A randomized controlled study comparing rofecoxib, diclofenac sodium, and placebo in post-bunionectomy pain

Safety and Efficacy of Vocacapsaicin for Management of Postsurgical Pain: A Randomized Clinical Trial

BACKGROUND

Nonopioid management of postsurgical pain remains a major unmet need. Few studies have evaluated transient receptor potential vanilloid subfamily member 1 agonists for analgesia after surgery. This study examines intraoperative vocacapsaicin, a novel prodrug of the transient receptor potential vanilloid subfamily member 1 agonist capsaicin, in a validated model of postsurgical pain.

METHODS

This was a triple-blinded, randomized, placebo-controlled, dose-ranging trial in patients undergoing bunionectomy. Patients were randomized 1:1:1:1 to surgical site administration of 14 ml of placebo or one of three vocacapsaicin concentrations: 0.30, 0.15, or 0.05 mg/ml. The prespecified primary endpoint was the area-under-the-curve of the numerical rating scale pain score at rest through 96 h for the 0.30 mg/ml group. Prespecified ordered, secondary endpoints for the 0.30 mg/ml group included the percentage of patients who did not require opioids from 0 to 96 h, total opioid consumption through 96 h, and the area-under-the-curve of the numerical rating scale pain score for the first week.

RESULTS

The 147 patients were randomized. During the first 96 h, vocacapsaicin (0.30 mg/ml) reduced pain at rest by 33% versus placebo (primary endpoint, 95% CI [10%, 52%], effect size [Cohen's d] = 0.61, P = 0.005). Of patients receiving vocacapsaicin (0.30 mg/ml), 26% did not require postoperative opioids for analgesia (P = 0.025) versus 5% of patients receiving placebo. Vocacapsaicin (0.30 mg/ml) reduced opioid consumption over the first 96 h by 50% versus placebo (95% CI [26%, 67%], effect size = 0.76, P = 0.002). Vocacapsaicin (0.30 mg/ml) reduced pain over the first week by 37% versus placebo (95% CI [12%, 57%], effect size = 0.62, P = 0.004). The treatment effect persisted for at least 2 weeks. All study endpoints showed an administered concentration-versus-response relationship. Vocacapsaicin was well tolerated with no differences between groups in any safety parameter.

CONCLUSIONS

A single, local administration of vocacapsaicin during surgery reduced pain and opioid consumption for at least 96 h after surgery compared to control.

EDITOR’S PERSPECTIVE

Analgesic efficacy of local versus proximal nerve blocks after hallux valgus surgery: a systematic review

Background

Hallux valgus (HV) surgery is an orthopaedic procedure that commonly causes mild to moderate postoperative pain. Effective management of this pain has become an important element of modern hallux valgus surgical treatment. A local anaesthetic (LA) with an antinociceptive effect can control this pain. However, relatively few papers have evaluated this strategy in depth. The objective of the current systematic review was to address this demand by comparing the efficacy of proximal and local blocks in controlling postoperative pain following hallux valgus surgery.

Main text

Ovid-MEDLINE, Cochrane Central, PubMed, Web of Science (WOS), Scopus, and Embase were searched from their inceptions through December 29, 2021. Observational and clinical trial publications in peer-reviewed English-language journals with a sample size of at least 20 were included. The trials involved adults over 18 who could describe their discomfort and had a bunionectomy. The included studies were evaluated using the Cochrane risk of bias 2 method. Descriptive analysis synthesised the results.

Among the 439 articles identified, five studies compromising 459 participants were included. Ankle blocks were superior to control in two studies (P = 0.001, P < 0.001) and superior to local blocks in one study (P < 0.001). Additionally, one study showed that popliteal and ankle blocks administered with lidocaine or levobupivacaine were equivalent (P = 0.123 and P = 0.055, respectively). However, one of these five included studies indicated that ankle blocks were not effective (P = 0.123) in reducing postoperative pain.

Conclusions

The key findings presented herein suggest that regional blocks effectively reduce postoperative pain and that an ankle block has more supportive evidence for its effectiveness. However, an adequate assessment of the effectiveness of various administrative routes was challenging due to the lack of reliable evidence. This needs to be addressed in future studies.

Trial registration

PROSPERO registration: CRD42022307974.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13047-022-00581-0.

