Treatment of severe pain from osteoarthritis with slow-release tramadol or dihydrocodeine in combination with NSAID's: a randomised study comparing analgesia, antinociception and gastrointestinal effects

Impact of COVID-19 on opioid use in those awaiting hip and knee arthroplasty: a retrospective cohort study

BACKGROUND

COVID-19 has had a detrimental impact on access to hip and knee arthroplasty surgery. We set out to examine whether this had a subsequent impact on preoperative opioid prescribing rates for those awaiting surgery.

METHODS

Data regarding patient demographics and opioid utilisation were collected from the electronic health records of included patients at a large university teaching hospital. Patients on the outpatient waiting list for primary hip and knee arthroplasty as of September 2020 (COVID-19 group) were compared with historical controls (Controls) who had previously undergone surgery. A sample size calculation indicated 452 patients were required to detect a 15% difference in opioid prescription rates between groups.

RESULTS

A total of 548 patients (58.2% female) were included, 260 in the COVID-19 group and 288 in the Controls. Baseline demographics were similar between the groups. For those with data available, the proportion of patients on any opioid at follow-up in the COVID-19 group was significantly higher: 55.0% (143/260) compared with 41.2% (112/272) in the Controls (p=0.002). This remained significant when adjusted for confounding (age, gender, Scottish Index of Multiple Deprivation, procedure and wait time). The proportion of patients on a strong opioid was similar (4.2% (11/260) vs 4.8% (13/272)) for COVID-19 and Controls, respectively. The median waiting time from referral to follow-up was significantly longer in the COVID-19 group compared with the Controls (455 days vs 365 days; p<0.0001).

CONCLUSION

The work provides evidence of potential for an emerging opioid problem associated with the influence of COVID-19 on elective arthroplasty services. Viable alternatives to opioid analgesia for those with end-stage arthritis should be explored, and prolonged waiting times for surgery ought to be avoided in the recovery from COVID-19 to prevent more widespread opioid use.

Comparative risk-benefit profiles of weak opioids in the treatment of osteoarthritis: a network meta-analysis of randomized controlled trials

BACKGROUND

Despite their poor tolerance, weak opioids are still the most commonly-prescribed medicine for osteoarthritis (OA)-related pain. The objective of this network meta-analysis was to comparatively examine the efficacy and safety of weak opioids in OA treatment.

METHODS

Databases including PubMed, Embase, Cochrane Library and Web of Science were searched from inception to 4 April 2022 to retrieve randomized controlled trials (RCTs) comparing weak opioids with placebo or between one another in OA patients. Bayesian network meta-analysis was performed on the following outcomes of interest, namely the change-from-baseline score in pain relief, gastrointestinal (GI) adverse events (AEs), central nervous system (CNS) AEs, and total number of AEs (i.e. the number of subjects experiencing any AE for at least once) during follow-up. The surface under the cumulative ranking curve (SUCRA) was used to rank the effectiveness of each treatment and identify the best treatment.

RESULTS

A total of 14 RCTs invoving four types of weak opioids were included in this meta-analysis. Compared to placebo, tramadol (standardized mean difference [SMD] = -0.34, 95% credible interval [CrI]: -0.53 to -0.18) and codeine (SMD = -0.39, 95% CrI: -0.79 to -0.04) were effective for pain relief, but involved a higher risk of GI AEs, CNS AEs and total number of AEs. Dextropropoxyphene demonstrated a significantly lower risk of GI AEs (OR = 0.28, 95%CrI: 0.17 to 0.51), CNS AEs (OR = 0.29, 95%CrI: 0.11 to 0.78) and total number of AEs (OR = 0.35, 95%CrI: 0.15 to 0.82) compared to codeine. Dihydrocodeine had a better safety profile in CNS AEs (SUCRA = 64.8%) and total number of AEs (SUCRA = 66.6%).

CONCLUSIONS

The results of the present study confirmed that tramadol and codeine were effective drugs for the treatment of OA, but involved considerable safety issues. Dextropropoxyphene and dihydrocodeine exhibited a relatively good safety profile but their efficacy still warrant further investigation.

Psychological Flexibility, Pain Characteristics and Risk of Opioid Misuse in Noncancerous Chronic Pain Patients

Chronic pain has an estimated annual prevalence rate between 10 and 35%. In the US, first-line treatment for chronic pain is often opioids.

OBJECTIVE

To our knowledge, this is the first study exploring psychological flexibility and its association with pain severity, pain interference and risk of opioid misuse in chronic pain patients.

METHODS

Data were collected at two outpatient pain clinics in the northeastern United States. Adults (N = 99) completed a cross-sectional survey with validated measures. Pain severity and pain interference were hypothesized to uniquely predict the risk of opioid misuse. Pain severity was hypothesized to predict pain interference. Finally, psychological flexibility was hypothesized as an indirect effect in these relationships.

RESULTS

Main findings suggest that pain severity predicts risk of opioid misuse, mediated by psychological flexibly. Pain interference also predicts risk of opioid misuse, mediated by psychological flexibility. Finally, results suggest pain severity predicts pain interference, mediated by psychological flexibility.

DISCUSSION

Implications of findings are discussed in terms of future psychological and medical assessments and interventions for chronic pain patients seeking prescription opioids.

Orthodontic Treatment Protocols for Patients with Idiopathic Condylar Resorption

Treatment of orthodontic patients with idiopathic condylar resorption (ICR) is challenging for clinicians due to the continuous change of occlusion caused by the unstable condylar position and symptoms in the temporomandibular joint (TMJ). As an unstable condylar position can lead to confusion during orthodontic evaluation, stabilization of TMJ with splint therapy should precede orthodontic and/or orthognathic treatment. In this case report, a patient with Class II open bite and progressive condylar resorption was treated with an appropriate treatment protocol. Her condylar position was stabilized with a stabilization splint and her occlusion and facial esthetics were improved with intrusion of her maxillary posterior teeth after extraction of four premolars. Her occlusion was stable without recurrence of joint symptoms 2 years after active treatment.

Microneedles Coated with Tramadol Exhibit Antinociceptive Effect in a Rat Model of Temporomandibular Hypernociception

Coated microneedles have emerged as a promising drug delivery system for inflammatory pain treatment. We have previously shown that tramadol injection into the rat temporomandibular joint (TMJ) induces an antinociceptive and anti-inflammatory effect. In this study, microneedles coated with tramadol were investigated as a platform to treat TMJ pain. Male Wistar rats were administered tramadol using an intra-TMJ injection or with microneedles coated with tramadol, followed by 1.5% formalin nociceptive challenge administered 15 minutes later. The nociceptive behavior of rats was evaluated, and their periarticular tissues were removed after euthanasia for analysis. The duration of antinociceptive effect was determined by performing the formalin challenge at different time points extending up to 6 days post tramadol administration. Microneedles coated with tramadol produced an antinociceptive effect similar to injection of tramadol into the rat TMJ. Surprisingly, tramadol delivery using coated microneedles produced a more durable antinociceptive effect lasting as much as 2 days post tramadol delivery as compared with an antinociceptive effect lasting under 2 hours from intra-TMJ injection of tramadol. The proinflammatory cytokines tumor necrosis factor-α and interleukin-1β (IL-1β) were found to be reduced, whereas the anti-inflammatory cytokine IL-10 was found to be elevated in tramadol-treated groups. In conclusion, microneedles coated with tramadol can offer a therapeutic option for pain control of inflammatory disorders in the TMJ.

