BACKGROUND: Chronic pain is common in adults, and often has a detrimental impact upon physical ability, well-being, and quality of life. Previous reviews have shown that certain antidepressants may be effective in reducing pain with some benefit in improving patients' global impression of change for certain chronic pain conditions. However, there has not been a network meta-analysis (NMA) examining all antidepressants across all chronic pain conditions.
OBJECTIVES: To assess the comparative efficacy and safety of antidepressants for adults with chronic pain (except headache).
SEARCH METHODS: We searched CENTRAL, MEDLINE, Embase, CINAHL, LILACS, AMED and PsycINFO databases, and clinical trials registries, for randomised controlled trials (RCTs) of antidepressants for chronic pain conditions in January 2022.
SELECTION CRITERIA: We included RCTs that examined antidepressants for chronic pain against any comparator. If the comparator was placebo, another medication, another antidepressant, or the same antidepressant at different doses, then we required the study to be double-blind. We included RCTs with active comparators that were unable to be double-blinded (e.g. psychotherapy) but rated them as high risk of bias. We excluded RCTs where the follow-up was less than two weeks and those with fewer than 10 participants in each arm. DATA COLLECTION AND ANALYSIS: Two review authors separately screened, data extracted, and judged risk of bias. We synthesised the data using Bayesian NMA and pairwise meta-analyses for each outcome and ranked the antidepressants in terms of their effectiveness using the surface under the cumulative ranking curve (SUCRA). We primarily used Confidence in Meta-Analysis (CINeMA) and Risk of Bias due to Missing Evidence in Network meta-analysis (ROB-MEN) to assess the certainty of the evidence. Where it was not possible to use CINeMA and ROB-MEN due to the complexity of the networks, we used GRADE to assess the certainty of the evidence. Our primary outcomes were substantial (50%) pain relief, pain intensity, mood, and adverse events. Our secondary outcomes were moderate pain relief (30%), physical function, sleep, quality of life, Patient Global Impression of Change (PGIC), serious adverse events, and withdrawal.
MAIN RESULTS: This review and NMA included 176 studies with a total of 28,664 participants. The majority of studies were placebo-controlled (83), and parallel-armed (141). The most common pain conditions examined were fibromyalgia (59 studies); neuropathic pain (49 studies) and musculoskeletal pain (40 studies). The average length of RCTs was 10 weeks. Seven studies provided no useable data and were omitted from the NMA. The majority of studies measured short-term outcomes only and excluded people with low mood and other mental health conditions. Across efficacy outcomes, duloxetine was consistently the highest-ranked antidepressant with moderate- to high-certainty evidence. In duloxetine studies, standard dose was equally efficacious as high dose for the majority of outcomes. Milnacipran was often ranked as the next most efficacious antidepressant, although the certainty of evidence was lower than that of duloxetine. There was insufficient evidence to draw robust conclusions for the efficacy and safety of any other antidepressant for chronic pain. Primary efficacy outcomes Duloxetine standard dose (60 mg) showed a small to moderate effect for substantial pain relief (odds ratio (OR) 1.91, 95% confidence interval (CI) 1.69 to 2.17; 16 studies, 4490 participants; moderate-certainty evidence) and continuous pain intensity (standardised mean difference (SMD) -0.31, 95% CI -0.39 to -0.24; 18 studies, 4959 participants; moderate-certainty evidence). For pain intensity, milnacipran standard dose (100 mg) also showed a small effect (SMD -0.22, 95% CI -0.39 to 0.06; 4 studies, 1866 participants; moderate-certainty evidence). Mirtazapine (30 mg) had a moderate effect on mood (SMD -0.5, 95% CI -0.78 to -0.22; 1 study, 406 participants; low-certainty evidence), while duloxetine showed a small effect (SMD -0.16, 95% CI -0.22 to -0.1; 26 studies, 7952 participants; moderate-certainty evidence); however it is important to note that most studies excluded participants with mental health conditions, and so average anxiety and depression scores tended to be in the 'normal' or 'subclinical' ranges at baseline already. Secondary efficacy outcomes Across all secondary efficacy outcomes (moderate pain relief, physical function, sleep, quality of life, and PGIC), duloxetine and milnacipran were the highest-ranked antidepressants with moderate-certainty evidence, although effects were small. For both duloxetine and milnacipran, standard doses were as efficacious as high doses. Safety There was very low-certainty evidence for all safety outcomes (adverse events, serious adverse events, and withdrawal) across all antidepressants. We cannot draw any reliable conclusions from the NMAs for these outcomes.
