The analgesic effect of etoricoxib relative to that of cetaminophen analgesics: a randomized, controlled single-dose study in acute dental impaction pain

Efficacy of oxycodone for postoperative dental pain: A systematic review and meta-analysis

OBJECTIVES

Dental pain is a commonly managed presentation in medicine and dentistry, where oxycodone is often prescribed. The aim of this systematic review and meta-analysis was to determine and quantify the effectiveness of oxycodone for acute dental pain.

DATA

Randomised controlled trials, controlled trials and comparative studies were included involving patients >12 years, where oxycodone was trialled for dental pain.

SOURCES

Three databases were searched: Medline Ovid, Embase Ovid and Web of Science. Two authors independently screened title and abstracts for relevance, extracted data and performed bias assessments.

STUDY SELECTION

Of 148 potentially relevant studies, 13 articles met the inclusion criteria for the systematic review and of the 13, nine studies were included in the meta-analysis. All studies were single-dose analgesia for surgical third molar extractions.

CONCLUSIONS

Oxycodone produced more effective analgesia in combination with paracetamol. In the meta-analysis, monotherapy etoricoxib and rofecoxib showed significant pain relief compared to combination oxycodone/paracetamol (SPID6 mean difference=-2.13, CI=-3.29, -0.98; TOTPAR6 mean difference=-2.98, CI=-4.90, -1.06). Non-steroidal anti-inflammatory drugs (NSAIDs) were more effective than oxycodone/paracetamol combinations, however, the evidence would become weak in a future study with a similar patient setting due to substantial statistical heterogeneity (SPID6 and TOTPAR6 prediction interval -4.471, 0.207 and -7.28, 1.32 respectively).

CLINICAL SIGNIFICANCE

Non-steroidal anti-inflammatory drugs were superior than oxycodone/paracetamol combinations, although some patient populations may experience similar effects to the combined oxycodone/paracetamol combination.

Does low dose of etoricoxib play pre-emptive analgesic effect in third molar surgery? A randomized clinical trial

Background

How to prevent pain after the extraction of impacted teeth is a serious challenge for all patients. The purpose of this clinical trial was to investigate whether pre-emptive low dose of etoricoxib can reduce postoperative pain in patients undergoing third molars surgery.

Methods

Patients were randomised to receive etoricoxib 60 mg or placebo 30 min before surgery. Post-operative pain was recorded using a visual analogue scale during 24 h within the post-operative period. The total dose of ibuprofen rescue intake was recorded. Kaplan–Meier curves and log-rank analyses were used to evaluate the proportion of patients without rescue analgesic.

Results

Scores for the post-operative pain in the etoricoxib group were significantly lower than those in the placebo group during first 12 h (p < 0.05). The number of patients without analgesic rescue medication was significantly lower in the etoricoxib group than in the placebo group. The average amount of rescue medication in the etoricoxib group (0.4 ± 0.9 dose) was lower than that in the placebo group (1.1 ± 0.9 doses, p = 0.004). Etoricoxib resulted in the long-term survival of patients without rescue analgesic (p < 0.001).

Conclusions

This study revealed that etoricoxib has a substantial pre-emptive analgesic effect, resulting in the reduced use of analgesics after third molar removal.

Trial registration: Registered on ChiCTR1900024503. Date of Registration: 13/07/2019.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12903-021-01837-0.

Managing postoperative pain in adult outpatients: a systematic review and meta-analysis comparing codeine with NSAIDs

BACKGROUND

Analgesics that contain codeine are commonly prescribed for postoperative pain, but it is unclear how they compare with nonopioid alternatives. We sought to compare the effectiveness of codeine and nonsteroidal anti-inflammatory drugs (NSAIDs) for adults who underwent outpatient surgery.

METHODS

We conducted a systematic review and meta-analysis of randomized controlled trials comparing codeine and NSAIDs for postoperative pain in outpatient surgery. We searched MEDLINE and Embase from inception to October 2019 for eligible studies. Our primary outcome was the patient pain score, converted to a standard 10-point intensity scale. Our secondary outcomes were patient-reported global assessments and adverse effects. We used random-effects models and grading of recommendations assessment, development and evaluation (GRADE) to assess the quality of evidence.

