OBJECTIVE: To update a systematic review of published research on pharmacotherapy for pain post-spinal cord injury (SCI).
DATA SOURCES: PubMed/MEDLINE, CINAHL, Embase, and PsycINFO databases were searched for articles from 2009 to September 2015 examining treatment of pain post-SCI.
STUDY SELECTION: Studies were included for analysis if they met the following 4 a priori criteria: (1) written in the English language; (2) ≥50% of subjects had an SCI, unless results were stratified by population type; (3) participants included ≥3 subjects with an SCI; and (4) any intervention involving pharmacologic treatment for the improvement of pain.
DATA EXTRACTION: Randomized controlled trials were assessed for methodologic quality using the Physiotherapy Evidence Database scoring system. All research designs were given a level of evidence according to a modified Sackett Scale.
DATA SYNTHESIS: Seven new studies met our inclusion criteria. The new studies fell into the following categories: analgesics (n=1), anticonvulsants (n=2), antidepressants (n=2), antispastics (n=1), and cannabinoids (n=1). There was evidence for 5 new pharmacotherapies among the SCI population; these included the following: oxycodone, duloxetine, venlafaxine, phenol block, and dronabinol. Levels of evidence for all therapy modalities were updated based on the new evidence.
CONCLUSIONS: Anticonvulsants remain the most studied and supported pharmacotherapy for neuropathic pain post-SCI. Antidepressants showed reduction in pain only among those with comorbid depression. Botulinum toxin and phenol blocks were supported for the reduction of mixed pain post-SCI.
BACKGROUND: New drug treatments, clinical trials, and standards of quality for assessment of evidence justify an update of evidence-based recommendations for the pharmacological treatment of neuropathic pain. Using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE), we revised the Special Interest Group on Neuropathic Pain (NeuPSIG) recommendations for the pharmacotherapy of neuropathic pain based on the results of a systematic review and meta-analysis. METHODS: Between April, 2013, and January, 2014, NeuPSIG of the International Association for the Study of Pain did a systematic review and meta-analysis of randomised, double-blind studies of oral and topical pharmacotherapy for neuropathic pain, including studies published in peer-reviewed journals since January, 1966, and unpublished trials retrieved from ClinicalTrials.gov and websites of pharmaceutical companies. We used number needed to treat (NNT) for 50% pain relief as a primary measure and assessed publication bias; NNT was calculated with the fixed-effects Mantel-Haenszel method. FINDINGS: 229 studies were included in the meta-analysis. Analysis of publication bias suggested a 10% overstatement of treatment effects. Studies published in peer-reviewed journals reported greater effects than did unpublished studies (<i>r</i>² 9·3%, p = 0·009). Trial outcomes were generally modest: in particular, combined NNTs were 6·4 (95% CI 5·2–8·4) for serotonin-noradrenaline reuptake inhibitors, mainly including duloxetine (nine of 14 studies); 7·7 (6·5–9·4) for pregabalin; 7·2 (5·9–9·21) for gabapentin, including gabapentin extended release and enacarbil; and 10·6 (7·4–19·0) for capsaicin high-concentration patches. NNTs were lower for tricyclic antidepressants, strong opioids, tramadol, and botulinum toxin A, and undetermined for lidocaine patches. Based on GRADE, final quality of evidence was moderate or high for all treatments apart from lidocaine patches; tolerability and safety, and values and preferences were higher for topical drugs; and cost was lower for tricyclic antidepressants and tramadol. These findings permitted a strong recommendation for use and proposal as first-line treatment in neuropathic pain for tricyclic antidepressants, serotonin-noradrenaline reuptake inhibitors, pregabalin, and gabapentin; a weak recommendation for use and proposal as second line for lidocaine patches, capsaicin high-concentration patches, and tramadol; and a weak recommendation for use and proposal as third line for strong opioids and botulinum toxin A. Topical agents and botulinum toxin A are recommended for peripheral neuropathic pain only. INTERPRETATION: Our results support a revision of the NeuPSIG recommendations for the pharmacotherapy of neuropathic pain. Inadequate response to drug treatments constitutes a substantial unmet need in patients with neuropathic pain. Modest efficacy, large placebo responses, heterogeneous diagnostic criteria, and poor phenotypic profiling probably account for moderate trial outcomes and should be taken into account in future studies. (PsycInfo Database Record (c) 2022 APA, all rights reserved)
BACKGROUND: Antiepileptic drugs have been used in pain management since the 1960s; some have shown efficacy in treating different neuropathic pain conditions. The efficacy of levetiracetam for relief of neuropathic pain has not previously been reviewed.
OBJECTIVES: To assess the analgesic efficacy and adverse events of levetiracetam in chronic neuropathic pain conditions in adults.
SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (2014, Issue 6) (via the Cochrane Library), MEDLINE, EMBASE, and two clinical trials databases (ClinicalTrials.gov. and the World Health Organisation Clinical Trials Registry Platform) to 3 July 2014, together with reference lists of retrieved papers and reviews.
SELECTION CRITERIA: We included randomised, double-blind studies of two weeks duration or longer, comparing levetiracetam with placebo or another active treatment in adults with chronic neuropathic pain conditions. Studies had to have a minimum of 10 participants per treatments arm.
