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European Review For Medical and... Jul 2021This study's main objective is to carry out a systematic review of the onset of psychotic symptoms after opioid withdrawal. The opiate dependence correlated to...
OBJECTIVE
This study's main objective is to carry out a systematic review of the onset of psychotic symptoms after opioid withdrawal. The opiate dependence correlated to psychiatric symptoms has been well described.
MATERIALS AND METHODS
Following the PRISMA methodology. The consecutive search strategy was applied: (morphine OR buprenorphine OR oxycodone OR tramadol OR fentanyl OR remifentanil OR opioids OR heroin OR methadone) AND (Psychosis OR psychotic symptoms OR schizophrenia).
RESULTS
12 case reports, 3 series of cases, 2 clinical studies, and 2 reviews were found. It seems that the time association is present in all of them; symptoms appear days after the interruption of the opioid. Most of the articles reported are case reports that describe symptoms that appear after the suspension of the opioid substance; in most cases, the reintroduction of the opioid had therapeutic effects and provoked a remission of these symptoms. These preliminary findings indicate that opiates could have an antipsychotic effect; however, the literature is scarce. It is critical to consider, if needed, in opioid-dependent patients who start with psychosis after the opioid withdrawal the possible replacement or reintroduction of opioids to prevent further deterioration in the patient's mental status.
CONCLUSIONS
This study encompasses a comprehensive description of the literature concerning the possible not well-studied outcome of opioid withdrawal. There are some reports of temporal association between withdrawal and psychotic symptoms that improved after the reintroduction of the opioid; it could be taken into consideration in the clinical practice.
Topics: Analgesics, Opioid; Buprenorphine; Heroin; Humans; Methadone; Morphine; Oxycodone; Psychotic Disorders; Substance Withdrawal Syndrome; Tramadol
PubMed: 34286498
DOI: 10.26355/eurrev_202107_26248 -
BMJ Supportive & Palliative Care Jun 2022Opioids are recommended for moderate-to-severe cancer pain; however, in patients with cancer, impaired hepatic function can affect opioid metabolism. The aim of this...
PURPOSE
Opioids are recommended for moderate-to-severe cancer pain; however, in patients with cancer, impaired hepatic function can affect opioid metabolism. The aim of this systematic review was to evaluate the evidence for the use of opioids in patients with cancer with hepatic impairment.
METHODS
A systematic review was conducted and the following databases searched: AMED (-2021), MEDLINE (-2021), EMBASECLASSIC + EMBASE (-2021) and Cochrane Central Register of Controlled Trials (-2021). Eligible studies met the following criteria: patients with cancer-related pain, taking an opioid (as defined by the WHO Guidelines for the pharmacological and radiotherapeutic management of cancer pain in adults and adolescents); >18 years of age; patients with hepatic impairment defined using recognised or study-defined definitions; clinical outcome hepatic impairment related; and primary studies. All eligible studies were appraised using the Grading of Recommendations Assessment, Development and Evaluation system.
RESULTS
Three studies (n=95) were eligible but heterogeneity meant meta-analysis was not possible. Each individual study focused on only one each of oxycodone±hydrocotarnine, oxycodone/naloxone and morphine. No recommendations could be formulated on the preferred opioid in patients with hepatic impairment.
CONCLUSIONS
Morphine is the preferred opioid in hepatic impairment owing to clinical experience and pharmacokinetics. This review, however, found little clinical evidence to support this. Dose adjustments of morphine and the oxycodone formulations reviewed remain necessary in the absence of quality evidence. Overall, the quality of existing evidence on opioid treatments in cancer pain and hepatic impairment is low and there remains a need for high-quality clinical studies examining this.
