Further look at dextropropoxyphene with or without paracetamol in the treatment of arthritis

Oral or transdermal opioids for osteoarthritis of the knee or hip

BACKGROUND

Osteoarthritis is the most common form of joint disease and the leading cause of pain and physical disability in older people. Opioids may be a viable treatment option if people have severe pain or if other analgesics are contraindicated. However, the evidence about their effectiveness and safety is contradictory. This is an update of a Cochrane review first published in 2009.

OBJECTIVES

To determine the effects on pain, function, safety, and addiction of oral or transdermal opioids compared with placebo or no intervention in people with knee or hip osteoarthritis.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE and CINAHL (up to 28 July 2008, with an update performed on 15 August 2012), checked conference proceedings, reference lists, and contacted authors.

SELECTION CRITERIA

We included randomised or quasi-randomised controlled trials that compared oral or transdermal opioids with placebo or no treatment in people with knee or hip osteoarthritis. We excluded studies of tramadol. We applied no language restrictions.

DATA COLLECTION AND ANALYSIS

We extracted data in duplicate. We calculated standardised mean differences (SMDs) and 95% confidence intervals (CI) for pain and function, and risk ratios for safety outcomes. We combined trials using an inverse-variance random-effects meta-analysis.

MAIN RESULTS

We identified 12 additional trials and included 22 trials with 8275 participants in this update. Oral oxycodone was studied in 10 trials, transdermal buprenorphine and oral tapentadol in four, oral codeine in three, oral morphine and oral oxymorphone in two, and transdermal fentanyl and oral hydromorphone in one trial each. All trials were described as double-blind, but the risk of bias for other domains was unclear in several trials due to incomplete reporting. Opioids were more beneficial in pain reduction than control interventions (SMD -0.28, 95% CI -0.35 to -0.20), which corresponds to a difference in pain scores of 0.7 cm on a 10-cm visual analogue scale (VAS) between opioids and placebo. This corresponds to a difference in improvement of 12% (95% CI 9% to 15%) between opioids (41% mean improvement from baseline) and placebo (29% mean improvement from baseline), which translates into a number needed to treat (NNTB) to cause one additional treatment response on pain of 10 (95% CI 8 to 14). Improvement of function was larger in opioid-treated participants compared with control groups (SMD -0.26, 95% CI -0.35 to -0.17), which corresponds to a difference in function scores of 0.6 units between opioids and placebo on a standardised Western Ontario and McMaster Universities Arthritis Index (WOMAC) disability scale ranging from 0 to 10. This corresponds to a difference in improvement of 11% (95% CI 7% to 14%) between opioids (32% mean improvement from baseline) and placebo (21% mean improvement from baseline), which translates into an NNTB to cause one additional treatment response on function of 11 (95% CI 7 to 14). We did not find substantial differences in effects according to type of opioid, analgesic potency, route of administration, daily dose, methodological quality of trials, and type of funding. Trials with treatment durations of four weeks or less showed larger pain relief than trials with longer treatment duration (P value for interaction = 0.001) and there was evidence for funnel plot asymmetry (P value = 0.054 for pain and P value = 0.011 for function). Adverse events were more frequent in participants receiving opioids compared with control. The pooled risk ratio was 1.49 (95% CI 1.35 to 1.63) for any adverse event (9 trials; 22% of participants in opioid and 15% of participants in control treatment experienced side effects), 3.76 (95% CI 2.93 to 4.82) for drop-outs due to adverse events (19 trials; 6.4% of participants in opioid and 1.7% of participants in control treatment dropped out due to adverse events), and 3.35 (95% CI 0.83 to 13.56) for serious adverse events (2 trials; 1.3% of participants in opioid and 0.4% of participants in control treatment experienced serious adverse events). Withdrawal symptoms occurred more often in opioid compared with control treatment (odds ratio (OR) 2.76, 95% CI 2.02 to 3.77; 3 trials; 2.4% of participants in opioid and 0.9% of participants control treatment experienced withdrawal symptoms).

AUTHORS' CONCLUSIONS

The small mean benefit of non-tramadol opioids are contrasted by significant increases in the risk of adverse events. For the pain outcome in particular, observed effects were of questionable clinical relevance since the 95% CI did not include the minimal clinically important difference of 0.37 SMDs, which corresponds to 0.9 cm on a 10-cm VAS.

Opioid therapy for treating rheumatoid arthritis pain

BACKGROUND

Despite improvements in the management of rheumatoid arthritis (RA), pain control is often inadequate even when inflammation is well controlled.

OBJECTIVES

To assess the efficacy and safety of opioid analgesics for treating pain in patients with RA.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library), MEDLINE and EMBASE for studies to May 2010. We also searched the 2008 to 2009 American College of Rheumatology (ACR) and European League against Rheumatism (EULAR) abstracts and performed a handsearch of the reference lists of articles.