RESULTS

Forty studies, including 102 trial arms and 5116 patients, met inclusion criteria. The studies had low risk of bias and low-to-moderate heterogeneity. Compared with codeine, NSAIDs were associated with better pain scores at 6 hours (weighted mean difference [WMD] 0.93 points, 95% confidence interval [CI] 0.71 to 1.15) and at 12 hours (WMD 0.79, 95% CI 0.38 to 1.19). Stronger NSAID superiority at 6 hours was observed among trials where acetaminophen was coadministered at equivalent doses between groups (WMD 1.18, 95% CI 0.87 to 1.48). NSAIDs were associated with better global assessments at 6 hours (WMD -0.88, 95% CI -1.04 to -0.72) and at 24 hours (WMD -0.67, 95% CI -0.95 to -0.40), and were associated with fewer adverse effects, including bleeding events.

INTERPRETATION

We found that adult outpatients report better pain scores, better global assessments and fewer adverse effects when their postoperative pain is treated with NSAIDs than with codeine. Clinicians across all specialties can use this information to improve both pain management and opioid stewardship.

Preemptive Oral Etoricoxib on Health-Related Quality of Life after Mandibular Third Molar Surgery: A Randomized, Double-Blind, Placebo-Controlled Clinical Trial

This study was aimed at evaluating the use of oral etoricoxib for preemptive analgesia on the health-related quality of life (QoL) outcome after the extraction of mandibular third molar. The study population consisted of 60 participants that required extraction of a single partial bony impacted mandibular third molar under local anesthesia and met the inclusion criteria. The participants were randomized into two groups. The etoricoxib group orally received 60 mg etoricoxib 30 min before surgery, whereas the control group was given a placebo. The patients were assessed postoperatively after 1, 2, 3, 4, 5, 6, and 7 days using the United Kingdom oral health-related QoL questionnaire and visual analog scale for maximum postoperative pain. The total dose of ibuprofen rescue intake and total number of days the drug was taken were recorded. Surgical removal of impacted teeth had a negative influence on the patient's QoL across various physical, social, and psychological aspects. The scores for postoperative pain in the etoricoxib group were significantly lower than those in the control group on each postoperative observation day. The number of patients without analgesic rescue medication, the average amount, and total number of days emergency analgesics were taken were significantly lower in the etoricoxib group than in the control group. The etoricoxib group showed better QoL score than the control group. Preemptive oral etoricoxib is an effective therapeutic strategy for improving the QoL after surgical removal of the impacted lower third molar.

A review of dexketoprofen trometamol in acute pain

OBJECTIVE

Dexketoprofen trometamol is a modified non-selective COX inhibitor with a rapid onset of action that is available as both oral and parenteral formulations. The aim of this narrative review was to assess the efficacy and tolerability/safety of dexketoprofen trometamol in acute pain states using the best available published scientific evidence (randomized controlled clinical trials and systematic reviews/meta-analyses).

METHODS

Literature retrieval was performed via Medline, Embase and the Cochrane Library (from inception up to March 2017) using combinations of the terms "randomized controlled trials", "dexketoprofen", "celecoxib", "etoricoxib", "parecoxib" and "acute pain".

RESULTS

Single-dose dexketoprofen trometamol provides effective analgesia in the treatment of acute pain, such as postoperative pain (dental and non-dental surgery), renal colic, acute musculoskeletal disorders and dysmenorrhea, and reduces opioid consumption in the postoperative setting. It has a rapid onset of action (within 30 minutes) and is well tolerated during short-term treatment. Direct comparisons with COX-2 inhibitors are lacking; however, the efficacy and tolerability of single-dose dexketoprofen trometamol appears to be consistent with that seen with celecoxib, etoricoxib and parecoxib in the acute pain setting.

CONCLUSION

In conclusion, dexketoprofen trometamol appears to provide similar analgesic efficacy to COX-2 inhibitors when used to treat acute pain, has a rapid onset of action, is well tolerated, and has an opioid-sparing effect when used as part of a multimodal regimen in the acute pain setting.

