Tramadol/acetaminophen combination tablets for the treatment of osteoarthritis flare pain: a multicenter, outpatient, randomized, double-blind, placebo-controlled, parallel-group, add-on study

Paracetamol Combination Therapy for Back Pain and Osteoarthritis: A Systematic Review and Meta-Analyses

BACKGROUND AND OBJECTIVE

Although paracetamol (acetaminophen) combined with other analgesics can reduce pain intensity in some pain conditions, its effectiveness in managing low back pain and osteoarthritis is unclear. This systematic review investigated whether paracetamol combination therapy is more effective and safer than monotherapy or placebo in low back pain and osteoarthritis.

METHODS

Online database searches were conducted for randomised trials that evaluated paracetamol combined with another analgesic compared to a placebo or the non-paracetamol ingredient in the combination (monotherapy) in low back pain and osteoarthritis. The primary outcome was a change in pain. Secondary outcomes were (serious) adverse events, changes in disability and quality of life. Follow-up was immediate (≤ 2 weeks), short (> 2 weeks but ≤ 3 months), intermediate (> 3 months but < 12 months) or long term (≥ 12 months). A random-effects meta-analysis was conducted. Risk of bias was assessed using the original Cochrane tool, and quality of evidence using Grading of Recommendations Assessment, Development and Evaluation (GRADE).

RESULTS

Twenty-two studies were included. Pain was reduced with oral paracetamol plus a non-steroidal anti-inflammatory drug (NSAID) at immediate term in low back pain (paracetamol plus ibuprofen vs ibuprofen [mean difference (MD) - 6.2, 95% confidence interval (CI) -10.4 to -2.0, moderate evidence]) and in osteoarthritis (paracetamol plus aceclofenac vs aceclofenac [MD - 4.7, 95% CI - 8.3 to - 1.2, moderate certainty evidence] and paracetamol plus etodolac vs etodolac [MD - 15.1, 95% CI - 18.5 to - 11.8; moderate certainty evidence]). Paracetamol plus oral tramadol reduced pain compared with placebo at intermediate term for low back pain (MD - 11.7, 95% CI - 19.2 to - 4.3; very low certainty evidence) and osteoarthritis (MD - 6.8, 95% CI - 12.7 to -0.9; moderate certainty evidence). Disability scores improved in half the comparisons. Quality of life was infrequently measured. All paracetamol plus NSAID combinations did not increase the risk of adverse events compared to NSAID monotherapy.

CONCLUSIONS

Low-to-moderate quality evidence supports the oral use of some paracetamol plus NSAID combinations for short-term pain relief with no increased risk of harm for low back pain and osteoarthritis compared to its non-paracetamol monotherapy comparator.

Opioids for Acute Musculoskeletal Pain: A Systematic Review with Meta-Analysis

OBJECTIVE

To evaluate the efficacy of opioids for people with acute musculoskeletal pain against placebo.

STUDY DESIGN

Systematic review and meta-analyses of randomised, placebo-controlled trials of opioid analgesics for acute musculoskeletal pain in any setting. The primary outcomes were pain and disability at the immediate timepoint (< 24 h).

DATA SOURCES

Multiple databases were searched from their inception to February 22nd, 2023.

DATA SYNTHESIS

Continuous outcomes were converted to a 0-100 scale. Dichotomous outcomes were presented as risk differences. Risk of bias and certainty of evidence was assessed.

RESULTS

We located 17 trials (1 intravenous and 16 oral route of administration). For adults, high certainty evidence from 11 comparisons shows that oral opioids provide small benefits relative to placebo in the immediate term for pain (mean difference [MD] - 8.8 95% confidence interval [CI] - 12.0 to - 5.6). For disability, the difference is uncertain (MD - 6.2, 95% CI - 17.8 to 5.4). Opioid groups were at higher risk of adverse events (MD 14.3%, 95% CI 8.3-20.4%, very low certainty). There was moderate certainty evidence of a large effect of IV morphine on sciatica pain (MD -42.5, 95% CI - 49.9 to - 35.1, n = 197, 1 study). In paediatric populations, moderate certainty evidence from 3 trials shows that oral opioids probably do not provide benefit beyond that of placebo for pain (MD 6.1, 95% CI - 1.7 to 12.8) and there was no evidence for disability. There was low certainty evidence that there may be no difference in adverse events (MD 10.4%, 95% CI - 0.6 to 21.4%).

DISCUSSION

Intravenous morphine likely offers benefits, but oral opioids may not provide clinically meaningful benefits.

PROSPERO REGISTRATION

CRD42021249346.

Antinociceptive and anti-inflammatory activity of DW-1021, the ionic complex of pelubiprofen and tramadol, in rodents

Although drugs such as acetaminophen, opioids, and nonsteroidal anti-inflammatory drugs (NSAIDs), are commonly used for pain management, the side effects of these drugs such as hepatotoxicity, nephrotoxicity, nausea, and vomiting, can not be neglected. Therefore, combinations of analgesics with different mechanisms raise the possibility of developing novel analgesics. Therefore, the aim of the present study was to evaluate whether DW-1021, the ionic complex of pelubiprofen (NSAID) and tramadol (opioid), has synergic antinociceptive and anti-inflammatory effects in nociceptive as well as inflammation-induced nociceptive models compared to pelubiprofen- or tramadol-only administration. Strong synergistic antinociceptive efficacy of DW-1021 was observed in the mouse writhing test and von Frey paw withdrawal threshold test in the carrageenan-induced rats. The hot plate test in mice and the Randall-Selitto mechanical paw pressure test in carrageenan-induced rats revealed that DW-1021 had a preferable effect on relieving pain to pelubiprofen, but not as much as tramadol. In the carrageenan-induced rats, DW-1021 had a more potent effect on reducing paw inflammation (paw volume, width, and thickness) via the suppression of PGE₂ production than tramadol, but less than that of pelubiprofen. Taken together, our results suggest that the administration of DW-1021, a combination of pelubiprofen and tramadol, exerted a potent effect and can be used as a potential therapeutic agent for relieving pain and inflammation.

Is There Any Role for Opioids in the Management of Knee and Hip Osteoarthritis? A Systematic Review and Meta-Analysis

OBJECTIVE

Opioids have long been prescribed for chronic pain conditions, including osteoarthritis (OA). However, there is little information about their temporal efficacy, or differences in efficacy and safety between opioids with strong versus weak/intermediate μ opioid receptor-binding affinity. To explore these research questions, we conducted a systematic review and meta-analyses of randomized controlled trials (RCTs) conducted in patients with knee and/or hip OA.

METHODS

We searched Medline, Embase, PubMed Central, and the Cochrane Central Register of Controlled Trials from inception to December 2019 and sought unpublished data. Placebo-controlled RCTs of oral opioids in patients with knee and/or hip OA were included. Standardized mean differences (SMDs) were calculated for pain and function at 2, 4, 8, and 12 weeks. Subgroup analyses for strong and weak/intermediate opioids were conducted. Meta-regression was performed to assess the impact of dosage (morphine equivalency) on pain relief. Risk ratios were calculated for safety at the final follow-up.

RESULTS

A total of 18 RCTs (9,283 participants) were included. Opioids demonstrated small benefits on pain at each time point, with SMDs ranging from -0.28 (95% confidence interval [95% CI] -0.38, -0.17) to -0.19 (95% CI -0.29, -0.08); similar effects were observed for function. Strong opioids demonstrated consistently inferior efficacy and overall worse safety than weak/intermediate opioids. Meta-regression revealed that incremental pain relief achieved beyond 20-50-mg doses was not substantial in the context of increased safety risks.