PROSPECT guideline for hallux valgus repair surgery: a systematic review and procedure-specific postoperative pain management recommendations

Hallux valgus repair is associated with moderate-to-severe postoperative pain. The aim of this systematic review was to assess the available literature and develop recommendations for optimal pain management after hallux valgus repair. A systematic review using PROcedure SPECific Postoperative Pain ManagemenT (PROSPECT) methodology was undertaken. Randomized controlled trials (RCTs) published in the English language from inception of database to December 2019 assessing postoperative pain using analgesic, anesthetic, and surgical interventions were identified from MEDLINE, EMBASE, and Cochrane Database, among others. Of the 836 RCTs identified, 55 RCTs and 1 systematic review met our inclusion criteria. Interventions that improved postoperative pain relief included paracetamol and non-steroidal anti-inflammatory drugs or cyclo-oxygenase-2 selective inhibitors, systemic steroids, ankle block, and local anesthetic wound infiltration. Insufficient evidence was found for the use of gabapentinoids or wound infiltration with extended release bupivacaine or dexamethasone. Conflicting evidence was found for percutaneous chevron osteotomy. No evidence was found for homeopathic preparation, continuous local anesthetic wound infusion, clonidine and fentanyl as sciatic perineural adjuncts, bioabsorbable magnesium screws, and plaster slippers. No studies of sciatic nerve block met the inclusion criteria for PROSPECT methodology due to a wider scope of included surgical procedures or the lack of a control (no block) group. The analgesic regimen for hallux valgus repair should include, in the absence of contraindication, paracetamol and a non-steroidal anti-inflammatory drug or cyclo-oxygenase-2 selective inhibitor administered preoperatively or intraoperatively and continued postoperatively, along with systemic steroids, and postoperative opioids for rescue analgesia.

Exploring the Interplay between Rescue Drugs, Data Imputation, and Study Outcomes: Conceptual Review and Qualitative Analysis of an Acute Pain Data Set

In placebo-controlled acute surgical pain studies, provisions must be made for study subjects to receive adequate analgesic therapy. As such, most protocols allow study subjects to receive a pre-specified regimen of open-label analgesic drugs (rescue drugs) as needed. The selection of an appropriate rescue regimen is a critical experimental design choice. We hypothesized that a rescue regimen that is too liberal could lead to all study arms receiving similar levels of pain relief (thereby confounding experimental results), while a regimen that is too stringent could lead to a high subject dropout rate (giving rise to a preponderance of missing data). Despite the importance of rescue regimen as a study design feature, there exist no published review articles or meta-analysis focusing on the impact of rescue therapy on experimental outcomes. Therefore, when selecting a rescue regimen, researchers must rely on clinical factors (what analgesics do patients usually receive in similar surgical scenarios) and/or anecdotal evidence. In the following article, we attempt to bridge this gap by reviewing and discussing the experimental impacts of rescue therapy on a common acute surgical pain population: first metatarsal bunionectomy. The function of this analysis is to (1) create a framework for discussion and future exploration of rescue as a methodological study design feature, (2) discuss the interplay between data imputation techniques and rescue drugs, and (3) inform the readership regarding the impact of data imputation techniques on the validity of study conclusions. Our findings indicate that liberal rescue may degrade assay sensitivity, while stringent rescue may lead to unacceptably high dropout rates.

Single dose oral diclofenac for acute postoperative pain in adults

BACKGROUND

Diclofenac is a nonsteroidal anti-inflammatory drug, available as a potassium salt (immediate release) or sodium salt (enteric coated to suppress dissolution in the stomach). This review updates an earlier review published in the Cochrane Database of Systematic Reviews (Issue 2, 2009) entitled 'Single dose oral diclofenac for acute postoperative pain in adults'.

OBJECTIVES

To assess the analgesic efficacy and adverse effects of a single oral dose of diclofenac for moderate to severe postoperative pain, using methods that permit comparison with other analgesics evaluated in standardised trials using almost identical methods and outcomes.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, the Oxford Pain Relief Database, two clinical trial registries, and the reference lists of articles. The date of the most recent search was 9 March 2015.

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 considered studies for inclusion in the review, assessed risk of bias, and extracted data. We used the area under the pain relief versus time curve to derive the proportion of participants with at least 50% pain relief over six hours prescribed either diclofenac or placebo. We calculated the risk ratio (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.

