Single dose oral paracetamol (acetaminophen) for postoperative pain in adults

[Post-operative pain management in hospitals]

BACKGROUND

Relief of post-operative pain has a bearing on the patient's well-being, mobilisation and time confined to bed. The article discusses indications, contraindications and the efficacy of the various treatment modalities.

MATERIAL AND METHOD

We have examined review articles, meta-analyses and randomised controlled trials, identified through literature searches in PubMed.

RESULTS

The use of several medicines and techniques (multimodal pain treatment) is necessary to achieve a good balance between pain relief, side effects and risk. Systemic administration of paracetamol, NSAIDs, opioids and glucocorticoids is effective for post-operative pain. The same applies to epidural analgesia, peripheral nerve blocks and local anaesthetic wound infiltration. Subanaesthetic doses of ketamine have an opioid-sparing effect, but the optimal dosing regimen is uncertain. Gabapentinoids have an effect on post-operative pain, but the effect appears to vary depending on the type of operation and analgesic regimen. The effect of one analgesic will depend on which other drugs are used in multimodal pain treatment. Epidural analgesia, peripheral nerve blocks or extensive local infiltration analgesia is often necessary to relieve movement-related pain.

INTERPRETATION

Many treatment modalities are effective for post-operative pain. It is crucial that the treatment is well organised and that it includes routines for systematic pain assessment, efficacy and side effects of the pain management.

Single dose intravenous propacetamol or intravenous paracetamol for postoperative pain

BACKGROUND

Paracetamol (acetaminophen) is the most commonly prescribed analgesic for the treatment of acute pain. It may be administered orally or intravenously. The efficacy and safety of intravenous (IV) formulations of paracetamol, IV paracetamol and IV propacetamol, compared with placebo and other analgesics, is unclear.

OBJECTIVES

To assess the efficacy and safety of IV formulations of paracetamol for treatment of postoperative pain in both adults and children.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2010, Issue 2), MEDLINE (1950 to May 2010), EMBASE (1980 to 2010, Week 18), LILACS (1992 to May 2010) and reference lists of retrieved articles.

SELECTION CRITERIA

Randomized, double-blind, placebo- or active-controlled single dose clinical trials of IV propacetamol or IV paracetamol for acute postoperative pain in adults or children.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed the risk of bias and extracted data. We contacted study authors for additional information. We collected adverse event information from the studies.

MAIN RESULTS

Thirty-six studies (3896 participants) were included. Thirty-seven percent of participants receiving IV propacetamol/paracetamol experienced at least 50% pain relief over four hours compared with 16% of those receiving placebo (number needed to treat to benefit (NNT = 4.0; 95% confidence interval 3.5 to 4.8). The proportion of participants in IV propacetamol/paracetamol groups experiencing at least 50% pain relief diminished over six hours, as reflected in a higher NNT of 5.3 (4.2 to 6.7). Participants receiving IV propacetamol/paracetamol required 30% less opioid over four hours than those receiving placebo. However, this did not translate to a reduction in opioid-induced adverse events.Meta-analysis of efficacy comparisons between IV propacetamol/paracetamol and active comparators (opioids or nonsteroidal anti-inflammatories (NSAIDs)) were either not statistically significant, not clinically significant, or both.Adverse events occurred at similar rates with IV propacetamol or IV paracetamol and placebo. However, pain on infusion occurred more frequently in those receiving IV propacetamol versus placebo (23% versus 1%).Meta-analysis did not demonstrate statistically significant differences between IV propacetamol/paracetamol and active comparators for any adverse event except a reduction in the rate of hypotension versus NSAIDs and a reduction in the rate of gastrointestinal disorders versus opioids.

AUTHORS' CONCLUSIONS

A single dose of both IV propacetamol and IV paracetamol provides around four hours of effective analgesia for about 37% of patients with acute postoperative pain. Both formulations are associated with few adverse events, although patients receiving IV propacetamol have a higher incidence of pain on infusion than both placebo and IV paracetamol.

Single dose oral analgesics for acute postoperative pain in adults

BACKGROUND

Thirty-five Cochrane Reviews of randomised trials testing the analgesic efficacy of individual drug interventions in acute postoperative pain have been published. This overview brings together the results of all those reviews and assesses the reliability of available data.

OBJECTIVES

To summarise data from all Cochrane Reviews that have assessed the effects of pharmaceutical interventions for acute pain in adults with at least moderate pain following surgery, who have been given a single dose of oral analgesic taken alone.

METHODS

We identified systematic reviews in The Cochrane Library through a simple search strategy. All reviews were overseen by a single Review Group, had a standard title, and had as their primary outcome numbers of participants with at least 50% pain relief over four to six hours compared with placebo. For individual reviews we extracted the number needed to treat (NNT) for this outcome for each drug/dose combination, and also the percentage of participants achieving at least 50% maximum pain relief, the mean of mean or median time to remedication, the percentage of participants remedicating by 6, 8, 12, or 24 hours, and results for participants experiencing at least one adverse event.

MAIN RESULTS

The overview included 35 separate Cochrane Reviews with 38 analyses of single dose oral analgesics tested in acute postoperative pain models, with results from about 45,000 participants studied in approximately 350 individual studies. The individual reviews included only high-quality trials of standardised design and outcome reporting. The reviews used standardised methods and reporting for both efficacy and harm. Event rates with placebo were consistent in larger data sets. No statistical comparison was undertaken.There were reviews but no trial data were available for acemetacin, meloxicam, nabumetone, nefopam, sulindac, tenoxicam, and tiaprofenic acid. Inadequate amounts of data were available for dexibuprofen, dextropropoxyphene 130 mg, diflunisal 125 mg, etoricoxib 60 mg, fenbufen, and indometacin. Where there was adequate information for drug/dose combinations (at least 200 participants, in at least two studies), we defined the addition of four comparisons of typical size (400 participants in total) with zero effect as making the result potentially subject to publication bias and therefore unreliable. Reliable results were obtained for 46 drug/dose combinations in all painful postsurgical conditions; 45 in dental pain and 14 in other painful conditions.NNTs varied from about 1.5 to 20 for at least 50% maximum pain relief over four to six hours compared with placebo. The proportion of participants achieving this level of benefit varied from about 30% to over 70%, and the time to remedication varied from two hours (placebo) to over 20 hours in the same pain condition. Participants reporting at least one adverse event were few and generally no different between active drug and placebo, with a few exceptions, principally for aspirin and opioids.Drug/dose combinations with good (low) NNTs were ibuprofen 400 mg (2.5; 95% confidence interval (CI) 2.4 to 2.6), diclofenac 50 mg (2.7; 95% CI 2.4 to 3.0), etoricoxib 120 mg (1.9; 95% CI 1.7 to 2.1), codeine 60 mg + paracetamol 1000 mg (2.2; 95% CI 1.8 to 2.9), celecoxib 400 mg (2.5; 95% CI 2.2 to 2.9), and naproxen 500/550 mg (2.7; 95% CI 2.3 to 3.3). Long duration of action (≥ 8 hours) was found for etoricoxib 120 mg, diflunisal 500 mg, oxycodone 10 mg + paracetamol 650 mg, naproxen 500/550 mg, and celecoxib 400 mg.Not all participants had good pain relief and for many drug/dose combinations 50% or more did not achieve at last 50% maximum pain relief over four to six hours.

AUTHORS' CONCLUSIONS

There is a wealth of reliable evidence on the analgesic efficacy of single dose oral analgesics. There is also important information on drugs for which there are no data, inadequate data, or where results are unreliable due to susceptibility to publication bias. This should inform choices by professionals and consumers.

Single-dose intravenous paracetamol or propacetamol for prevention or treatment of postoperative pain: a systematic review and meta-analysis

Paracetamol is the most commonly prescribed analgesic for the treatment of acute pain. The efficacy and safety of i.v. formulations of paracetamol is unclear. We performed a systematic search (multiple databases, bibliographies, any language, to May 2010) for single-dose, randomized, controlled clinical trials of propacetamol or i.v. paracetamol for acute postoperative pain in adults or children. Thirty-six studies involving 3896 patients were included. For the primary outcome, 37% of patients (240/367) receiving propacetamol or i.v. paracetamol experienced at least 50% pain relief over 4 h compared with 16% (68/527) receiving placebo (number needed to treat=4.0; 95% confidence interval, 3.5-4.8). The proportion of patients in propacetamol or i.v. paracetamol groups experiencing at least 50% pain relief diminished over 6 h. Patients receiving propacetamol or paracetamol required 30% less opioid over 4 h and 16% less opioid over 6 h than those receiving placebo. However, this did not translate to a reduction in opioid-induced adverse events (AEs). Similar comparisons between propacetamol or i.v. paracetamol and active comparators were either not statistically significant, not clinically significant, or both. AEs occurred at similar rates with propacetamol or i.v. paracetamol and placebo. However, pain on infusion occurred more frequently in those receiving propacetamol compared with placebo (23% vs 1%). A single dose of either propacetamol or i.v. paracetamol provides around 4 h of effective analgesia for about 37% of patients with acute postoperative pain. Both formulations are associated with few AEs, although patients receiving propacetamol have a higher incidence of pain on infusion.

Single dose oral mefenamic acid for acute postoperative pain in adults

BACKGROUND

Mefenamic acid is a non-steroidal anti-inflammatory drug (NSAID). It is most often used for treating pain of dysmenorrhoea in the short term (seven days or less), as well as mild to moderate pain including headache, dental pain, postoperative and postpartum pain. It is widely available in many countries worldwide.

OBJECTIVES

To assess the efficacy of single dose oral mefenamic acid in acute postoperative pain, and any associated adverse events.

SEARCH STRATEGY

We searched Cochrane CENTRAL, MEDLINE, EMBASE and the Oxford Pain Relief Database for studies to December 2010.

SELECTION CRITERIA

Single oral dose, randomised, double-blind, placebo-controlled trials of mefenamic acid for relief of established moderate to severe postoperative pain in adults.