AUTHORS' CONCLUSIONS: Our review and NMAs show that despite studies investigating 25 different antidepressants, the only antidepressant we are certain about for the treatment of chronic pain is duloxetine. Duloxetine was moderately efficacious across all outcomes at standard dose. There is also promising evidence for milnacipran, although further high-quality research is needed to be confident in these conclusions. Evidence for all other antidepressants was low certainty. As RCTs excluded people with low mood, we were unable to establish the effects of antidepressants for people with chronic pain and depression. There is currently no reliable evidence for the long-term efficacy of any antidepressant, and no reliable evidence for the safety of antidepressants for chronic pain at any time point.
OBJECTIVES: The aim of this systematic review (SR) was to answer the following question: "In adult patients with temporomandibular disorders (TMD) related-pain, what is the placebo or nocebo effect of different therapies?"
METHODS: A SR was performed with randomized clinical placebo-controlled trials on diagnosed painful TMD studies from five main databases and from three grey literature. Studies included must to have sample older than 18 years, with painful TMD, which diagnosis was done by Research Diagnostic Criteria (RDC/TMD) or Diagnostic Criteria (DC/TMD).
RESULTS: Out of 770 articles obtained, 42 met the inclusion criteria for qualitative and 26 for quantitative analysis. Meta-analysis indicated mean variation on pain intensity for placebo therapy was higher on laser acupuncture with 45.5mm points reduction, followed by avocado soybean extract with 36mm, and amitriptyline 25mg with 25.2mm. Laser showed a 29% of placebo effect, as well medicine with 19% and other therapies with 26%. Possible nocebo effect of 8% pain increase was found for intra-articular injection of ultracain.
CONCLUSIONS: Based on the available data, the placebo response could play a major effect on TMD pain management and may be responsible from 10 to 75% of pain relief. Laser acupuncture, avocado soybean and amitriptyline promoted the higher placebo effect. Possible nocebo effect was found only for Ultracain Injection with 8%.
CLINICAL RELEVANCE: Clinicians could apply such evidence to optimize pain management and judgment about treatment efficacy and researches may find it useful when designing their investigations. This article is protected by copyright. All rights reserved.
BACKGROUND: Chemotherapy-induced peripheral neuropathy (CIPN) is a commonly encountered disease entity following chemotherapy for cancer treatment. Although only duloxetine is recommended by the American Society of Clinical Oncology (ASCO) for the treatment of CIPN in 2014, the evidence of the clinical outcome for new pharmaceutic therapies and non-pharmaceutic treatments has not been clearly determined.
OBJECTIVE: To provide a comprehensive review and evidence-based recommendations on the treatment of CIPN.
STUDY DESIGN: A systematic review of each treatment regimen in patients with CIPN.
METHODS: The literature on the treatment of CIPN published from 1990 to 2017 was searched and reviewed. The 2011 American Academy of Neurology Clinical Practice Guidelines Process Manual was used to grade the evidence and risk of bias. We reviewed and updated the recommendations of the ASCO in 2014, and evaluated new approaches for treating CIPN.