MAIN RESULTS

This update included three new studies, providing a 26% increase in participants in comparisons between diclofenac and placebo. We included 18 studies involving 3714 participants, 1902 treated with diclofenac and 1007 with placebo. This update has also changed the focus of the review, examining the effects of formulation in more detail than previously. This is a result of increased understanding of the importance of speed of onset in determining analgesic efficacy in acute pain.The largest body of information, for diclofenac potassium 50 mg, in seven studies, produced an NNT for at least 50% of maximum pain relief compared with placebo of 2.1 (95% confidence interval (CI) 1.9 to 2.5) (high quality evidence). There was a graded improvement in efficacy as doses rose from 25 mg to 100 mg, both for participants achieving at least 50% maximum pain relief, and for remedication within 6 to 8 hours. Fast-acting formulations (dispersible products, solutions, and softgel formulations) had a similar efficacy for a 50 mg dose, with an NNT of 2.4 (2.0 to 3.0). Diclofenac sodium in a small number of studies produced a lesser effect, with an NNT of 6.6 (4.1 to 17) for the 50 mg dose.Adverse event rates were low in these single dose studies, with no difference between diclofenac and placebo (moderate quality evidence).

AUTHORS' CONCLUSIONS

Diclofenac potassium provides good pain relief at 25 mg, 50 mg, and 100 mg doses. Diclofenac sodium has limited efficacy and should probably not be used in acute pain.

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.

Acute postoperative pain relief with immediate-release tapentadol: randomized, double-blind, placebo-controlled study conducted in South Korea

OBJECTIVE

To broaden the ethnic groups in which tapentadol IR is evaluated for treating acute postoperative pain to include Asians.

METHODS

In this phase 3, multicenter, double-blind, randomized study, 352 Korean adults with moderate-to-severe pain following hallux valgus surgery received tapentadol IR 50 or 75 mg or placebo orally every 4-6 hours for 72 hours. Patients requesting other (rescue) analgesics during this period were discontinued for lack of efficacy. The primary endpoint, sum of pain intensity difference (SPID) over 48 hours, was evaluated based on the difference between tapentadol IR and placebo in least squares (LS) mean change from baseline using analysis of covariance (ANCOVA). Secondary endpoints included the time to first rescue medication use and the distribution of responder rates.

RESULTS

A treatment effect, favoring tapentadol IR, was observed for SPID48 (p < 0.001 for both doses vs. placebo, ANCOVA). The between-group difference (vs. placebo) in LS means of SPID48 was 76.4 (95% CI: 51.0, 101.7) for tapentadol IR 50 mg and 90.6 (95% CI: 65.1, 116.1) for tapentadol IR 75 mg. Time to first rescue medication use was delayed for tapentadol IR (p < 0.001 for both doses vs. placebo; log-rank test). The distribution of responders at 12, 24, 48, and 72 hours favored tapentadol IR (p ≤ 0.001 for both doses vs. placebo; Cochran-Mantel-Haenszel test). Dizziness, nausea, and vomiting were each reported in ≥ 10% tapentadol-treated patients and at an incidence ≥ 2-fold higher vs. placebo. The study findings may be limited by study drug dosing every 4 to 6 hours and frequent monitoring during treatment, neither of which mimic pain treatment in clinical practice. However, any potential bias based on this systematic monitoring of patients would be mitigated by the randomized, double-blind nature of the study, with all treatment groups similarly affected by such biases, if any.

CONCLUSIONS

Tapentadol IR reduced acute pain intensity, significantly more than placebo, after orthopedic surgery in Korean patients.

CLINICAL TRIAL REGISTRATION

NCT01516008.

Pain Management for Elective Foot and Ankle Surgery: A Systematic Review of Randomized Controlled Trials

Pain after foot and ankle surgery can significantly affect the postoperative outcomes. We performed a systematic review of randomized controlled trials assessing postoperative pain after foot and ankle surgery, because the surgery will lead to moderate-to-severe postoperative pain, but the optimal pain therapy has been controversial. A systematic review of randomized controlled trials in English reporting on pain after foot and ankle surgery in adults published from January 1946 to February 2013 was performed. The primary outcome measure was the postoperative pain scores. The secondary outcome measures included supplemental analgesic requirements and other recovery outcomes. With 953 studies identified, 45 met the inclusion criteria. The approaches improving pain relief (reduced pain scores or opioid requirements) included peripheral nerve blocks, wound infiltration, intravenous dexamethasone, acetaminophen, nonsteroidal anti-inflammatory drugs, cyclooxygenase-2 selective inhibitors, and opioids. Wound instillation, intra-articular injection, and intravenous regional analgesia had variable analgesia. The lack of homogeneous study design precluded quantitative analyses. Optimal pain management strategies included locoregional analgesic techniques plus acetaminophen and nonsteroidal anti-inflammatory drugs or cyclooxygenase-2 selective inhibitors, with opioids used for "rescue," and 1 intraoperative dose of parenteral dexamethasone. Popliteal sciatic nerve blocks would be appropriate when expecting severe postoperative pain (extensive surgical procedure), and ankle blocks and surgical incision infiltration would be appropriate when expecting moderate postoperative pain (less extensive and minimally invasive surgical procedures). Additional studies are needed to assess multimodal analgesia techniques.

