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

The modern pharmacology of paracetamol: therapeutic actions, mechanism of action, metabolism, toxicity and recent pharmacological findings

Paracetamol is used worldwide for its analgesic and antipyretic actions. It has a spectrum of action similar to that of NSAIDs and resembles particularly the COX-2 selective inhibitors. Paracetamol is, on average, a weaker analgesic than NSAIDs or COX-2 selective inhibitors but is often preferred because of its better tolerance. Despite the similarities to NSAIDs, the mode of action of paracetamol has been uncertain, but it is now generally accepted that it inhibits COX-1 and COX-2 through metabolism by the peroxidase function of these isoenzymes. This results in inhibition of phenoxyl radical formation from a critical tyrosine residue essential for the cyclooxygenase activity of COX-1 and COX-2 and prostaglandin (PG) synthesis. Paracetamol shows selectivity for inhibition of the synthesis of PGs and related factors when low levels of arachidonic acid and peroxides are available but conversely, it has little activity at substantial levels of arachidonic acid and peroxides. The result is that paracetamol does not suppress the severe inflammation of rheumatoid arthritis and acute gout but does inhibit the lesser inflammation resulting from extraction of teeth and is also active in a variety of inflammatory tests in experimental animals. Paracetamol often appears to have COX-2 selectivity. The apparent COX-2 selectivity of action of paracetamol is shown by its poor anti-platelet activity and good gastrointestinal tolerance. Unlike both non-selective NSAIDs and selective COX-2 inhibitors, paracetamol inhibits other peroxidase enzymes including myeloperoxidase. Inhibition of myeloperoxidase involves paracetamol oxidation and concomitant decreased formation of halogenating oxidants (e.g. hypochlorous acid, hypobromous acid) that may be associated with multiple inflammatory pathologies including atherosclerosis and rheumatic diseases. Paracetamol may, therefore, slow the development of these diseases. Paracetamol, NSAIDs and selective COX-2 inhibitors all have central and peripheral effects. As is the case with the NSAIDs, including the selective COX-2 inhibitors, the analgesic effects of paracetamol are reduced by inhibitors of many endogenous neurotransmitter systems including serotonergic, opioid and cannabinoid systems. There is considerable debate about the hepatotoxicity of therapeutic doses of paracetamol. Much of the toxicity may result from overuse of combinations of paracetamol with opioids which are widely used, particularly in USA.

Single dose oral ibuprofen plus codeine for acute postoperative pain in adults

BACKGROUND

There is good evidence that combining two different analgesics in fixed doses in a single tablet can provide better pain relief in acute pain and headache than either drug alone, and that the drug-specific effects are essentially additive. This appears to be broadly true in postoperative pain and migraine headache across a range of different drug combinations and when tested in the same and different trials. Some combinations of ibuprofen and codeine are available without prescription (but usually only from a pharmacy) where the dose of codeine is lower, and with a prescription when the dose of codeine is higher.

OBJECTIVES

To assess the analgesic efficacy and adverse effects of a single oral dose of ibuprofen plus codeine for moderate to severe postoperative pain. We compared ibuprofen plus codeine with placebo and with the same dose of ibuprofen alone.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, the Oxford Pain Database, ClinicalTrials.gov, and reference lists of articles. The date of the most recent search was 30 September 2012.

SELECTION CRITERIA

Randomised, double-blind, placebo- or active-controlled clinical trials of single dose oral ibuprofen plus codeine for acute postoperative pain in adults.

DATA COLLECTION AND ANALYSIS

Two review authors independently considered trials for inclusion in the review, assessed quality, and extracted data. We used the area under the pain relief versus time curve to derive the proportion of participants prescribed ibuprofen plus codeine, placebo, or the same dose of ibuprofen alone with at least 50% pain relief over six hours, using validated equations. We calculated the relative risk (RR) and number needed to treat to benefit (NNT). We used information on the use of rescue medication to calculate the proportion of participants requiring rescue medication and the weighted mean of the median time to use. We also collected information on adverse effects. Analyses were planned for different doses of ibuprofen and codeine, but especially for codeine where we set criteria for low (< 10 mg), medium (10 to 20 mg), and high (> 20 mg) doses.