RESULTS: A total of 26 treatment options in 35 studies were identified. Among these, 7 successful RCTs, 6 failed RCTs, 18 prospective studies, and 4 retrospective studies were included. The included studies examined not only pharmacologic therapy but also other modalities, including laser therapy, scrambler therapy, magnetic field therapy and acupuncture, etc. Most of the included studies had small sample sizes, and short follow-up periods. Primary outcome measures were highly variable across the included studies. No studies were prematurely closed owing to its adverse effects.
LIMITATIONS: The limitations of this systematic review included relatively poor homogeneous, with variations in timing of treatment, primary outcomes, and chemotherapeutic agents used.
CONCLUSION: The evidence is considered of moderate benefit for duloxetine. Photobiomodulation, known as low level laser therapy, is considered of moderate benefit based on the evidence review. Evidence did not support the use of lamotrigine and topical KA (4% ketamine and 2% amitriptyline). The evidence for tricyclic antidepressants was inconclusive as amitriptyline showed no benefit but nortriptyline had insufficient evidence. Further research on CIPN treatment is needed with larger sample sizes, long-term follow-up, standardized outcome measurements, and standardized treatment timing.
KEY WORDS: Chemotherapy-induced neuropathy, peripheral neuropathy, chemotherapy-tumor, neuropathic pain, chronic pain, toxicology, treatment, reduction of pain, level of evidence.
CONTEXT: In patients with cancer, pain is one of the most feared and burdensome symptoms. Adjuvant analgesics are an important cornerstone on which treatment of pain in patients with cancer is based.
OBJECTIVES: To update our guidelines for the treatment of pain in patients with cancer, we performed a systematic review on the use of adjuvant analgesics in pain in cancer.
METHODS: A systematic search of the literature was performed searching for articles that studied the effect of (1) antidepressants, (2) anti-epileptics, (3) N-methyl-d-aspartate (NMDA) receptor antagonists, and (4) other adjuvant analgesics in patients with cancer pain and described their effects on pain intensity and/or side effects.
RESULTS: Based on the keywords and after reading the full papers, we could include 12 papers on anticonvulsants, 10 papers on antidepressants, four on NMDA receptor antagonists, and 10 papers on other adjuvant analgesics. The methodological quality of the included papers was graded as low to very low. Overall, there was a low quality of evidence that gabapentin, pregabalin, amitriptyline, and venlafaxine were effective in reducing pain intensity in patients with cancer pain. There was insufficient evidence on the effectiveness of lamotrigine, levetiracetam, NMDA antagonists, cannabinoids, corticosteroids, and local anesthetics on reducing pain intensity in patients with cancer pain.
CONCLUSION: The quality of currently available evidence on the effectiveness of adjuvant analgesics in the treatment of cancer pain is low. The treatment of pain associated with cancer should be tailored to the patient's personal preferences.
Chronic pain occurs in as many as 85% of individuals with HIV and is associated with substantial functional impairment. Little guidance is available for HIV providers seeking to address their patients' chronic pain. We conducted a systematic review to identify clinical trials and observational studies that examined the impact of pharmacologic or non-pharmacologic interventions on pain and/or functional outcomes among HIV-infected individuals with chronic pain in high-development countries. Eleven studies met inclusion criteria and were mostly low or very low quality. Seven examined pharmacologic interventions (gabapentin, pregabalin, capsaicin, analgesics including opioids) and four examined non-pharmacologic interventions (cognitive behavioral therapy, self-hypnosis, smoked cannabis). The only controlled studies with positive results were of capsaicin and cannabis, and had short-term follow-up (≤12 weeks). Among the seven studies of pharmacologic interventions, five had substantial pharmaceutical industry sponsorship. These findings highlight several important gaps in the HIV/chronic pain literature that require further research.
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.