An assessment of the efficacy and safety of diclofenac potassium liquid-filled capsules in patients with various levels of baseline pain intensity

CONTEXT

Diclofenac potassium liquid-filled soft gelatin capsule (DPSGC; Zipsor*) is a novel formulation of diclofenac potassium used to treat mild to moderate acute pain.

OBJECTIVE

To investigate whether DPSGC 25 mg provided significant reduction in pain intensity compared with placebo, regardless of baseline pain intensity, a post hoc analysis was performed of pooled data from two replicate randomized controlled trials (NCT00366444 and NCT00375934) that evaluated the safety and efficacy of DPSGC in postbunionectomy treatment.

METHODS

Patients from the two randomized trials were assigned to one of two subgroups: patients with baseline numerical pain rating scale (NPRS) scores of 4 or greater to less than 7 and those with baseline NPRS scores of 7 or greater. Within each subgroup, efficacy and safety of DPSGC was compared with placebo.

RESULTS

Across the two studies, 73 DPSGC- and 59 placebo-treated patients had baseline pain intensity scores ranging from 4 or greater to less than 7, while 128 DPSGC- and 141 placebo-treated patients had baseline pain intensity scores of 7 or greater. Significantly lower mean 48-hour NPRS scores were observed in the DPSGC group, regardless of baseline pain intensity (P < 0.0001). In both subgroups, at least twice as many patients treated with DPSGC rated the study drug as very good or excellent compared with patients taking placebo. Potential limitations for this post hoc analysis include study design and patient population. As with all studies investigating treatment for pain, the use of rescue medication may also be a potential limitation.

CONCLUSIONS

DPSGC provided significantly greater improvements in pain compared with placebo following bunionectomy, regardless of patients' baseline pain level.

Onset of action of diclofenac potassium liquid-filled capsules in dental surgery patients

OBJECTIVE

Diclofenac potassium soft gelatin capsules (DPSGC) are a low-dose, liquid-filled formulation that uses patented dispersion technology to facilitate rapid and consistent gastrointestinal absorption. Onset of pain relief experienced by patients receiving DPSGC was evaluated in two dental pain studies. Confirmed perceptible pain relief was evaluated in a post hoc analysis from these randomized controlled trials.

RESEARCH DESIGN AND METHODS

Adult patients (n = 514) were enrolled in two multicenter, parallel group, double-blind, placebo-controlled studies. Patients undergoing third molar extraction and experiencing a requisite level of pain (≥50 mm on a 100-mm visual analog scale within 4 hours post-surgery) were randomized to receive single doses of DPSGC 25 mg, 50 mg, 100 mg, or placebo. Pain was assessed at baseline and during 6 hours after dosing. Times to onset of perceptible and meaningful pain relief were recorded using the two-stopwatch method. Confirmed perceptible pain relief was determined in the DPSGC and placebo groups by calculating the median time to onset of perceptible pain relief (first stopwatch) in only those individuals who reported meaningful pain relief (second stopwatch).

RESULTS

More than 80% of patients achieved confirmed perceptible pain relief in the DPSGC groups compared with less than 30% of patients in the placebo group (Study 1 and Study 2, p < 0.0001). The median time to onset of confirmed perceptible pain relief in the two studies was less than 30 minutes for patients receiving any dose of DPSGC and more than 360 minutes in the placebo group (Study 1 and Study 2, p < 0.0001). DPSGC was well tolerated and no serious adverse events were reported. Study design limitations include the short duration of the trial and evaluation of a relatively limited patient population.

CONCLUSIONS

These results indicate that DPSGC was efficacious in providing a rapid onset of confirmed perceptible pain relief within 30 minutes of administration in these single dose postoperative dental pain studies.

