term pain relief in acute low back pain but caused sedation. Systemic corticosteroids do not seem to be effective. For effective interventions, pain relief was small to moderate and generally short-term; improvements in function were generally smaller. Evidence is insufficient to determine the effects of antiseizure medications.
LIMITATIONS:
Qualitatively synthesized new trials with prior meta-analyses. Only English-language studies were included, many of which had methodological shortcomings. Medications injected for local effects were not addressed.
CONCLUSION:
Several systemic medications for low back pain are associated with small to moderate, primarily short-term effects on pain. New evidence suggests that acetaminophen is ineffective for acute low back pain, and duloxetine is associated with modest effects for chronic low back pain.