Topics: Adolescent; Analgesics, Opioid; Cancer Pain; Humans; Morphine; Neoplasms; Oxycodone
PubMed: 34470772
DOI: 10.1136/bmjspcare-2021-003065 -
The Cochrane Database of Systematic... Sep 2022Opioid-induced bowel dysfunction (OIBD) is characterised by constipation, incomplete evacuation, bloating, and gastric reflux. It is one of the major adverse events... (Review)
Review
BACKGROUND
Opioid-induced bowel dysfunction (OIBD) is characterised by constipation, incomplete evacuation, bloating, and gastric reflux. It is one of the major adverse events (AEs) of treatment for pain in cancer and palliative care, resulting in increased morbidity and reduced quality of life. This review is a partial update of a 2008 review, and critiques as previous update (2018) trials only for people with cancer and people receiving palliative care.
OBJECTIVES
To assess for OIBD in people with cancer and people receiving palliative care the effectiveness and safety of mu-opioid antagonists (MOAs) versus different doses of MOAs, alternative pharmacological/non-pharmacological interventions, placebo, or no treatment.
SEARCH METHODS
We searched CENTRAL, MEDLINE, Embase, CINAHL, and Web of Science (December 2021), clinical trial registries and regulatory websites. We sought contact with MOA manufacturers for further data.
SELECTION CRITERIA
Randomised controlled trials (RCTs) assessing the effectiveness and safety of MOAs for OIBD in people with cancer and people at a palliative stage irrespective of the type of terminal disease.
DATA COLLECTION AND ANALYSIS
Two review authors assessed risk of bias and extracted data. The appropriateness of combining data from the trials depended upon sufficient homogeneity across trials. Our primary outcomes were laxation response, effect on analgesia, and AEs. We assessed the certainty of evidence using GRADE and created summary of findings tables.
MAIN RESULTS
We included 10 studies (two new trials) randomising in-total 1343 adults with cancer irrespective of stage, or at palliative care stage of any disease. The MOAs were oral naldemedine and naloxone (alone or in combination with oxycodone), and subcutaneous methylnaltrexone. The trials compared MOAs with placebo, MOAs at different doses, or in combination with other drugs. Two trials of naldemedine and three of naloxone with oxycodone were in people with cancer irrespective of disease stage. The trial on naloxone alone was in people with advanced cancer. Four trials on methylnaltrexone were in palliative care where most participants had advanced cancer. All trials were vulnerable to biases; most commonly, blinding of the outcome assessor was not reported. Oral naldemedine versus placebo Risk (i.e. chance) of spontaneous laxations in the medium term (over two weeks) for naldemedine was over threefold greater risk ratio (RR) 2.00, 95% confidence interval (CI) 1.59 to 2.52, 2 trials, 418 participants, I² = 0%. Number needed to treat for an additional beneficial outcome (NNTB) 3, 95% CI 3 to 4; moderate-certainty evidence). Earlier risk of spontaneous laxations and patient assessment of bowel change was not reported. Very low-certainty evidence showed naldemedine had little to no effect on opioid withdrawal symptoms. There was little to no difference in the risk of serious (non-fatal) AEs (RR 3.34, 95% CI 0.85 to 13.15: low-certainty evidence). Over double the risk of AEs (non-serious) reported with naldemedine (moderate-certainty evidence). Low-dose oral naldemedine versus higher dose Risk of spontaneous laxations was lower for the lower dose (medium term, 0.1 mg versus 0.4 mg: RR 0.69, 95% CI 0.53 to 0.89, 1 trial, 111 participants (low-certainty evidence)). Earlier risk of spontaneous laxations and patient assessment of bowel change not reported. Low-certainty evidence showed little to no difference on opioid withdrawal symptoms (0.1 mg versus 0.4 mg mean difference (MD) -0.30, 95% CI -0.85 to 0.25), and occurrences of serious AEs (0.1 mg versus 0.4 mg RR 0.25, 95% CI 0.03 to 2.17). Low-certainty evidence showed little to no difference on non-serious AEs. Oral naloxone versus placebo Risk of spontaneous laxations and AEs not reported. Little to no