MAIN RESULTS

Information was available from six studies with 1342 participants, with a variety of doses of ibuprofen and codeine. In four studies (443 participants) using ibuprofen 400 mg plus codeine 25.6 to 60 mg (high dose codeine) 64% of participants had at least 50% maximum pain relief with the combination compared to 18% with placebo. The NNT was 2.2 (95% CI 1.8 to 2.6). In three studies (204 participants) ibuprofen plus codeine (any dose) was better than the same dose of ibuprofen (69% versus 55%) but the result was barely significant with a relative benefit of 1.3 (95% CI 1.01 to 1.6). In two studies (159 participants) ibuprofen plus codeine appeared to be better than the same dose of codeine alone (69% versus 33%), but no analysis was done. There was no difference between the combination and placebo in the reporting of adverse events in these acute studies.

AUTHORS' CONCLUSIONS

The combination of ibuprofen 400 mg plus codeine 25.6 to 60 mg demonstrates good analgesic efficacy. Very limited data suggest that the combination is better than the same dose of either drug alone. Use of combination analgesics that contain codeine has been a source of some concern because of misuse from over-the-counter preparations.

Pre emptive analgesia for reducing pain after cholecystectomy: Oral tramadol vs. acetaminophen codeine

Background:

Considering that protocols of postoperative pain management would be planned regarding the facilities of each center or region and the importance of its proper management to reduce its related complication and improve patient's satisfaction, in this study we compared the effect of orally administrated tramadol and acetaminophen-codeine in this regard.

Materials and Methods:

In this prospective randomized double-blind clinical trial, 136 (68 in tramadol and 68 in acetaminophen codeine groups) ASA I and II patients scheduled for open cholecystectomy under general anaesthesia were enrolled. They randomly allocated to receive oral tramadol (50 mg capsule) or acetaminophen-codeine (325/10 mg) 1 hour before surgery. After surgery they evaluated for postoperative pain using VAS score, analgesic consumption and vomiting.

Results:

Mean of postoperative pain score during 24 hours after surgery was 2.1 ± 1.0 and 3.8 ± 2.0 in tramadol and acetaminophen-codeine groups, respectively (P < 0.05). Mean of analgesic consumption (morphine) during 24 hours after surgery was 6.2 ± 4.4 mg and 12.9 ± 5.7 mg in tramadol and acetaminophen-codeine groups, respectively (P < 0.05). Mean of vomiting during 24 hours after surgery was 1.2 ±0.9 and 0.4 ± 0.5 in tramadol and acetaminophen-codeine groups, respectively (P < 0.05).

Conclusion:

The findings of current study indicated that in lower dose of tramadol (50 mg) and acetaminophen/codeine (325 mg/10 mg) the analgesic effect of tramadol is better and its side effects are higher than acetaminophen/codeine, which limit its use for mentioned purpose. It seems that administration of each of studied agents it depends on patients’ tolerance and decision of the physician.

Preoperative analgesics for additional pain relief in children and adolescents having dental treatment

BACKGROUND

Fear of dental pain is a major barrier to children needing dental care. The use of preoperative analgesics has the potential to reduce postoperative discomfort. In addition it might also reduce intraoperative pain. Reviewing the available evidence will determine whether further research is warranted and will inform the development of prescribing guidelines.

OBJECTIVES

To assess the effects of preoperative analgesics for pain relief in children and adolescents undergoing dental treatment.

SEARCH METHODS

We searched the following electronic databases: the Cochrane Oral Health Group Trials Register (to 8 March 2012), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2012, Issue 1), MEDLINE via OVID (1950 to 8 March 2012), EMBASE via OVID (1980 to 8 March 2012), LILACS via BIREME (1982 to 8 March 2012) and the ISI Web of Knowledge (1945 to 8 March 2012). There were no restrictions regarding language or date of publication.The reference lists of all eligible trials were checked for additional studies. Specialists in the field were contacted for any unpublished data.