SELECTION CRITERIA

Studies were included if they were randomized or quasi-randomized controlled trials (RCTs or CCTs) which compared opioid therapy to another therapy (active or placebo) for pain in patients with RA. Outcomes of interest were pain, adverse effects, function and quality of life.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected the studies for inclusion, extracted the data, and performed a risk of bias assessment.

MAIN RESULTS

Eleven studies (672 participants) were included in the review. Four studies assessed the efficacy of single doses of various opioid and non-opioid analgesics; a pooled analysis of these studies was not performed but in each study opioids reduced pain more than placebo. There were no differences between analgesic drugs in these studies.Seven studies were between one and six weeks in duration and assessed six different oral opioids (dextropropoxyphene, codeine, tramadol, tilidine, pentazocine, morphine), either alone or combined with non-opioid analgesics. The only strong opioid investigated was controlled-release morphine sulphate, in a single study with 20 participants. Six studies compared an opioid to placebo. Opioids were superior to placebo in patient-reported global impression of change (3 studies, 324 participants: relative risk (RR) 1.44, 95% CI 1.03 to 2.03) but not for the number of withdrawals due to inadequate analgesia (4 studies, 345 participants: RR 0.82, 95% CI 0.34 to 2.0). Adverse events (most commonly nausea, vomiting, dizziness and constipation) were more frequent in patients receiving opioids compared to placebo (4 studies, 371 participants: odds ratio 3.90, 95% CI 2.31 to 6.56); the pooled risk ratio for withdrawal due to adverse events was 2.67 (3 studies, 331 participants: 95% CI 0.52 to 13.75). One study compared an opioid (codeine with paracetamol) to an NSAID (diclofenac) and found no difference in efficacy or safety between interventions.

AUTHORS' CONCLUSIONS

There is limited evidence that weak oral opioids may be effective analgesics for some patients with RA, but adverse effects are common and may offset the benefits of this class of medications. There is insufficient evidence to draw conclusions regarding the use of weak opioids for longer than six weeks, or the role of strong opioids.

Combination therapy for pain management in inflammatory arthritis (rheumatoid arthritis, ankylosing spondylitis, psoriatic arthritis, other spondyloarthritis)

BACKGROUND

Despite optimal therapy with disease-modifying antirheumatic drugs, many people with inflammatory arthritis (IA) continue to have persistent pain that may require additional therapy.

OBJECTIVES

To assess the benefits and safety of combination pain therapy for people with IA (rheumatoid arthritis (RA), ankylosing spondylitis (AS), psoriatic arthritis (PsA) and other spondyloarthritis (SpA)). We planned to assess differences in effects between patients on background disease-modifying antirheumatic drug (DMARD) therapy and patients on no background therapy in subgroup analyses.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library); MEDLINE; and EMBASE. We did not impose any date or language restrictions in the search. We also handsearched conference proceedings of the American College of Rheumatology and the European League against Rheumatism (2008-10).

SELECTION CRITERIA

Randomised and controlled clinical trials (RCTs and CCTs) assessing combination therapy (at least two drugs from the following classes: analgesics, non-steroidal anti-inflammatory drugs (NSAIDs), opioids, opioid-like drugs and neuromodulators (antidepressants, anticonvulsants and muscle relaxants)) compared with monotherapy, for adults with IA (RA, AS, PsA and other SpA). We speficically excluded studies that did not report pain or studies without a standardised pain scale as an outcome measure.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials for inclusion, assessed risk of bias and extracted data.

MAIN RESULTS

Twenty-three trials (total of 912 patients) met the inclusion criteria (22 in RA; one in a mixed population of RA and osteoarthritis); all except one were published before 1990. Most study populations were not taking DMARDs (e.g. methotrexate, sulphasalazine, hydroxychloroquine and leflunomide) and all studies were performed prior to the introduction of biologic therapies (e.g. etanercept, infliximab and adalimumab). All trials were at high risk of bias, heterogeneity precluded meta-analysis, and we were only able to report a general description of results.The majority (18 studies, 78%) found no differences between the combination and monotherapy treatments they studied, while five (22%) reported conflicting results, favouring either the combination or monotherapy arms.From the 12 trials on NSAID + analgesic vs NSAID, nine reported no significant difference between the interventions, while three did: in two, the combination therapy achieved better pain control; and the third trial compared combination therapy with two different dosages of monotherapy (NSAID alone) and reported that a high dose phenylbutazone was superior to combination therapy (paracetamol + aspirin), which was superior to low dose phenylbutazone.From the five studies on the combination of two NSAIDS vs one NSAID, four reported no significant differences between interventions, and one reported significantly better pain control with combination therapy.The single trial comparing a combination of opioid + neuromodulator vs opioid reported better pain control with monotherapy.The remaining trials (NSAID + neuromodulator vs NSAID (3 trials); opioid + NSAID vs NSAID (1 trial); and opioid + analgesic vs analgesic (1 trial)) found no significant difference between combination therapy and monotherapy.Information regarding withdrawals due to inadequate analgesia and safety was incompletely reported, but in general there were no differences between combination therapy and monotherapy.No data were available that addressed the value of combination pain therapy or monotherapy for people with IA who have optimal disease suppression. There were no studies that included patients with AS, PsA or SpA.