CONCLUSION

Opioids provide minimal relief of OA symptoms within a 12-week period, and they are known to cause discomfort in a majority of patients. Clinicians and policy makers should reconsider the utility of opioids in the management of OA.

A Malaysian Delphi consensus on managing knee osteoarthritis

BACKGROUND

The 2013 Malaysian Clinical Practice Guidelines on the Management of Osteoarthritis (OA) recommend a linear step-up approach to manage knee OA. However, patients with knee OA often require a multimodal approach to address OA-related pain symptoms and functional limitations. This consensus aimed to provide doctors with an updated set of evidence-based, clinical experience-guided recommendations to manage knee OA.

METHODS

A multi-speciality expert panel consisting of nine Malaysian physicians from different healthcare settings who manage a diverse OA patient population was convened. Using a combination of the ADAPTE process and modified Delphi method, the panel reviewed current evidence on the management of knee OA and synthesised a set of nine recommendations on the management of knee OA, supported by an algorithm that summarises the consensus' core messages.

RESULTS

A multimodal intervention strategy is the mainstay of OA management and the choice of any single or multimodal intervention may vary over the course of the disease. Overall, a non-pharmacological core treatment set of patient education, weight loss and exercise is recommended for all patients. When pharmacotherapy is indicated, symptomatic slow-acting drugs for osteoarthritis are recommended at the early stage of disease, and they can be paired with physical therapy as background treatment. Concurrent advanced pharmacotherapy that includes non-steroidal anti-inflammatory drugs, intraarticular injections and short-term weak opioids can be considered if patients do not respond sufficiently to background treatment. Patients with severe symptomatic knee OA should be considered for knee replacement surgery. Management should begin with specific treatments with the least systemic exposure or toxicity, and the choice of treatment should be determined as a shared decision between patients and their team of healthcare providers.

CONCLUSIONS

This consensus presents nine recommendations that advocate an algorithmic approach in the management of patients living with knee OA. They are applicable to patients receiving treatment from primary to tertiary care providers in Malaysia as well as other countries.

Preoperative Pain Management: Is Tramadol a Safe Alternative to Traditional Opioids Before Total Hip Arthroplasty?

BACKGROUND

Preoperative opioid use has been associated with worse clinical outcomes and higher rates of prolonged opioid use following lower extremity arthroplasty. Tramadol has been recommended for management of osteoarthritis-related pain; however, outcomes following total hip arthroplasty (THA) in patients taking tramadol in the preoperative period have not been well described. The aim of this study is to examine the effect of preoperative tramadol use on postoperative outcomes in patients undergoing elective THA.

METHODS

A total of 5304 patients who underwent primary THA for degenerative hip pathology from 2008 to 2014 were identified using the Humana Claims Database. Patients were grouped by preoperative pain management modality into 3 mutually exclusive populations including tramadol, traditional opioid, or nonopioid only. A multivariate logistic regression was used to evaluate all postsurgical outcomes of interest.

RESULTS

Tramadol users had an increased risk of developing prolonged narcotic use (odds ratio [OR], 2.17; confidence interval [CI], 1.89-2.49; P < .001) following surgery compared to nonopioid-only users. When compared to traditional opioid use, tramadol use was associated with decreased risk of subsequent 90-day minor medical complications (OR, 0.75; CI, 0.62-0.90; P = .002), emergency department visits (OR, 0.70; CI, 0.57-0.85; P < .001), and prolonged narcotic use (OR, 0.43; CI, 0.37-0.49; P < .001). Traditional opioid use significantly increased length of stay by 0.20 days (P = .001) when compared to tramadol use.

CONCLUSION

Preoperative tramadol use is associated with prolonged opioid use following THA but is not associated with other postoperative complications. Patients taking tramadol preoperatively appear to have a lower risk of postoperative complications compared to patients taking traditional opioids preoperatively.

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.

[Consensus statement on the use of acetaminophen/tramadol in patients with moderate-severe pain]

OBJECTIVES

To present recommendations on the use of the paracetamol/tramadol (P/T) combination in patients with moderate-intense pain based on best evidence and experience.

METHODS

The method of nominal groups and Delphi was followed, and supported by a systematic literature review (SLR). A multidisciplinary panel of 12 experts in pain management was selected. In the first nominal group meeting, the aim, scope, users, and sections of the consensus document, were defined, along with the preliminary general recommendations. For the SLR, the inclusion and exclusion criteria, as well as the search strategies, were defined. Two reviewers selected and analysed the articles. This evidence was discussed in a second nominal group meeting, and definitive recommendations were developed. For each recommendation, the evidence levels and grade of recommendation grades were classified according to the Oxford model, and the grade according to the Delphi technique. It was defined as an agreement if at least 70% of the participants scored ≥7 for each recommendation (1=total disagreement to 10=total agreement).

RESULTS

A total of 20 recommendations were produced, which covered general aspects, such as the assessment of pain, and those specific to P/T management. These latter included the indications of the P/T combination (patient profile, dosing, prescription, formulations), risk management (contraindications, precautions, interactions, concomitant use with other medications, follow-up, special situations), and patient education.

CONCLUSIONS

These recommendations attempt to resolve any of the routine clinical questions, and help in the making of decisions on the use of the P/T combination in patients with moderate-intense pain.

Monoamines as Drug Targets in Chronic Pain: Focusing on Neuropathic Pain

Monoamines are involved in regulating the endogenous pain system and indeed, peripheral and central monoaminergic dysfunction has been demonstrated in certain types of pain, particularly in neuropathic pain. Accordingly, drugs that modulate the monaminergic system and that were originally designed to treat depression are now considered to be first line treatments for certain types of neuropathic pain (e.g., serotonin and noradrenaline (and also dopamine) reuptake inhibitors). The analgesia induced by these drugs seems to be mediated by inhibiting the reuptake of these monoamines, thereby reinforcing the descending inhibitory pain pathways. Hence, it is of particular interest to study the monoaminergic mechanisms involved in the development and maintenance of chronic pain. Other analgesic drugs may also be used in combination with monoamines to facilitate descending pain inhibition (e.g., gabapentinoids and opioids) and such combinations are often also used to alleviate certain types of chronic pain. By contrast, while NSAIDs are thought to influence the monoaminergic system, they just produce consistent analgesia in inflammatory pain. Thus, in this review we will provide preclinical and clinical evidence of the role of monoamines in the modulation of chronic pain, reviewing how this system is implicated in the analgesic mechanism of action of antidepressants, gabapentinoids, atypical opioids, NSAIDs and histaminergic drugs.

Defining acute flares in knee osteoarthritis: a systematic review

OBJECTIVE

To identify and critically synthesise definitions of acute flares in knee osteoarthritis (OA) reported in the medical literature.

DESIGN

Systematic review and narrative synthesis. We searched Medline, EMBASE, Web of science and six other electronic databases (inception to July 2017) for original articles and conference abstracts reporting a definition of acute flare (or synonym) in humans with knee OA. There were no restrictions by language or study design (apart from iatrogenic-induced flare-ups, eg, injection-induced). Data extraction comprised: definition, pain scale used, flare duration or withdrawal period, associated symptoms, definition rationale, terminology (eg, exacerbation or flare), baseline OA severity, age, gender, sample size and study design.