DATA COLLECTION AND ANALYSIS

Studies were assessed for methodological quality and the data extracted by two review authors independently. Summed total pain relief (TOTPAR) or pain intensity difference (SPID) over 4 to 6 hours was used to calculate the number of participants achieving at least 50% pain relief. These derived results were used to calculate, with 95% confidence intervals, the relative benefit compared to placebo, and the number needed to treat (NNT) for one participant to experience at least 50% pain relief over 4 to 6 hours. Numbers of participants using rescue medication over specified time periods, and time to use of rescue medication, were sought as additional measures of efficacy. Information on adverse events and withdrawals was collected.

MAIN RESULTS

Four studies with 842 participants met the inclusion criteria; 126 participants were treated with mefenamic acid 500 mg, 67 with mefenamic acid 250 mg, 197 with placebo, and 452 with lignocaine, aspirin, zomepirac or nimesulide. Participants had pain following third molar extraction, episiotomy and orthopaedic surgery. The NNT for at least 50% pain relief over 6 hours with a single dose of mefenamic acid 500 mg compared to placebo was 4.0 (2.7 to 7.1), and the NNT to prevent use of rescue medication over 6 hours was 6.5 (3.6 to 29). There were insufficient data to analyse other doses or active comparators, or numbers of participants experiencing any adverse events. No serious adverse events or adverse event withdrawals were reported in these studies.

AUTHORS' CONCLUSIONS

Oral mefenamic acid 500 mg was effective at treating moderate to severe acute postoperative pain, based on limited data. Efficacy of other doses, and safety and tolerability could not be assessed.

Single dose oral fenoprofen for acute postoperative pain in adults

BACKGROUND

Fenoprofen is a non-steroidal anti-inflammatory drug (NSAID), available in several different countries, but not widely used.

OBJECTIVES

To assess the efficacy of single dose oral fenoprofen in acute postoperative pain, and associated adverse events.

SEARCH STRATEGY

We searched Cochrane CENTRAL, MEDLINE, EMBASE and the Oxford Pain Relief Database for studies to December 2010.

SELECTION CRITERIA

Single oral dose, randomised, double-blind, placebo-controlled trials of fenoprofen for relief of established moderate to severe postoperative pain in adults.

DATA COLLECTION AND ANALYSIS

Studies were assessed for methodological quality and data extracted by two review authors independently. Summed total pain relief (TOTPAR) or pain intensity difference (SPID) over 4 to 6 hours was used to calculate the number of participants achieving at least 50% pain relief. These derived results were used to calculate, with 95% confidence intervals, the relative benefit compared to placebo, and the number needed to treat (NNT) for one participant to experience at least 50% pain relief over 4 to 6 hours. Numbers of participants using rescue medication over specified time periods, and time to use of rescue medication, were sought as additional measures of efficacy. Information on adverse events and withdrawals was collected.

MAIN RESULTS

Five studies (696 participants) met the inclusion criteria; 24 participants were treated with fenoprofen 12.5 mg, 23 with fenoprofen 25 mg, 79 with fenoprofen 50 mg, 78 with fenoprofen 100 mg, 146 with fenoprofen 200 mg, 55 with fenoprofen 300 mg, 43 with zomepirac 100 mg, 30 with morphine 8 mg, 77 with codeine 60 mg, and 141 with placebo. Participants had pain following third molar extraction, laparoscopy, minor day surgery and episiotomy. The NNT for at least 50% pain relief over 4 to 6 hours with a single dose of fenoprofen 200 mg compared to placebo was 2.3 (1.9 to 3.0). There were insufficient data to analyse other doses or active comparators, time to use of rescue medication, or numbers of participants needing rescue medication. There was no difference in numbers of participants experiencing any adverse events between fenoprofen 200 mg and placebo. No serious adverse events or adverse event withdrawals were reported in these studies.

AUTHORS' CONCLUSIONS

Oral fenoprofen 200 mg is effective at treating moderate to severe acute postoperative pain, based on limited data for at least 50% pain relief over 4 to 6 hours. Efficacy of other doses, other efficacy outcomes, and safety and tolerability could not be assessed.

A risk-benefit assessment of paracetamol (acetaminophen) combined with caffeine

OBJECTIVE

To determine the risk: benefit of paracetamol combined with caffeine in the short-term management of acute pain conditions.

DESIGN

Database searches were conducted to identify double-blind trials comparing paracetamol/caffeine with paracetamol alone (benefit analysis) and any data pertaining to hepatotoxicity of paracetamol when combined with caffeine (risk analysis).

INTERVENTIONS

Paracetamol/caffeine (1,000 mg/130 mg) vs paracetamol (1,000 mg) alone.

OUTCOME MEASURES

Assessment of benefit has been derived by meta-analysis. Information on the pain condition and number of patients studied, dosing regimen, study design and analgesic outcome measures (total pain relief scores) was extracted and dichotomous outcomes were obtained by calculating the number of patients in each treatment group who achieved at least 50% of the maximum total pain relief score. Assessment of risk has been made by appraisal of the literature.

RESULTS

Eight studies from four papers provided sufficient quantitative data for satisfactory meta-analysis. The relative benefit (of achieving at least 50% pain relief) of paracetamol/caffeine vs paracetamol alone was 1.12 (95% Confidence Interval 1.05-1.19) across a number of acute pain states (dysmenorrhoea, headache, post-partum pain, and dental pain). Review of the effects of the combination of paracetamol and caffeine on the liver revealed no compelling data to suggest a clinically meaningful increase in hepatotoxicity with use of paracetamol/caffeine combinations.

CONCLUSIONS

Paracetamol/caffeine (1,000 mg/130 mg) is effective and safe for use in acute management of pain. The hepatotoxicity of overdoses of paracetamol results from its oxidative metabolism, caffeine does not produce any increase in oxidative metabolism of therapeutic concentrations of paracetamol.

Single dose dipyrone for acute postoperative pain

BACKGROUND

Dipyrone (metamizole) is a non-steroidal anti-inflammatory drug used in some countries to treat pain (postoperative, colic, cancer, and migraine); it is banned in others because of an association with life-threatening blood agranulocytosis. This review updates a 2001 Cochrane review, and no relevant new studies were identified, but additional outcomes were sought.

OBJECTIVES

To assess the efficacy and adverse events of single dose dipyrone in acute postoperative pain.

SEARCH STRATEGY

The earlier review searched CENTRAL, MEDLINE, EMBASE, LILACS and the Oxford Pain Relief Database to December 1999. For the update we searched CENTRAL, MEDLINE,EMBASE and LILACS to February 2010.

SELECTION CRITERIA

Single dose, randomised, double-blind, placebo or active controlled trials of dipyrone for relief of established moderate to severe postoperative pain in adults. We included oral, rectal, intramuscular or intravenous administration of study drugs.

DATA COLLECTION AND ANALYSIS

Studies were assessed for methodological quality and data extracted by two review authors independently. Summed total pain relief over six hours (TOTPAR) was used to calculate the number of participants achieving at least 50% pain relief. Derived results were used to calculate, with 95% confidence intervals, relative benefit compared to placebo, and the number needed to treat (NNT) for one participant to experience at least 50% pain relief over six hours. Use and time to use of rescue medication were additional measures of efficacy. Information on adverse events and withdrawals was collected.

MAIN RESULTS

Fifteen studies tested mainly 500 mg oral dipyrone (173 participants), 2.5 g intravenous dipyrone (101), 2.5 g intramuscular dipyrone (99); fewer than 60 participants received any other dose. All studies used active controls (ibuprofen, paracetamol, aspirin, flurbiprofen, ketoprofen, dexketoprofen, ketorolac, pethidine, tramadol, suprofen); eight used placebo controls.Over 70% of participants experienced at least 50% pain relief over 4 to 6 hours with oral dipyrone 500 mg compared to 30% with placebo in five studies (288 participants; NNT 2.4 (1.9 to 3.2)). Fewer participants needed rescue medication with dipyrone (7%) than with placebo (34%; four studies, 248 participants). There was no difference in participants experiencing at least 50% pain relief with 2.5 g intravenous dipyrone and 100 mg intravenous tramadol (70% vs 65%; two studies, 200 participants). No serious adverse events were reported.

AUTHORS' CONCLUSIONS

Based on very limited information, single dose dipyrone 500 mg provides good pain relief to 70% of patients. For every five individuals given dipyrone 500 mg, two would experience this level of pain relief who would not have done with placebo, and fewer would need rescue medication, over 4 to 6 hours.

Single dose oral lumiracoxib for postoperative pain in adults

BACKGROUND

Lumiracoxib is a selective cyclooxygenase-2 (COX-2) inhibitor. COX-2 inhibitors were developed to avoid COX-1-related gastrointestinal (GI) problems while maintaining the analgesic and anti-inflammatory activity of traditional non-steriodal anti-inflammatory drugs (NSAIDs).

OBJECTIVES

To review the analgesic efficacy, duration of analgesia, and adverse effects of a single oral dose of lumiracoxib for moderate to severe postoperative pain in adults.

SEARCH STRATEGY

We searched Cochrane CENTRAL, MEDLINE, and EMBASE to February 2010.

SELECTION CRITERIA

Single oral dose, randomised, double-blind, placebo-controlled trials of lumiracoxib for relief of established moderate to severe postoperative pain in adults.

DATA COLLECTION AND ANALYSIS

Studies were assessed for methodological quality and the data extracted by two review authors independently. Summed total pain relief over six hours (TOTPAR 6) was used to calculate the number of participants achieving at least 50% pain relief. These derived results were used to calculate, with 95% confidence intervals, the relative benefit compared to placebo, and the number needed to treat (NNT) for one participant to experience at least 50% pain relief over six hours. Numbers of participants using rescue medication, and time to use of rescue medication, were sought as additional measures of efficacy. Information on adverse events and withdrawals was collected.