We present a systematic of the randomized, double-blind, placebo-controlled studies published in the scientific literature concerning the pharmacological treatment and complementary therapies of the painful peripheral neuropathy associated with the human acquired immunodeficiency virus (HIV), between January, 1996 and octubre, 2015. The analysis comprises 20 studies selected from a total of 219 articles located. The 20 controlled studies selected included 2246 patients with HIV-associated distal sensory neuropathy (HIV-SN), characteristically painful, in the form of distal sensory polyneuropathy (DSP) or antiretroviral neuropathy (ATN). The results of this revision show the efficacy of 8% capsaicin, smoked cannabis and recombinant human neural growth factor (rhNGF) in pain management of DSP. Lamotrigine and Acetyl-L carnitine are promising medications in the ATN of HIV patients. Notwithstanding, a search for new therapeutic strategies for the management of DSP and ATN is still necessary.
Background: This is an updated version of the original Cochrane review published in Issue 12, 2011. Phantom limb pain (PLP) is pain that arises in the missing limb after amputation and can be severe, intractable, and disabling. Various medications have been studied in the treatment of phantom pain. There is currently uncertainty in the optimal pharmacologic management of PLP. Objectives: This review aimed to summarise the evidence of effectiveness of pharmacologic interventions in treating PLP. Search methods: For this update, we searched the Cochrane Central Register of Controlled Trials (CENTRAL, the Cochrane Library), MEDLINE, and Embase for relevant studies. We ran the searches for the original review in September 2011 and subsequent searches for this update up to April 2016. We sought additional studies from clinical trials databases and reference lists of retrieved papers. Selection criteria: We included randomised and quasi-randomised trials studying the effectiveness of pharmacologic interventions compared with placebo, another active treatment, or no treatment, in established PLP. We considered the following outcomes: change in pain intensity, function, sleep, depression or mood, quality of life, adverse events, treatment satisfaction, and withdrawals from the study. Data collection and analysis: We independently assessed issues of study quality and extracted efficacy and adverse event data. Due to the wide variability in the studies, we did not perform a meta-analysis for all the interventions and outcomes, but attempted to pool the results of some studies where possible. We prepared a qualitative description and narrative summary of results. We assessed clinical heterogeneity by making qualitative comparisons of the populations, interventions, outcomes/outcome measures, and methods. Main results: We added only one new study with 14 participants to this updated review. We included a 14 studies (10 with low risk of bias and 4 with unclear risk of bias overall) with a total of 269 participants. We added another drug class, botulinum neurotoxins (BoNTs), in particular botulinum toxin A (BoNT/A), to the group of medications reviewed previously. Our primary outcome was change in pain intensity. Most studies did not report our secondary outcomes of sleep, depression or mood, quality of life, treatment satisfaction, or withdrawals from the study. BoNT/A did not improve phantom limb pain intensity during the six months of follow-up compared with lidocaine/methylprednisolone. Compared with placebo, morphine (oral and intravenous) was effective in decreasing pain intensity in the short term with reported adverse events being constipation, sedation, tiredness, dizziness, sweating, voiding difficulty, vertigo, itching, and respiratory problems. The N-methyl D-aspartate (NMDA) receptor antagonists ketamine (versus placebo; versus calcitonin) and dextromethorphan (versus placebo), but not memantine, had analgesic effects. The adverse events of ketamine were more serious than placebo and calcitonin and included loss of consciousness, sedation, hallucinations, hearing and position impairment, and insobriety. The results for gabapentin in terms of pain relief were conflicting, but combining the results favoured treatment group (gabapentin) over control group (placebo) (mean difference -1.16, 95% confidence interval -1.94 to -0.38; 2 studies). However, gabapentin did not improve function, depression score, or sleep quality. Adverse events experienced were somnolence, dizziness, headache, and nausea. Compared with an active control benztropine mesylate, amitriptyline was not effective in PLP, with dry mouth and dizziness as the most frequent adverse events based on one study. The findings