Assay sensitivity of pain intensity versus pain relief in acute pain clinical trials: ACTTION systematic review and meta-analysis

The magnitude of the effect size of an analgesic intervention can be influenced by several factors, including research design. A key design component is the choice of the primary endpoint. The purpose of this meta-analysis was to compare the assay sensitivity of 2 efficacy paradigms: pain intensity (calculated using summed pain intensity difference [SPID]) and pain relief (calculated using total pain relief [TOTPAR]). A systematic review of the literature was performed to identify acute pain studies that calculated both SPIDs and TOTPARs within the same study. Studies were included in this review if they were randomized, double-blind, placebo-controlled investigations involving medications for postsurgical acute pain and if enough data were provided to calculate TOTPAR and SPID standardized effect sizes. Based on a meta-analysis of 45 studies, the mean standardized effect size for TOTPAR (1.13) was .11 higher than that for SPID (1.02; P = .01). Mixed-effects meta-regression analyses found no significant associations between the TOTPAR - SPID difference in standardized effect size and trial design characteristics. Results from this review suggest that for acute pain studies, utilizing TOTPAR to assess pain relief may be more sensitive to treatment effects than utilizing SPID to assess pain intensity.

PERSPECTIVE

The results of this meta-analysis suggest that TOTPAR may be more sensitive to treatment effects than SPIDs are in analgesic trials examining acute pain. We found that standardized effect sizes were higher for TOTPAR compared to SPIDs.

Single dose oral etoricoxib for acute postoperative pain in adults

BACKGROUND

This is an updated version of the original Cochrane review first published in Issue 2, 2009, and updated in Issue 4, 2012.Etoricoxib is a selective cyclo-oxygenase-2 (COX-2) inhibitor licensed for the relief of chronic pain in osteoarthritis and rheumatoid arthritis, and acute pain in some jurisdictions. This class of drugs is believed to be associated with fewer upper gastrointestinal adverse effects than conventional non-steroidal anti-inflammatory drugs (NSAIDs).

OBJECTIVES

To assess the efficacy and adverse effects of single dose etoricoxib for acute postoperative pain using methods that permit accurate comparison with other analgesics evaluated in the same way, using criteria of efficacy recommended by in-depth studies at the individual patient level.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, the Oxford Pain Database, www.clinicaltrials.gov, and reference lists of articles. The date of the most recent search was 31 January 2014.

SELECTION CRITERIA

Randomised, double-blind, placebo-controlled clinical trials of single dose, oral etoricoxib for acute postoperative pain in adults.

DATA COLLECTION AND ANALYSIS

Two review authors independently considered studies 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 etoricoxib or placebo with at least 50% pain relief over six hours, using validated equations. We calculated relative risk (RR) and number needed to treat to benefit (NNT). We used information on 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 events.

MAIN RESULTS

We identified no new studies for this updated review, which includes six studies with 1214 participants in comparisons of etoricoxib with placebo. All six studies reported on the 120 mg dose (798 participants in a comparison with placebo). Sixty-six per cent of participants with etoricoxib 120 mg and 12% with placebo reported at least 50% pain relief (NNT 1.8 (1.7 to 2.0); high-quality evidence). For dental studies only, the NNT was 1.6 (1.5 to 1.8). A single dose of 90 mg produced similar results in one large trial. Other doses (60, 180, and 240 mg) were each studied in only one treatment arm.Significantly fewer participants used rescue medication over 24 hours when taking etoricoxib 120 mg than placebo (NNT to prevent remedication 2.2 (1.9 to 2.8)), and the median time to use of rescue medication was 20 hours for etoricoxib and two hours for placebo. Adverse events were reported at a similar rate to placebo (moderate-quality evidence), with no serious events.

AUTHORS' CONCLUSIONS

Single-dose oral etoricoxib produces high levels of good quality pain relief after surgery, and adverse events did not differ from placebo in these studies. The 120 mg dose is as effective as, or better than, other commonly used analgesics.