MAIN RESULTS

In this updated review four studies met the inclusion criteria. In total 366 participants were treated with lumiracoxib 400 mg, 51 with lumiracoxib 100 mg, and 212 with placebo. Active comparators were naproxen 500 mg, rofecoxib 50 mg, celecoxib 200 mg, celecoxib 400 mg, and ibuprofen 400 mg. With lumiracoxib 400 mg 50% of participants had at least 50% pain relief over six hours, compared with 8% given placebo; RB 6.9 (95% CI 4.1 to 12), NNT 2.4 (2.1 to 2.8).Median time to onset of analgesia was shorter for lumiracoxib 400 mg (0.6 to 1.5 hours) than placebo (>12 hours). Fewer participants needed rescue medication with lumiracoxib (64%) than with placebo (91%) over 12 to 24 hours; NNT to prevent remedication 3.7 (2.9 to 5.0). The weighted median time to use of rescue medication was 9.4 hours for lumiracoxib 400 mg and 1.7 hours for placebo.Adverse events were generally mild to moderate in severity, with one serious event reported in a placebo patient.

AUTHORS' CONCLUSIONS

Lumiracoxib 400 mg given as a single oral dose is an effective analgesic for acute postoperative pain, and has a relatively long duration of action. Adverse events with lumiracoxib did not differ from placebo.

Single dose oral gabapentin for established acute postoperative pain in adults

BACKGROUND

Gabapentin is an antiepileptic drug, also used in the treatment of neuropathic pain, which is the subject of a Cochrane review, currently under revision. Its efficacy in treating established acute postoperative pain has not been demonstrated.

OBJECTIVES

To assess the efficacy and safety of single dose oral gabapentin compared with placebo in established acute postoperative pain using methods that permit comparison with other analgesics.

SEARCH STRATEGY

We searched Cochrane CENTRAL, MEDLINE, EMBASE, and the Oxford Pain Relief Database. Additional studies were sought from reference lists of retrieved articles and reviews. Clinical trials databases were searched for unpublished studies; clinical trial reports of several unpublished studies have been made public following litigation in the US.

SELECTION CRITERIA

Single oral dose, randomised, double-blind, placebo-controlled trials of gabapentin for relief of established moderate to severe postoperative pain in adults.

DATA COLLECTION AND ANALYSIS

Studies were assessed for methodological quality and data extracted by two review authors independently. Numbers of participants with at least 50% of maximum possible total pain relief (TOTPAR) or summed pain intensity difference (SPID) with gabapentin or placebo were calculated and used to derive relative benefit (RB) or risk (RR), and number-needed-to-treat-to-benefit (NNT). Numbers of participants using rescue medication, and time to its use, were sought as additional measures of efficacy. Information on adverse events and withdrawals was collected.

MAIN RESULTS

Four unpublished studies met inclusion criteria; in three, participants had pain following dental surgery, and one followed major orthopaedic surgery; 177 participants were treated with a single dose of gabapentin 250 mg, 21 with gabapentin 500 mg, and 172 with placebo. At least 50% pain relief over 6 hours was achieved by 15% with gabapentin 250 mg and 5% with placebo; giving a RB of 2.5 (95% CI 1.2 to 5.0) and an NNT of 11 (6.4 to 35). Significantly fewer participants needed rescue medication within 6 hours with gabapentin 250 mg than with placebo; NNT to prevent use 5.8. About one third of participants reported adverse events with both gabapentin 250 mg and placebo. No serious adverse events occurred with gabapentin.

AUTHORS' CONCLUSIONS

Gabapentin 250 mg is statistically superior to placebo in the treatment of established acute postoperative pain, but the NNT of 11 for at least 50% pain relief over 6 hours with gabapentin 250 mg is of limited clinical value and inferior to commonly used analgesics. Gabapentin 250 mg is not clinically useful as a stand-alone analgesic in established acute postoperative pain, though this is probably the first demonstration of analgesic effect of an antiepileptic in established acute pain.

Single dose oral diflunisal for acute postoperative pain in adults

BACKGROUND

Diflunisal is a long-acting non-steroidal anti-inflammatory drug (NSAID) most commonly used to treat acute postoperative pain or chronic joint pain from osteoarthritis and rheumatoid arthritis. This review analyses the effectiveness and harm of different doses of diflunisal in the context of moderate to severe postoperative pain.

OBJECTIVES

To assess efficacy, duration of action, and associated adverse events of single dose oral diflunisal in acute postoperative pain in adults.

SEARCH STRATEGY

We searched Cochrane CENTRAL, MEDLINE, EMBASE and the Oxford Pain Relief Database for studies to January 2010.

SELECTION CRITERIA

Randomised, double blind, placebo-controlled trials of single dose orally administered diflunisal in adults with moderate to severe acute postoperative pain.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data. Pain relief or pain intensity data were extracted and converted into the dichotomous outcome of number of participants with at least 50% pain relief over 4 to 6 hours, from which relative risk and number-needed-to-treat-to-benefit (NNT) were calculated. Numbers of participants using rescue medication over specified time periods, and time to use of rescue medication, were sought as additional measures of efficacy. Information on adverse events and withdrawals were collected.

MAIN RESULTS

Nine studies in dental, orthopedic and gynaecological surgery met the inclusion criteria, testing doses of diflunisal from 125 mg to 1000 mg.For diflunisal 1000 mg, the NNT for at least 50% pain relief over 4 to 6 hours was 2.1 (1.8 to 2.6) (6 studies, 391 participants); the NNT to prevent remedication within 6 hours was 1.9 (1.7 to 2.3), and within 12 hours was 2.2 (1.9 to 2.7) (6 studies, 409 participants). More participants experienced adverse events with diflunisal 100 mg than with placebo, but none were serious or led to withdrawal.For diflunisal 500 mg, the NNT for at least 50% pain relief over 4 to 6 hours was 2.6 (2.1 to 3.3) (6 studies, 357 participants); the NNT to prevent remedication within 6 hours was 2.6 (2.1 to 3.4) (6 studies, 390 participants), and within 12 hours was 2.9 (2.3 to 4.0) (5 studies, 329 participants). Adverse events did not differ significantly from placebo.

AUTHORS' CONCLUSIONS

Diflunisal has an analgesic effect similar to other NSAIDs in single dose, but benefits from providing significant analgesia for about twelve hours. This property may be useful when regular dosing is needed, or when taking several doses of a shorter acting analgesic is impractical.

Single dose oral codeine, as a single agent, for acute postoperative pain in adults

BACKGROUND

Codeine is an opioid metabolised to active analgesic compounds, including morphine. It is widely available by prescription, and combination drugs including low doses of codeine are commonly available without prescription.

OBJECTIVES

To assess the efficacy, the time to onset of analgesia, the time to use of rescue medication and any associated adverse events of single dose oral codeine in acute postoperative pain.

SEARCH STRATEGY

We searched CENTRAL, MEDLINE, EMBASE and PubMed to November 2009.

SELECTION CRITERIA

Single oral dose, randomised, double-blind, placebo-controlled trials of codeine for relief of established moderate to severe postoperative pain in adults.

DATA COLLECTION AND ANALYSIS

Studies were assessed for methodological quality and data independently extracted by two review authors. Summed total pain relief (TOTPAR) or pain intensity difference (SPID) over 4 to 6 hours were used to calculate the number of participants achieving at least 50% pain relief, which were used to calculate, with 95% confidence intervals, the relative benefit compared to placebo, and the number needed to treat (NNT) for one participant to experience at least 50% pain relief over 4 to 6 hours. Numbers using rescue medication over specified time periods, and time to use of rescue medication, were sought as additional measures of efficacy. Data on adverse events and withdrawals were collected.

MAIN RESULTS

Thirty-five studies were included (1223 participants received codeine 60 mg, 27 codeine 90 mg, and 1252 placebo). Combining all types of surgery (33 studies, 2411 participants), codeine 60 mg had an NNT of at least 50% pain relief over 4 to 6 hours of 12 (8.4 to 18) compared with placebo. At least 50% pain relief was achieved by 26% on codeine 60 mg and 17% on placebo.Following dental surgery the NNT was 21 (12 to 96) (15 studies, 1146 participants), and following other types of surgery the NNT was 6.8 (4.6 to 13) (18 studies, 1265 participants). The NNT to prevent use of rescue medication within 4 to 6 hours was 11 (6.3 to 50) (11 studies, 765 participants, mostly non-dental); the mean time to its use was 2.7 hours with codeine and 2.0 hours with placebo. More participants experienced adverse events with codeine 60 mg than placebo; the difference was not significant and none were serious. Two adverse event withdrawals occurred with placebo.

AUTHORS' CONCLUSIONS

Single dose codeine 60 mg provides good analgesia to few individuals, and does not compare favourably with commonly used alternatives such as paracetamol, NSAIDs and their combinations with codeine, especially after dental surgery; the large difference between dental and other surgery was unexpected. Higher doses were not evaluated.

Paracetamol/acetaminophen (single administration) for perineal pain in the early postpartum period

BACKGROUND

Perineal pain is a common but poorly studied adverse outcome following childbirth. Pain may result from perineal trauma due to bruising, spontaneous tears, surgical incisions (episiotomies), or in association with operative births (ventouse or forceps assisted births).

OBJECTIVES

To determine the efficacy of a single administration of paracetamol (acetaminophen) systemic drugs used in the relief of acute postpartum perineal pain

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (December 2009).

SELECTION CRITERIA

Randomised controlled trials (RCTs) assessing paracetamol (acetaminophen) in a single dose compared with placebo for women with early postpartum perineal pain. We excluded quasi-RCTs and cross-over studies.

DATA COLLECTION AND ANALYSIS

Two review authors assessed each paper for inclusion and extracted data. One review author reviewed the decisions and confirmed calculations for pain relief scores.

MAIN RESULTS

We have included 10 studies describing two dosages of paracetamol. Of these, five studies (526 women) assessed 500 mg to 650 mg and six studies (841 women) assessed 1000 mg of paracetamol. We chose to use random-effects meta-analyses because of the heterogeneity in dosage used. Studies were from the 1970s to the early 1990s, and there was insufficient information to assess the risk of bias adequately, hence the findings need to be interpreted within this context.More women experienced pain relief with paracetamol compared with placebo (average risk ratio (RR) 2.14, 95% confidence interval (CI) 1.59 to 2.89, 10 studies, 1279 women). In addition, there were significantly fewer women having additional pain relief with paracetamol compared with placebo (RR 0.34, 95% CI 0.21 to 0.55, eight studies, 1132 women). Both the 500 mg to 650 mg and 1000 mg doses were effective in providing more pain relief than placebo.Maternal and neonatal potential adverse drug effects were not assessed in any of the included studies. Indeed few secondary outcomes were assessed.