Tramadol for osteoarthritis

BACKGROUND

Tramadol is often prescribed to treat pain and is associated physical disability in osteoarthritis (OA). Due to the pharmacologic mechanism of tramadol, it may lead to fewer associated adverse effects (i.e. gastrointestinal bleeding or renal problems) compared to non-steroidal anti-inflammatory drugs (NSAIDs). This is an update of a Cochrane Review originally published in 2006.

OBJECTIVES

To determine the benefits and harms of oral tramadol or tramadol combined with acetaminophen or NSAIDs in people with osteoarthritis.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and Embase databases, as well as the US National Institutes of Health and World Health Organization trial registries up to February 2018. We searched the LILACS database up to August 2015.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) that evaluated the effect of tramadol, or tramadol in combination with acetaminophen (paracetamol) or NSAIDs versus placebo or any comparator in people with osteoarthritis.

DATA COLLECTION AND ANALYSIS

We used standard methodologic procedures expected by Cochrane.

MAIN RESULTS

We included 22 RCTs (11 more than the previous review) of which 21 RCTs were included in meta-analyses for 3871 participants randomized to tramadol alone or tramadol in combination with another analgesic and 2625 participants randomized to placebo or active control. Seventeen studies evaluated tramadol alone and five evaluated tramadol plus acetaminophen. Thirteen studies used placebo controls and eleven studies used active controls (two trials had both placebo and active arms). The dose of tramadol ranged from 37.5 mg to 400 mg daily; all doses were pooled. Most trials were multicenter with a mean duration of two months. Participants were predominantly women with hip or knee osteoarthritis, with a mean age of 63 years and moderate to severe pain. There was a high risk of selection bias as only four trials reported both adequate sequence generation and allocation concealment. There was a low risk for performance bias as most studies blinded participants. There was a high risk of attrition bias as 10/22 trials showed incomplete outcome data. Most of the trials were funded by the pharmaceutical industry.Moderate quality evidence (downgraded due to risk of bias) indicated that tramadol alone and in combination with acetaminophen had no important benefit on pain reduction compared to placebo control (tramadol alone: 4% absolute improvement, 95% confidence interval (CI) 3% to 5%; 8 studies, 3972 participants; tramadol in combination with acetaminophen: 4% absolute improvement, 95% CI 2% to 6%; 2 studies, 614 participants).Fifteen out of 100 people in the tramadol group improved by 20% (which corresponded to a clinically important difference in pain) compared to 10/100 in the placebo group (5% absolute improvement). Twelve out of 100 people improved by 20% in the tramadol in combination with acetaminophen group compared to 7/100 in the placebo group (5% absolute improvement).Moderate quality evidence (downgraded due to risk of bias) indicated that tramadol alone and in combination with acetaminophen led to no important benefit in physical function compared to placebo (tramadol alone: 4% absolute improvement, 95% CI 2% to 6%; 5 studies, 2550 participants; tramadol in combination with acetaminophen: 4% absolute improvement, 95% CI 2% to 7%; 2 studies, 614 participants).Twenty-one out of 100 people in the tramadol group improved by 20% (which corresponded to a clinically important difference in physical function) compared to 16/100 in the placebo group (5% absolute improvement). Fifteen out of 100 people improved by 20% in the tramadol in combination with acetaminophen group compared to 10/100 in the placebo group (5% absolute improvement).Moderate quality evidence (downgraded due to risk of bias) indicated that, compared to placebo, there was a greater risk of developing adverse events with tramadol alone (risk ratio (RR) 1.34, 95% CI 1.24 to 1.46; 4 studies, 2039 participants) and tramadol in combination with acetaminophen compared to placebo (RR 1.91, 95% CI 1.32 to 2.76; 1 study, 308 participants). This corresponded to a 17% increase (95% CI 12% to 23%) with tramadol alone and 22% increase (95% CI 8% to 41%) with tramadol in combination with acetaminophen.The three most frequent adverse events were nausea, dizziness and tiredness. Moderate quality evidence (downgraded due to risk of bias) indicated that there was a greater risk of withdrawing from the study because of adverse events with tramadol alone compared to placebo (RR 2.64, 95% CI 2.17 to 3.20; 9 studies, 4533 participants), which corresponded to a 12% increase (95% CI 9% to 16%).Low quality evidence (downgraded due to risk of bias and inconsistency) indicated that there was a greater risk of withdrawing from the study because of adverse events with tramadol in combination with acetaminophen compared to placebo (RR 2.78, 95% CI 1.50 to 5.16; 2 studies, 614 participants), which corresponded to a 8% absolute improvement (95% CI 2% to 19%).Low quality evidence (downgraded due to risk of bias and imprecision) indicated that there was a greater risk of developing serious adverse events with tramadol alone compared to placebo (110/2459 participants with tramadol compared to 22/1153 participants with placebo; RR 1.78, 95% CI 1.11 to 2.84; 7 studies, 3612 participants), which corresponded to a 1% increase (95% CI 0% to 4%). There were no serious adverse events reported in one small study (15 participants) of tramadol with acetaminophen compared to placebo.

AUTHORS' CONCLUSIONS

Moderate quality evidence indicates that compared to placebo, tramadol alone or in combination with acetaminophen probably has no important benefit on mean pain or function in people with osteoarthritis, although slightly more people in the tramadol group report an important improvement (defined as 20% or more). Moderate quality evidence shows that adverse events probably cause substantially more participants to stop taking tramadol. The increase in serious adverse events with tramadol is less certain, due to the small number of events.

Aspects of Pain, Its Assessment and Evaluation from An Acupuncture Perspective

Pain is a major clinical problem that causes great suffering for the individual and incurs costs for society. Accurate assessment and evaluation of perceived pain is necessary for diagnosis, for choice of treatment, and for the evaluation of treatment efficacy. The assessment of an individual's pain is a challenge since pain is a subjective, multidimensional experience, and assessment is based on the person's own self-report. The results are often varied, possibly due to inter-individual variation, but also in relation to gender and aetiology.

A gold standard for pain assessment is still lacking, but rating scales, questionnaires, and methods derived from psychophysical concepts, such as threshold assessments and perceptual matching, are used. In the evaluation of pain and associated variables, both systematic and individual variation should be taken into account, as should pain-associated symptoms.

Recommendations for pain treatment should be based on the patient's specific needs. Therefore, it is important to assess the level of perceived pain taking individual variation into account. The methods used should preferably have proved to be useful in randomised controlled trials, and analysis of pain assessment should consider its non-metric properties. In the future, the use of studies with a naturalistic protocol together with individual assessment of individual pain responses could increase the internal and external validity.

Joint pain epidemiology and analgesic usage in Madagascar

Introduction

To describe the epidemiology of joint pains and document analgesics usage in an African context.

Methods

Patients suffering from joint pain were recruited from nine sites located in Antananarivo, Madagascar, including 6 hospital services and 3 clinics. Doctors collected information on the etiology and characteristics of the patients’ pain. Analgesics prescribed by these doctors were also documented.