RESULTS

Sixty-nine articles were included (46 flare design trials, 17 observational studies, 6 other designs; sample sizes: 15-6085). Domains used to define flares included: worsening of signs and symptoms (61 studies, 27 different measurement tools), specifically increased pain intensity; minimum pain threshold at baseline (44 studies); minimum duration (7 studies, range 8-48 hours); speed of onset (2 studies, defined as 'sudden' or 'quick'); requirement for increased medication (2 studies). No definitions included activity interference.

CONCLUSIONS

The concept of OA flare appears in the medical literature but most often in the context of flare design trials (pain increases observed after stopping usual treatment). Key domains, used to define acute events in other chronic conditions, appear relevant to OA flare and could provide the basis for consensus on a single, agreed definition of 'naturally occurring' OA flares for research and clinical application.

PROSPERO REGISTRATION NUMBER

CRD42014010169.

Comparison of tramadol/acetaminophen fixed-dose combination, tramadol, and acetaminophen in patients undergoing ambulatory arthroscopic meniscectomy

OBJECTIVES

Preemptive analgesia is a technique in which analgesics are administered before a surgery to provide better postoperative pain relief with fewer side effects. In this study, we aimed to compare the preemptive efficacy of tramadol/acetaminophen fixed-dose combination, tramadol, and acetaminophen in patients undergoing ambulatory arthroscopic partial meniscectomy.

METHODS

We evaluated the patient records of 75 patients who underwent ambulatory arthroscopic partial meniscectomy. We divided the patients into three groups consisting of 20 patients each to equalize the groups. Group A comprised patients who were administered 37.5 mg tramadol/325 mg acetaminophen fixed-dose combination, Group B comprised patients who were administered 50 mg tramadol, and Group C comprised patients who were administered 500 mg acetaminophen. Premedication was not used in any group.

RESULTS

There were no significant differences between the groups in terms of age, sex, BMI, and duration of surgery and anesthesia. All patients in Group B and Group C and 17 patients in Group A required rescue analgesics in the first 6 h. Visual analog scale (VAS) was 4.75 ± 3.05 in Group B at time 0 and was 6.10 ± 1.86 in Group C in the first hour and was higher than the other groups with a statistically significance (p = 0.030 and 0.020, respectively). VAS at 24 h postoperatively was ≤3 (1.60 ± 1.63, 1.55 ± 1.84 and 1.70 ± 0.65 respectively in each group), and none of the patients in any group required rescue analgesics. No major side effects, except for slight nausea in one patient requiring no medication, were noted in any group.

CONCLUSION

The fixed-dose combination of tramadol/acetaminophen or tramadol alone is better than acetaminophen alone as a preemptive analgesic in patients undergoing ambulatory arthroscopic meniscectomy.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Efficacy and Safety of Oral and Transdermal Opioid Analgesics for Musculoskeletal Pain in Older Adults: A Systematic Review of Randomized, Placebo-Controlled Trials

This systematic review with meta-analysis was performed to evaluate the efficacy and safety of using opioid analgesics in older adults with musculoskeletal pain. We searched Cochrane Library, MEDLINE, EMBASE, Web of Science, AMED, CINAHL, and LILACS for randomized controlled trials with mean population age of 60 years or older, comparing the efficacy and safety of opioid analgesics with placebo for musculoskeletal pain conditions. Reviewers extracted data, assessed risk of bias, and evaluated the quality of evidence using the Grading of Recommendations Assessment, Development and Evaluation approach. Random effects models were used to calculate standardized mean differences (when different scales were used across trials), mean differences and odds ratios with respective 95% confidence intervals (CIs). Meta-regressions were carried out to assess the influence of opioid analgesic daily dose and treatment duration on our main outcomes. We included 23 randomized placebo-controlled trials in the meta-analysis. Opioid analgesics had a small effect on decreasing pain intensity (standardized mean difference = -.27; 95% CI = -.33 to -.20) and improving function (standardized mean difference = -.27, 95% CI = -.36 to -.18), which was not associated with daily dose or treatment duration. The odds of adverse events were 3 times higher (odds ratio = 2.94; 95% CI = 2.33-3.72) and the odds of treatment discontinuation due to adverse events 4 times higher (odds ratio = 4.04; 95% CI = 3.10-5.25) in patients treated with opioid analgesics. The results show that in older adults suffering from musculoskeletal pain, using opioid analgesics had only a small effect on pain and function at the cost of a higher odds of adverse events and treatment discontinuation. For this specific population, the opioid-related risks may outweigh the benefits.

PERSPECTIVE

The systematic review shows that, in older adults suffering from musculoskeletal conditions, opioid analgesics have only a small effect on pain and disability. Conversely, this population is at higher risk of adverse events. The results may reflect age-related physiological changes in pain processing, pharmacokinetics, and pharmacodynamics.

Novel management of postoperative pain using only oral analgesics after LADG

PURPOSE

Managing postoperative pain is important to ensure a good quality of life and fast recovery after surgery. We examined the feasibility of peroral management for the postoperative pain after laparoscopic-assisted distal gastrectomy (LADG).

METHODS

Between June 2012 and September 2013, we enrolled 34 patients prospectively to receive peroral tramadol/acetaminophen combination tablets, celecoxib and prochlorperazine maleate after LADG through postoperative day 3 (ORAL group). The postoperative pain was assessed using a visual analogue scale. Postoperative outcomes related to the analgesic methods were compared with those of patients who used epidural anesthesia between January 2010 and December 2011 (EPI group).

RESULTS

The ORAL group pain scale scores on postoperative days 1-3 were 3.96, 3.06 and 2.40, respectively. The frequency of additional analgesic use in the ORAL group was significantly lower than in the EPI group (P = 0.006). The rate of urethral catheter reinsertion was 20.6 % in the EPI group (P = 0.054). A multivariate analysis revealed that only epidural anesthesia was a significant risk factor for the need for additional medication four times or more for breakthrough pain (P = 0.048).

CONCLUSION

Postoperative pain management using oral analgesics after LADG is feasible and safe, and is an ideal pain treatment associated with few adverse events while providing pain relief not inferior to epidural anesthesia.

Evaluation of the effectiveness and tolerability of controlled-release diclofenac-potassium versus immediate-release diclofenac-potassium in the treatment of knee osteoarthritis

Abstract.

BACKGROUND

A controlled-release (CR) form of diclofenac-potassium has been developed, which delivers 100 mg over the course of 24 hours. This formulation is administered QD and provides steady plasmatic levels of the drug.

OBJECTIVE

The aim of this study was to compare the effectiveness and tolerability of CR diclofenac-potassium versus the immediate-release (IR) formulation, when used for treatment of pain in patients with knee osteoarthritis.

METHODS

This prospective, randomized, double-blind, comparative, multi-center, parallel-group study was conducted in male and female patients who had been previously diagnosed with knee osteoarthritis. Inclusion criteria included knee joint pain and ≥3 of the following: age >50 years, morning rigidity lasting <30 minutes, crackling in the joint, pain with applied pressure to the bones, bone hypertrophy, absence of articular heat, and a radiology status of I to III on the Kellgren-Lawrence scale. Patients were randomly divided into 1 of 2 equal-sized groups: 1 group received diclofenac-potassium IR 50 mg BID for 30 days and 1 group received diclofenac-potassium CR 100 mg QD for 30 days. Patients were assessed at baseline and again at 15 and 30 days after initiation of treatment with a physical examination, pain measurement via 100-mm visual analog scale (VAS), and Western Ontario McMaster (WOMAC) osteoarthritis index questionnaire. Adverse events (AEs) were assessed by direct interrogation, hematology controls, blood chemistry, hepatic tests, coagulation tests, and urine tests performed on patients before treatment initiation and on day 30.