A pharmacokinetic analysis of diclofenac potassium soft-gelatin capsule in patients after bunionectomy

The clinical utility of diclofenac potassium, a nonsteroidal anti-inflammatory drug, may be lessened by inconsistent gastrointestinal absorption. Diclofenac potassium liquid filled soft-gelatin capsule (DPSGC) is an investigational formulation that uses ProSorb dispersion technology to facilitate rapid and consistent gastrointestinal absorption. In this study, the pharmacokinetic (PK) properties of DPSGC are investigated and compared with a commercially available oral diclofenac potassium tablet in patients after primary unilateral first metatarsal bunionectomy. In an open-label, randomized study, 53 patients received ProSorb-D 12.5 mg (the liquid equivalent of DPSGC), DPSGC 25 mg, DPSGC 50 mg, or immediate-release diclofenac potassium 50-mg tablet administered every 8 hours for a 24-hour inpatient period followed by 7 days of outpatient dosing. Diclofenac steady-state PK was evaluated over an 8-hour sampling period 4 days after surgery. Delayed and/or multiple peaks in the diclofenac plasma concentration-time course profiles occurred more frequently with the commercially available oral diclofenac potassium 50-mg tablet than with the other DPSGC formulations. PK data for ProSorb-D 12.5-mg liquid, DPSGC 25 mg, DPSGC 50 mg, and diclofenac potassium 50-mg tablet revealed mean peak plasma concentrations (Cmax) of 302, 749, 1006, and 902 ng/mL, respectively, whereas area under the plasma concentration curve values were 316, 595, 1029, and 1166 ng-hour/mL, respectively. Mean times to Cmax (tmax) were 0.49, 0.63, 0.95, and 1.26 h, respectively. When compared with absorption characteristics of diclofenac potassium 50-mg tablet, DPSGC was more rapidly and consistently absorbed after bunionectomy. These characteristics should be advantageous when rapid pain relief is desired.

Efficacy and safety of oxycodone HCl/niacin tablets for the treatment of moderate-to-severe postoperative pain following bunionectomy surgery

OBJECTIVE

To evaluate the efficacy and safety of two dose strengths of oxycodone hydrochloride (HCl)/niacin tablets * for the treatment of moderate-to-severe postoperative pain following bunionectomy surgery.

RESEARCH DESIGN AND METHODS

Randomized, double-blind, placebo-controlled, US multicenter, repeat-dose study (Clinicaltrials.gov: NCT00654069). A total of 606 patients aged ≥18 years with moderate-to-severe pain post-bunionectomy were screened, and 405 patients were randomized to receive placebo, 2 × 5/30 mg oxycodone HCl/niacin tablets, or 2 × 7.5/30 mg oxycodone HCl/niacin tablets administered every 6 hours for 48 hours. Ketorolac tromethamine was available as rescue medication.

MAIN OUTCOME MEASURES

Primary efficacy endpoint was the sum of pain-intensity difference scores during the 48 hours (SPID(48)) following the initial dose of study drug. Secondary efficacy endpoints included a responder analysis and use of rescue medication. Safety evaluations included adverse events (AEs), vital signs, and clinical laboratory assessments.

RESULTS

Both doses of oxycodone HCl/niacin tablets demonstrated superior reductions in pain intensity compared with placebo as evidenced by the SPID(48) (p < 0.0001 for both oxycodone HCl/niacin 2 × 5/30 mg and 2 × 7.5/30 mg). AEs were consistent with the known effects of oxycodone HCl and niacin. Most AEs were mild or moderate in intensity, and no serious AEs occurred. There were no discontinuations due to AEs in the placebo group; 2/135 (1.5%) discontinued due to AEs in the 2 × 5/30 mg group and 4/134 (3.0%) in the 2 × 7.5/30 mg group. A limitation of this study was that there was no active comparator arm.

CONCLUSIONS

Oxycodone HCl/niacin tablets (5/30 mg and 7.5/30 mg) provide effective analgesia and are generally well tolerated in patients with moderate-to-severe pain following bunionectomy surgery.

An enhanced bunionectomy model as a potential tool for early decision-making in the development of new analgesics

BACKGROUND

bunionectomy has been used as a model of postoperative pain for opioids and nonsteroidal anti-inflammatory drugs/cyclooxygenase-2 inhibitors with a fast onset of analgesia. The present study was conducted to assess whether the utility of the model can be broadened in assessing the efficacy of analgesics with diverse mechanisms and pharmacokinetic profiles in drug development and to enhance the sensitivity of a bunionectomy model.