difference in pain intensity (very low-certainty evidence). Full data not given. The trial reported that no serious AEs occurred. Oral naloxone + oxycodone versus oxycodone Risk of spontaneous laxations within 24 hours and in the medium term not reported. Low-certainty evidence showed naloxone with oxycodone reduced the risk of opioid withdrawal symptoms. There was little to no difference in the risk of serious (non-fatal) AEs (RR 0.68, 95% CI 0.44 to 1.06), 3 trials, 362 participants, I² = 55%: very low-certainty evidence). There was little to no difference in risk of AEs (low-certainty evidence). Subcutaneous methylnaltrexone versus placebo Risk of spontaneous laxations within 24 hours with methylnaltrexone was fourfold greater than placebo (RR 2.97, 95% CI 2.13 to 4.13. 2 trials, 287 participants, I² = 31%. NNTB 3, 95% CI 2 to 3; low-certainty evidence). Risk of spontaneous laxations in the medium term was over tenfold greater with methylnaltrexone (RR 8.15, 95% CI 4.76 to 13.95, 2 trials, 305 participants, I² = 47%. NNTB 2, 95% CI 2 to 2; moderate-certainty evidence). Low-certainty evidence showed methylnaltrexone reduced the risk of opioid withdrawal symptoms, and did not increase risk of a serious AE (RR 0.59, 95% CI 0.38 to 0.93. I² = 0%; 2 trials, 364 participants). The risk of AEs was higher for methylnaltrexone (low-certainty evidence). Lower-dose subcutaneous methylnaltrexone versus higher dose There was little to no difference in risk of spontaneous laxations in the medium-term (1 mg versus 5 mg or greater: RR 2.91, 95% CI 0.82 to 10.39; 1 trial, 26 participants very low-certainty evidence), or in patient assessment of improvement in bowel status (RR 0.98, 95% CI 0.71 to 1.35, 1 trial, 102 participants; low-certainty evidence). Medium-term assessment of spontaneous laxations and serious AEs not reported. There was little to no difference in symptoms of opioid withdrawal (MD -0.25, 95% CI -0.84 to 0.34, 1 trial, 102 participants) or occurrence of AEs (low-certainty evidence).
AUTHORS' CONCLUSIONS
This update's findings for naldemedine and naloxone with oxycodone have been strengthened with two new trials, but conclusions have not changed. Moderate-certainty evidence for oral naldemedine on risk of spontaneous laxations and non-serious AEs suggests in people with cancer that naldemedine may improve bowel function over two weeks and increase the risk of AEs. There was low-certainty evidence on serious AEs. Moderate-certainty evidence for methylnaltrexone on spontaneous laxations over two weeks suggests subcutaneous methylnaltrexone may improve bowel function in people receiving palliative care, but certainty of evidence for AEs was low. More trials are needed, more evaluation of AEs, outcomes patients rate as important, and in children.
Topics: Adult; Analgesics, Opioid; Child; Humans; Naloxone; Naltrexone; Narcotic Antagonists; Neoplasms; Opioid-Induced Constipation; Oxycodone; Palliative Care; Quaternary Ammonium Compounds; Substance Withdrawal Syndrome
PubMed: 36106667
DOI: 10.1002/14651858.CD006332.pub4 -
BMC Urology Mar 2023Catheter-related bladder discomfort (CRBD) is a common postoperative bladder pain syndrome. Many drugs and interventions for managing CRBD have been studied, but their... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Catheter-related bladder discomfort (CRBD) is a common postoperative bladder pain syndrome. Many drugs and interventions for managing CRBD have been studied, but their comparative effectiveness remains controversial. We made a study to assess the comparative effectiveness of interventions included Ketorolac, Lidocaine, Chlorpheniramine, Gabapentin, Magnesium, Nefopam, Oxycodone, Parecoxib, Solifenacin, Tolterodine, Bupivancaine, Dexmedetomidine, Hyoscine N-butyl bromide, Ketamine, Penile nerve block on urological postoperative CRBD.
METHODS
We performed a network meta-analysis via Aggregate Data Drug Inormation System software included 18 studies with 1816 patients and assessed the risk of bias by Cochrane Collaboration tool. The incidence of moderate to severe CRBD at 0, 1, and 6 h after surgery and the incidence severe CRBD at 1 h after surgery were compared.