for calcitonin (versus placebo; versus ketamine) and local anaesthetics (versus placebo) were variable. Adverse events of calcitonin were headache, vertigo, drowsiness, nausea, vomiting, and hot and cold flushes. Most of the studies were limited by their small sample sizes. Authors' conclusions: Since the last version of this review, we identified another study that added another form of medical therapy, BoNTs, specifically BoNT/A, to the list of pharmacologic interventions being reviewed for clinical efficacy in phantom limb pain. However, the results of this study did not substantially change the main conclusions. The short- and long-term effectiveness of BoNT/A, opioids, NMDA receptor antagonists, anticonvulsants, antidepressants, calcitonins, and local anaesthetics for clinically relevant outcomes including pain, function, mood, sleep, quality of life, treatment satisfaction, and adverse events remain unclear. Based on a small study, BoNT/A (versus lidocaine/methylprednisolone) does not decrease phantom limb pain. Morphine, gabapentin, and ketamine demonstrate favourable short-term analgesic efficacy compared with placebo. Memantine and amitriptyline may not be effective for PLP. However, results must be interpreted with caution, as they were based mostly on a small number of studies with limited sample sizes that varied considerably and also lacked long-term efficacy and safety outcomes. The direction of efficacy of calcitonin, local anaesthetics, and dextromethorphan needs further clarification. Overall, the efficacy evidence for the reviewed medications is thus far inconclusive. Larger and more rigorous randomised controlled trials are needed for us to reach more definitive conclusions about which medications would be useful for clinical practice.
INTRODUCTION: Pain is a common symptom in patients with Guillain-Barre syndrome. Intensity is moderate to severe in most cases and pain may persist after resolution of the disease.
OBJECTIVE: Identify the most appropriate analgesic therapy for pain management in patients with Guillain-Barre syndrome.
MATERIAL AND METHODS: Systematic review and selection of scientific articles on treatment of pain in Guillain-Barre syndrome patients, published between January 1985 and December 2012. We included only randomised, double-blind, controlled trials assessing the effectiveness of drugs for pain management in these patients.
RESULTS: Four articles met the inclusion criteria. One evaluated the use of gabapentin, another evaluated carbamazepine, a third compared gabapentin to carbamazepine, and the last evaluated use of methylprednisolone. Both carbamazepine and gabapentin were useful for pain management. Patients experienced lower-intensity pain with gabapentin treatment in the study comparing that drug to carbamazepine. Methylprednisolone was not shown to be effective for reducing pain. The published data did not permit completion of a meta-analysis.
CONCLUSIONS: There is no robust evidence at present that would point to a single treatment option for this disorder. Further clinical studies of larger patient samples and with a longer duration are needed to characterise types of pain for each patient and measure pain intensity in an objective way.
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.
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.
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”).
Chronic pain is common in adults, and often has a detrimental impact upon physical ability, well-being, and quality of life. Previous reviews have shown that certain antidepressants may be effective in reducing pain with some benefit in improving patients' global impression of change for certain chronic pain conditions. However, there has not been a network meta-analysis (NMA) examining all antidepressants across all chronic pain conditions.
OBJECTIVES:
To assess the comparative efficacy and safety of antidepressants for adults with chronic pain (except headache).
SEARCH METHODS:
We searched CENTRAL, MEDLINE, Embase, CINAHL, LILACS, AMED and PsycINFO databases, and clinical trials registries, for randomised controlled trials (RCTs) of antidepressants for chronic pain conditions in January 2022.
SELECTION CRITERIA:
We included RCTs that examined antidepressants for chronic pain against any comparator. If the comparator was placebo, another medication, another antidepressant, or the same antidepressant at different doses, then we required the study to be double-blind. We included RCTs with active comparators that were unable to be double-blinded (e.g. psychotherapy) but rated them as high risk of bias. We excluded RCTs where the follow-up was less than two weeks and those with fewer than 10 participants in each arm.