RESULTS

Sixty-five patients were screened and 62 patients (mean [SD]age, 61.8 [8.9] years; mean [SD] weight, 71.3 [12.4] kg; female sex, 55 [88.9%]) were included in the study; each study group had 31 patients. After 30 days, both products were equally effective in relieving pain, as measured by VAS (IR, 17.3 vs CR, 21.6; P = NS), and changes in the WOMAC score (IR, 14.5 vs CR, 19.2; P = NS). Significantly more patients in the IR group reported feeling better after 30 days than in the CR group (94% vs 76%; P = 0.002) and, according to the physician's opinion, significantly more patients treated with diclofenac-potassium IR felt better (97% vs 83%; P = 0.03). Significantly more patients in the IR group required rescue medication than those in the CR group (36% vs 26%; P = 0.03). In the CR group, 7 patients experienced AEs: 6 were gastrointestinal (ie, pyrosis, epigastralgia, dyspepsia) and 1 patient experienced increased arterial pressure. One patient from this group discontinued treatment due to a lack of efficacy. In the IR group, 6 patients experienced AEs (ie, tachycardia, epigastralgia, and pyrosis). One patient discontinued because of AEs, and 3 withdrew due to a lack of efficacy.

CONCLUSION

Based on the results from this small study in a Venezuelan population, both IR and CR formulations of diclofenac-potassium have similar effectiveness and tolerability profiles.

Tramadol/Paracetamol fixed-dose combination for chronic pain management in family practice: a clinical review

The family practitioner plays an important role in the prevention, diagnosis, and early management of chronic pain. He/she is generally the first to be consulted, the one most familiar with the patients and their medical history, and is likely the first to be alerted in case of inadequate pain control or safety and tolerability issues. The family practitioner should therefore be at the center of the multidisciplinary team involved in a patient's pain management. The most frequent indications associated with chronic pain in family practice are of musculoskeletal origin, and the pain is often multimechanistic. Fixed-dose combination analgesics combine compounds with different mechanisms of action; their broader analgesic spectrum and potentially synergistic analgesic efficacy and improved benefit/risk ratio might thus be useful. A pain specialist meeting held in November 2010 agreed that the fixed-dose combination tramadol/paracetamol might be a useful pharmacological option for chronic pain management in family practice. The combination is effective in a variety of pain conditions with generally good tolerability. Particularly in elderly patients, it might be considered as an alternative to conventional analgesics such as NSAIDs, which should be used rarely with caution in this population.

Pain treatment in arthritis-related pain: beyond NSAIDs

Managing pain from chronic conditions, such as, but not limited to, osteoarthritis and rheumatoid arthritis, requires the clinician to balance the need for effective analgesia against safety risks associated with analgesic agents. Osteoarthritis and rheumatoid arthritis pain is incompletely understood but involves both nociceptive and non-nociceptive mechanisms, including neuropathic mechanisms. Prevailing guidelines for arthritis-related pain do not differentiate between nociceptive and non-nociceptive pain, sometimes leading to recommendations that do not fully address the nature of pain. NSAIDs are effective in treating the nociceptive arthritis-related pain. However, safety concerns of NSAIDs may cause clinicians to undertreat arthritis-related pain. In this context, combination therapy may be more appropriate to manage the different pain mechanisms involved. A panel convened in November 2010 found that among the currently recommended analgesic products for arthritis-related pain, fixed-low-dose combination products hold promise for pain control because such products allow lower doses of individual agents resulting in decreased toxicity and acceptable efficacy due to synergy between the individual drugs. Better evidence and recommendations are required to improve treatment of chronic arthritis-related pain.

Extended-release tramadol/paracetamol in moderate-to-severe pain: a randomized, placebo-controlled study in patients with acute low back pain

OBJECTIVE

Combinations of oral analgesics may offer several potential benefits compared with an individual agent. The objective of this study was to investigate the efficacy and safety of an extended-release, twice-daily fixed combination of 75 mg tramadol/650 mg paracetamol (DDS-06C) in the treatment of moderate-to-severe pain, using acute low back pain as a model.

RESEARCH DESIGN AND METHODS

In this phase III study, 277 patients with moderate-to-severe acute low back pain were randomized to 1-2 tablets of DDS-06C or placebo every 10-12 h for 2.5 days during the double-blind phase. Following the double-blind phase, patients had the option to continue for a 2.5-day open-label phase.

CLINICAL TRIAL REGISTRATION

Clinicaltrials.gov (Identifier: NCT00643383)

MAIN OUTCOME MEASURES

The primary end point was the sum of pain intensity differences (SPID) over the 50-h double-blind phase (SPID50). Secondary end points included total pain relief score over the 50-h double-blind phase (TOTPAR50), patient's global impression of medication, and SPID over the first 4 h.

RESULTS

A statistically significant (p = 0.038) greater decrease in pain intensity was observed in the DDS-06C group (median SPID50: -6.0) versus placebo (median SPID50: -4.0). Greater pain relief was also observed in patients randomized to DDS-06C: the median TOTPAR50 was 13.0 for the DDS-06C group and 11.0 for placebo (p = 0.026). DDS-06C demonstrated statistically significant superior efficacy compared with placebo for the majority of the other secondary end points. Overall, 38% of patients treated with DDS-06C experienced at least one adverse event; the intensity was mild-to-moderate in 81% of cases. The most commonly reported adverse events (>5% of patients receiving DDS-06C) were nausea, dizziness, vomiting, and somnolence.

CONCLUSIONS

Using acute low back pain, a model with a high degree of heterogeneity and intrinsic variability, DDS-06C was superior to placebo on measures of pain intensity and relief, and was well-tolerated.

A comparison between enriched and nonenriched enrollment randomized withdrawal trials of opioids for chronic noncancer pain

BACKGROUND

An enriched enrollment randomized withdrawal (EERW) design excludes potential participants who are nonresponders or who cannot tolerate the experimental drug before random assignment. It is unclear whether EERW design has an influence on the efficacy and safety of opioids for chronic noncancer pain (CNCP).

OBJECTIVES

The primary objective was to compare the results from EERW and non-EERW trials of opioids for CNCP. Secondary objectives were to compare weak versus strong opioids, subgroups of patients with different types of pain, and the efficacy of opiods compared with placebo versus other drugs.

METHODS

MEDLINE, EMBASE and CENTRAL were searched up to July 2009, for randomized controlled trials of any opioid for CNCP. Metaanalyses and meta-regressions were conducted to compare the results. Treatment efficacy was assessed by effect sizes (small, medium and large) and the incidence of adverse effects was assessed by a clinically relevant mean difference of 10% or greater.

RESULTS

Sixty-two randomized trials were included. In 61 trials, the duration was less than 16 weeks. There was no difference in efficacy between EERW and non-EERW trials for both pain (P=0.6) and function (P=0.3). However, EERW trials failed to detect a clinically relevant difference for nausea, vomiting, somnolence, dizziness and dry skin⁄itching compared with non-EERW. Opioids were more effective than placebo in patients with nociceptive pain (effect size=0.60, 95% CI 0.49 to 0.72) and neuropathic pain (effect size=0.56, 95% CI 0.38 to 0.73).

CONCLUSION

EERW trial designs appear not to bias the results of efficacy, but they underestimate the adverse effects. The present updated meta- analysis shows that weak and strong opioids are effective for CNCP of both nociceptive and neuropathic origin.