SELECTION CRITERIA

Randomised controlled clinical trials of analgesics given before dental treatment versus placebo or no analgesics in children and adolescents aged up to 17 years. We excluded children and adolescents having dental treatment under sedation (including nitrous oxide/oxygen) or general anaesthesia.

DATA COLLECTION AND ANALYSIS

Two review authors assessed titles and abstracts for eligibility and undertook data extraction and assessment of risk of bias.

MAIN RESULTS

Five trials met the review's inclusion criteria with 190 participants in total. Three trials were dentally related i.e. restorative and extraction treatments; two trials related to orthodontic treatment. None of the included trials were judged to be at low risk of bias. Three trials compared paracetamol with placebo, only two of which provided data for analysis (presence or absence of parent-reported postoperative pain behaviour). The meta-analysis of the two trials showed a nonsignificant risk ratio (RR) for postoperative pain-related behaviours of 0.81 (95% confidence interval (CI) 0.53 to 1.22; P = 0.31), which showed no evidence of a benefit in taking paracetamol preoperatively (52% reporting pain in placebo versus 42% in test group). One of these trials was at unclear risk of bias, the other at high risk. Four trials compared ibuprofen with placebo. Three of these trials provided useable data. One trial reported no statistical difference in postoperative pain experienced by the ibuprofen group and the control group for children undergoing dental treatment. Data from two trials, including patients who were having orthodontic separator replacement without a general anaesthetic, were pooled to determine the effect of preoperative ibuprofen on the severity of postoperative pain. There was a statistically significant benefit, with regard to severity of postoperative pain, for giving ibuprofen preoperatively with mean difference -19.12 (95% CI -29.36 to -8.87; P = 0.0003; moderate quality evidence) on a visual analogue scale (0 to 100) indicating a probable benefit for preoperative ibuprofen before this orthodontic procedure. However, both these trials were at high risk of bias. Adverse events were only reported in one trial (one patient from the ibuprofen group and one from the placebo group reporting a lip or cheek biting injury).

AUTHORS' CONCLUSIONS

From the available evidence we cannot determine whether or not preoperative analgesics are of benefit in paediatric dentistry for procedures under local anaesthetic. There is probably a benefit in prescribing preoperative analgesics prior to orthodontic separator placement.

Adding pregabalin to a multimodal analgesic regimen does not reduce pain scores following cosmetic surgery: a randomized trial

PURPOSE

Multimodal analgesia increases the chance of successful discharge and pain control after surgery, and pregabalin is being promoted as an effective analgesic, based on placebo-controlled studies. We investigated whether adding pregabalin improved pain control and reduced opioid requests when it was added to a multimodal analgesic regimen for cosmetic surgery.

METHODS

One hundred and ten women who underwent same-day cosmetic surgery were randomized to receive oral pregabalin, 75 mg q12 h for five consecutive days starting the night before surgery, or identical placebos. Participants, outcomes assessors, and the statistician were blinded. The primary outcome was postoperative numerical movement-evoked pain scores at 2, 24, 48, 72, and 96 h after surgery. The secondary outcomes included pain scores at rest; incidence of moderate to severe pain; and analgesic and antiemetic requirements; as well as the incidence of nausea, vomiting, and somnolence.

RESULTS

Based on 99 patients who completed the study, we found no difference between the groups in the primary outcome; 72 h after surgery, movement-evoked median pain scores were <4/10 in both groups. We found no differences in opioid requirements (p = 0.95) or anti-inflammatory requirements (p = 0.45), and no difference in opioid-related adverse events.

CONCLUSION

Perioperative pregabalin 75 mg twice a day does not increase benefit when it is added to an already multimodal analgesic regimen for patients undergoing cosmetic surgery. Several factors could explain our findings, including the possibility of publication bias in the current literature.

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.

Strategies Aimed at Preventing Chronic Post-surgical Pain: Comprehensive Perioperative Pain Management after Total Joint Replacement Surgery

PURPOSE

Chronic post-surgical pain (CPSP) is a frequent outcome of musculoskeletal surgery. Physiotherapists often treat patients with pain before and after musculoskeletal surgery. The purposes of this paper are (1) to raise awareness of the nature, mechanisms, and significance of CPSP; and (2) to highlight the necessity for an inter-professional team to understand and address its complexity. Using total joint replacement surgeries as a model, we provide a review of pain mechanisms and pain management strategies.