Results

In total, 400 patients were enrolled in the study (52.5% women, mean age of 42.34 years ± 17.7 [4-86]). Pain of mechanical type was found in 260 participants, 65%; 95% CI [60.1% to 69.6%] and inflammatory type pains in 128 cases 32%; 95% CI [27.5% to 36.9%]. Mixed pains were found in 12 patients (3%). The median duration of pain prior to the consultation was 6.5 days. The average pain intensity was 57.9 ± 19.9 mm of a total of 100 mm maximum on a visual analogue scale, VAS. The etiologies of mechanical type pains were dominated by fracture, common low back pain and tendonitis. Arthrosis was the dominant cause of inflammatory type pain, followed by rheumatoid arthritis and gout. NSAIDs (74.5%) were the most frequently prescribed analgesics followed by paracetamol (49.5%), weak opioids (23%) and corticosteroids (12.25%). Two-thirds of medical prescriptions (65.3%) were of combined analgesics.

Conclusion

These findings demonstrated that mechanical type pains were the main reason for consultations for joint pain in these situations in Antananarivo, Madagascar. The most frequently prescribed pain-relieving medications were NSAIDs, paracetamol, weak opioids and corticosteroids. This descriptive study may be a useful starting point for further epidemiological studies of pain in the African context.

Multimodal Treatment of Chronic Pain

Most patients with chronic pain receive multimodal treatment. There is scant literature to guide us, but when approaching combination pharmacotherapy, the practitioner and patient must weigh the benefits with the side effects; many medications have modest effect yet carry significant side effects that can be additive. Chronic pain often leads to depression, anxiety, and deconditioning, which are targets for treatment. Structured interdisciplinary programs are beneficial but costly. Interventions have their place in the treatment of chronic pain and should be a part of a multidisciplinary treatment plan. Further research is needed to validate many common combination treatments.

Altered Central Sensitization and Pain Modulation in the CNS in Chronic Joint Pain

Musculoskeletal pain disorders are the second largest contributor to global disability underlining the significance of effective treatments. However, treating chronic musculoskeletal pain, and chronic joint pain (osteoarthritis (OA)) in particular, is challenging as the underlying peripheral and central pain mechanisms are not fully understood, and safe and efficient analgesic drugs are not available. The pain associated with joint pain is highly individual, and features from radiological imaging have not demonstrated robust associations with the pain manifestations. In recent years, a variety of human quantitative pain assessment tools (quantitative sensory testing (QST)) have been developed providing new opportunities for profiling patients and reaching a greater understanding of the mechanisms involved in chronic joint pain. As joint pain is a complex interaction between many different pain mechanisms, available tools are important for patent profiling and providing the basic knowledge for development of new drugs and for developing pain management regimes.

WITHDRAWN: Botulinum toxin for subacute/chronic neck pain

Withdrawn due to non‐compliance with The Cochrane Collaboration’s Commercial Sponsorship Policy

The editorial group responsible for this previously published document have withdrawn it from publication.

WITHDRAWN: Medicinal and injection therapies for mechanical neck disorders

Withdrawn due to non‐compliance with The Cochrane Collaboration’s Commercial Sponsorship Policy

The editorial group responsible for this previously published document have withdrawn it from publication.

Analgesic opioid dose is an important indicator of postoperative ileus following radical cystectomy with ileal conduit: experience in the robotic surgery era

PURPOSE

Postoperative ileus (POI) is common following bowel resection for radical cystectomy with ileal conduit (RCIC). We investigated perioperative factors associated with prolonged POI following RCIC, with specific focus on opioid-based analgesic dosage.

MATERIALS AND METHODS

From March 2007 to January 2013, 78 open RCICs and 26 robot-assisted RCICs performed for bladder carcinoma were identified with adjustment for age, gender, American Society of Anesthesiologists grade, and body mass index (BMI). Perioperative records including operative time, intraoperative fluid excess, estimated blood loss, lymph node yield, and opioid analgesic dose were obtained to assess their associations with time to passage of flatus, tolerable oral diet, and length of hospital stay (LOS). Prior to general anaesthesia, patients received epidural patient-controlled analgesia (PCA) consisted of fentanyl with its dose adjusted for BMI. Postoperatively, single intravenous injections of tramadol were applied according to patient desire.

RESULTS

Multivariate analyses revealed cumulative dosages of both PCA fentanyl and tramadol injections as independent predictors of POI. According to surgical modality, linear regression analyses revealed cumulative dosages of PCA fentanyl and tramadol injections to be positively associated with time to first passage of flatus, tolerable diet, and LOS in the open RCIC group. In the robot-assisted RCIC group, only tramadol dose was associated with time to flatus and tolerable diet. Compared to open RCIC, robot-assisted RCIC yielded shorter days to diet and LOS; however, it failed to shorten days to first flatus.

CONCLUSION

Reducing opioid-based analgesics shortens the duration of POI. The utilization of the robotic system may confer additional benefit.

Myofascial pain syndrome treatments

Myofascial pain syndrome (MPS) is a regional pain disorder caused by taut bands of muscle fibers in skeletal muscles called myofascial trigger points. MPS is a common disorder, often diagnosed and treated by physiatrists. Treatment strategies for MPS include exercises, patient education, and trigger point injection. Pharmacologic interventions are also common, and a variety of analgesics, antiinflammatories, antidepressants, and other medications are used in clinical practice. This review explores the various treatment options for MPS, including those therapies that target myofascial trigger points and common secondary symptoms.

Systematic literature review and meta-analysis of the efficacy and safety of prescription opioids, including abuse-deterrent formulations, in non-cancer pain management

OBJECTIVE

This study was conducted to compare safety and efficacy outcomes between opioids formulated with technologies designed to deter or resist tampering (i.e., abuse-deterrent formulations [ADFs]) and non-ADFs for commonly prescribed opioids for treatment of non-cancer pain in adults.

METHODS

PubMed and Cochrane Library databases were searched for opioid publications between September 1, 2001 and August 31, 2011, and pivotal clinical trials from all years; abstracts from key pain conferences (2010-2011) were also reviewed. One hundred and ninety-one publications were initially identified, 68 of which met eligibility criteria and were systematically reviewed; a subset of 16 involved a placebo group (13 non-ADFs vs placebo, 3 ADFs vs placebo) and reported both efficacy and safety outcomes, and were included for a meta-analysis. Summary estimates of standardized difference in mean change of pain intensity (DMCPI), standardized difference in sum of pain intensity difference (DSPID), and odds ratios (ORs) of each adverse event (AE) were computed through random-effects estimates for ADFs (and non-ADFs) vs placebo. Indirect treatment comparisons were conducted to compare ADFs and non-ADFs.

RESULTS

Summary estimates for standardized DMCPI and for standardized DSPID indicated that ADFs and non-ADFs showed significantly greater efficacy than placebo in reducing pain intensity. Indirect analyses assessing the efficacy outcomes between ADFs and non-ADFs indicated that they were not significantly different (standardized DMCPI [0.39 {95% confidence interval (CI) 0.00-0.76}]; standardized DSPID [-0.22 {95% CI -0.74 to 0.30}]). ADFs and non-ADFs both were associated with higher odds of AEs than placebo. Odds ratios from indirect analyses comparing AEs for ADFs vs non-ADFs were not significant (nausea, 0.87 [0.24-3.12]; vomiting, 1.54 [0.40-5.97]; dizziness/vertigo, 0.61 [0.21-1.76]; headache, 1.42 [0.57-3.53]; somnolence/drowsiness, 0.47 [0.09-2.58]; constipation, 0.64 [0.28-1.49]; pruritus 0.41 [0.05-3.51]).