AUTHORS' CONCLUSIONS

More women experienced pain relief, and fewer had additional pain relief, with paracetamol compared with placebo, although potential adverse effects were not assessed and generally the quality of studies was unclear.

Single dose oral nabumetone for acute postoperative pain in adults

BACKGROUND

Nabumetone is a non-steroidal anti-inflammatory drug (NSAID) used mainly in treating pain associated with arthritis. The usual oral dose for osteoarthritis is 1000 mg daily, and higher doses are not advised in older patients. There are no known systematic reviews of its analgesic efficacy in acute postoperative pain. This review sought to evaluate the efficacy and safety of oral nabumetone in acute postoperative pain, using clinical studies of patients with established pain, and with outcomes measured primarily over 6 hours using standard methods. This type of study has been used for many decades to establish whether drugs have analgesic properties.

OBJECTIVES

To assess the efficacy of single dose oral nabumetone in acute postoperative pain, and any associated adverse events.

SEARCH STRATEGY

We searched The Cochrane Library (Issue 2, 2009), MEDLINE (May 2009); EMBASE via Ovid (May 2009); and the Oxford Pain Relief Database.

SELECTION CRITERIA

Randomised, double-blind, placebo-controlled clinical trials of oral nabumetone for relief of acute postoperative pain in adults.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data. The area under the "pain relief versus time" curve was used to derive the proportion of participants with nabumetone and placebo experiencing at least 50% pain relief over 4 to 6 hours, using validated equations. The number needed to treat to benefit (NNT) was calculated using 95% confidence intervals (CI). The proportion of participants using rescue analgesia over a specified time period, and time to use of rescue analgesia, were sought as additional measures of efficacy. Information on adverse events and withdrawals was also collected.

MAIN RESULTS

No studies were identified by the searches that examined oral nabumetone in participants with established postoperative pain.

AUTHORS' CONCLUSIONS

In the absence of evidence of efficacy, at present, for oral nabumetone in acute postoperative pain, its use in this indication is not justified. Because trials clearly demonstrating analgesic efficacy in the most basic of acute pain studies is lacking, use in other indications should be evaluated carefully. Given the large number of available drugs of this and similar classes, there is no urgent research agenda.

Single dose oral fenbufen for acute postoperative pain in adults

BACKGROUND

Fenbufen is a non-selective non-steroidal anti-inflammatory drug (NSAID), used to treat acute and chronic painful conditions. There is no known systematic review of its use in acute postoperative pain.

OBJECTIVES

To assess efficacy, duration of action, and associated adverse events of single dose oral fenbufen in acute postoperative pain in adults.

SEARCH STRATEGY

We searched Cochrane CENTRAL, MEDLINE, EMBASE and the Oxford Pain Relief database for studies to June 2009.

SELECTION CRITERIA

Randomised, double blind, placebo-controlled trials of single dose orally administered fenbufen in adults with moderate to severe acute postoperative pain.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data. Pain relief or pain intensity data were extracted and converted into the dichotomous outcome of number of participants with at least 50% pain relief over 4 to 6 hours, from which relative risk and number needed to treat to benefit (NNT) were calculated. Numbers of participants using rescue medication over specified time periods, and time to use of rescue medication, were sought as additional measures of efficacy. Information on adverse events and withdrawals were collected.

MAIN RESULTS

Searches identified only one study with (90 participants in total, 31 taking fenbufen). The study compared oral fenbufen 800 mg, fenbufen 400 mg, and placebo in participants with established postoperative pain. Fenbufen at both doses had apparent analgesic efficacy, but the numbers of participants was too small to allow sensible analysis. Gastrointestinal adverse events were noted in 4 of 15 participants taking fenbufen 800 mg.

AUTHORS' CONCLUSIONS

In the absence of evidence of efficacy for oral fenbufen in acute postoperative pain, its use in this indication is not justified at present. Because trials clearly demonstrating analgesic efficacy in the most basic of acute pain studies is lacking, use in other indications should be evaluated carefully. Given the large number of available drugs of this and similar classes which are effective, there is no urgent research agenda for this particular drug.

Single dose oral sulindac for acute postoperative pain in adults

BACKGROUND

Sulindac is a non-steroidal anti-inflammatory drug (NSAID) licensed for use in rheumatic disease and other musculoskeletal disorders in the UK, and widely available in other countries worldwide. This review sought to evaluate the efficacy and safety of oral sulindac in acute postoperative pain, using clinical studies of patients with established pain, and with outcomes measured primarily over 6 hours using standard methods. This type of study has been used for many decades to establish that drugs have analgesic properties.

OBJECTIVES

To assess the efficacy of single dose oral sulindac in acute postoperative pain, and any associated adverse events.

SEARCH STRATEGY

We searched Cochrane CENTRAL, MEDLINE, EMBASE and the Oxford Pain Relief Database for studies up to June 2009.

SELECTION CRITERIA

Randomised, double-blind, placebo-controlled clinical trials of oral sulindac for relief of acute postoperative pain in adults.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data. We planned to use area under the "pain relief versus time" curve to derive the proportion of participants with meloxicam experiencing least 50% pain relief over 4 to 6 hours, using validated equations; to use number needed to treat to benefit (NNT); the proportion of participants using rescue analgesia over a specified time period; time to use of rescue analgesia; information on adverse events and withdrawals.

MAIN RESULTS

No studies were identified by the searches that examined oral sulindac in patients with established postoperative pain.

AUTHORS' CONCLUSIONS

In the absence of evidence of efficacy, at present, for oral sulindac in acute postoperative pain, its use in this indication is not justified. Because trials clearly demonstrating analgesic efficacy in the most basic of acute pain studies is lacking, use in other indications should be evaluated carefully. Given the large number of available drugs of this and similar classes, there is no urgent research agenda.

Single dose oral ketoprofen and dexketoprofen for acute postoperative pain in adults

BACKGROUND

Ketoprofen is a non-selective non-steroidal anti-inflammatory drug (NSAID) used to treat acute and chronic painful conditions. Dexketoprofen is the (S)-enantiomer, which is believed to confer analgesia. Theoretically dexketoprofen is expected to provide equivalent analgesia to ketoprofen at half the dose, with a consequent reduction in gastrointestinal adverse events.

OBJECTIVES

To assess efficacy, duration of action, and associated adverse events of single dose oral ketoprofen and dexketoprofen in acute postoperative pain in adults.

SEARCH STRATEGY

We searched Cochrane CENTRAL, MEDLINE, EMBASE and the Oxford Pain Relief Database for studies to August 2009.

SELECTION CRITERIA

Randomised, double blind, placebo-controlled trials of single dose orally administered ketoprofen and dexketoprofen in adults with moderate to severe acute postoperative pain.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data. Pain relief or pain intensity data were extracted and converted into the dichotomous outcome of number of participants with at least 50% pain relief over 4 to 6 hours, from which relative risk and number-needed-to-treat-to-benefit (NNT) were calculated. Numbers of participants using rescue medication over specified time periods, and time to use of rescue medication, were sought as additional measures of efficacy. Information on adverse events and withdrawals was collected.

MAIN RESULTS

Fourteen studies compared ketoprofen (968 participants) at mainly 25 mg and 50 mg with placebo (520 participants). Seven studies compared dexketoprofen (681 participants) at mainly 10 mg to 25 mg with placebo (289 participants). Studies were of adequate reporting quality, and participants had pain following dental, orthopaedic, obstetric, gynaecological and general surgery. There was considerable clinical heterogeneity between studies in dental and other types of surgery, particularly bunionectomy, which limited analysis.Ketoprofen at doses between 12.5 mg and 100 mg produced NNTs for at least 50% pain relief over 4 to 6 hours of 2.4 to 3.3. For dental studies only there was a trend to more efficacy at higher doses, with NNT decreasing from 2.4 at 12.5 mg to 1.6 at 100 mg. Dexketoprofen at doses of 10/12.5 mg and 20/25 mg produced NNTs for at least 50% pain relief over 4 to 6 hours of 3.2 and 3.6, with no obvious dose response. Significantly fewer participants used rescue medication with ketoprofen and dexketoprofen than placebo. The median time to remedication was about 5 hours with ketoprofen and 4 hours with dexketoprofen. The expected equivalent efficacy with a half dose of dexketoprofen compared to ketoprofen was not demonstrated.Adverse events were uncommon with both drugs, and not significantly different from placebo.

AUTHORS' CONCLUSIONS

Ketoprofen at doses of 25 mg to 100 mg is an effective analgesic in moderate to severe acute postoperative pain with an NNT for at least 50% pain relief of 3.3 with a 50 mg dose. This is similar to that of commonly used NSAIDs such as ibuprofen (NNT 2.5 for 400 mg dose) and diclofenac (NNT 2.7 at 50 mg dose). Duration of action is about 5 hours. Dexketoprofen is also effective with NNTs of 3.2 to 3.6 in the dose range 10 mg to 25 mg. Both drugs were well tolerated in single doses.

Single dose oral meloxicam for acute postoperative pain in adults

BACKGROUND

Meloxicam is a non-steroidal anti-inflammatory drug (NSAID) used mainly in treating pain associated with arthritis. The usual oral dose for osteoarthritis is 15 mg daily, but lower doses of 7.5 mg are advised in older patients. This review sought to evaluate the efficacy and safety of oral meloxicam in acute postoperative pain, using clinical studies of patients with established pain, and with outcomes measured primarily over 6 hours using standard methods. This type of study has been used for many decades to establish that drugs have analgesic properties.

OBJECTIVES

To assess the efficacy of single dose oral meloxicam in acute postoperative pain, and any associated adverse events.

SEARCH STRATEGY

We searched Cochrane CENTRAL (Issue 2, 2009), MEDLINE (June 2009); EMBASE (June 2009); the Oxford Pain Relief Database.