SUMMARY OF KEY POINTS

By understanding the mechanisms by which pain alters the body's normal physiological responses to surgery, clinicians selectively target pain in post-surgical patients through the use of multi-modal management strategies. Clinicians should not assume that patients receiving multiple medications have a problem with pain. Rather, the modern-day approach is to manage pain using preventive strategies, with the aims of reducing the intensity of acute postoperative pain and minimizing the development of CPSP.

CONCLUSIONS

The roles of biological, surgical, psychosocial, and patient-related risk factors in the transition to pain chronicity require further investigation if we are to better understand their relationships with pain. Measuring pain intensity and analgesic use is not sufficient. Proper evaluation and management of risk factors for CPSP require inter-professional teams to characterize a patient's experience of postoperative pain and to examine pain arising during functional activities.

Clinical practice guideline: tonsillectomy in children

OBJECTIVE

Tonsillectomy is one of the most common surgical procedures in the United States, with more than 530,000 procedures performed annually in children younger than 15 years. Tonsillectomy is defined as a surgical procedure performed with or without adenoidectomy that completely removes the tonsil including its capsule by dissecting the peritonsillar space between the tonsil capsule and the muscular wall. Depending on the context in which it is used, it may indicate tonsillectomy with adenoidectomy, especially in relation to sleep-disordered breathing. This guideline provides evidence-based recommendations on the preoperative, intraoperative, and postoperative care and management of children 1 to 18 years old under consideration for tonsillectomy. In addition, this guideline is intended for all clinicians in any setting who interact with children 1 to 18 years of age who may be candidates for tonsillectomy.

PURPOSE

The primary purpose of this guideline is to provide clinicians with evidence-based guidance in identifying children who are the best candidates for tonsillectomy. Secondary objectives are to optimize the perioperative management of children undergoing tonsillectomy, emphasize the need for evaluation and intervention in special populations, improve counseling and education of families of children who are considering tonsillectomy for their child, highlight the management options for patients with modifying factors, and reduce inappropriate or unnecessary variations in care.

RESULTS

The panel made a strong recommendation that clinicians should administer a single, intraoperative dose of intravenous dexamethasone to children undergoing tonsillectomy. The panel made a strong recommendation against clinicians routinely administering or prescribing perioperative antibiotics to children undergoing tonsillectomy. The panel made recommendations for (1) watchful waiting for recurrent throat infection if there have been fewer than 7 episodes in the past year or fewer than 5 episodes per year in the past 2 years or fewer than 3 episodes per year in the past 3 years; (2) assessing the child with recurrent throat infection who does not meet criteria in statement 2 for modifying factors that may nonetheless favor tonsillectomy, which may include but are not limited to multiple antibiotic allergy/intolerance, periodic fever, aphthous stomatitis, pharyngitis and adenitis, or history of peritonsillar abscess; (3) asking caregivers of children with sleep-disordered breathing and tonsil hypertrophy about comorbid conditions that might improve after tonsillectomy, including growth retardation, poor school performance, enuresis, and behavioral problems; (4) counseling caregivers about tonsillectomy as a means to improve health in children with abnormal polysomnography who also have tonsil hypertrophy and sleep-disordered breathing; (5) counseling caregivers that sleep-disordered breathing may persist or recur after tonsillectomy and may require further management; (6) advocating for pain management after tonsillectomy and educating caregivers about the importance of managing and reassessing pain; and (7) clinicians who perform tonsillectomy should determine their rate of primary and secondary posttonsillectomy hemorrhage at least annually. The panel offered options to recommend tonsillectomy for recurrent throat infection with a frequency of at least 7 episodes in the past year or at least 5 episodes per year for 2 years or at least 3 episodes per year for 3 years with documentation in the medical record for each episode of sore throat and 1 or more of the following: temperature >38.3°C, cervical adenopathy, tonsillar exudate, or positive test for group A β-hemolytic streptococcus.

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 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.

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 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.