CONCLUSION

ADFs and non-ADFs had comparable efficacy and safety profiles, while both were more efficacious than placebo in reducing pain intensity.

Efficacy and Safety Assessment of a Novel Once-Daily Tablet Formulation of Tramadol : A Randomised, Controlled Study versus Twice-Daily Tramadol in Patients with Osteoarthritis of the Knee

OBJECTIVE

To compare the 24-hour sustained efficacy and safety of a new tramadol once-daily formulation (tramadol OAD) using Contramid((R)) controlled-release technology with a marketed twice-daily formulation (tramadol BID). PATIENTS, DESIGN AND SETTING: 431 patients with osteoarthritis of the knee were enrolled in this randomised, double-blind, multicentre, parallel study. After titration to optimum dose (range 100-400mg), patients received medication for 12 weeks.

MAIN OUTCOME MEASURES AND RESULTS

Efficacy evaluations included: Western Ontario and McMaster University Osteoarthritis Index (WOMAC) scores (pain, stiffness, physical function and global), daily efficacy ratings (post-dose: tramadol OAD 24 hours; tramadol BID 12 hours), pain ratings over 24 hours, and patient and investigator overall ratings. Non-inferiority was demonstrated for the primary endpoint, mean percentage change in WOMAC pain score from baseline to week 12 (tramadol OAD 58%; tramadol BID 59%) [95% CI -7.67, 3.82]. The median optimum dose received was 200mg (both treatments). In 73% of patients, pain was mild to absent at the end of the dosing interval for both treatments (tramadol OAD 24 hours; tramadol BID 12 hours). Pain ratings over 24 hours were similar between groups, indicating 24-hour sustained efficacy for tramadol OAD. More tramadol BID patients reported dizziness/vertigo (37% vs 26%), vomiting (14% vs 8%) and headache (18% vs 13%) while tramadol OAD patients reported more somnolence (30% vs 21%).

CONCLUSIONS

This study demonstrated that this novel tramadol OAD formulation provides sustained analgesic efficacy over the entire 24-hour dosing interval and a clinically favourable safety profile, both of which will provide a clear clinical benefit.

Quantitative sensory testing in painful osteoarthritis: a systematic review and meta-analysis

OBJECTIVE

To systematically review the use of quantitative sensory testing (QST) in pain characterisation (phenotyping) in osteoarthritis (OA).

METHODS

Six bibliographic databases (Medline, Embase, Amed, Cinahl, PubMed, Web of Science) were searched to identify studies published before May 2011. Data were extracted based on the primary site of OA, QST modalities, outcome measures and test sites. Standardised mean difference (SMD) and 95% confidence intervals (CIs) were calculated if possible. Publication bias was determined using funnel plot and Egger's test. Heterogeneity was examined using Cochran Q test and I2 statistic. Random effects model was used to pool the results.

RESULTS

Of 41 studies (2281 participants) included, 23 were case control studies, 15 case only studies, two randomised controlled trials, and one uncontrolled trial. The majority of studies examined pressure pain with smaller numbers using electrical and/or thermal stimuli. QST was more often applied to the affected joint than distal and remote sites. Of 20 studies comparing people with OA and healthy controls, seven provided sufficient information for meta-analysis. Compared with controls, people with OA had lower pressure pain thresholds (PPTs) both at the affected joint (SMD = -1.24, 95% CI -1.54, -0.93) and at remote sites (SMD = -0.88, 95% CI -1.11, -0.65).

CONCLUSION

QST of PPTs demonstrated good ability to differentiate between people with OA and healthy controls. Lower PPTs in people with OA in affected sites may suggest peripheral, and in remote sites central, sensitisation. PPT measurement merits further evaluation as a tool for phenotyping OA pain.

Human experimental pain models for assessing the therapeutic efficacy of analgesic drugs

Pain models in animals have shown low predictivity for analgesic efficacy in humans, and clinical studies are often very confounded, blurring the evaluation. Human experimental pain models may therefore help to evaluate mechanisms and effect of analgesics and bridge findings from basic studies to the clinic. The present review outlines the concept and limitations of human experimental pain models and addresses analgesic efficacy in healthy volunteers and patients. Experimental models to evoke pain and hyperalgesia are available for most tissues. In healthy volunteers, the effect of acetaminophen is difficult to detect unless neurophysiological methods are used, whereas the effect of nonsteroidal anti-inflammatory drugs could be detected in most models. Anticonvulsants and antidepressants are sensitive in several models, particularly in models inducing hyperalgesia. For opioids, tonic pain with high intensity is attenuated more than short-lasting pain and nonpainful sensations. Fewer studies were performed in patients. In general, the sensitivity to analgesics is better in patients than in healthy volunteers, but the lower number of studies may bias the results. Experimental models have variable reliability, and validity shall be interpreted with caution. Models including deep, tonic pain and hyperalgesia are better to predict the effects of analgesics. Assessment with neurophysiologic methods and imaging is valuable as a supplement to psychophysical methods and can increase sensitivity. The models need to be designed with careful consideration of pharmacological mechanisms and pharmacokinetics of analgesics. Knowledge obtained from this review can help design experimental pain studies for new compounds entering phase I and II clinical trials.

Botulinum toxin for subacute/chronic neck pain

BACKGROUND

Neck disorders are common, disabling and costly. Botulinum toxin (BoNT) intramuscular injections are often used with the intention of treating neck pain.

OBJECTIVES

To systematically evaluate the literature on the treatment effectiveness of BoNT for neck pain, disability, global perceived effect and quality of life in adults with neck pain with or without associated cervicogenic headache, but excluding cervical radiculopathy and whiplash associated disorder.

SEARCH STRATEGY

We searched CENTRAL, MEDLINE, AMED, Index to Chiropractic Literature, CINAHL, LILACS, and EMBASE from their origin to 20 September 2010.

SELECTION CRITERIA

We included randomised and quasi-randomised controlled trials in which BoNT injections were used to treat subacute or chronic neck pain.

DATA COLLECTION AND ANALYSIS

A minimum of two review authors independently selected articles, abstracted data, and assessed risk of bias, using the Cochrane Back Review Group criteria. In the absence of clinical heterogeneity, we calculated standardized mean differences (SMD) and relative risks, and performed meta-analyses using a random-effects model. The quality of the evidence and the strength of recommendations were assigned an overall grade for each outcome.

MAIN RESULTS

We included nine trials (503 participants). Only BoNT type A (BoNT-A) was used in these studies.High quality evidence suggests there was little or no difference in pain between BoNT-A and saline injections at four weeks (five trials; 252 participants; SMD pooled -0.07 (95% confidence intervals (CI) -0.36 to 0.21)) and six months for chronic neck pain. Very low quality evidence indicated little or no difference in pain between BoNT-A combined with physiotherapeutic exercise and analgesics and saline injection with physiotherapeutic exercise and analgesics for patients with chronic neck pain at four weeks (two trials; 95 participants; SMD pooled 0.09 (95% CI -0.55 to 0.73)) and six months (one trial; 24 participants; SMD -0.56 (95% CI -1.39 to 0.27)). Very low quality evidence from one trial (32 participants) showed little or no difference between BoNT-A and placebo at four weeks (SMD 0.16 (95% CI -0.53 to 0.86)) and six months (SMD 0.00 (95% CI -0.69 to 0.69)) for chronic cervicogenic headache. Very low quality evidence from one trial (31 participants), showed a difference in global perceived effect favouring BoNT-A in chronic neck pain at four weeks (SMD -1.12 (95% CI: -1.89 to -0.36)).