METHODS

this was a single center, randomized, double-blind, placebo-controlled, three-arm, parallel group methodology study to evaluate the effects of pregabalin and naproxen sodium on postoperative pain following bunionectomy. Patients (n=100) were randomized 1:1:1 to three treatments (administered 1 hour before and at defined intervals after surgery): pregabalin 300 mg before surgery and 150 mg every 8 hours; naproxen sodium 550 mg before surgery and 550 mg every 12 hours; or placebo in a double-dummy fashion. Primary endpoints were patient-controlled analgesic (PCA) hydromorphone consumption and the time to first PCA hydromorphone use postsurgery over 24 hours.

RESULTS

of the 100 patients randomized, 96 completed the study. Relative to placebo, pregabalin and naproxen sodium, respectively, reduced PCA hydromorphone consumption by 51% (P=0.005) and 65% (P<0.001) and increased the median time to first use of PCA hydromorphone by 1.5 hours (P=0.004) and 3.7 hours (P<0.001). Both drugs significantly (P<0.050) decreased use of oral opioid rescue medication over 24-48 hours postsurgery relative to placebo. Although there were no statistically significant differences between naproxen sodium and pregabalin in opioid consumption and global evaluation of medication, overall naproxen sodium appeared to be more effective at reducing pain.

CONCLUSIONS

the model provided a sensitive method for evaluating efficacy of compounds with diverse mechanisms and pharmacokinetic profiles. The robustness of the enhanced pain model renders bunionectomy pain a valuable tool to assess novel analgesic compounds in small numbers of subjects early in drug development.

Diclofenac potassium liquid-filled soft gelatin capsules for the treatment of postbunionectomy pain

OBJECTIVE

Diclofenac potassium liquid-filled soft gelatin capsule (DPSGC) is a rapidly absorbed formulation of diclofenac approved for the treatment of mild to moderate acute pain in adults (≥18 years of age). The objective of this study was to investigate the efficacy and safety of DPSGC 25 mg in a multicenter, randomized, double-blind, placebo-controlled study in patients experiencing pain following first metatarsal bunionectomy.

RESEARCH DESIGN AND METHODS

Patients experiencing a requisite level of pain (≥4 based on an 11-point numeric pain rating scale [NPRS]; 0 = no pain, 10 = worst pain possible) on the day following surgery were randomized to receive DPSGC 25 mg or placebo. Patients received a second dose (remedication) on request or at 8 hours postdose followed by additional doses every 6 hours through the end of postsurgery Day 4. Rescue medication (hydrocodone/acetaminophen) was available as needed after the second dose.

CLINICAL TRIAL REGISTRATION

NCT00375934.

MAIN OUTCOME MEASURE

The primary efficacy endpoint was the average NPRS score over the 48 hour inpatient multiple-dose period.

RESULTS

DPSGC provided a significant improvement in mean 48 hour NPRS scores over placebo (3.29 vs 5.74, respectively; p < 0.0001), as well as for summed pain intensity difference (203.1 vs 86.6; p < 0.0001). Patients treated with DPSGC experienced a faster onset of meaningful pain relief compared with placebo (p = 0.0034). Rescue medication use on Day 1 and Day 2 was reduced in the DPSGC group compared with placebo (53.5% vs 92.1% on Day 1; 30.3% vs 67.3% on Day 2; p < 0.0001). DPSGC was well tolerated and no patients treated with DPSGC reported serious adverse events. As with any study, there are potential limitations including study design and patient population.

CONCLUSION

These results indicate that DPSGC reduced pain in patients who underwent bunionectomy and this novel formulation of diclofenac potassium may be a practical option for treating mild to moderate acute pain.

Pain management after elective hallux valgus surgery: a prospective randomized double-blind study comparing etoricoxib and tramadol

BACKGROUND

Pain is a common complaint after day surgery, and there is still a controversy surrounding the use of selective cyclooxygenase-2 (COX-2) inhibitors. In the present prospective, randomized, double-blind study we compared pain management with a selective (COX-2) inhibitor (etoricoxib) with pain management using sustained-release tramadol after elective hallux valgus surgery.