AUTHORS' CONCLUSIONS

Based on 23 trials, all at high risk of bias, there is insufficient evidence to establish the value of combination therapy over monotherapy for people with IA. Importantly, there are no studies addressing the value of combination therapy for patients with IA who have persistent pain despite optimal disease suppression. Well designed trials are needed to address this question.

Oral or transdermal opioids for osteoarthritis of the knee or hip

BACKGROUND

Osteoarthritis is the most common form of joint disease and the leading cause of pain and physical disability in the elderly. Opioids may be a viable treatment option if patients suffer from severe pain or if other analgesics are contraindicated. However, the evidence about their effectiveness and safety is contradictory.

OBJECTIVES

To determine the effects on pain and function and the safety of oral or transdermal opioids as compared with placebo or no intervention in patients with osteoarthritis of the hip or knee.

SEARCH STRATEGY

We searched CENTRAL, MEDLINE, EMBASE, and CINAHL (up to 28 July 2008), checked conference proceedings, reference lists, and contacted authors.

SELECTION CRITERIA

Studies were included if they were randomised or quasi-randomised controlled trials that compared oral or transdermal opioids with placebo or no treatment in patients with osteoarthritis of the knee or hip. Studies of tramadol were excluded. No language restrictions were applied.

DATA COLLECTION AND ANALYSIS

We extracted data in duplicate. Standardised mean differences (SMDs) and 95% confidence intervals (CI) were calculated for pain and function, and risk ratios for safety outcomes. Trials were combined using inverse-variance random-effects meta-analysis.

MAIN RESULTS

Ten trials with 2268 participants were included. Oral codeine was studied in three trials, transdermal fentanyl and oral morphine in one trial each, oral oxycodone in four, and oral oxymorphone in two trials. Overall, opioids were more effective than control interventions in terms of pain relief (SMD -0.36, 95% CI -0.47 to -0.26) and improvement of function (SMD -0.33, 95% CI -0.45 to -0.21). We did not find substantial differences in effects according to type of opioid, analgesic potency (strong or weak), daily dose, duration of treatment or follow up, methodological quality of trials, and type of funding. Adverse events were more frequent in patients receiving opioids compared to control. The pooled risk ratio was 1.55 (95% CI 1.41 to 1.70) for any adverse event (4 trials), 4.05 (95% CI 3.06 to 5.38) for dropouts due to adverse events (10 trials), and 3.35 (95% CI 0.83 to 13.56) for serious adverse events (2 trials). Withdrawal symptoms were more severe after fentanyl treatment compared to placebo (SMD 0.60, 95% CI 0.42 to 0.79; 1 trial).

AUTHORS' CONCLUSIONS

The small to moderate beneficial effects of non-tramadol opioids are outweighed by large increases in the risk of adverse events. Non-tramadol opioids should therefore not be routinely used, even if osteoarthritic pain is severe.

Treatment of chronic pain in osteoarthritis: do opioids have a clinical role?

Pain is the most prominent symptom and clinical finding in osteoarthritis (OA). Acetaminophen and nonsteroidal anti-inflammatory drug (NSAID) therapy are the mainstays of OA analgesia, but other drug and non-drug therapy, joint injections, and surgery may be needed to provide reasonable quality of life. Regularly scheduled, low-dose opioids can produce good relief of chronic nonmalignant pain including pain caused by OA. This paper reviews the potential risks and benefits of opioids, the evidence supporting their use in OA pain, and guidelines for their use in OA pain.

Pharmacotherapy and osteoarthritis

Therapy for osteoarthritis (OA) is aimed at relieving symptoms and at maximizing function. Therapies can be considered as either symptom modifying OA drugs (SMOADs) or as disease modifying OA drugs (DMOADs). Currently available agents fall into the category of SMOADs. Analgesic medications, particularly paracetamol and capsaicin, have proven efficacy in OA and are recommended first line therapies. Non-steroidal anti-inflammatory drugs (NSAIDs) do appear to provide extra symptomatic benefit for some patients but have greater toxicity. Newer generation NSAIDs may have safety advantages which remain to be confirmed in practice. Further therapies are being developed which aim to prevent cartilage damage and/or aid cartilage restoration, but these DMOADs remain in the experimental stage.

A double-blind crossover trial of diflunisal and naproxen in osteoarthritis

Fifty patients with osteoarthritis were studied in a double-blind, crossover trial of diflunisal (1000 mg daily) and naproxen (750 mg daily). In the 45 patients who completed the study, no significant difference was noted between the drugs in most of the parameters studied, including evening pain intensity and effectiveness rating by patient and investigator. There was a trend towards greater patient preference for diflunisal, although this trend did not reach statistical significance. Naproxen produced significantly fewer side-effects, although side-effects with both drugs were mild.