Single dose oral etoricoxib for acute postoperative pain in adults

BACKGROUND

Etoricoxib is a selective cyclo-oxygenase-2 (COX-2) inhibitor licensed for the relief of chronic pain in osteoarthritis and rheumatoid arthritis, and acute pain in some jurisdictions. This class of drugs is believed to be associated with fewer upper gastrointestinal adverse effects than conventional non-steroidal anti-inflammatory drugs (NSAIDs). One additional study in acute postoperative pain has been published since the original review was completed in Issue 2, 2009.

OBJECTIVES

To assess the analgesic efficacy and adverse effects of a single oral dose of etoricoxib for moderate to severe postoperative pain.

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 3 January 2012.

SELECTION CRITERIA

Randomised, double-blind, placebo-controlled clinical trials of single dose, oral etoricoxib 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 etoricoxib or placebo with at least 50% pain relief over six hours, using validated equations. We calculated relative risk (RR) and number needed to treat to benefit (NNT). We used information on 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.

MAIN RESULTS

One additional study has been added to this updated review, making a total of six included studies with 1214 participants in comparisons of etoricoxib with placebo. All six studies reported on the 120 mg dose (798 participants in a comparison with placebo). At least 50% pain relief was reported by 66% with etoricoxib 120 mg and 12% with placebo (NNT 1.8 (1.7 to 2.0)). For dental studies only the NNT was 1.6 (1.5 to 1.8). Although the new study almost doubled the number of participants in included studies it added only about 25% more data for the 120 mg dose and the result was unchanged. Other doses (60, 90, 180, and 240 mg) were each studied in only one treatment arm and we did not undertake pooled analysis.Significantly fewer participants used rescue medication over 24 hours when taking etoricoxib 120 mg than placebo (NNT to prevent remedication 2.2 (1.9 to 2.8)), and the median time to use of rescue medication was 20 hours for etoricoxib and two hours for placebo. Adverse events were reported at a similar rate to placebo, with no serious events.

AUTHORS' CONCLUSIONS

The additional study did not change the results from the first review published in 2009, but does make the result more robust. Single dose oral etoricoxib produces high levels of good quality pain relief after surgery and adverse events did not differ from placebo. The 120 mg dose is as effective as, or better than, other commonly used analgesics.

Minimum efficacy criteria for comparisons between treatments using individual patient meta-analysis of acute pain trials: examples of etoricoxib, paracetamol, ibuprofen, and ibuprofen/paracetamol combinations after third molar extraction

We defined response in acute pain trials according to percentage of maximum possible efficacy. Minimum efficacy criteria (MEC) of 0%, or at least 15%, 30%, 50%, and 70% pain relief were used to examine stability over time using total pain relief and summed pain intensity difference (SPID), sex differences, and sensitivity. We used individual patient data from placebo-controlled third molar extraction trials: 4 with single-dose oral etoricoxib 120 mg, and 2 with paracetamol, ibuprofen, and ibuprofen plus paracetamol combinations. With etoricoxib, numbers needed to treat (NNTs) were stable between response levels of at least 15% (MEC15) and 50% pain relief (MEC50), and similar for total pain relief and SPID. NNTs were higher (worse) at extremes of MEC, especially with SPID. Results for women and men were similar. NNTs of lower efficacy treatments (paracetamol 500 and 1000 mg) rose rapidly at higher MEC. NNTs of high efficacy treatments (ibuprofen plus paracetamol combinations) showed greater separation at higher MEC. The highest degree of discrimination between treatments was with MEC50 and MEC70. Etoricoxib 120 mg (NNT for ≥50% maximum 6-hour pain relief 1.7) and ibuprofen 200/400 mg plus paracetamol 500/1000 mg (NNTs 1.5 and 1.6, respectively) produced the lowest (best) NNTs in the dental pain model. Timing of patient request for additional analgesia is an alternative analgesic efficacy outcome measure.

Evaluation of the dose range of etoricoxib in an acute pain setting using the postoperative dental pain model

OBJECTIVE

This study was conducted to evaluate the dose range of etoricoxib in acute pain using the postoperative dental pain model further.