AUTHORS' CONCLUSIONS

Current evidence fails to confirm either a clinically important or a statistically significant benefit of BoNT-A injection for chronic neck pain associated with or without associated cervicogenic headache. Likewise, there was no benefit seen for disability and quality of life at four week and six months.

Combination drug therapy for chronic pain: a call for more clinical studies

Chronic pain is a debilitating clinical condition associated with a variety of disease entities including diabetic neuropathy, postherpetic neuralgia, low back pathology, fibromyalgia, and neurological disorders. For many general practitioners and specialists, managing chronic pain has become a daunting challenge. As a modality of multidisciplinary chronic pain management, medications are often prescribed in combinations, an approach referred to as combination drug therapy (CDT). However, many medications for pain therapy, including antidepressants and opioid analgesics, have significant side effects that can compound when used in combination and impact the effectiveness of CDT. To date, clinical practice of CDT for chronic pain has been based largely on clinical experiences. In this article, we will focus on (1) the scientific basis and rationales for CDT, (2) current clinical data on CDT, and (3) the need for more clinical studies to establish a framework for the use of CDT.

PERSPECTIVE

More preclinical, clinical, and translational studies are needed to improve the efficacy of combination drug therapy that is an integral part of a comprehensive approach to the management of chronic pain.

The impact of tramadol and dihydrocodeine treatment on quality of life of patients with cancer pain

BACKGROUND

Tramadol and dihydrocodeine (DHC) are analgesics of step 2 WHO analgesic ladder (opioids for mild to moderate pain, weak opioids) frequently used in the treatment of cancer pain of moderate intensity. The aim of the study was to assess the impact of tramadol and DHC treatment on quality of life (QL) and performance status (PS) of patients with cancer pain.

PATIENTS AND METHODS

Randomised, cross-over, clinical study of 40 opioid-naive patients with nociceptive cancer pain who received tramadol or DHC controlled release tablets for 7 days, and then drugs were switched and administered for another 7 days. Pain was assessed by visual analogue scale (VAS), QL by EORTC QLQ C 30, and PS by Eastern Cooperative Oncology Group (ECOG) and Karnofsky.

RESULTS

From 40 patients recruited, 30 completed the study. DHC treatment provided better analgesia (VAS). In QL functional scales, better emotional functioning in tramadol group and better global QL and cognitive functioning in DHC group were observed. In symptom scales, less fatigue, pain and sleep disturbances, less nausea and vomiting and better appetite in DHC group were noted. In tramadol group, less constipation and less financial problems were observed. No differences in dyspnoea and diarrhoea were noted. ECOG and Karnofsky PS were low and did not differ between tramadol and DHC groups.

CONCLUSIONS

Dihydrocodeine treatment was associated with better global QL, cognitive functioning, analgesia and appetite, less fatigue, sleep disturbances, nausea and vomiting. Tramadol therapy was connected with better emotional functioning, less constipation and financial problems. PS deteriorated in both tramadol and DHC groups.

Treating stress-related pain with the flotation restricted environmental stimulation technique: are there differences between women and men?

The aim of the present study was to explore, for the first time, sex differences among patients diagnosed with stress-related pain before and after flotation restricted environmental stimulation technique (REST) treatment, delivered 12 times during seven weeks. The present study included 88 patients (69 women, 19 men) from three different studies (post hoc analysis). They had been diagnosed by a physician as having chronic stress-related muscle tension pain. The analyses indicated that the flotation- REST treatment had beneficial effects on stress, anxiety, depression, sleep quality and pain and that there were few sex differences. Women were more depressed than men before treatment, but after treatment there was no difference between sexes. However, there was a sex difference in the ability to endure experimentally induced pain, suggesting that men exhibited greater endurance both before and after the flotation-REST treatment. The results also showed, for the first time, that both sexes improved their ability to endure experimentally induced pain (higher scores for upper pain threshold) following the successful flotation-REST pain treatment.

Impact of opioid rescue medication for breakthrough pain on the efficacy and tolerability of long-acting opioids in patients with chronic non-malignant pain

Background

There is little evidence that short-acting opioids as rescue medication for breakthrough pain is an optimal long-term treatment strategy in chronic non-malignant pain. We compared clinical studies of long-acting opioids that allowed short-acting opioid rescue medication with those that did not, to determine the impact of opioid rescue medication use on the analgesic efficacy and tolerability of chronic opioid therapy in patients with chronic non-malignant pain.

Methods

We searched MEDLINE (1950 to July 2006) and EMBASE (1974 to July 2006) using terms for chronic non-malignant pain and long-acting opioids. Independent review of the search results identified 48 studies that met the study selection criteria. The effect of opioid rescue medication on analgesic efficacy and the incidence of common opioid-related side-effects were analysed using meta-regression.

Results

After adjusting for potentially confounding variables (study design and type of opioid), the difference in analgesic efficacy between the ‘rescue’ and the ‘no rescue’ studies was not significant, with regression coefficients close to 0 and 95% confidence intervals that excluded an effect of more than 18 points on a 0–100 scale in each case. There was also no significant difference between the ‘rescue’ and the ‘no rescue’ studies for the incidence of nausea, constipation, or somnolence in both the unadjusted and the adjusted analyses.

Conclusions

We found no evidence that rescue medication with short-acting opioids for breakthrough pain affects analgesic efficacy of long-acting opioids or the incidence of common opioid-related side-effects among chronic non-malignant pain patients.

What percentage of chronic nonmalignant pain patients exposed to chronic opioid analgesic therapy develop abuse/addiction and/or aberrant drug-related behaviors? A structured evidence-based review

DESIGN

This is a structured evidence-based review of all available studies on the development of abuse/addiction and aberrant drug-related behaviors (ADRBs) in chronic pain patients (CPPs) with nonmalignant pain on exposure to chronic opioid analgesic therapy (COAT).

OBJECTIVES

To determine what percentage of CPPs develop abuse/addiction and/or ADRBs on COAT exposure.

METHOD

Computer and manual literature searches yielded 79 references that addressed this area of study. Twelve of the studies were excluded from detailed review based on exclusion criteria important to this area. Sixty-seven studies were reviewed in detail and sorted according to whether they reported percentages of CPPs developing abuse/addiction or developing ADRBs, or percentages diagnosed with alcohol/illicit drug use as determined by urine toxicology. Study characteristics were abstracted into tabular form, and each report was characterized according to the type of study it represented based on the Agency for Health Care Policy and Research Guidelines. Each study was independently evaluated by two raters according to 12 quality criteria and a quality score calculated. Studies were not utilized in the calculations unless their quality score (utilizing both raters) was greater than 65%. Within each of the above study groupings, the total number of CPPs exposed to opioids on COAT treatment was calculated. Similarly, the total number of CPPs in each grouping demonstrating abuse/addiction, ADRBs, or alcohol/illicit drug use was also calculated. Finally, a percentage for each of these behaviors was calculated in each grouping, utilizing the total number of CPPs exposed to opioids in each grouping.