RESULT
The number of best rank is 0.48(Nefopam) and 0.22(Nefopam) in the incidence of moderate to severe CRBD at 1 h and incidence severe CRBD at 1 h. More than half of studies at unclear or high risk of bias.
CONCLUSION
Nefopam reduced the incidence of CRBD and prevented severe events, but limited by the small number of studies for each intervention and heterogeneous patients.
Topics: Humans; Network Meta-Analysis; Nefopam; Urinary Bladder; Urinary Catheters; Cystitis, Interstitial
PubMed: 36869313
DOI: 10.1186/s12894-023-01195-9 -
The Clinical Journal of Pain May 2020Tapentadol (TAP) immediate release (IR) is a newer opioid option for acute pain. The aim of this systematic review was to examine the efficacy and safety of TAP IR... (Meta-Analysis)
Meta-Analysis
OBJECTIVE
Tapentadol (TAP) immediate release (IR) is a newer opioid option for acute pain. The aim of this systematic review was to examine the efficacy and safety of TAP IR compared with other opioids for acute pain.
METHODS
A systematic literature search as conducted using the Cochrane Library, Embase, International Pharmaceutical Abstracts, MEDLINE, PubMed, and Web of Science. The search included all randomized controlled trials and observational studies examining TAP IR versus other orally administered IR opioids for acute pain. The protocol for this study was registered on PROSPERO (CRD42018110267).
RESULTS
Thirteen studies and 1 abstract were included in the systematic review (n=12,814 patients). Of these, 5 studies and 1 abstract were included in the qualitative review (n=9108 patients). Eight randomized controlled trials (n=3706 patients) comparing 50 to 100 mg TAP IR versus 5 to 15 mg oxycodone IR were included in the meta-analysis. The lowest dose of TAP IR (ie, 50 mg) was associated with less pain control compared with oxycodone IR (standardized mean difference=0.25, 95% confidence interval: 0.06-0.44, P<0.01). However, there were no significant differences at higher doses (ie, 75, 100 mg, or when a titration strategy was used). In the qualitative analysis, pain control with TAP IR was also similar to morphine IR and tramadol IR. TAP IR was less likely to have gastrointestinal adverse effects such as nausea and constipation compared with other opioids.
DISCUSSION
TAP IR is as effective as other opioids at higher doses for acute pain and is associated with fewer gastrointestinal adverse effects. On the basis of these findings, TAP IR can be considered as a first-line opioid for acute pain.
Topics: Acute Pain; Analgesics, Opioid; Humans; Observational Studies as Topic; Oxycodone; Randomized Controlled Trials as Topic; Tapentadol
PubMed: 31990693
DOI: 10.1097/AJP.0000000000000809 -
The Journal of Arthroplasty Feb 2024Pain is challenging after recovery from total knee arthroplasty (TKA) and total hip arthroplasty (THA) procedures, and patients often receive prescription opioids....
BACKGROUND
Pain is challenging after recovery from total knee arthroplasty (TKA) and total hip arthroplasty (THA) procedures, and patients often receive prescription opioids. However, opioid consumption by patients remains unclear, and unused opioids may lead to risks including misuse and diversion. The objective of this systematic review and meta-analysis was to compare prescription size versus patient-reported consumption of opioids after discharge following TKA and THA.
METHODS
PubMed and Embase were systematically searched for publications published between 2015 and 2022 on patient-reported consumption of opioids after TKA and THA. The primary outcome was opioid use in oxycodone 5-mg equivalents. Team members independently reviewed studies for screening, inclusion, data extraction, and risk of bias.