METHODS

One hundred ASA 1 to 2 female patients were randomized into 2 groups of 50 patients each; oral etoricoxib 120 mg x 1 x IV + 90 mg x 1 x day V-VII and oral tramadol sustained-release 100 mg x 2 x VII. Pain, pain relief, satisfaction with pain management, and need for rescue medication were evaluated during the first 7 postoperative days. A computed tomography scan evaluating bone healing was performed 12 weeks after surgery. A clinical evaluation of outcome (healing, mobility, and patient-assessed satisfaction) was performed 16 weeks after surgery.

RESULTS

Two patients withdrew before discharge from the hospital. Ninety-eight patients, 81 ASA 1 and 17 ASA 2 (82 nonsmokers and 14 smokers), mean age 49 years (19-65), weight 64 (47-83) kg, and height 167 (154-183) cm were evaluated. Overall pain was well managed, but the mean visual analog scale (VAS) was significantly lower among etoricoxib patients evaluated during the entire 7-day period studied (12.5 + or - 8.3 vs. 17.3 + or - 11, P < 0.05). patient's grading of pain relief (92 + or - 12 vs. 85 + or - 15, P < 0.05) and satisfaction with pain medication (47/49 vs. 39/49, P < 0.05) was higher among etoricoxib patients. Patients receiving tramadol reported significantly more side effects. Six patients, all in the tramadol group, discontinued the study because of side effects (P < 0.05). At 14-day follow-up 1 patient in the etoricoxib group and 5 patients in the tramadol group exhibited minor irritation in the wound area. The 12-week computed tomography scan showed good healing in 82 patients, 43 in the etoricoxib group, and 39 in the tramadol group. The study found ongoing healing in 11 patients, 4 in the etoricoxib group and 7 in the tramadol group. The 16-week patient-assessed Health Profile Quality of life revealed high patient satisfaction overall; 47 patients in each study group rated the outcome as satisfactory and the mean change in the patient-assessed quality of life VAS score was 6.2 and 2.6 for the etoricoxib and tramadol groups, respectively. Clinical follow-up at 16 weeks showed high functionality and no signs or symptoms of improper healing in any patient.

CONCLUSION

Etoricoxib was found to be more effective and associated with fewer side effects in comparison with tramadol sustained release as a component of multimodel analgesia after elective hallux valgus surgery. There were no signs of impaired wound or bone healing associated with the use of etoricoxib.

A walking model to assess the onset of analgesia in osteoarthritis knee pain

OBJECTIVE

To assess a walking model utilizing a set of standardized treadmill walks to measure acute analgesic response in osteoarthritis (OA) of the knee.

DESIGN

Randomized, double-blind, placebo-controlled, multiple dose, three-period crossover study. Patients > or =45 years of age (N=22) with symptomatic knee OA were randomized to naproxen 500 mg bid, tramadol/acetaminophen 37.5 mg/325 mg in forced titration, or placebo in each of three periods. Patients performed multiple 20-minute treadmill walks on Day 1 and Day 3 at a consistent self-selected pace predetermined at screening. Pain intensity (PI) during the walks was assessed on an 11-point numerical rating scale at 0, 3, 6, 9, 12, 15, 18, and 20 min. The primary endpoint was the time-weighted average (TWA) change from baseline PI on Day 3 for the two self-paced walks for the active treatments vs placebo. Time to moderate pain (TTMP) was a key secondary endpoint.

RESULTS

Compared with placebo, the TWA change from baseline PI on Day 3 was significantly better with tramadol/acetaminophen (P=0.043) but not with naproxen (P=0.089). TWA change from baseline on Day 1 was also significantly better with both tramadol/acetaminophen (P=0.001) and naproxen (P=0.048) compared with placebo. TTMP was significantly better for tramadol/acetaminophen and naproxen than placebo (P<0.001 to P=0.015) for walks on Day 1 after a single dose and on Day 3.

CONCLUSIONS

This novel OA pain model was able to discriminate both tramadol/acetaminophen and naproxen from placebo after single and multiple doses. ClinicalTrials.gov identifier: NCT00772967.

Traumeel S for pain relief following hallux valgus surgery: a randomized controlled trial

BACKGROUND

In spite of recent advances in post-operative pain relief, pain following orthopedic surgery remains an ongoing challenge for clinicians. We examined whether a well known and frequently prescribed homeopathic preparation could mitigate post-operative pain.