SELECTION CRITERIA

Randomised, double-blind, placebo-controlled clinical trials of oral meloxicam for relief of acute postoperative pain in adults.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data. We planned to use area under the "pain relief versus time" curve to derive the proportion of participants with meloxicam experiencing least 50% pain relief over 4 to 6 hours, using validated equations; to use number needed to treat to benefit (NNT); the proportion of participants using rescue analgesia over a specified time period; time to use of rescue analgesia; information on adverse events and withdrawals.

MAIN RESULTS

No studies were identified by the searches that examined oral meloxicam in patients with established postoperative pain.

AUTHORS' CONCLUSIONS

In the absence of evidence of efficacy, at present, for oral meloxicam in acute postoperative pain, its use in this indication is not justified. Because trials clearly demonstrating analgesic efficacy in the most basic of acute pain studies is lacking, use in other indications should be evaluated carefully. Given the large number of available drugs of this and similar classes, there is no urgent research agenda.

Single dose oral tiaprofenic acid for acute postoperative pain in adults

BACKGROUND

Tiaprofenic acid is a a non-steroidal anti-inflammatory drug (NSAID). It is widely available around the world, with indications for osteoarthritis, rheumatoid arthritis, ankylosing spondylitis, periarticular disorders, and strains and sprains. This review sought to evaluate the efficacy and safety of oral tiaprofenic acid in acute postoperative pain, using clinical studies of patients with established pain, and with outcomes measured primarily over 6 hours using standard methods. This type of study has been used for many decades to establish that drugs have analgesic properties.

OBJECTIVES

To assess the efficacy of single dose oral tiaprofenic acid in acute postoperative pain, and any associated adverse events.

SEARCH STRATEGY

We searched Cochrane CENTRAL, MEDLINE, EMBASE and the Oxford Pain Relief Database for studies to June 2009.

SELECTION CRITERIA

Randomised, double blind, placebo-controlled trials of single dose orally administered tiaprofenic acid in adults with moderate to severe acute postoperative pain.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data. We planned to use area under the "pain relief versus time" curve to derive the proportion of participants with tiaprofenic acid experiencing at least 50% pain relief over 4 to 6 hours, using validated equations; to use number needed to treat to benefit (NNT); the proportion of participants using rescue analgesia over a specified time period; time to use of rescue analgesia; information on adverse events and withdrawals.

MAIN RESULTS

Not one of eleven studies identified by the searches and examined in detail studied oral tiaprofenic acid against placebo in patients with established postoperative pain and therefore no results are available.

AUTHORS' CONCLUSIONS

In the absence of evidence of efficacy for oral tiaprofenic acid in acute postoperative pain, its use in this indication is not justified at present. Because trials clearly demonstrating analgesic efficacy in the most basic of acute pain studies is lacking, use in other indications should be evaluated carefully. Given the large number of available drugs of this and similar classes which are effective, there is no urgent research agenda for this particular drug.

Single dose oral rofecoxib for acute postoperative pain in adults

BACKGROUND

Editor's note: The anti-inflammatory drug rofecoxib (Vioxx) was withdrawn from the market at the end of September 2004 after it was shown that long-term use (greater than 18 months) could increase the risk of heart attack and stroke in a study of secondary prevention of adenoma recurrence. Further information is available at www.vioxx.com.Rofecoxib is a selective cyclooxygenase-2 (COX-2) inhibitor previously licensed for treating acute and chronic pain; it was associated with fewer gastrointestinal adverse events than conventional NSAIDs. An earlier Cochrane review (Barden 2005) showed that rofecoxib is at least as effective as conventional non-steroidal anti-inflammatory drugs (NSAIDs) for postoperative pain.

OBJECTIVES

To assess the analgesic efficacy and adverse effects of rofecoxib in single oral doses for moderate and severe postoperative pain.

SEARCH STRATEGY

We searched Cochrane CENTRAL, MEDLINE, EMBASE and the Oxford Pain Relief Database for studies to June 2009.

SELECTION CRITERIA

Randomised, double blind, placebo-controlled trials of single dose orally administered rofecoxib in adults with moderate to severe acute postoperative pain.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data. Pain relief or pain intensity data were extracted and converted into the dichotomous outcome of number of participants with at least 50% pain relief over 4 to 6 hours, from which relative risk and number needed to treat to benefit (NNT) were calculated. Numbers of participants using rescue medication over specified time periods, and time to use of rescue medication, were sought as additional measures of efficacy. Information on adverse events and withdrawals was collected.

MAIN RESULTS

Twenty new studies and seven from the earlier review met the inclusion criteria. Twenty-four studies were in dental surgery and three in other types of surgery. In total, 2636 participants were treated with rofecoxib 50 mg, 20 with rofecoxib 500 mg, and 1251 with placebo. The NNT for at least 50% pain relief over 4 to 6 hours with rofecoxib 50 mg was 2.2 (2.0 to 2.3) in all studies combined, 1.9 (1.8 to 2.0) in dental studies, and 6.8 (4.6 to 13) in other types of surgery. The median time to use of rescue medication was 14 hours for rofecoxib 50 mg and 2 hours for placebo. Significantly fewer participants used rescue medication following rofecoxib 50 mg than with placebo. Adverse events did not differ from placebo.

AUTHORS' CONCLUSIONS

Rofecoxib 50 mg (two to four times the standard daily dose for chronic pain) is an effective single dose oral analgesic for acute postoperative pain in adults, with a relatively long duration of action.

Single dose oral lornoxicam for acute postoperative pain in adults

BACKGROUND

Lornoxicam is one of the oxicam class of non-steroidal anti-inflammatory drugs (NSAIDs), producing analgesic and antipyretic effects in part through the non-selective inhibition of cyclo-oxygenase-1 and -2. It is prescribed for osteoarthritis, rheumatoid arthritis, acute lumbar-sciatica conditions and for postoperative pain management. Lornoxicam is available in 31 countries in Europe, the Middle East, Far East and South America, and is becoming more widely available.

OBJECTIVES

To assess the efficacy, the time to onset of analgesia, the time to use of rescue medication and any associated adverse events of single dose oral lornoxicam in acute postoperative pain.

SEARCH STRATEGY

We searched CENTRAL, MEDLINE, EMBASE and PubMed to June 2009.

SELECTION CRITERIA

Single oral dose, randomised, double-blind, placebo-controlled trials of lornoxicam for relief of established moderate to severe postoperative pain in adults.

DATA COLLECTION AND ANALYSIS

Studies were assessed for methodological quality and the data extracted by two review authors independently. Summed total pain relief over 6 hours (TOTPAR 6) was used to calculate the number of participants achieving at least 50% pain relief. These derived results were used to calculate, with 95% confidence intervals (CIs), the relative benefit compared to placebo, and the number needed to treat (NNT) for one participant to experience at least 50% pain relief over 6 hours. Numbers of participants using rescue medication over specified time periods, and time to use of rescue medication, were sought as additional measures of efficacy. Information on adverse events and withdrawals was collected.

MAIN RESULTS

Three studies, with 628 participants, met the inclusion criteria; 434 participants were treated with various doses (2 mg to 32 mg) of lornoxicam, 118 with placebo, and 76 with other active therapies. All the participants had pain following third molar extraction, and study duration was 8 to 24 hours. The NNT for at least 50% pain relief over 6 hours after a single dose of lornoxicam 8 mg was 2.9 (2.3 to 4.0). There were insufficient data to analyse other doses or use of rescue medication. No serious adverse events or withdrawals were reported by any of the studies.

AUTHORS' CONCLUSIONS

Oral lornoxicam is effective at treating moderate to severe acute postoperative pain, based on limited data. Adverse events did not differ significantly from placebo.

Consensus statement on the anticipation and prevention of acute postoperative pain: multidisciplinary RADAR approach

BACKGROUND

There has been considerable investment in efforts to improve postoperative pain management, including the introduction of acute pain teams. There have also been a number of guidelines published on postoperative pain management and there is widespread agreement on how pain should be practically managed. Despite these advances, there is no apparent improvement in the number of patients experiencing moderately severe or extreme pain after surgery. This highlights significant scope for improvement in acute postoperative pain management.

SCOPE

In January 2009, a multidisciplinary UK expert panel met to define and agree a practical framework to encourage implementation of the numerous guidelines and fundamentals of pain management at a local level. The panel recognised that to do this, there was a need to organise the information and guidelines into a simplified, accessible and easy-to-implement system based on their practical clinical experience. Given the volume of literature in this area, the Chair recommended that key international guidelines from professional bodies should be distributed and then reviewed during the meeting to form the basis of the framework. Consensus was reached by unanimous agreement of all ten participants.

FINDINGS

This report provides a framework for the key themes, including consensus recommendations based upon practical experience agreed during the meeting, with the aim of consolidating the key guidelines to provide a fundamental framework which is simple to teach and implement in all areas. Key priorities that emerged were: Responsibility, Anticipation, Discussion, Assessment and Response. This formed the basis of RADAR, a novel framework to help pain specialists educate the wider care team on understanding and prioritising the management of acute pain.

CONCLUSION

Acute postoperative pain can be more effectively managed if it is prioritised and anticipated by a well-informed care team who are educated with regard to appropriate analgesic options and understand what the long-term benefits of pain relief are. The principles of RADAR provide structure to help with training and implementation of good practice, to achieve effective postoperative pain management.

Single dose oral etodolac for acute postoperative pain in adults

BACKGROUND

Etodolac is a selective cyclo-oxygenase-2 (COX-2) inhibitor, with evidence of efficacy in osteoarthritis and rheumatoid arthritis. Its analgesic efficacy in postoperative pain has not been clearly established. There are no systematic reviews on Etodolac's use in this condition.

OBJECTIVES

To assess the analgesic efficacy of etodolac in single oral doses for moderate and severe postoperative pain.

SEARCH STRATEGY

We searched Cochrane CENTRAL, MEDLINE, EMBASE and the Oxford Pain Relief Database for studies to May 2009.