RESULTS
Among the 17 included studies (15 TKA and 11 THA), discharge opioid prescribing exceeded consumption for both TKA (88.4 versus 65.0 pills at 6 weeks) and THA (64.0 versus 29.8 pills at 12 weeks). For both TKA and THA, the range of opioids prescribed varied significantly, by 1.6-fold for TKA and 2.8-fold for THA. Most studies reported pain outcomes (89%) and the use of nonopioid medications (72%). Of the 4 studies offering prescribing recommendations, the amounts ranged from 50 to 104 pills for TKA and 30 to 45 pills for THA.
CONCLUSIONS
Opioid prescribing exceeds the amount consumed following TKA and THA. These findings serve as a call to action to tailor prescribing guidelines to how much patients actually consume while emphasizing the use of nonopioid medications to better optimize recovery from surgery.
PubMed: 38336301
DOI: 10.1016/j.arth.2024.01.063 -
The Cochrane Database of Systematic... Sep 2022There are ongoing concerns regarding pharmaceutical opioid-related harms, including overdose and dependence, with an associated increase in treatment demand. People... (Review)
Review
BACKGROUND
There are ongoing concerns regarding pharmaceutical opioid-related harms, including overdose and dependence, with an associated increase in treatment demand. People dependent on pharmaceutical opioids appear to differ in important ways from people who use heroin, yet most opioid agonist treatment research has been conducted in people who use heroin. OBJECTIVES: To assess the effects of maintenance opioid agonist pharmacotherapy for the treatment of pharmaceutical opioid dependence.
SEARCH METHODS
We updated our searches of the following databases to January 2022: the Cochrane Drugs and Alcohol Group Specialised Register, CENTRAL, MEDLINE, four other databases, and two trial registers. We checked the reference lists of included studies for further references to relevant randomised controlled trials (RCTs).
SELECTION CRITERIA
We included RCTs with adults and adolescents examining maintenance opioid agonist treatments that made the following two comparisons. 1. Full opioid agonists (methadone, morphine, oxycodone, levo-alpha-acetylmethadol (LAAM), or codeine) versus different full opioid agonists or partial opioid agonists (buprenorphine) for maintenance treatment. 2. Full or partial opioid agonist maintenance versus non-opioid agonist treatments (detoxification, opioid antagonist, or psychological treatment without opioid agonist treatment).
DATA COLLECTION AND ANALYSIS
We used standard Cochrane methods.
MAIN RESULTS
We identified eight RCTs that met inclusion criteria (709 participants). We found four studies that compared methadone and buprenorphine maintenance treatment, and four studies that compared buprenorphine maintenance to either buprenorphine taper (in addition to psychological treatment) or a non-opioid maintenance treatment comparison. We found low-certainty evidence from three studies of a difference between methadone and buprenorphine in favour of methadone on self-reported opioid use at end of treatment (risk ratio (RR) 0.49, 95% confidence interval (CI) 0.28 to 0.86; 165 participants), and low-certainty evidence from four studies finding a difference in favour of methadone for retention in treatment (RR 1.21, 95% CI 1.02 to 1.43; 379 participants). We found low-certainty evidence from three studies showing no difference between methadone and buprenorphine on substance use measured with urine drug screens at end of treatment (RR 0.81, 95% CI 0.57 to 1.17; 206 participants), and moderate-certainty evidence from one study of no difference in days of self-reported opioid use (mean difference 1.41 days, 95% CI 3.37 lower to 0.55 days higher; 129 participants). There was low-certainty evidence from three studies of no difference between methadone and buprenorphine on adverse events (RR 1.13, 95% CI 0.66 to 1.93; 206 participants). We found low-certainty evidence from four studies favouring maintenance buprenorphine treatment over non-opioid treatments in terms of fewer opioid positive urine drug tests at end of treatment (RR 0.66, 95% CI 0.52 to 0.84; 270 participants), and very low-certainty evidence from four studies finding no difference on self-reported opioid use in the past 30 days at end of treatment (RR 0.63, 95% CI 0.39 to 1.01; 276 participants). There was low-certainty evidence from three studies of no difference in the number of days of unsanctioned opioid use (standardised mean difference (SMD) -0.19, 95% CI -0.47 to 0.09; 205 participants). There was moderate-certainty evidence from four studies favouring buprenorphine maintenance over non-opioid treatments on retention in treatment (RR 3.02, 95% CI 1.73 to 5.27; 333 participants). There was moderate-certainty evidence from three studies of no difference in adverse effects between buprenorphine maintenance and non-opioid treatments (RR 0.50, 95% CI 0.07 to 3.48; 252 participants). The main weaknesses in the quality of the data was the use of open-label study designs, and difference in follow-up rates between treatment arms.