Civamide Cream 0.075% in Patients with Osteoarthritis of the Knee: A 12-Week Randomized Controlled Clinical Trial with a Longterm Extension

Objective.

To evaluate the safety and efficacy of civamide cream 0.075% for the treatment of osteoarthritis (OA) of the knee.

Methods.

We conducted a 12-week, multicenter, randomized, double-blind study with a 52-week open-label extension. Patients with OA of the knee received either civamide cream 0.075% or a lower dose of civamide cream, 0.01%, as the control. The 3 co-primary endpoints in the double-blind study were the time-weighted average (TWA) of change from baseline to Day 84 in the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain subscale, the WOMAC physical function subscale, and the Subject Global Evaluation (SGE). In the 52-week open-label extension study, the Osteoarthritis Pain Score and SGE were assessed.

Results.

A total of 695 patients were randomized to receive civamide cream 0.075% (n = 351) or civamide cream 0.01% (control; n = 344) in the double-blind study. Significance in favor of civamide cream 0.075% was achieved for the TWA for all 3 co-primary efficacy variables: WOMAC pain (p = 0.009), WOMAC physical function (p < 0.001), and SGE (p = 0.008); and at Day 84 for these 3 variables (p = 0.013, p < 0.001, and p = 0.049, respectively). These analyses accounted for significant baseline-by-treatment interactions. In the 52-week open-label extension, efficacy was maintained. Civamide cream 0.075% was well tolerated throughout the studies.

Conclusion.

These studies demonstrate the efficacy of civamide cream for up to 1 year of continuous use. Civamide cream, with its lack of systemic absorption, does not have the potential for serious systemic toxicity, in contrast to several other OA treatments.

The efficacy of tramadol/acetaminophen combination tablets (Ultracet®) as add-on and maintenance therapy in knee osteoarthritis pain inadequately controlled by nonsteroidal anti-inflammatory drug (NSAID)

The purpose of this study is to compare the efficacy of tramadol 37.5 mg/acetaminophen 325 mg combination tablets (tramadol/APAP) with that of nonsteroidal anti-inflammatory drugs (NSAIDs) as maintenance therapy following tramadol/APAP and NSAID combination therapy in knee osteoarthritis (OA) pain which was inadequately controlled by NSAIDs. Subjects with knee OA for over 1 year and moderate pain (numerical rating scale [NRS] ≥5) despite at least 4 weeks' NSAID therapy (meloxicam 7.5 mg or 15 mg qd or aceclofenac 100 mg bid) received tramadol/APAP add-on (combination with NSAID) for 4 weeks. Thereafter, subjects with significant pain improvement (NRS <4) were randomized to receive either tramadol/APAP or NSAID for 8 weeks. On days 29 and 57, Western Ontario and McMaster Universities (WOMAC) OA index score was measured. Secondary measures included pain intensity (NRS), pain relief score, and subjects' and investigators' overall medication assessments. Of 143 subjects enrolled, 112 completed the 4-week tramadol/APAP and NSAID combination phase and 97 (67.8%) experienced significant pain improvement. Of the 97 subjects randomized, 36 in tramadol/APAP group and 47 in NSAID group completed the 8-week comparator study. On days 29 and 57, WOMAC scores and pain intensities did not increase in both groups compared to measurements immediately after the combination therapy. At these two time points, there were no significant differences in WOMAC scores, pain intensities, and other secondary measures between the two groups. Overall adverse event rates were similar in both groups. Tramadol/APAP add-on significantly improved knee OA pain which had been inadequately controlled by NSAIDs. In those subjects who showed favorable response to tramadol/APAP and NSAID combination therapy, both tramadol/APAP and NSAIDs were effective at maintaining the pain-reduced state and there was no significant difference in efficacy between tramadol/APAP and NSAIDs.

Epidemiological data, efficacy and safety of a paracetamol-tramadol fixed combination in the treatment of moderate-to-severe pain. SALZA: a post-marketing study in general practice

OBJECTIVE

To evaluate the efficacy and safety of the paracetamol-tramadol combination (PTC) in treating moderate-to-severe pain, in patients aged 65 years and over within general practitioner (GP) practice centers.

RESEARCH DESIGN AND METHODS

This was an observational, non-interventional, longitudinal, multicenter, open, non-comparative, prospective study. This intermediary analysis was of patients recruited before the French Health Authority confirmation (25th June, 2009) of the EMEA decision to withdraw all analgesics containing dextropropoxyphen. Trial registration information: This study has been submitted for approval to the CNIL and French Medical Council (CNOM) only.

RESULTS

A total of 2663 patients aged 65 years or over were assessed 1 month after inclusion in the study. PTC was prescribed as first-line treatment in 30% of patients and, in the other cases, after failed or inadequate efficacy (69.8%), and/or as a result of safety problems (7.8%) with at least one other analgesic. During the month of the study period 14.7% of patients received an additional rescue analgesic. The study confirmed the efficacy of PTC with regard to pain intensity (-3.1 points reduction of pain scored 6.1 points on inclusion), pain relief (64.8% of patients experienced significant pain relief), patient satisfaction (90.5% of patients satisfied or completely satisfied) and clinical global impression evaluated by the patient (78.7% much or very much improved), regardless of the pain etiologies or duration of the underlying pathology. PTC was well-tolerated in this patient group, who had a mean age of 73.6 ± 6.6 years. A total of 119 patients (4.5%) reported at least one adverse event (AE). All were known and predictable AEs. This percentage is comparable to that found under similar conditions in patients of all ages (4.2%).

CONCLUSIONS

PTC, due to the complementary action of its two analgesics, is effective in treating the different types of pain in a GP's practice setting and is well-tolerated, even in an elderly population. Study limitations include all those inherent to non-interventional and open-label observations.

Tramadol/paracetamol combination tablet for postoperative pain following ambulatory hand surgery: a double-blind, double-dummy, randomized, parallel-group trial

This randomized, double-blind, double-dummy, multicenter trial compared efficacy and safety of tramadol HCL 37.5 mg/paracetamol 325 mg combination tablet with tramadol HCL 50 mg capsule in the treatment of postoperative pain following ambulatory hand surgery with iv regional anesthesia. Patients received trial medication at admission, immediately after surgery, and every 6 hours after discharge until midnight of the first postoperative day. Analgesic efficacy was assessed by patients (n = 128 in each group, full analysis set) and recorded in a diary on the evening of surgery day and of the first postoperative day. They also documented the occurrence of adverse events. By the end of the first postoperative day, the proportion of treatment responders based on treatment satisfaction (primary efficacy variable) was comparable between the groups (78.1% combination, 71.9% tramadol; P = 0.24) and mean pain intensity (rated on a numerical scale from 0 = no pain to 10 = worst imaginable pain) had been reduced to 1.7 ± 2.0 for both groups. Under both treatments, twice as many patients experienced no pain (score = 0) on the first postoperative day compared to the day of surgery (35.9% vs 16.4% for tramadol/paracetamol and 36.7% vs 18% for tramadol treatment). Rescue medication leading to withdrawal (diclofenac 50 mg) was required by 17.2% patients with tramadol/paracetamol and 13.3% with tramadol. Adverse events (mainly nausea, dizziness, somnolence, vomiting, and increased sweating) occurred less frequently in patients under combination treatment (P = 0.004). Tramadol/paracetamol combination tablets provided comparable analgesic efficacy with a better safety profile to tramadol capsules in patients experiencing postoperative pain following ambulatory hand surgery.