SELECTION CRITERIA

Randomised, double blind, placebo-controlled trials of single dose orally administered etodolac (any formulation) in adults with moderate to severe acute postoperative pain.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data. Pain relief or pain intensity data were extracted and converted into the dichotomous outcome of number of participants with at least 50% pain relief over 4 to 6 hours, from which relative risk (RR) and number needed to treat to benefit (NNT) were calculated. Numbers of participants using rescue medication over specified time periods, and time to use of rescue medication, were sought as additional measures of efficacy. Information on adverse events and withdrawals were collected.

MAIN RESULTS

Nine studies (1459 participants) compared etodolac and placebo. Studies were of adequate reporting quality, and the majority of participants had pain following dental extractions. The dose of etodolac used was 25 mg to 1200 mg, with most of the information for 100 mg and 200 mg. For at least 50% pain relief over 4 to 6 hours compared with placebo the NNT for etodolac 100 mg (498 participants) was 4.8 (3.5 to 7.8) and for etodolac 200 mg (670 participants) it was 3.3 (2.7 to 4.2). Very limited information with the extended release formulation did not suggest improved benefit for this outcome.The proportion of participants with at least 50% pain relief was 41% with 100 mg and 44% with 200 mg. Remedication was needed by about 60% with etodolac 200 mg or 400 mg over 6 to 8 hours, compared with almost 80% with placebo.Adverse events were uncommon, and not significantly different form placebo.

AUTHORS' CONCLUSIONS

Etodolac 200 mg may be a useful analgesic in postoperative pain, with efficacy similar to paracetamol 1000 mg and celecoxib 200 mg. Higher doses may provide analgesia equivalent to more commonly used drugs, such as ibuprofen 400 mg, naproxen 500 mg and diclofenac 50 mg.

Single dose oral ibuprofen for acute postoperative pain in adults

BACKGROUND

This review updates a 1999 Cochrane review showing that ibuprofen at various doses was effective in postoperative pain in single dose studies designed to demonstrate analgesic efficacy. New studies have since been published. Ibuprofen is one of the most widely used non-steroidal anti-inflammatory (NSAID) analgesics both by prescription and as an over-the-counter medicine. Ibuprofen is used for acute and chronic painful conditions.

OBJECTIVES

To assess analgesic efficacy of ibuprofen in single oral doses for moderate and severe postoperative pain in adults.

SEARCH STRATEGY

We searched Cochrane CENTRAL, MEDLINE, EMBASE and the Oxford Pain Relief Database for studies to May 2009.

SELECTION CRITERIA

Randomised, double blind, placebo-controlled trials of single dose orally administered ibuprofen (any formulation) in adults with moderate to severe acute postoperative pain.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data. Pain relief or pain intensity data were extracted and converted into the dichotomous outcome of number of participants with at least 50% pain relief over 4 to 6 hours, from which relative risk and number-needed-to-treat-to-benefit (NNT) were calculated. Numbers of participants using rescue medication over specified time periods, and time to use of rescue medication, were sought as additional measures of efficacy. Information on adverse events and withdrawals were collected.

MAIN RESULTS

Seventy-two studies compared ibuprofen and placebo (9186 participants). Studies were predominantly of high reporting quality, and the bulk of the information concerned ibuprofen 200 mg and 400 mg. For at least 50% pain relief compared with placebo the NNT for ibuprofen 200 mg (2690 participants) was 2.7 (2.5 to 3.0) and for ibuprofen 400 mg (6475 participants) it was 2.5 (2.4 to 2.6). The proportion with at least 50% pain relief was 46% with 200 mg and 54% with 400 mg. Remedication within 6 hours was less frequent with higher doses, with 48% remedicating with 200 mg and 42% with 400 mg. The median time to remedication was 4.7 hours with 200 mg and 5.4 hours with 400 mg. Sensitivity analysis indicated that pain model and ibuprofen formulation may both affect the result, with dental impaction models and soluble ibuprofen salts producing better efficacy estimates. Adverse events were uncommon, and not different from placebo.

AUTHORS' CONCLUSIONS

The very substantial amount of high quality evidence demonstrates that ibuprofen is an effective analgesic in treating postoperative pain. NNTs for 200 mg and 400 mg ibuprofen did not change significantly from the previous review even when a substantial amount of new information was added. New information is provided on remedication.

Single dose oral acemetacin for acute postoperative pain in adults

BACKGROUND

Acemetacin is a non-steroidal anti-inflammatory drug (NSAID) licensed for use in rheumatic disease and other musculoskeletal disorders in the UK, and widely available in other countries worldwide. This review sought to evaluate the efficacy and safety of oral acemetacin in acute postoperative pain, using clinical studies of patients with established pain, and with outcomes measured primarily over 6 hours using standard methods. This type of study has been used for many decades to establish that drugs have analgesic properties.

OBJECTIVES

To assess the efficacy of single dose oral acemetacin in acute postoperative pain, and any associated adverse events.

SEARCH STRATEGY

We searched CENTRAL (Issue 2, 2009), MEDLINE via Ovid (1966 to May 2009); EMBASE via Ovid (1980 to May 2009); the Oxford Pain Relief Database (1950 to 1994); and reference lists of articles.

SELECTION CRITERIA

Randomised, double-blind, placebo-controlled clinical trials of oral acemetacin for relief of acute postoperative pain in adults.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data. The area under the "pain relief versus time" curve was used to derive the proportion of participants with acemetacin and placebo experiencing least 50% pain relief over 4 to 6 hours, using validated equations. The number needed to treat to benefit (NNT) was calculated using 95% confidence intervals. The proportion of participants using rescue analgesia over a specified time period, and time to use of rescue analgesia, were sought as additional measures of efficacy. Information on adverse events and withdrawals was also collected.

MAIN RESULTS

No study fulfilled the inclusion criteria.

AUTHORS' CONCLUSIONS

In the absence of randomised evidence of efficacy for oral acemetacin in acute postoperative pain, we cannot, at present, make any conclusions regarding its effectiveness. Because trials clearly demonstrating analgesic efficacy in the most basic of acute pain studies is lacking, use in other indications should be evaluated carefully. Given the large number of available drugs of this kind and similar classes, there is no urgent research agenda for this drug.

Single dose oral oxycodone and oxycodone plus paracetamol (acetaminophen) for acute postoperative pain in adults

BACKGROUND

Oxycodone is a strong opioid agonist used to treat severe pain. It is commonly combined with milder analgesics such as paracetamol. This review updates a previous review that concluded, based on limited data, that all doses of oxycodone exceeding 5 mg, with or without paracetamol, provided analgesia in postoperative pain, but with increased incidence of adverse events compared with placebo. Additional new studies provide more reliable estimates of efficacy and harm.

OBJECTIVES

To assess efficacy, duration of action, and associated adverse events of single dose oral oxycodone, with or without paracetamol, in acute postoperative pain in adults.

SEARCH STRATEGY

Cochrane CENTRAL, MEDLINE, EMBASE and Oxford Pain Relief Database, searched in May 2009.

SELECTION CRITERIA

Randomised, double blind, placebo-controlled trials of single dose orally administered oxycodone, with or without paracetamol, in adults with moderate to severe acute postoperative pain.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data. Pain relief or pain intensity data were extracted and converted into the dichotomous outcome of number of participants with at least 50% pain relief over 4 to 6 hours, from which relative risk and number-needed-to-treat-to-benefit (NNT) were calculated. Numbers of participants remedicating over specified time periods, and time-to-use of rescue medication, were sought as additional measures of efficacy. Adverse events and withdrawals information was collected.

MAIN RESULTS

This updated review includes 20 studies, with 2641 participants. For oxycodone 15 mg alone compared with placebo, the NNT for at least 50% pain relief was 4.6 (95% Confidence Interval 2.9 to 11). For oxycodone 10 mg plus paracetamol 650 mg, the NNT was 2.7 (2.4 to 3.1). A dose response was demonstrated for this outcome with combination therapy. Duration of effect was 10 hours with oxycodone 10 mg plus paracetamol 650 mg, and 4 hours with half that dose. Fewer participants needed rescue medication over 6 hours at the higher dose. Adverse events occurred more frequently with combination therapy than placebo, but were generally described as mild to moderate in severity and rarely led to withdrawal.

AUTHORS' CONCLUSIONS

Single dose oxycodone is an effective analgesic in acute postoperative pain at doses over 5 mg; oxycodone is two to three times stronger than codeine. Efficacy increases when combined with paracetamol. Oxycodone 10 mg plus paracetamol 650 mg provides good analgesia to half of those treated, comparable to commonly used non-steroidal anti-inflammatory drugs, with the benefit of longer duration of action.

Single dose oral aceclofenac for postoperative pain in adults

BACKGROUND

Aceclofenac is the prodrug of the non-steroidal anti-inflammatory drug (NSAID) diclofenac, widely used to treat acute and chronic pain. There are no known systematic reviews of its analgesic efficacy in acute postoperative pain. This review sought to evaluate the efficacy and safety of oral aceclofenac in acute postoperative pain, using clinical studies of patients with established pain, and with outcomes measured primarily over 6 hours using standard methods. This type of study has been used for many decades to establish that drugs have analgesic properties.

OBJECTIVES

To assess the efficacy of single dose oral aceclofenac in acute postoperative pain, and any associated adverse events.

SEARCH STRATEGY

We searched The Cochrane Library (Issue 1, 2009), MEDLINE via Ovid (1966 to March 2009); EMBASE via Ovid (1980 to March 2009); the Oxford Pain Relief Database (1950 to 1994); and reference lists of articles.

SELECTION CRITERIA

Randomised, double-blind, placebo-controlled clinical trials of oral aceclofenac for relief of acute postoperative pain in adults.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data. The area under the "pain relief versus time" curve was used to derive the proportion of participants with paracetamol plus codeine and placebo or paracetamol alone experiencing least 50% pain relief over 4 to 6 hours, using validated equations. The number needed to treat to benefit (NNT) was calculated using 95% confidence intervals (CI). The proportion of participants using rescue analgesia over a specified time period, and time to use of rescue analgesia, were sought as additional measures of efficacy. Information on adverse events and withdrawals was also collected.