DATA COLLECTION AND ANALYSIS: Two review authors independently extracted efficacy and adverse event data, and examined issues of study quality. We performed analysis using three tiers of evidence. First tier evidence derived from data meeting current best standards and subject to minimal risk of bias (outcome equivalent to substantial pain intensity reduction; intention-to-treat analysis without imputation for dropouts; at least 200 participants in the comparison; 8 to 12 weeks duration; parallel design); second tier evidence from data that failed to meet one or more of these criteria and that we considered at some risk of bias but with at least 200 participants in the comparison; and third tier evidence from data involving fewer than 200 participants that was considered very likely to be biased or used outcomes of limited clinical utility, or both.
MAIN RESULTS: We included six studies: five small, cross-over studies with 174 participants, and one parallel group study with 170 participants. Participants were treated with levetiracetam (2000 mg to 3000 mg daily) or placebo for between four and 14 weeks. Each study included participants with a different type of neuropathic pain; central pain due to multiple sclerosis, pain following spinal cord injury, painful polyneuropathy, central post-stroke pain, postherpetic neuralgia, and post-mastectomy pain.
None of the included studies provided first or second tier evidence. The evidence was very low quality, downgraded because of the small size of the treatment arms, and because studies reported results using last observation carried forward (LOCF) imputation for withdrawals or using only participants who completed the study according to the protocol, where there were greater than 10% withdrawals. There were insufficient data for a pooled efficacy analysis in particular neuropathic pain conditions, but individual studies did not show any analgesic effect of levetiracetam compared with placebo. We did pool results for any outcome considered substantial pain relief (≥ 50% pain intensity reduction or ‘complete’ or ‘good’ responses on the verbal rating scale) for four studies with dichotomous data; response rates across different types of neuropathic pain was similar with levetiracetam (10%) and placebo (12%), with no statistical difference (risk ratio 0.9; 95% confidence interval (CI) 0.4 to1.7).
We pooled data across different conditions for adverse events and withdrawals. Based on very limited data, significantly more participants experienced an adverse event with levetiracetam than with placebo (number needed to treat for an additional harmful event (NNH) 8.0 (95% CI 4.6 to 32)). There were significantly more adverse event withdrawals with levetiracetam (NNH 9.7 (6.7 to 18)).
AUTHORS' CONCLUSIONS: The amount of evidence for levetiracetam in neuropathic pain conditions was very small and potentially biased because of the methods of analysis used in the studies. There was no indication that levetiracetam was effective in reducing neuropathic pain, but it was associated with an increase in participants who experienced adverse events and who withdrew due to adverse events.
Randomized, double-blind, placebo-controlled trials on neuropathic pain treatment are accumulating, so an updated review of the available evidence is needed. Studies were identified using MEDLINE and EMBASE searches. Numbers needed to treat (NNT) and numbers needed to harm (NNH) values were used to compare the efficacy and safety of different treatments for a number of neuropathic pain conditions. One hundred and seventy-four studies were included, representing a 66% increase in published randomized, placebo-controlled trials in the last 5 years. Painful poly-neuropathy (most often due to diabetes) was examined in 69 studies, postherpetic neuralgia in 23, while peripheral nerve injury, central pain, HIV neuropathy, and trigeminal neuralgia were less often studied. Tricyclic antidepressants, serotonin noradrenaline reuptake inhibitors, the anticonvulsants gabapentin and pregabalin, and opioids are the drug classes for which there is the best evidence for a clinical relevant effect. Despite a 66% increase in published trials only a limited improvement of neuropathic pain treatment has been obtained. A large proportion of neuropathic pain patients are left with insufficient pain relief. This fact calls for other treatment options to target chronic neuropathic pain. Large-scale drug trials that aim to identify possible subgroups of patients who are likely to respond to specific drugs are needed to test the hypothesis that a mechanism-based classification may help improve treatment of the individual patients. (PsycInfo Database Record (c) 2021 APA, all rights reserved)
To update a systematic review of published research on pharmacotherapy for pain post-spinal cord injury (SCI).
DATA SOURCES:
PubMed/MEDLINE, CINAHL, Embase, and PsycINFO databases were searched for articles from 2009 to September 2015 examining treatment of pain post-SCI.
STUDY SELECTION:
Studies were included for analysis if they met the following 4 a priori criteria: (1) written in the English language; (2) ≥50% of subjects had an SCI, unless results were stratified by population type; (3) participants included ≥3 subjects with an SCI; and (4) any intervention involving pharmacologic treatment for the improvement of pain.
DATA EXTRACTION:
Randomized controlled trials were assessed for methodologic quality using the Physiotherapy Evidence Database scoring system. All research designs were given a level of evidence according to a modified Sackett Scale.
DATA SYNTHESIS:
Seven new studies met our inclusion criteria. The new studies fell into the following categories: analgesics (n=1), anticonvulsants (n=2), antidepressants (n=2), antispastics (n=1), and cannabinoids (n=1). There was evidence for 5 new pharmacotherapies among the SCI population; these included the following: oxycodone, duloxetine, venlafaxine, phenol block, and dronabinol. Levels of evidence for all therapy modalities were updated based on the new evidence.
CONCLUSIONS:
Anticonvulsants remain the most studied and supported pharmacotherapy for neuropathic pain post-SCI. Antidepressants showed reduction in pain only among those with comorbid depression. Botulinum toxin and phenol blocks were supported for the reduction of mixed pain post-SCI.
Systematic Review Question»Systematic review of interventions