[Economic evaluation of tramadol/paracetamol in the management of pain in patients with osteoarthritis in Spain]

OBJECTIVE

To compare the costs of treating osteoarthritis (OA) pain using combination tramadol/paracetamol tablets, Non-Steroidal Anti-Inflammatory Agents (NSAID) alone or NSAID plus proton pump inhibitors (PPI) from the perspective of the Spanish National Health System.

METHODS

A decision-analytical model was constructed to analyze the cost associated with three treatment strategies over 6 months. A cost-minimization approach was used, which considered data related to resource use, medication costs and costs for the treatment of adverse events.

RESULTS

In the base-case analysis, costs for 6 months of treatment of OA pain using tramadol/paracetamol were €232.86, compared with €274.60 for NSAID + PPI and €133.75 for NSAID alone. This provided a savings of €41.74 per patient over 6 months for tramadol/paracetamol compared with NSAID + PPI and a cost increase of €99.11 compared with NSAID alone. When renal adverse events associated with NSAID were considered, tramadol/paracetamol was cost saving compared with all NSAID-based regimens (saving €140.02 vs NSAID alone, €280.86 vs NSAID + PPI).

CONCLUSION

Based on the results of a theoretical decision-analytic model, the data obtained may suggest that tramadol/paracetamol is cost saving compared with NSAID + PPI for the treatment of OA pain over a period of 6 months. Tramadol/paracetamol is also cost saving compared with treatment with NSAID alone if considering renal adverse events.

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.

Outcomes associated with opioid use in the treatment of chronic noncancer pain in older adults: a systematic review and meta-analysis

This systematic review summarizes existing evidence regarding the efficacy, safety, and abuse and misuse potential of opioids as treatment for chronic noncancer pain in older adults. Multiple databases were searched to identify relevant studies published in English (1/1/80-7/1/09) with a mean study population age of 60 and older. Forty-three articles were identified and retained for review (40 reported safety and efficacy data, the remaining 3 reported misuse or abuse outcome data). The weighted mean subject age was 64.1 (mean age range 60-73). Studies enrolled patients with osteoarthritis (70%), neuropathic pain (13%), and other pain-producing disorders (17%). The mean duration of treatment studies was 4 weeks (range 1.5-156 weeks), and only five (12%) lasted longer than 12 weeks. In meta-analyses, effect sizes were -0.557 (P<.001) for pain reduction, -0.432 (P<.001) for physical disability reduction, and 0.859 (P=.31) for improved sleep. The effect size for the Medical Outcomes Study 36-item Health Survey was 0.191 (P=.17) for the physical component score and -0.220 (P=.04) for the mental component score. Adults aged 65 and older were as likely as those younger than 65 to benefit from treatment. Common adverse events included constipation (median frequency of occurrence 30%), nausea (28%), and dizziness (22%) and prompted opioid discontinuation in 25% of cases. Abuse and misuse behaviors were negatively associated with older age. In older adults with chronic pain and no significant comorbidity, short-term use of opioids is associated with reduction in pain intensity and better physical functioning but poorer mental health functioning. The long-term safety, efficacy, and abuse potential of this treatment practice in diverse populations of older persons remain to be determined.

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.

Assessment of the impact of flares in ankylosing spondylitis disease activity using the Flare Illustration

OBJECTIVES

Many AS patients report periods of perceived higher disease activity (flares). This pilot study aims to document disease activity patterns reported by AS patients and examine associations with disease-specific health status measures.

METHODS

Consecutive AS patients (n = 114) were asked whether they experience flares, and if they experience symptoms of AS between flares. They were shown the Flare Illustration of disease patterns over time and asked to select the pattern that best described their disease (i) since symptom onset and (ii) in the past year. Associations between reported disease pattern and disease activity (Bath AS Disease Activity Index, BASDAI); functional impairment (Bath AS Functional Index, BASFI); AS Quality of Life (ASQoL); Back Pain (Nocturnal and Overall) and demographic features were assessed in a subsample (n = 83) (statistical significance defined at P <or= 0.05).

RESULTS

Since disease onset 108/113 patients (96%) reported flares, and 82/99 (83%) reported symptoms of AS between flares. Flares typically lasted days or weeks. When patients were asked to characterize their disease pattern using the Flare Illustration, patterns with constant symptoms predominated (>70% of patients) and patterns with constant symptoms since onset (vs intermittent symptoms) were associated with worse health status (ASQoL: P = 0.007; BASDAI: P = 0.029; BASFI: P = 0.013, overall back pain: P = 0.025).

CONCLUSIONS

Almost all AS patients report flares in disease activity: 70-80% report constant symptoms with single/repeated flares, while 20-30% report flares with no intermittent symptoms. The former is associated with a significantly poorer health status. These findings will be validated in a prospective study.

A 2-week, multicenter, randomized, double-blind, double-dummy, add-on study of the effects of titration on tolerability of tramadol/acetaminophen combination tablet in Korean adults with knee osteoarthritis pain

BACKGROUND

Combined tramadol/acetaminophen is used to treat pain related to osteoarthritis. However, adverse events (AEs) leading to discontinuation can occur. Dose titration may decrease the risk for AEs.

OBJECTIVE

The aim of this study was to assess the effect of tramadol/acetaminophen titration on the development of AEs leading to treatment discontinuation in patients with knee osteoarthritis.

METHODS

This 2-week, multicenter, randomized, double-blind, double-dummy, add-on study was conducted at 12 tertiary referral university hospitals in the Republic of Korea. Patients aged 35 to 75 years with knee osteoarthritis receiving a stable dose of NSAIDs and with a daily mean pain-intensity score of > or = 4 on a numeric rating scale (NRS) (0 = no pain to 10 = worst pain) during the 48 hours prior to enrollment were eligible. Patients were randomly assigned to receive 1 tablet of tramadol/acetaminophen 37.5/325 mg QD and 1 placebo BID for 3 days, followed by 1 active tablet BID and 1 placebo QD for 4 days, followed by 1 active tablet TID for 7 days (titration group) or 1 tablet of combined tramadol 37.5 mg/acetaminophen 325 mg TID for 14 days (nontitration group). The primary outcome measure was the rate of treatment discontinuation due to AEs. Secondary outcome measures were time to discontinuation due to AEs, prevalences and characteristics of AEs, decrease from baseline in pain intensity as measured on the NRS, and change in the Korean version of the Western Ontario and McMaster Universities (K-WOMAC) index score (scale: 0 = best to 100 = worst).

RESULTS

A total of 250 patients were enrolled (92.0% female; mean [SD] age, 60.2 [7.8] years; mean [SD] weight, 60.0 [9.2] kg [range, 37.5-90.7 kg]; all Korean). The discontinuation rate was significantly lower in the titration group than in the nontitration group (10.5% vs 26.2%; P < 0.001). The Kaplan-Meier survival curve showed that the rates of discontinuation due to AEs were similar in the 2 groups up to day 2, but thereafter the discontinuation rate was significantly lower in the titration group. The most common AEs were nausea (12.1% and 24.6% in the titration and nontitration groups, respectively; P = 0.008), vomiting (4.0% and 17.2%; P < 0.001), and dizziness (9.7% and 22.1%; P = 0.005). No serious AEs were reported in either group. Tramadol/acetaminophen use was associated with a similar decrease from baseline in pain in both the titration and nontitration groups (mean [SD] Delta: NRS, -1.60 [1.62] vs -1.68 [1.58]; total K-WOMAC, -12.86 [13.73] vs -12.52 [16.58]).