METHODS

This double-blind, randomized controlled study evaluated etoricoxib (90 and 120 mg), ibuprofen (600 mg), and acetaminophen (600 mg/codeine) (60 mg, (A/C)) in patients aged ≥ 18 years with moderate or severe pain after surgical extraction of ≥ 2 third molars (≥ 1 impacted). The patients reported pain intensity and pain relief over 24 hours. The primary efficacy endpoint was total pain relief over 6 hours (TOPAR6). Adverse events were evaluated throughout the study.

RESULTS

There were 588 patients randomized to placebo (n=46),etoricoxib (90 mg (n=191)), etoricoxib (120 mg (n=97)), ibuprofen(2400 mg (n=192)), and A/C (n=62). The overall analgesic effect (TOPAR6) of etoricoxib (90, 120 mg) was significantly greater than that of placebo (P ≤ 0.001), and not inferior to that of ibuprofen; no discernible difference was observed between etoricoxib 90 and 120 mg. Both etoricoxib doses were superior to A/C (P ≤ 0.001). Etoricoxib (90 and 120 mg) and ibuprofen(2400 mg) were generally well tolerated and had a similar incidence of adverse events (AEs). A/C was associated with significantly more AEs that led to discontinuation (ie, nausea and vomiting).

CONCLUSIONS

Etoricoxib (90 and 120 mg) showed similar efficacy in the postoperative dental pain model, which was noninferior to ibuprofen and superior to A/C. A higher number of tooth extractions or a higher mean impaction score may have led to a greater separation in efficacy between the 2 etoricoxib doses.

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 etoricoxib for acute postoperative pain in adults

BACKGROUND

Etoricoxib is a selective cyclo-oxygenase-2 (COX-2) inhibitor prescribed for the relief of chronic pain in osteoarthritis and rheumatoid arthritis, and acute pain. The drug is believed to be associated with fewer upper gastrointestinal adverse effects than conventional non-steroidal anti-inflammatory drugs (NSAIDs). A number of studies in acute postoperative pain have now been published.

OBJECTIVES

To assess the analgesic efficacy and adverse effects of a single oral dose of etoricoxib for moderate to severe postoperative pain.

SEARCH STRATEGY

We searched Cochrane CENTRAL, MEDLINE, EMBASE, and the Oxford Pain Database, and reference lists of articles. Date of the most recent search: December 2008.

SELECTION CRITERIA

Randomised, double-blind, placebo-controlled clinical trials of single dose, oral etoricoxib for acute postoperative pain in adults.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion in the review and quality, and extracted data. The area under the pain relief versus time curve was used to derive the proportion of participants prescribed etoricoxib or placebo with at least 50% pain relief over six hours, using validated equations. Relative risk (RR) and number needed to treat to benefit (NNT) were calculated. Information on use of rescue medication was used to calculate the proportion of participants requiring rescue medication and the weighted mean of the median time to use. Information on adverse effects was also collected.

MAIN RESULTS

Five studies (880 participants) were included in the review. All five studies reported on 120 mg, with 655 participants in a comparison with placebo. At least 50% pain relief was reported by 64% with etoricoxib 120 mg and 10% with placebo (NNT 1.9 (1.7 to 2.1)). For dental studies only the NNT was 1.6 (1.5 to 1.8). Two studies also reported on higher doses of 180 and 240 mg, with 249 participants. At least 50% pain relief was reported by 79% with etoricoxib 120 mg and 12% with placebo (NNT 1.5 (1.3 to 1.7)).Significantly fewer participants used rescue medication when taking etoricoxib 120 mg than those taking placebo (NNT to prevent remedication 2.4 (2.1 to 2.9)), and the median time to use of rescue medication was 20 hours. Adverse events were reported at a similar rate to placebo, with no serious events.

AUTHORS' CONCLUSIONS

Single dose oral etoricoxib produces high levels of good quality pain relief after surgery. The 120 mg dose is as effective as, or better than, other commonly used analgesics.