DATA COLLECTION AND ANALYSIS:
Two review authors separately screened, data extracted, and judged risk of bias. We synthesised the data using Bayesian NMA and pairwise meta-analyses for each outcome and ranked the antidepressants in terms of their effectiveness using the surface under the cumulative ranking curve (SUCRA). We primarily used Confidence in Meta-Analysis (CINeMA) and Risk of Bias due to Missing Evidence in Network meta-analysis (ROB-MEN) to assess the certainty of the evidence. Where it was not possible to use CINeMA and ROB-MEN due to the complexity of the networks, we used GRADE to assess the certainty of the evidence. Our primary outcomes were substantial (50%) pain relief, pain intensity, mood, and adverse events. Our secondary outcomes were moderate pain relief (30%), physical function, sleep, quality of life, Patient Global Impression of Change (PGIC), serious adverse events, and withdrawal.
MAIN RESULTS:
This review and NMA included 176 studies with a total of 28,664 participants. The majority of studies were placebo-controlled (83), and parallel-armed (141). The most common pain conditions examined were fibromyalgia (59 studies); neuropathic pain (49 studies) and musculoskeletal pain (40 studies). The average length of RCTs was 10 weeks. Seven studies provided no useable data and were omitted from the NMA. The majority of studies measured short-term outcomes only and excluded people with low mood and other mental health conditions. Across efficacy outcomes, duloxetine was consistently the highest-ranked antidepressant with moderate- to high-certainty evidence. In duloxetine studies, standard dose was equally efficacious as high dose for the majority of outcomes. Milnacipran was often ranked as the next most efficacious antidepressant, although the certainty of evidence was lower than that of duloxetine. There was insufficient evidence to draw robust conclusions for the efficacy and safety of any other antidepressant for chronic pain. Primary efficacy outcomes Duloxetine standard dose (60 mg) showed a small to moderate effect for substantial pain relief (odds ratio (OR) 1.91, 95% confidence interval (CI) 1.69 to 2.17; 16 studies, 4490 participants; moderate-certainty evidence) and continuous pain intensity (standardised mean difference (SMD) -0.31, 95% CI -0.39 to -0.24; 18 studies, 4959 participants; moderate-certainty evidence). For pain intensity, milnacipran standard dose (100 mg) also showed a small effect (SMD -0.22, 95% CI -0.39 to 0.06; 4 studies, 1866 participants; moderate-certainty evidence). Mirtazapine (30 mg) had a moderate effect on mood (SMD -0.5, 95% CI -0.78 to -0.22; 1 study, 406 participants; low-certainty evidence), while duloxetine showed a small effect (SMD -0.16, 95% CI -0.22 to -0.1; 26 studies, 7952 participants; moderate-certainty evidence); however it is important to note that most studies excluded participants with mental health conditions, and so average anxiety and depression scores tended to be in the 'normal' or 'subclinical' ranges at baseline already. Secondary efficacy outcomes Across all secondary efficacy outcomes (moderate pain relief, physical function, sleep, quality of life, and PGIC), duloxetine and milnacipran were the highest-ranked antidepressants with moderate-certainty evidence, although effects were small. For both duloxetine and milnacipran, standard doses were as efficacious as high doses. Safety There was very low-certainty evidence for all safety outcomes (adverse events, serious adverse events, and withdrawal) across all antidepressants. We cannot draw any reliable conclusions from the NMAs for these outcomes.
AUTHORS' CONCLUSIONS:
Our review and NMAs show that despite studies investigating 25 different antidepressants, the only antidepressant we are certain about for the treatment of chronic pain is duloxetine. Duloxetine was moderately efficacious across all outcomes at standard dose. There is also promising evidence for milnacipran, although further high-quality research is needed to be confident in these conclusions. Evidence for all other antidepressants was low certainty. As RCTs excluded people with low mood, we were unable to establish the effects of antidepressants for people with chronic pain and depression. There is currently no reliable evidence for the long-term efficacy of any antidepressant, and no reliable evidence for the safety of antidepressants for chronic pain at any time point.
Systematic Review Question»Systematic review of interventions