RESULTS

All 67 reports had quality scores greater than 65%. For the abuse/addiction grouping there were 24 studies with 2,507 CPPs exposed for a calculated abuse/addiction rate of 3.27%. Within this grouping for those studies that had preselected CPPs for COAT exposure for no previous or current history of abuse/addiction, the percentage of abuse/addiction was calculated at 0.19%. For the ADRB grouping, there were 17 studies with 2,466 CPPs exposed and a calculated ADRB rate of 11.5%. Within this grouping for preselected CPPs (as above), the percentage of ADRBs was calculated at 0.59%. In the urine toxicology grouping, there were five studies (15,442 CPPs exposed). Here, 20.4% of the CPPs had no prescribed opioid in urine and/or a nonprescribed opioid in urine. For five studies (1,965 CPPs exposed), illicit drugs were found in 14.5%.

CONCLUSION

The results of this evidence-based structured review indicate that COAT exposure will lead to abuse/addiction in a small percentage of CPPs, but a larger percentage will demonstrate ADRBs and illicit drug use. These percentages appear to be much less if CPPs are preselected for the absence of a current or past history of alcohol/illicit drug use or abuse/addiction.

A randomized, double-blind, crossover comparison of the efficacy and safety of oral controlled-release tramadol and placebo in patients with painful osteoarthritis

OBJECTIVE

To compare the efficacy and safety of controlled-release (CR) tramadol (Zytram XL, Purdue Pharma, Canada) and placebo in patients with painful osteoarthritis.

METHODS

Patients underwent analgesic washout for two to seven days before random assignment to 150 mg daily of CR tramadol or placebo, and were titrated weekly to 200 mg, 300 mg or a maximum of 400 mg once daily. After four weeks, patients crossed over to the alternate treatment for another four weeks. Plain acetaminophen was provided as a rescue analgesic. All patients who completed the crossover study were eligible to receive open label CR tramadol for six months.

RESULTS

Seventy-seven of 100 randomly assigned patients were evaluable for efficacy. CR tramadol resulted in significantly lower visual analogue scale pain intensity scores (37.4+/-23.9 versus 45.1+/-24.3, P=0.0009). Western Ontario and McMaster Universities osteoarthritis index subscale scores for pain (189.0+/-105.0 versus 230.0+/-115.4; P=0.0001) and physical function (632.4+/-361.3 versus 727.4+/-383.4; P=0.0205) were significantly better with CR tramadol. Total pain and disability (22.8+/-14.5 versus 27.2+/-14.8; P=0.0004), and overall pain and sleep (104.7+/-98.0 versus 141.0+/-108.2; P=0.0005) scores in the Pain and Sleep Questionnaire were significantly lower for CR tramadol. Short-form 36 Health Survey scores were significantly better during CR tramadol treatment for the pain index (38.8+/-10.8 versus 35.6+/-9.0; P=0.0100), general health perception (46.5+/-11.2 versus 44.4+/-11.6; P=0.0262), vitality (43.1+/-13.2 versus 40.2+/-13.7; P=0.0255) and overall physical components (40.8+/-8.9 versus 37.8+/-7.7; P=0.0002). CR tramadol treatment was preferred by 55.8% of patients (P=0.0005) versus 20.8% and 23.4% of patients who chose placebo or had no preference, respectively. These improvements were sustained for up to six months, and 86.5% of patients reported at least moderate benefit from CR tramadol during long-term treatment.

CONCLUSION

CR tramadol is effective for the management of painful osteoarthritis.

Comparison of analgesic effects and patient tolerability of nabilone and dihydrocodeine for chronic neuropathic pain: randomised, crossover, double blind study

OBJECTIVE

To compare the analgesic efficacy and side effects of the synthetic cannabinoid nabilone with those of the weak opioid dihydrocodeine for chronic neuropathic pain.

DESIGN

Randomised, double blind, crossover trial of 14 weeks' duration comparing dihydrocodeine and nabilone.

SETTING

Outpatient units of three hospitals in the United Kingdom.

PARTICIPANTS

96 patients with chronic neuropathic pain, aged 23-84 years.

MAIN OUTCOME MEASURES

The primary outcome was difference between nabilone and dihydrocodeine in pain, as measured by the mean visual analogue score computed over the last 2 weeks of each treatment period. Secondary outcomes were changes in mood, quality of life, sleep, and psychometric function. Side effects were measured by a questionnaire.

INTERVENTION

Patients received a maximum daily dose of 240 mg dihydrocodeine or 2 mg nabilone at the end of each escalating treatment period of 6 weeks. Treatment periods were separated by a 2 week washout period. Results Mean baseline visual analogue score was 69.6 mm (range 29.4-95.2) on a 0-100 mm scale. 73 patients were included in the available case analysis and 64 patients in the per protocol analysis. The mean score was 6.0 mm longer for nabilone than for dihydrocodeine (95% confidence interval 1.4 to 10.5) in the available case analysis and 5.6 mm (10.3 to 0.8) in the per protocol analysis. Side effects were more frequent with nabilone.

CONCLUSION

Dihydrocodeine provided better pain relief than the synthetic cannabinoid nabilone and had slightly fewer side effects, although no major adverse events occurred for either drug.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN15330757 controlled-trials.com] .

A randomized, double-blind, 8-week crossover study of once-daily controlled-release tramadol versus immediate-release tramadol taken as needed for chronic noncancer pain

OBJECTIVE

The purpose of this study was to evaluate the efficacy of controlled-release (CR) tramadol and immediate-release (IR) tramadol in patients with moderate or greater intensity chronic noncancer pain.

METHODS

A total of 122 patients underwent washout from all opioids 2 to 7 days before randomization to 1 of 2 groups: active CR tramadol 200 mg every morning plus placebo IR tramadol 50 mg every 4 to 6 hours PRN rescue, or placebo CR tramadol 200 mg every morning plus active IR tramadol 50 mg every 4 to 6 hours PRN rescue. After 2 weeks, the doses were increased to CR tramadol 400 mg or placebo and IR tramadol 100 mg every 4 to 6 hours PRN or placebo, as rescue. After 4 weeks in the first phase, patients crossed over to the alternative treatment for another 4 weeks. Pain intensity (100-mm visual analog scale [VAS] and 5-point ordinal scales) was assessed twice daily in diaries. Pain intensity, Pain and Disability Index (PDI; 0-10 ordinal scale), Pain and Sleep Questionnaire (100-mm VAS), and analgesic effectiveness (7-point ordinal scale) were assessed at biweekly clinic visits.

RESULTS

Sixty-five patients (35 men, 30 women) completed the study. Mean (SD) age was 56.5 (12.7) years; mean (SD) weight was 82.0 (18.5) kg. Daily diary pain intensity (mean [SD]) was significantly lower in the CR tramadol group than in the IR tramadol group in the last 2 weeks of each phase (completers: VAS, 29.9 [20.5] vs 36.2 [20.4] mm, P < 0.001; ordinal scale, 1.41 [0.7] vs 1.64 [0.6], P < 0.001; intent-to-treat [ITT] population: VAS, 32.5 [22.9] vs 38.6 [21.2] mm, P < 0.003; ordinal scale, 1.50 [0.8] vs 1.72 [0.7], P < 0.002). The overall pain intensity scores from the daily diary were also significantly better with CR tramadol for both the completers and ITT. Similar results were obtained on the biweekly VAS pain intensity questionnaire. No differences were found between treatments in total PDI or overall Pain and Sleep scores in either population. For the completers, both patients and investigators rated effectiveness higher for CR tramadol than for IR tramadol (P < 0.004 and P < 0.008 for patients and investigators, respectively).