MAIN RESULTS

Searches identified only one study (217 participants total), which used oral aceclofenac 150 mg in patients with established postoperative pain. Aceclofenac 150 mg could not be distinguished from placebo, though ibuprofen 400 mg was distinguished from placebo.

AUTHORS' CONCLUSIONS

In the absence of evidence of efficacy for oral aceclofenac in acute postoperative pain (at least at 150 mg single dose), its use in this indication is not justified. Because trials clearly demonstrating analgesic efficacy in the most basic of acute pain studies are lacking, use in other indications should be evaluated carefully. Given the large number of effective drugs available in this and similar classes of analgesics, there is no urgent research agenda required to demonstrate the effective dose of aceclofenac in acute postoperative pain.

Single dose oral nefopam for acute postoperative pain in adults

BACKGROUND

Nefopam is a centrally-acting but non-opioid analgesic drug of the benzoxazocine chemical class, developed in the early 1970s. It is widely used, mainly in European countries, for the relief of moderate to severe pain as an alternative to opioid analgesic drugs, and used in rheumatic disease and other musculoskeletal disorders in the UK. This review sought to evaluate the efficacy and safety of oral nefopam in acute postoperative pain, using clinical studies of patients with established pain, and with outcomes measured primarily over 6 hours using standard methods. This type of study has been used for many decades to establish that drugs have analgesic properties.

OBJECTIVES

To assess the efficacy of single dose oral nefopam in acute postoperative pain, and any associated adverse events.

SEARCH STRATEGY

We searched CENTRAL (Issue 2, 2009), MEDLINE (1966 to May 2009); EMBASE via Ovid (1980 to May 2009); the Oxford Pain Relief Database (1950 to 1994); and reference lists of studies found.

SELECTION CRITERIA

Randomised, double-blind, placebo-controlled clinical trials of oral nefopam for relief of acute postoperative pain in adults.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data. The area under the "pain relief versus time" curve was used to derive the proportion of participants with nefopam and placebo experiencing least 50% pain relief over 4 to 6 hours, using validated equations. The number-needed-to-treat-to-benefit (NNT) was calculated using 95% confidence intervals (CIs). The proportion of participants using rescue analgesia over a specified time period, and time to use of rescue analgesia, were sought as additional measures of efficacy. Information on adverse events and withdrawals was also collected.

MAIN RESULTS

No included studies were identified after examining in detail thirteen studies on oral nefopam in participants with established postoperative pain.

AUTHORS' CONCLUSIONS

In the absence of evidence of efficacy for oral nefopam in acute postoperative pain, its use in this indication is not justified. Because trials clearly demonstrating analgesic efficacy in the most basic of acute pain studies are lacking, use in other indications should be evaluated carefully. Given the large number of available drugs of this and similar classes, there is no urgent research agenda.

Single dose oral tenoxicam for acute postoperative pain in adults

BACKGROUND

Tenoxicam is a non-steroidal anti-inflammatory drug (NSAID) licensed for use in rheumatic disease and other musculoskeletal disorders in the UK, and is widely available in other countries worldwide. This review sought to evaluate the efficacy and safety of oral tenoxicam in acute postoperative pain, using clinical studies of patients with established pain, and with outcomes measured primarily over 6 hours using standard methods. This type of study has been used for many decades to establish that drugs have analgesic properties.

OBJECTIVES

To assess the efficacy of single dose oral tenoxicam in acute postoperative pain, and any associated adverse events.

SEARCH STRATEGY

We searched The Cochrane Library (Issue 1, 2009), MEDLINE (March 2009); EMBASE via Ovid (March 2009); the Oxford Pain Relief Database.

SELECTION CRITERIA

Randomised, double-blind, placebo-controlled clinical trials of oral tenoxicam for relief of acute postoperative pain in adults.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data. The area under the "pain relief versus time" curve was used to derive the proportion of participants with tenoxicam experiencing least 50% pain relief over 4 to 6 hours, using validated equations. The number needed to treat to benefit (NNT) was calculated using 95% confidence intervals (CI). The proportion of participants using rescue analgesia over a specified time period, and time to use of rescue analgesia, were sought as additional measures of efficacy. Information on adverse events and withdrawals was also collected.

MAIN RESULTS

Not one of sixteen studies identified by the searches and examined in detail studied oral tenoxicam in patients with established postoperative pain and therefore no results are available.

AUTHORS' CONCLUSIONS

In the absence of evidence of efficacy for oral tenoxicam in acute postoperative pain, its use in this indication is not justified at present. Because trials clearly demonstrating analgesic efficacy in the most basic of acute pain studies is lacking, use in other indications should be evaluated carefully. Given the large number of available drugs of this and similar classes which are effective, there is no urgent research agenda for this particular drug.

Single dose oral dexibuprofen [S(+)-ibuprofen] for acute postoperative pain in adults

BACKGROUND

Dexibuprofen (S(+)-ibuprofen) is a non-steroidal anti-inflammatory drug (NSAID) licensed for use in rheumatic disease and other musculoskeletal disorders in the UK, and widely available in other countries worldwide. It is an active isomer of ibuprofen. This review sought to evaluate the efficacy and safety of oral dexibuprofen in acute postoperative pain, using clinical studies of patients with established pain, and with outcomes measured primarily over 6 hours using standard methods. This type of study has been used for many decades to establish that drugs have analgesic properties.

OBJECTIVES

To assess efficacy, duration of action, and associated adverse events of single dose oral dexibuprofen in acute postoperative pain in adults.

SEARCH STRATEGY

We searched Cochrane CENTRAL, MEDLINE, EMBASE and the Oxford Pain Relief Database for studies to May 2009.

SELECTION CRITERIA

Randomised, double blind, placebo-controlled clinical trials of oral dexibuprofen for relief of acute postoperative pain in adults.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data. Pain relief or pain intensity data were extracted and converted into the dichotomous outcome of number of participants with at least 50% pain relief over 4 to 6 hours, from which relative risk and number needed to treat to benefit (NNT) were calculated. Numbers of participants using rescue medication over specified time periods, and time to use of rescue medication, were sought as additional measures of efficacy. Information on adverse events and withdrawals were collected.

MAIN RESULTS

In the single included study, both S(+)-ibuprofen (dexibuprofen, an active isomer of ibuprofen) 200 mg and 400 mg gave high levels of response, with 31/51 (61%) and 35/50 (70%) respectively having at least 50% pain relief over 4 to 6 hours, compared with 2/25 (8%) with placebo. The median time to additional analgesic use was 5.8 hours, 6.1 hours, and 1.8 hours respectively. The numbers of participants was too small to calculate NNTs with any meaning.

AUTHORS' CONCLUSIONS

The information from the single trial in acute postoperative pain suggests it to be a useful analgesic, but at doses not very different from racemic ibuprofen.

Single dose oral flurbiprofen for acute postoperative pain in adults

BACKGROUND

Flurbiprofen is a non-selective non-steroidal anti-inflammatory drug (NSAID), related to ibuprofen and naproxen, used to treat acute and chronic painful conditions. There is no systematic review of its use in acute postoperative pain.

OBJECTIVES

To assess efficacy, duration of action, and associated adverse events of single dose oral flurbiprofen in acute postoperative pain in adults.

SEARCH STRATEGY

We searched Cochrane CENTRAL, MEDLINE, EMBASE and the Oxford Pain Relief Database for studies to January 2009.

SELECTION CRITERIA

Randomised, double blind, placebo-controlled trials of single dose orally administered flurbiprofen in adults with moderate to severe acute postoperative pain.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data. Pain relief or pain intensity data were extracted and converted into the dichotomous outcome of number of participants with at least 50% pain relief over 4 to 6 hours, from which relative risk (RR) and number needed to treat to benefit (NNT) were calculated. Numbers of participants using rescue medication over specified time periods, and time to use of rescue medication, were sought as additional measures of efficacy. Information on adverse events and withdrawals were collected.

MAIN RESULTS

Eleven studies compared flurbiprofen (699 participants) with placebo (362 participants) in studies lasting 6 to 12 hours. Studies were of adequate reporting quality, and most participants had pain following dental extractions.The dose of flurbiprofen used was 25 mg to 100 mg, with most information for 50 mg and 100 mg. The NNT for at least 50% pain relief over 4 to 6 hours for flurbiprofen 50 mg compared with placebo (692 participants) was 2.7 (2.3 to 3.3) and for 100 mg (416 participants) it was 2.5 (2.0 to 3.1). With flurbiprofen 50 mg and 100 mg 65% to 70% of participants experienced at least 50% pain relief, compared with 25% to 30% with placebo. Rescue medication was used by 25% and 16% of participants with flurbiprofen 50 mg and 100 mg over 6 hours, compared with almost 70% with placebo.Adverse events were uncommon, and not significantly different from placebo.

AUTHORS' CONCLUSIONS

Flurbiprofen at doses of 50 mg and 100 mg is an effective analgesic in moderate to severe acute postoperative pain. The NNT for at least 50% pain relief is similar to that of commonly used NSAIDs such as ibuprofen and naproxen at usual doses. Use of rescue medication indicates a duration of action exceeding 6 hours.

Multimodal analgesia for hip arthroplasty

Multimodal analgesia incorporates the use of analgesic adjuncts with different mechanisms of action to enhance postoperative pain management. Acetaminophen, anti-inflammatories, and gabapentinoids provide effective analgesia while reducing opioid requirements and opioid-related side effects. Intrathecal morphine and periarticular local anesthetic infiltration further enhance dynamic analgesia and improve postoperative mobilization. Epidural analgesia, peripheral nerve blocks, tramadol, ketamine, and/or clonidine can be added for improved benefit in opioid-tolerant individuals.

Intravenous or intramuscular parecoxib for acute postoperative pain in adults

BACKGROUND

Parecoxib was the first COX-2 available for parenteral administration, and may, given intravenously or intramuscularly, offer advantages over oral medication when patients have nausea and vomiting or are unable to swallow, such as in the immediate postoperative period.

OBJECTIVES

Assess the efficacy of single dose intravenous or intramuscular parecoxib in acute postoperative pain, the requirement for rescue medication, and any associated adverse events.