CONCLUSIONS

In this population of Korean patients with knee osteoarthritis pain managed with a stable dose of NSAIDs, titration of tramadol/acetaminophen over 12 days was associated with improved tolerability and a significantly lower discontinuation rate compared with nontitration. Both regimens significantly reduced from baseline associated with osteoarthritis.

Efficacy and safety of opioids for osteoarthritis: a meta-analysis of randomized controlled trials

OBJECTIVES

To determine the analgesic effectiveness, the effect on physical function and the safety of opioids in patients with osteoarthritis (OA).

SEARCH STRATEGY

A systematic literature search was performed in electronic databases up to October 2006. A hand search of references was also performed.

SELECTION CRITERIA

All randomized controlled trials evaluating the efficacy and/or the safety of opioids vs placebo or non-opioid analgesics in patients with OA were selected.

DATA COLLECTION AND ANALYSIS

Data were collected using a predetermined form. Statistical analysis determined in each trial the effect size to assess the magnitude of treatment effect and the number needed to harm (NNH) to evaluate opioids safety.

MAIN RESULTS

Eighteen randomized placebo-controlled trials were analyzed, i.e., a total of 3244 participants who received opioids and 1612 who received placebo. The mean trial duration was 13+/-18 weeks. The pooled effect sizes of all opioids vs placebo for pain intensity and physical function were -0.79 (95% confidence interval, CI, -0.98 to -0.59) and -0.31 (95% CI -0.39 to -0.24), respectively. The NNH was calculated to be 5 vs placebo. The number of studies (n=4) that compared opioids with non-opioid analgesics (paracetamol and non-steroidal anti-inflammatory drugs) was too limited to provide robust data.

CONCLUSIONS

Opioids significantly decrease pain intensity and have small benefits on function compared with placebo in patients with OA. Adverse events, although reversible and not life threatening, often cause participants to stop taking the medication and could limit opioid usefulness. Moreover, the long-term efficacy and safety of these drugs for OA is yet to be determined due to the short mean trial duration.

Tramadol/Acetaminophen or Hydrocodone/Acetaminophen for the Treatment of Ankle Sprain: A Randomized, Placebo-Controlled Trial

STUDY OBJECTIVE

This randomized, multicenter study compares the analgesic efficacy and safety of tramadol/acetaminophen versus hydrocodone/acetaminophen versus placebo for the treatment of acute musculoskeletal pain caused by ankle sprain.

METHODS

Adults were enrolled with ankle sprain with a diagnosis of partial ligament tear, pain visual analog scale score of 50 to 100 mm (0="no pain," 100="extreme pain"), and pain numeric rating scale score of 2 to 3 (0="none," 3="severe"). Patients reported pain intensity on these scales and pain relief (-1="pain worse," 4="complete relief") hourly for 4 hours after the first dose of tramadol/acetaminophen 75 mg/650 mg, hydrocodone/acetaminophen 7.5 mg/650 mg, or placebo, and daily for 5 days, with as-needed dosing.

RESULTS

Tramadol/acetaminophen (n=192) and hydrocodone/acetaminophen (n=204) provided greater total pain relief than placebo (n=207; P<.001) during the first 4 hours (mean scores [95% confidence interval (CI)] 6.6 [95% CI 6.1 to 7.1], 6.8 [95% CI 6.3 to 7.3], and 5.4 [95% CI 4.9 to 5.9], respectively; possible range -4 to 16), decreased pain intensity during the first 4 hours, and increased average pain relief on days 1 to 5. No efficacy measure was significantly different between the tramadol/acetaminophen and hydrocodone/acetaminophen groups. Common adverse events included somnolence, nausea, dizziness, and vomiting.

CONCLUSION

One or 2 capsules of 37.5 mg tramadol/325 mg acetaminophen and 1 capsule of 7.5 mg hydrocodone/650 mg acetaminophen were well tolerated, had comparable clinical utility, and were more effective than placebo in the management of acute musculoskeletal pain caused by ankle sprain.

Tramadol 37.5-mg/acetaminophen 325-mg combination tablets added to regular therapy for rheumatoid arthritis pain: a 1-week, randomized, double-blind, placebo-controlled trial

OBJECTIVE

This study evaluated the efficacy and tolerability of tramadol 37.5-mg/acetaminophen 325-mg combination tablets (tramadoUAPAP) as add-on therapy in subjects with rheumatoid arthritis (RA) pain that was inadequately controlled by NSAIDs and disease-modifying antirheumatic drugs alone.

METHODS

Subjects in this multicenter, double-blind trial were randomized in a 3:1 ratio to receive 1 tramadol/ APAP tablet TID or a matching placebo for 1 week. Stable doses of previous medications were continued during the study. The primary efficacy variable was the mean daily pain relief score over 1 week, measured on a 6-point scale (4 = complete; ' = a lot; 2 = some; 1 = a little; 0 = none; -1 = worse). Secondary outcomes included the mean daily pain intensity score, measured on a 100-mm visual analog scale (VAS) (from 0 mm = no pain to 100 mm = extreme pain); pain intensity and pain relief at day 7; subjects' and investigators' mean overall assessments of study drug, measured on a Likert scale (from 2 = very good to -2 = very poor); and subjects' assessments of 8 aspects of physical function (measured on the Health Assessment Questionnaire).

RESULTS

Of 277 subjects randomized to treatment, 267 (201 tramadol/APAP, 66 placebo) were included in the intent-to-treat population. Mean (SD) daily pain relief scores at the end of 1 week were significantly greater in the tramadol/APAP group compared with the placebo group (1.04 [0.89] vs 0.78 [0.80], respectively; P = 0.037), and mean daily pain intensity scores at the end of 1 week were significantly lower (47.23 [19.96] vs 53.81 [16.59]; P = 0.018). Physical function at the end of 1 week did not differ significantly between tramadol/APAP and placebo. Two hundred seventy-two subjects (205 tramadol/APAP, 67 placebo) were evaluable for tolerability. One hundred thirty-three of these subjects had at least 1 adverse event. The incidence of adverse events was significantly higher in the tramadol/APAP group than in the placebo group (57.6% vs 22.4%; P < 0.001). Discontinuations due to adverse events occurred in 19.0% of the tramadol/APAP group and 3.0% of the placebo group (P = 0.001). Of 213 treatment-related adverse events in tramadol/APAP subjects, nausea (34.1%) was the most frequent, followed by dizziness (20.0%) and vomiting (15.6%). One serious adverse event--chest discomfort, nausea, and vomiting after taking study medication-occurred in a subject receiving tramadol/APAP The symptoms resolved 1 day after discontinuing tramadol/APAP.

CONCLUSIONS

In this study, tramadol/APAP used as add-on therapy in subjects with symptomatic RA was associated with a significant improvement in pain relief and a significant reduction in pain intensity compared with placebo, with no improvement in physical function. Use of tramadol/APAP may be considered when analgesics are needed in addition to conventional NSAIDs and disease-modifying antirheumatic drugs in subjects with RA.

Randomized study of tramadol/acetaminophen versus placebo in painful diabetic peripheral neuropathy

OBJECTIVE

To examine the efficacy and safety of tramadol/acetaminophen (APAP) for the management of painful diabetic peripheral neuropathy (DPN).