CONCLUSION

This study reports significant improvement in pain intensity with CR tramadol as compared with IR tramadol.

Medicinal and injection therapies for mechanical neck disorders

BACKGROUND

Controversy persists regarding medicinal therapies and injections.

OBJECTIVES

To determine the effects of medication and injections on primary outcomes (e.g. pain) for adults with mechanical neck disorders and whiplash.

SEARCH STRATEGY

We searched CENTRAL, MANTIS, CINAHL from their start to May 2006; MEDLINE and EMBASE to December 2006. We scrutinised reference lists for other trials.

SELECTION CRITERIA

We included randomised controlled trials with adults with neck disorders, with or without associated headache or radicular findings. We considered medicinal and injection therapies, regardless of route of administration.

DATA COLLECTION AND ANALYSIS

Two authors independently selected articles, abstracted data and assessed methodological quality. When clinical heterogeneity was absent, we combined studies using random-effects models.

MAIN RESULTS

We found 36 trials that examined the effects of oral NSAIDs, psychotropic agents, steroid injections, and anaesthetic agents. Trials had a mean of 3.1 on the Jadad Scale for methodological quality; 70% were high quality. For acute whiplash, administering intravenous methylprednisolone within eight hours of injury reduced pain at one week (SMD -0.90, 95% CI -1.57 to -0.24), and sick leave but not pain at six months compared to placebo in one trial. For chronic neck disorders at short-term follow-up, intramuscular injection of lidocaine was superior to placebo (SMD -1.36, 95% CI -1.93 to -0.80); NNT 3, treatment advantage 45% and dry needling, but similar to ultrasound in one trial each. In chronic neck disorders with radicular findings, epidural methylprednisolone and lidocaine reduced neck pain and improved function more than when given by intramuscular route at one-year follow-up, in one trial. In subacute and chronic neck disorders, muscle relaxants, analgesics and NSAIDs had limited evidence and unclear benefits. In participants with chronic neck disorders with or without radicular findings or headache, there was moderate evidence from five high quality trials that Botulinum toxin A intramuscular injections had similar effects to saline in improving pain (pooled SMD: -0.39, 95%CI -1.25 to 0.47), disability or global perceived effect.

AUTHORS' CONCLUSIONS

The major limitations are the lack of replication of the findings and sufficiently large trials. There is moderate evidence for the benefit of intravenous methylprednisolone given within eight hours of acute whiplash, from a single trial. Lidocaine injection into myofascial trigger points appears effective in two trials. There is moderate evidence that Botulinum toxin A is not superior to saline injection for chronic MND. Muscle relaxants, analgesics and NSAIDs had limited evidence and unclear benefits.

The enantiomers of tramadol and its major metabolite inhibit peristalsis in the guinea pig small intestine via differential mechanisms

Background

Inhibition of intestinal peristalsis is a major side effect of opioid analgesics. Although tramadol is an opioid-like analgesic, its effect on gut motility is little known. Therefore, the effect of (+)-tramadol, (-)-tramadol and the major metabolite O-desmethyltramadol on intestinal peristalsis in vitro and their mechanisms of action were examined. Distension-induced peristalsis was recorded in fluid-perfused segments of the guinea pig small intestine. The intraluminal peristaltic pressure threshold (PPT) was used to quantify the motor effects of extraserosally administered drugs.

Results

Racemic tramadol, its (+)- and (-)-enantiomers and the major metabolite O-desmethyltramadol (0.1 – 100 μM) concentration-dependently increased PPT until peristalsis was transiently or persistently abolished. The rank order of potency was (-)-tramadol < (+)-tramadol <O-desmethyltramadol. The peristaltic motor inhibition caused by (+)- and (-)-tramadol was markedly and that of O-desmethyltramadol nearly completely prevented by naloxone, but left unaltered by the 5-hydroxytryptamine receptor antagonists methysergide plus tropisetron. The adrenoceptor antagonists prazosin plus yohimbine reduced the effect of (+)- and (-)-tramadol but not that of O-desmethyltramadol.

Conclusion

The results show that the metabolite O-desmethyltramadol is more potent in inhibiting peristalsis than its parent compound. The action of all tramadol forms depends on opioid receptors, and that of (+)- and (-)-tramadol also involves adrenoceptors.

Tramadol for osteoarthritis

BACKGROUND

Tramadol is increasingly used for the treatment of osteoarthritis because, in contrast to nonsteroidal anti-inflammatory drugs (NSAIDs), tramadol does not produce gastrointestinal bleeding or renal problems, and does not affect articular cartilage.

OBJECTIVES

We sought to determine the analgesic effectiveness, the effect on physical function, the duration of benefit and the safety of oral tramadol in people with osteoarthritis.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE and LILACS databases up to August 2005.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) that evaluated the effect of tramadol or tramadol plus paracetamol on pain levels and/or physical function in people with osteoarthritis. No language restriction was applied.

DATA COLLECTION AND ANALYSIS

We analyzed separately placebo-controlled and active-controlled studies. We used fixed-effect models for the meta-analyses as the results across studies were similar.

MAIN RESULTS

We included eleven RCTs with a total of 1019 participants who received tramadol or tramadol/paracetamol and 920 participants who received placebo or active-control. The placebo-controlled studies indicated that participants who received tramadol had less pain (-8.5 units on a 0 to 100 scale; 95% confidence interval (CI) -12.0 to -5.0) than patients who received placebo. This represents a 12% relative decrease in pain intensity from baseline. Participants who received tramadol had a 37% increase (95% CI 1.2 to 1.5) in the likelihood of reporting moderate improvement (number needed to treat to benefit = 6; 95% CI 4 to 9). Participants who received tramadol had 2.27 times the risk of developing minor adverse events and 2.6 times the risk of developing major adverse events, compared to participants who received placebo. Of every eight people who receive tramadol or tramadol/paracetamol, one will stop taking the medication because of adverse events, number needed to treat to harm (NNTH)= 8 (95% CI 7 to 12) for major adverse events. No conclusion could be drawn on how tramadol or tramadol/paracetamol compared with available pharmacological treatments because of the limited number of studies that evaluated such therapies.

AUTHORS' CONCLUSIONS

Tramadol or tramadol/paracetamol decreases pain intensity, produces symptom relief and improves function, but these benefits are small. Adverse events, although reversible and not life threatening, often cause participants to stop taking the medication and could limit tramadol or tramadol plus paracetamol usefulness.

Treatment of Fibromyalgia, Myofascial Pain, and Related Disorders

Chronic muscle pain is a common complaint among patients who seek care for musculoskeletal disorders. A spectrum of clinical presentations exists, ranging from focal or regional complaints that usually represent myofascial pain syndromes to more wide spread pain that may meet criteria for a diagnosis of fibromyalgia. This article addresses the epidemiology, pathophysiology, and clinical management of myofascial pain syndrome and fibromyalgia. These conditions are challenging to treat and require physiatrists to be aware of the wide range of pharmacologic, rehabilitative,and psychosocial interventions that can be helpful.