AUTHORS' CONCLUSIONS
There is very low- to moderate-certainty evidence supporting the use of maintenance agonist pharmacotherapy for pharmaceutical opioid dependence. Methadone or buprenorphine did not differ on some outcomes, although on the outcomes of retention and self-reported substance use some results favoured methadone. Maintenance treatment with buprenorphine appears more effective than non-opioid treatments. Due to the overall very low- to moderate-certainty evidence and small sample sizes, there is the possibility that the further research may change these findings.
Topics: Adolescent; Analgesics, Opioid; Buprenorphine; Heroin; Humans; Methadone; Opioid-Related Disorders; Pharmaceutical Preparations
PubMed: 36063082
DOI: 10.1002/14651858.CD011117.pub3 -
Alimentary Pharmacology & Therapeutics Jul 2020When opioid-induced constipation is treated with centrally acting opioid antagonists, there may be opioid withdrawal or aggravation of pain due to inhibition of... (Meta-Analysis)
Meta-Analysis
BACKGROUND
When opioid-induced constipation is treated with centrally acting opioid antagonists, there may be opioid withdrawal or aggravation of pain due to inhibition of μ-opioid analgesia. This led to the development of peripherally acting μ-opioid receptor antagonists (PAMORAs).
AIM
To evaluate the efficacy of available PAMORAs and other approved or experimental treatments for relieving constipation in patients with opioid-induced constipation, based on a systematic review and meta-analysis of published studies.
METHODS
A search of MEDLINE, EMBASE and EBM Reviews Cochrane Central Register of Controlled Trials was completed in July 2019 for randomised trials compared to placebo. FDA approved doses or highest studied dose was evaluated. Efficacy was based on diverse endpoints, including continuous variables (the bowel function index, number of spontaneous bowel movements and stool consistency based on Bristol Stool Form Scale), or responder analysis (combination of >3 spontaneous bowel movements or complete spontaneous bowel movements plus 1 spontaneous bowel movement or complete spontaneous bowel movements, respectively, over baseline [so-called FDA endpoints]). Adverse effects evaluated included central opioid withdrawal, serious adverse events, abdominal pain and diarrhoea.
RESULTS
We included 35 trials at low risk of bias enrolling 13 566 patients. All PAMORAs demonstrated efficacy on diverse patient response endpoints. There was greater efficacy with approved doses of the PAMORAs (methylnaltrexone, naloxegol and naldemidine), with lower efficacy or lower efficacy and greater adverse effects with combination oxycodone with naloxone, lubiprostone and linaclotide.
CONCLUSIONS
Therapeutic response in opioid-induced constipation is best achieved with the PAMORAs, methylnaltrexone, naloxegol and naldemidine, which are associated with low risk of serious adverse events.
Topics: Analgesics, Opioid; Constipation; Humans; Laxatives; Narcotic Antagonists; Randomized Controlled Trials as Topic; Receptors, Opioid, mu; Treatment Outcome
PubMed: 32462777
DOI: 10.1111/apt.15791 -
Arquivos de Neuro-psiquiatria 2020Central neuropathic pain (CNP) is often refractory to available therapeutic strategies and there are few evidence-based treatment options. Many patients with neuropathic... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Central neuropathic pain (CNP) is often refractory to available therapeutic strategies and there are few evidence-based treatment options. Many patients with neuropathic pain are not diagnosed or treated properly. Thus, consensus-based recommendations, adapted to the available drugs in the country, are necessary to guide clinical decisions.