Clinical use and pharmacological properties of selective COX-2 inhibitors

Selective COX-2 inhibitors (coxibs) are approved for the relief of acute pain and symptoms of chronic inflammatory conditions such as osteoarthritis (OA) and rheumatoid arthritis (RA). They have similar pharmacological properties but a slightly improved gastrointestinal (GI) safety profile if compared to traditional nonsteroidal anti-inflammatory drugs (tNSAIDs). However, long-term use of coxibs can be associated with an increased risk for cardiovascular (CV) adverse events (AEs). For this reason, two coxibs were withdrawn from the market. Currently celecoxib, etoricoxib, and lumiracoxib are used. These three coxibs differ in their chemical structure and selectivity for COX-2, which might explain some of their pharmacological features. Following oral administration, the less lipophilic celecoxib has a lower bioavailability (20-40%) than the other two coxibs (74-100%). All are eliminated by hepatic metabolism involving mainly CYP2C9 (celecoxib, lumiracoxib) and CYP3A4 (etoricoxib). Elimination half-life varies from 5 to 8 h (lumiracoxib), 11 to 16 h (celecoxib) and 19 to 32 h (etoricoxib). In patients with liver disease, plasma levels of celecoxib and etoricoxib are increased about two-fold. Clinical efficacies of the coxibs are comparable to tNSAIDs. There is an ongoing discussion about whether the slightly better GI tolerability (which is lost if acetylsalicylic acid is coadministered) of the coxibs is offset by their elevated risks for CV AEs (also seen with tNSAIDs other than naproxen), which apparently increase with dose and duration of exposure. In addition, the higher costs for coxibs (if compared to tNSAIDs, even when a "gastroprotective" proton pump inhibitor is coadministered) should be taken into consideration, if a coxib will be selected for certain patients with a high risk for GI complications. For such treatment, the lowest effective dose should be used for a limited time. Monitoring of kidney function and blood pressure appears advisable. It is hoped that further controlled studies can better define the therapeutic place of the coxibs.

MK-0703 (a cyclooxygenase-2 inhibitor) in acute pain associated with dental surgery: a randomized, double-blind, placebo- and active comparator-controlled dose-ranging study

MK-0703 is a selective cyclooxygenase-2 inhibitor investigated for the treatment of acute pain and inflammation. The purpose of this single-dose, randomized, double-blind, double-dummy, placebo-controlled, parallel-group study was to compare MK-0703 12.5, 50, and 100 mg with ibuprofen 400 mg or placebo in patients who experienced moderate to severe pain after surgical removal of at least 2 third molars. Overall analgesic effect, duration of analgesic effect, time to onset of analgesic effect, peak analgesic effect, and tolerability were assessed over a 24-hour postdose period. The primary endpoint of this study was total pain relief over 8 hours postdose. The study included 121 patients (mean age, 23 yr); 16, 31, 28, 31, and 15 patients enrolled in the placebo, MK-0703 12.5 mg, MK-0703 50 mg, MK-0703 100 mg, and ibuprofen 400 mg groups, respectively. Both MK-0703 50 and 100 mg were significantly more effective than placebo for all endpoints (P < 0.01) and comparable with ibuprofen 400 mg. The onset of analgesic effect in the MK-0703 50 mg and 100 mg and ibuprofen 400 mg groups did not differ significantly from each other (P > 0.20). MK-0703 was generally well tolerated in single doses up to 100 mg. In summary, MK-0703 50 and 100 mg were efficacious in the treatment of postoperative dental pain and were indistinguishable from the active comparator, ibuprofen 400 mg.

Endogenous opiates and behavior: 2005

This paper is the 28th consecutive installment of the annual review of research concerning the endogenous opioid system, now spanning over a quarter-century of research. It summarizes papers published during 2005 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior (Section 2), and the roles of these opioid peptides and receptors in pain and analgesia (Section 3); stress and social status (Section 4); tolerance and dependence (Section 5); learning and memory (Section 6); eating and drinking (Section 7); alcohol and drugs of abuse (Section 8); sexual activity and hormones, pregnancy, development and endocrinology (Section 9); mental illness and mood (Section 10); seizures and neurologic disorders (Section 11); electrical-related activity, neurophysiology and transmitter release (Section 12); general activity and locomotion (Section 13); gastrointestinal, renal and hepatic functions (Section 14); cardiovascular responses (Section 15); respiration and thermoregulation (Section 16); immunological responses (Section 17).