The effects of tramadol and fentanyl on gastrointestinal motility in septic rats

In this study, we investigated the effects of tramadol and fentanyl on gastrointestinal transit (GIT) during acute systemic inflammation in an experimental model of cecal ligation and perforation (CLP). One-hundred-twenty male Swiss-Albino rats were divided randomly into 6 groups: Group I = sham-operated + saline; Group II = sham-operated + fentanyl; Group III = sham-operated + tramadol; Group IV = CLP + saline; Group V = CLP + fentanyl; Group VI = CLP + tramadol. Suspension of charcoal was administered as an intragastric meal to measure the GIT. GIT% (mean +/- sd) were 46.1% +/- 9.8%, 43.2% +/- 9.8%, 45.9% +/- 10.2%, 33.2% +/- 9.2%, 24.9% +/- 4.1%, and 31.8% +/- 8.4% in Groups I, II, III, IV, V, and VI, respectively. GIT% was significantly less in Group V than in Groups I, II, III, and IV (P < 0.05). The Group VI mean value was significantly lower than those of Groups I, II, and III (P < 0.05) but not different from those of Groups IV and V (P > 0.05). The antitransit effect of fentanyl was shown to have increased in the experimental sepsis model, but no decrease in GIT was obtained with tramadol. This was thought to be the result of an associated endogenic opioid system activation and receptor upregulation in sepsis.

The pharmacotherapy of chronic pain: a review

The past two decades have contributed a large body of preclinical work that has assisted in our understanding of the underlying pathophysiological mechanisms that cause chronic pain. In this context, it has been recognized that effective treatment of pain is a priority and that treatment often involves the use of one or a combination of agents with analgesic action. The current review presents an evidence-based approach to the pharmacotherapy of chronic pain. Medline searches were done for all agents used as conventional treatment in chronic pain. Published papers up to June 2005 were included. The search strategy included randomized, controlled trials, and where available, systematic reviews and meta-analyses. Further references were found in reference sections of papers located using the above search strategy. Agents for which there were no controlled trials supporting efficacy in treatment of chronic pain were not included in the present review, except in cases where preclinical science was compelling, or where initial human work has been positive and where it was thought the reader would be interested in the scientific evidence to date.

Medicinal and injection therapies for mechanical neck disorders

BACKGROUND

Medicinal therapies and injections are commonly recommended for neck pain, yet controversy persists over their effectiveness.

OBJECTIVES

To determine the effect of medicines and injections on pain, function/disability, patient satisfaction and range of motion in participants with mechanical neck disorders (MND).

SEARCH STRATEGY

We searched CENTRAL (Issue 4, 2002), and MEDLINE, EMBASE, MANTIS, CINHAL from their start to March 2003. We scrutinized reference lists for other trials.

SELECTION CRITERIA

We included randomized controlled trials with adults with MND, with or without associated headache or radicular findings. We considered medicinal and injection therapies, regardless of route of administration.

DATA COLLECTION AND ANALYSIS

Two authors independently selected articles, abstracted data and assessed methodological quality using the Jadad criteria. Consensus was used to resolve disagreements. When clinical heterogeneity was absent, we combined studies using random-effects meta-analysis models.

MAIN RESULTS

We found 32 trials that examined the effects of oral NSAIDs, psychotropic agents, injections of steroids, and anaesthetic agents. Overall, methodological quality had a mean of 3.2/5 on the Jadad Scale. For acute whiplash, administering intravenous methylprednisolone within eight hours reduced pain at one week, and sick leave but not pain at six months compared to placebo. For chronic MND at short-term follow-up, intramuscular injection of lidocaine was superior to placebo or dry needling, but similar to ultrasound. In chronic MND with radicular findings, epidural methylprednisolone and lidocaine reduced neck pain and improved function at one-year follow-up compared to the intramuscular route. In subacute/chronic MND, we found conflicting evidence of pain reduction for oral psychotropic agents compared to placebo or control. Single trials of eperison hydrochloride and tetrazepam showed positive results. Results for cyclobenzaprine were mixed. Diazepam did not show benefit. Other treatments including NSAIDS and nerve blocks had unclear or limited evidence of benefit. In participants with chronic MND with or without radicular findings or headache, there was moderate evidence from five high quality trials showing that Botox A intramuscular injections were not better than saline in improving pain (pooled SMD: -0.39 (95%CI: -1.25 to 0.47), disability or global perceived effect.

AUTHORS' CONCLUSIONS

Intra-muscular injection of lidocaine for chronic MND and intravenous injection of methylprednisolone for acute whiplash were effective treatments. There was limited evidence of effectiveness of epidural injection of methylprednisolone and lidocaine for chronic MND with radicular findings. Oral psychotropic agents had mixed results. There was moderate evidence that Botox A intramuscular injections for chronic MND were no better than saline. Other medications, including NSAIDs, had contradictory or limited evidence of effectiveness.

Clinical pharmacology of tramadol

Tramadol, a centrally acting analgesic structurally related to codeine and morphine, consists of two enantiomers, both of which contribute to analgesic activity via different mechanisms. (+)-Tramadol and the metabolite (+)-O-desmethyl-tramadol (M1) are agonists of the mu opioid receptor. (+)-Tramadol inhibits serotonin reuptake and (-)-tramadol inhibits norepinephrine reuptake, enhancing inhibitory effects on pain transmission in the spinal cord. The complementary and synergistic actions of the two enantiomers improve the analgesic efficacy and tolerability profile of the racemate. Tramadol is available as drops, capsules and sustained-release formulations for oral use, suppositories for rectal use and solution for intramuscular, intravenous and subcutaneous injection. After oral administration, tramadol is rapidly and almost completely absorbed. Sustained-release tablets release the active ingredient over a period of 12 hours, reach peak concentrations after 4.9 hours and have a bioavailability of 87-95% compared with capsules. Tramadol is rapidly distributed in the body; plasma protein binding is about 20%. Tramadol is mainly metabolised by O- and N-demethylation and by conjugation reactions forming glucuronides and sulfates. Tramadol and its metabolites are mainly excreted via the kidneys. The mean elimination half-life is about 6 hours. The O-demethylation of tramadol to M1, the main analgesic effective metabolite, is catalysed by cytochrome P450 (CYP) 2D6, whereas N-demethylation to M2 is catalysed by CYP2B6 and CYP3A4. The wide variability in the pharmacokinetic properties of tramadol can partly be ascribed to CYP polymorphism. O- and N-demethylation of tramadol as well as renal elimination are stereoselective. Pharmacokinetic-pharmacodynamic characterisation of tramadol is difficult because of differences between tramadol concentrations in plasma and at the site of action, and because of pharmacodynamic interactions between the two enantiomers of tramadol and its active metabolites. The analgesic potency of tramadol is about 10% of that of morphine following parenteral administration. Tramadol provides postoperative pain relief comparable with that of pethidine, and the analgesic efficacy of tramadol can further be improved by combination with a non-opioid analgesic. Tramadol may prove particularly useful in patients with a risk of poor cardiopulmonary function, after surgery of the thorax or upper abdomen and when non-opioid analgesics are contraindicated. Tramadol is an effective and well tolerated agent to reduce pain resulting from trauma, renal or biliary colic and labour, and also for the management of chronic pain of malignant or nonmalignant origin, particularly neuropathic pain. Tramadol appears to produce less constipation and dependence than equianalgesic doses of strong opioids.