SEARCH STRATEGY

We searched Cochrane CENTRAL, MEDLINE, EMBASE in November 2008.

SELECTION CRITERIA

Randomised, double-blind, placebo-controlled clinical trials of parecoxib compared with placebo for relief of acute postoperative pain in adults.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data. The area under the "pain relief versus time" curve was used to derive the proportion of participants with parecoxib and placebo experiencing at least 50% pain relief over 6 hours, using validated equations. The number-needed-to-treat-to-benefit (NNT) was calculated using 95% confidence intervals (CI). The proportion of participants using rescue analgesia over a specified time period, and time to use of rescue analgesia, were sought as additional measures of efficacy. Information on adverse events and withdrawals were also collected.

MAIN RESULTS

Seven studies (1446 participants) were included. There was no significant difference between doses, or between intravenous and intramuscular administration for 50% pain relief over 6 hours: NNTs compared with placebo were 3.1 (2.4 to 4.5), 2.4 (2.1 to 2.8), and 1.8 (1.5 to 2.3) for 10, 20, and 40 mg parecoxib respectively. Fewer participants required rescue medication over 24 hours with parecoxib than placebo: parecoxib 40 mg was significantly better than parecoxib 20 mg (NNTs to prevent use of rescue medication 7.5 (5.3 to 12.8) and 3.3 (2.6 to 4.5) respectively; P < 0.0007). Median time to use of rescue medication was 3.1 hours, 6.9 hours and 10.6 hours with parecoxib 10 mg, 20 mg and 40 mg respectively, and 1.5 hours with placebo. Adverse events were generally mild to moderate, rarely led to withdrawal, and did not differ in frequency between groups. No serious adverse events were reported with parecoxib or placebo.

AUTHORS' CONCLUSIONS

A single dose of parecoxib 20 mg or 40 mg provided effective analgesia for 50 to 60% of those treated compared to about 15% with placebo, and was well tolerated. Duration of analgesia was longer, and significantly fewer participants required rescue medication over 24 hours with the higher dose.

Single dose oral diclofenac for acute postoperative pain in adults

BACKGROUND

Diclofenac is a non-steroidal anti-inflammatory drug (NSAID), available as a potassium salt (immediate-release) or sodium salt (delayed-release). This review updates an earlier review published in The Cochrane Database of Systematic Reviews (Issue 2, 2004) on 'Single dose oral diclofenac for postoperative pain'.

OBJECTIVES

To assess single dose oral diclofenac for the treatment of acute postoperative pain.

SEARCH STRATEGY

Cochrane CENTRAL, MEDLINE, EMBASE, Biological Abstracts, the Oxford Pain Relief Database, and reference lists of articles were searched; last search December 2008.

SELECTION CRITERIA

Randomised, double-blind, placebo-controlled clinical trials of single dose, oral diclofenac (sodium or potassium) for acute postoperative pain in adults.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies for inclusion and quality, and extracted data. The area under the pain relief versus time curve was used to derive the proportion of participants with at least 50% pain relief over 4 to 6 hours, using validated equations. Relative benefit (risk) and number needed to treat to benefit (NNT) were calculated. Information on adverse events, time to remedication, and participants needing additional analgesia was also collected.

MAIN RESULTS

Fifteen studies (eight additional studies) with 1512 participants more than doubled the information available at each dose. Overall 50% to 60% of participants experienced at least 50% pain relief over 4 to 6 hours at any dose with diclofenac, compared to 10 to 20% with placebo, giving NNTs of about 2.5 for doses of 25 mg to 100 mg (similar to earlier review); no dose response was demonstrated. At 50 mg and 100 mg, NNTs for diclofenac potassium (2.1 (1.8 to 2.4) and 1.9 (1.7 to 2.2)) were significantly lower (better) than for diclofenac sodium (6.7 (4.2 to 17) and 4.5 (3.2 to 7.7)). The median time to use of rescue medication was 2 hours for placebo, 4.3 hours for diclofenac 50 mg and 4.9 hours for diclofenac 100 mg. Adverse events were reported at a similar rate to placebo, with no serious events.

AUTHORS' CONCLUSIONS

Oral diclofenac is an effective single-dose treatment for moderate to severe postoperative pain. Significantly more participants experienced at least 50% pain relief over 4 to 6 hours with diclofenac potassium than with diclofenac sodium. There was no significant difference between diclofenac and placebo in the incidence of adverse events.

Single dose oral naproxen and naproxen sodium for acute postoperative pain in adults

BACKGROUND

Naproxen, a non-steroidal anti-inflammatory drug, is used to treat various painful conditions including postoperative pain, and is often administered as the sodium salt to improve its solubility. This review updates a 2004 Cochrane review showing that naproxen sodium 550 mg (equivalent to naproxen 500 mg) was effective for treating postoperative pain. New studies have since been published.

OBJECTIVES

To assess efficacy, duration of action, and associated adverse events of single dose oral naproxen or naproxen sodium in acute postoperative pain in adults.

SEARCH STRATEGY

We searched Cochrane CENTRAL, MEDLINE, EMBASE and the Oxford Pain Relief Database for studies to October 2008.

SELECTION CRITERIA

Randomised, double blind, placebo-controlled trials of single dose orally administered naproxen or naproxen sodium in adults with moderate to severe acute postoperative pain.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data. Pain relief or pain intensity data were extracted and converted into the dichotomous outcome of number of participants with at least 50% pain relief over four to six hours, from which relative risk and number-needed-to-treat-to-benefit (NNT) were calculated. Numbers of participants using rescue medication over specified time periods, and time to use of rescue medication, were sought as additional measures of efficacy. Information on adverse events and withdrawals were collected.

MAIN RESULTS

The original review included 10 studies with 996 participants. This updated review included 15 studies (1509 participants); 11 assessed naproxen sodium and four naproxen. In nine studies (784 participants) using 500/550 mg naproxen or naproxen sodium the NNT for at least 50% pain relief over four to six hours was 2.7 (95% CI 2.3 to 3.2). No dose response was demonstrated over the range 200/220 mg to 500/550 mg, but limited data was identified. Median time to use of rescue medication was 8.9 hours for naproxen 500/550 mg and 2.0 hours for placebo. Use of rescue medication was significantly less common with naproxen than placebo. Associated adverse events were generally of mild to moderate severity and rarely led to withdrawal.

AUTHORS' CONCLUSIONS

Doses equivalent to 500 mg and 400 mg naproxen administered orally provided effective analgesia to adults with moderate to severe acute postoperative pain. About half of participants treated with these doses experienced clinically useful levels of pain relief, compared to 15% with placebo, and half required additional medication within nine hours, compared to two hours with placebo. Associated adverse events did not differ from placebo.

Single dose oral paracetamol (acetaminophen) with codeine for postoperative pain in adults

BACKGROUND

This is an updated version of the Cochrane review published in Issue 4, 1998. Combining drugs from different classes with different modes of action may offer opportunity to optimise efficacy and tolerability, using lower doses of each drug to achieve the same degree of pain relief. Previously we concluded that addition of codeine to paracetamol provided additional pain relief, but at expense of additional adverse events. New studies have been published since. This review sought to evaluate efficacy and safety of paracetamol plus codeine using current data, and compare findings with other analgesics evaluated similarly.

OBJECTIVES

Assess efficacy of single dose oral paracetamol plus codeine in acute postoperative pain, increase in efficacy due to the codeine component, and associated adverse events.

SEARCH STRATEGY

We searched CENTRAL, MEDLINE, EMBASE, the Oxford Pain Relief Database in October 2008 for this update.

SELECTION CRITERIA

Randomised, double-blind, placebo-controlled trials of paracetamol plus codeine, compared with placebo or the same dose of paracetamol alone, for relief of acute postoperative pain in adults.

DATA COLLECTION AND ANALYSIS

Two authors assessed trial quality and extracted data. The area under the "pain relief versus time" curve was used to derive proportion of participants with paracetamol plus codeine and placebo or paracetamol alone experiencing least 50% pain relief over four-to-six hours, using validated equations. Number-needed-to-treat-to-benefit (NNT) was calculated using 95% confidence intervals (CIs). Proportion of participants using rescue analgesia over a specified time period, and time to use of rescue analgesia, were sought as additional measures of efficacy. Information on adverse events and withdrawals were collected.

MAIN RESULTS

Twenty-six studies, with 2295 participants, were included comparing paracetamol plus codeine with placebo. Significant dose response was seen for the outcome of at least 50% pain relief over four-to-six hours, with NNTs of 2.2 (95% CI 1.8 to 2.9) for 800 to 1000 mg paracetamol plus 60 mg codeine, 3.9 (2.9 to 4.5) for 600 to 650 mg paracetamol plus 60 mg codeine, and 6.9 (4.8 to 12) for 300 mg paracetamol plus 30 mg codeine. Time to use of rescue medication was over four hours with paracetamol plus codeine and two hours with placebo. The NNT to prevent remedication was 5.6 (4.0 to 9.0) for 600 mg paracetamol plus 60 mg codeine over four to six hours. Adverse events increased of mainly mild to moderate severity with paracetamol plus codeine than placebo.Fourteen studies, with 926 participants, were included in the comparison of paracetamol plus codeine with the same dose of paracetamol alone. Addition of codeine increased proportion of participants achieving at least 50% pain relief over four-to-six hours by 10 to 15%, increased time to use of rescue medication by about one hour, and reduced proportion of participants needing rescue medication by about 15% (NNT to prevent remedication 6.9 (4.2 to 19). Adverse events were mainly mild to moderate in severity and incidence did not differ between groups.

AUTHORS' CONCLUSIONS

This update confirms previous findings that combining paracetamol with codeine provided clinically useful levels of pain relief in about 50% of patients with moderate to severe postoperative pain, compared with under 20% with placebo. New information for remedication shows that the combination extended the duration of analgesia by about one hour compared to treatment with the same dose of paracetamol alone. At higher doses, more participants experienced adequate pain relief, but the amount of information available for the 1000 mg paracetamol plus 60 mg codeine dose was small, and based on limited information.