Clinical pharmacology of etoricoxib

Etoricoxib is a highly selective COX-2 inhibitor (coxib) approved in Europe for the treatment of osteoarthritis (OA), rheumatoid arthritis and acute gouty arthritis. Etoricoxib is an effective analgesic drug that has shown some improved efficacy versus traditional NSAIDs and it is the only coxib approved for the treatment of acute gouty arthritis. Moreover, recent studies evidence its efficacy in patients with ankylosing spondylitis. In the Etoricoxib Diclofenac Gastrointestinal Evaluation study performed in patients with OA, etoricoxib significantly reduced the rate of discontinuation by 50% due to gastrointestinal adverse events versus diclofenac. Comparable rates of thrombotic cardiovascular events were detected. Rates of discontinuation due to hypertension-related adverse effects were higher on etoricoxib than diclofenac. Similarly to other selective COX-2 inhibitors, etoricoxib is contraindicated in patients with ischaemic heart disease or stroke and it should be used with caution in patients with risk factors for heart disease. The European Medicines Agency has contraindicated the use of etoricoxib in patients with uncontrolled hypertension. Selective COX-2 inhibitors remain an appropriate choice in patients at low cardiovascular risk, but with increased risk of gastrointestinal complications.

Update on cyclooxygenase inhibitors: has a third COX isoform entered the fray?

It has been more than 30 years since Sir John Vane first reported that the pharmacological actions of aspirin-like drugs could be explained by their ability to inhibit cyclooxygenase (COX). Since then, a second isoform of COX, named COX-2, has been discovered and highly selective inhibitors of this isoform have been marketed. Most recently, a splice variant of COX-1 mRNA, retaining intron 1, and given the names COX-3, COX-1b or COX-1v, has been described. Non-selective NSAIDs such as ibuprofen and naproxen, which inhibit both COX-1 and COX-2, have proven highly effective and safe in the short-term management of acute pain. Highly selective COX-2 inhibitors including celecoxib, rofecoxib, valdecoxib, lumiracoxib, and etoricoxib were developed with the hope of significantly reducing the serious gastrointestinal toxicities associated with chronic high-dose NSAID use. While long-term studies demonstrated that rofecoxib and lumiracoxib reduced the incidence of GI perforations, ulcerations and bleeds by approximately 60% compared to non-selective NSAIDs, recent reports also demonstrated that the chronic use of rofecoxib and celecoxib in arthritis and colorectal polyp patients, and the short-term use of parecoxib and valdecoxib in patients who had undergone coronary artery bypass surgery, resulted in a significant increase in serious cardiovascular events, including myocardial infarction and stroke compared to naproxen or placebo. COX-3 mRNA has been isolated in many tissues including canine and human cerebral cortex, human aorta, and rodent cerebral endothelium, heart, kidney and neuronal tissues. In transfected insect cells, canine COX-3 protein is expressed and was selectively inhibited by acetaminophen. However, in humans and rodents an acetaminophen sensitive COX-3 protein is not expressed because the retention of intron-1 adds 94 and 98 nucleotides to the COX-3 mRNA structure respectively. Since the genetic code is a triplicate code (3 nucleotides to form one amino acid), the retention of the intron in both species results in a frame shift in the RNA message and the production of a truncated protein with a completely different amino acid sequence than COX-1 or COX-2 lacking acetaminophen sensitivity. Advances made through a combination of basic molecular biological and pharmacological techniques, and well designed randomized controlled clinical trials have demonstrated that the apparent gastrointestinal advantage of selective COX-2 inhibitors appears to be outweighed by their potential for cardiovascular toxicity and that acetaminophen's analgesic and antipyretic effects do not involve the inhibition of the COX-1 splice variant protein, putative COX-3.