METHODS

Adults with painful DPN involving the lower extremities received 37.5 mg tramadol/325 mg APAP or placebo, up to 1-2 tablets four times daily, for 66 days. Subjects rated average daily pain and sleep interference from 0 ('none') to 10 ('pain as bad as you can imagine' or 'complete interference') every night. Baseline values were recorded for 7 days before starting study medication. The primary endpoint was change in mean of average daily pain scores from baseline to final week. Secondary efficacy outcomes included pain intensity, sleep interference, quality of life, mood, and global impression of change. Potential study limitations included permission to use serotonin reuptake inhibitors concomitantly (except venlafaxine or duloxetine) and the lack of a tramadol-alone or APAP-alone control group.

RESULTS

A total of 160 subjects received tramadol/APAP and 153 received placebo. Tramadol/APAP reduced average daily pain significantly compared to placebo from baseline to the final week (-2.71 vs. -1.83, p = 0.001). Tramadol/APAP was associated with significantly greater improvement than placebo (p < or = 0.05) for all measures of pain intensity, sleep interference, and global impression, as well as several measures of quality of life and mood. The only adverse event reported by > 10% of subjects in either the tramadol/APAP or placebo group was nausea (11.9% and 3.3%, respectively). Adverse events resulted in early study discontinuation for 8.1% and 6.5% of subjects in the tramadol/APAP and placebo groups, respectively.

CONCLUSION

Tramadol/APAP was more effective than placebo and was well tolerated in the management of painful DPN.

Opioids for neuropathic pain

Whether opioids are effective for neuropathic pain has been a matter of controversy for decades. Within limits, it is clear that opioids in general are effective for neuropathic pain. Furthermore, there is no evidence that opioids are any less effective for neuropathic pain than for non-neuropathic pain, no evidence that opioids are less effective for neuropathic pain than are other medications, and no evidence that one opioid is any more effective than another for neuropathic pain. It remains uncertain whether opioids are effective for central pain, although they may have a role. Although some patients appear to enjoy long-term benefits, most studies have been short-term. Opioids have an important role in the treatment of neuropathic pain; however, skillful opioid use balances the benefits with management of side effects and prevention and treatment of abuse and addiction.

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.

Combination analgesia in 2005 - a rational approach: focus on paracetamol-tramadol

A multimodal (or balanced) approach to anaesthesia is a familiar concept that offers important benefits in the management of both acute and chronic pain. Rational combinations of analgesic agents with different mechanisms of action can achieve improved efficacy and/or tolerability and safety compared with equianalgesic doses of the individual drugs. Combining different agents also enhances efficacy in complex pain states that involve multiple causes. Combinations of paracetamol plus a weak opioid agent are widely used. One such combination, paracetamol plus tramadol, exploits the well-established complementary pharmacokinetics and mechanisms of action of these two drugs. This combination has demonstrated genuine synergy in animal studies and also combines paracetamol's rapid onset of efficacy with tramadol's prolonged analgesic effect. Numerous studies have confirmed the efficacy and tolerability of paracetamol plus tramadol in both acute and chronic pain. As a single-dose treatment for acute post-operative pain, this combination delivers rapid and sustained pain relief that is greater than either agent alone. There is also extensive evidence for efficacy in the long-term management of chronic pain conditions, including osteoarthritis, low back pain and fibromyalgia. In the setting of chronic pain, paracetamol plus tramadol has shown sustained efficacy, safety and tolerability for up to 2 years without the development of tolerance. The efficacy of this combination has been demonstrated as well in respect to reduction of pain intensity and, more importantly, with regard to improvement of function and quality of life and the reduction of disability. Comparative trials have shown that paracetamol plus tramadol has comparable efficacy to paracetamol plus codeine, but with reduced somnolence and constipation compared with the codeine combination. The paracetamol plus tramadol combination is also free of organ toxicity associated with selective and non-selective non-steroidal anti-inflammatory drugs. Hence, paracetamol plus tramadol offers an effective and well-tolerated alternative to anti-inflammatory drugs or other paracetamol plus weak opioid combinations.

Pharmacological aspects of successful long-term analgesia

Persistent pain represents a major quality-of-life burden for patients and a challenge for their physician. Chronic pain often arises from multiple tissue sources and involves multiple chemical mediators and pain transmission pathways. Successful long-term pain management requires analgesic regimens that can treat pains of multiple origin and type. Safety and tolerability are also a high priority when prescribing chronic therapy. Recent publications and regulatory developments affecting anti-inflammatory drugs have limited the options available for the management of chronic pain. Major concerns in long-term use of anti-inflammatory drugs include renal toxicity, gastrointestinal ulceration and bleeding and cardiovascular events, which can be of particular concern for elderly patients. Opioid agents avoid the end-organ toxicity seen with anti-inflammatory drugs, but their use may be limited, especially in the long term, by side effects such as constipation or sedation and by concerns about the potential for physical or psychological dependence. Paracetamol (acetaminophen) has a favourable safety and tolerability profile, although exceeding the recommended dose (up to 4 g/day) carries a risk of liver damage. It exerts simultaneous anti-nociception at both spinal and supra-spinal sites, and has shown self-synergy between these two routes of activity. Tramadol, an atypical weak opioid with a multi-modal mechanism of action, inhibits re-uptake of multiple neurotransmitters and has an improved safety and tolerability profile compared with traditional opioids. Rational combinations of analgesic drugs offer a viable approach to managing persistent pain that involves multiple sites or pathways. The combination of paracetamol plus tramadol brings together two well-known analgesics that have different but complementary mechanisms of analgesic action. Laboratory studies have demonstrated that these agents interact to produce synergistic analgesia with a desirable safety/efficacy profile.

Opioids for chronic noncancer pain: a meta-analysis of effectiveness and side effects

BACKGROUND

Chronic noncancer pain (CNCP) is a major health problem, for which opioids provide one treatment option. However, evidence is needed about side effects, efficacy, and risk of misuse or addiction.

METHODS

This meta-analysis was carried out with these objectives: to compare the efficacy of opioids for CNCP with other drugs and placebo; to identify types of CNCP that respond better to opioids; and to determine the most common side effects of opioids. We searched MEDLINE, EMBASE, CENTRAL (up to May 2005) and reference lists for randomized controlled trials of any opioid administered by oral or transdermal routes or rectal suppositories for CNCP (defined as pain for longer than 6 mo). Extracted outcomes included pain, function or side effects. Methodological quality was assessed with the Jadad instrument; analyses were conducted with Revman 4.2.7.

RESULTS

Included were 41 randomized trials involving 6019 patients: 80% of the patients had nociceptive pain (osteoarthritis, rheumatoid arthritis or back pain); 12%, neuropathic pain (postherpetic neuralgia, diabetic neuropathy or phantom limb pain); 7%, fibromyalgia; and 1%, mixed pain. The methodological quality of 87% of the studies was high. The opioids studied were classified as weak (tramadol, propoxyphene, codeine) or strong (morphine, oxycodone). Average duration of treatment was 5 (range 1-16) weeks. Dropout rates averaged 33% in the opioid groups and 38% in the placebo groups. Opioids were more effective than placebo for both pain and functional outcomes in patients with nociceptive or neuropathic pain or fibromyalgia. Strong, but not weak, opioids were significantly superior to naproxen and nortriptyline, and only for pain relief. Among the side effects of opioids, only constipation and nausea were clinically and statistically significant.

INTERPRETATION

Weak and strong opioids outperformed placebo for pain and function in all types of CNCP. Other drugs produced better functional outcomes than opioids, whereas for pain relief they were outperformed only by strong opioids. Despite the relative shortness of the trials, more than one-third of the participants abandoned treatment.