OBJECTIVE
To develop recommendations for the treatment of CNP in Brazil.
METHODS
Systematic review, meta-analysis, and specialists opinions considering efficacy, adverse events profile, cost, and drug availability in public health.
RESULTS
Forty-four studies on CNP treatment were found, 20 were included in the qualitative analysis, and 15 in the quantitative analysis. Medications were classified as first-, second-, and third-line treatment based on systematic review, meta-analysis, and expert opinion. As first-line treatment, gabapentin, duloxetine, and tricyclic antidepressants were included. As second-line, venlafaxine, pregabalin for CND secondary to spinal cord injury, lamotrigine for CNP after stroke, and, in association with first-line drugs, weak opioids, in particular tramadol. For refractory patients, strong opioids (methadone and oxycodone), cannabidiol/delta-9-tetrahydrocannabinol, were classified as third-line of treatment, in combination with first or second-line drugs and, for central nervous system (CNS) in multiple sclerosis, dronabinol.
CONCLUSIONS
Studies that address the treatment of CNS are scarce and heterogeneous, and a significant part of the recommendations is based on experts opinions. The CNP approach must be individualized, taking into account the availability of medication, the profile of adverse effects, including addiction risk, and patients' comorbidities.
Topics: Analgesics, Opioid; Brazil; Consensus; Humans; Neuralgia; Neurology
PubMed: 33331468
DOI: 10.1590/0004-282X20200166 -
European Journal of Pain (London,... Jan 2020This updated systematic review evaluated the efficacy, tolerability and safety of opioids compared to placebo in chronic non-cancer neuropathic pain. (Meta-Analysis)
Meta-Analysis
Opioids for chronic non-cancer neuropathic pain. An updated systematic review and meta-analysis of efficacy, tolerability and safety in randomized placebo-controlled studies of at least 4 weeks duration.
BACKGROUND AND OBJECTIVE
This updated systematic review evaluated the efficacy, tolerability and safety of opioids compared to placebo in chronic non-cancer neuropathic pain.
DATABASES AND DATA TREATMENT
Clinicaltrials.gov, CENTRAL, PubMed and PsycINFO were searched from October 2013 to June 2019. Randomized controlled trials comparing opioids with placebo and at least 4 weeks double-blinded duration were analysed. Primary outcomes were pain relief of 50% or greater, disability, tolerability and safety. Effects were summarized by a random effects model using risk differences (RD) or standardized mean differences (SMD). We added four new studies with 662 participants for a total of 16 included studies with 2,199 participants. Study duration ranged between 4 and 12 weeks. Studies with a parallel and cross-over design: Based on low to moderate quality evidence, opioids (buprenorphine, hydromorphone, morphine, oxycodone, tramadol) provided a clinically relevant pain relief of 50% or greater and reduction of disability compared to placebo. There was no clinically relevant harm with regards to the drop out rate due to adverse and serious adverse events by opioids compared to placebo. Enriched enrolment randomized withdrawal design: Based on low to moderate quality evidence, tapentadol provided a clinically relevant pain relief of 50% or greater and reduction of disability compared to placebo in diabetic polyneuropathy. There was no clinically relevant harm with regards to the drop out rate due to adverse and serious adverse events by tapentadol compared to placebo.
CONCLUSIONS
Some opioids provided a short-term substantial pain relief in highly selected patients in some neuropathic pain syndromes.
SIGNIFICANCE
Some opioids (buprenorphine, morphine, oxycodone, tramadol, tapentadol) provide substantial pain relief compared to placebo in postherpetic neuralgia and peripheral neuropathies of different aetiologies for 4-12 weeks. There is insufficient evidence to support or refute the suggestion that these drugs are effective in other neuropathic pain conditions. The safety of opioids with regards to abuse and deaths in the studies analysed cannot be extrapolated to routine clinical care.
Topics: Analgesics, Opioid; Chronic Pain; Humans; Morphine; Neuralgia; Oxycodone; Tapentadol
PubMed: 31705717
DOI: 10.1002/ejp.1494