METHOD

We performed a randomized, double blind, placebo-controlled trial to evaluate the efficacy of the homeopathic preparation Traumeel S in minimizing post-operative pain and analgesic consumption following surgical correction of hallux valgus. Eighty consecutive patients were randomized to receive either Traumeel tablets or an indistinguishable placebo, and took primary and rescue oral analgesics as needed. Maximum numerical pain scores at rest and consumption of oral analgesics were recorded on day of surgery and for 13 days following surgery.

RESULTS

Traumeel was not found superior to placebo in minimizing pain or analgesic consumption over the 14 days of the trial, however a transient reduction in the daily maximum post-operative pain score favoring the Traumeel arm was observed on the day of surgery, a finding supported by a treatment-time interaction test (p = 0.04).

CONCLUSIONS

Traumeel was not superior to placebo in minimizing pain or analgesic consumption over the 14 days of the trial. A transient reduction in the daily maximum post-operative pain score on the day of surgery is of questionable clinical importance.

TRIAL REGISTRATION

This study was registered at ClinicalTrials.gov. # NCT00279513.

Diclofenac potassium liquid-filled soft gelatin capsules in the management of patients with postbunionectomy pain: a Phase III, multicenter, randomized, double-blind, placebo-controlled study conducted over 5 days

BACKGROUND

Diclofenac potassium liquid-filled soft gelatin capsule (DPSGC) is a rapidly absorbed formulation of diclofenac potassium developed for the treatment of mild to moderate acute pain.

OBJECTIVE

The present study was conducted to assess the efficacy and safety profile of DPSGC 25 mg in patients with pain after first-metatarsal bunionectomy.

METHODS

This was a Phase III, multicenter, randomized, double-blind, parallel-group, placebo-controlled study conducted over 5 days. Patients experiencing the requisite level of pain (score > or = 4 on an 11-point numeric pain rating scale [NPRS] from 0 = no pain to 10 = worst possible pain) on the day after bunionectomy were randomized to receive DPSGC 25 mg or matching placebo. A second dose was given when patients requested additional medication for pain. Subsequent doses were given every 6 hours over a 48-hour inpatient multiple-dose period and continued over an additional 48-hour outpatient multiple-dose period. Opioid rescue medication was available as needed after the second dose of study medication. The primary efficacy end point was the mean NPRS score over the 48-hour inpatient multiple-dose period. Additional measures included NPRS scores at predefined times over 48 hours, the summed pain intensity difference over 48 hours (SPID48), the time-weighted sum of pain relief scores over the first 8 hours, the mean dosing interval (the time from dosing to the time rescue medication or the next dose of study medication was administered, whichever was less), the proportion of patients requiring rescue medication, and the onset of perceptible and meaningful pain relief (2-stopwatch method). Tolerability was assessed based on physician monitoring and patient reporting of adverse events (AEs) and the results of standard laboratory tests.

RESULTS

Of 201 randomized patients (102 DPSGC 25 mg, 99 placebo; 86.6% female; 58.2% white; mean [SD] age, 45.2 [11.5] years; weight range, 49.4-108.0 kg), 198 completed the study. Mean baseline NPRS scores did not differ significantly between the DPSGC and placebo groups (6.9 and 7.3, respectively). DPSGC was associated with significant improvements compared with placebo in mean NPRS score over 48 hours (2.5 vs 5.6, respectively; P < 0.001), mean SPID48 (210.0 vs 90.3; P < 0.001), and overall mean dosing interval (331.5 vs 263.9 min; P < 0.001). Significant differences in NPRS scores between DPSGC 25 mg and placebo were noted at all time points from baseline through 48 hours (P < 0.001). The proportion of patients requiring rescue medication was significantly lower in the DPSGC group compared with the placebo group (39.2% vs 87.9% on day 1; 21.6% vs 64.6% on day 2; both, P < 0.001). Patients receiving DPSGC had a significantly faster onset of meaningful pain relief compared with those receiving placebo (P = 0.008). The most commonly reported AEs were nausea (7.8% vs 18.2%), headache (5.9% vs 9.1%), vomiting (3.9% vs 9.1%), and constipation (3.9% vs 2.0%). The overall incidence of AEs occurring in > or = 2% of patients was significantly lower in the DPSGC group than in the placebo group (20.6% vs 44.4%; P < 0.05); no patient receiving DPSGC had a serious AE.

CONCLUSIONS

DPSGC 25 mg taken every 6 hours was effective in reducing postbunionectomy pain in the patients studied. DPSGC was well tolerated, suggesting that it may be a practicable option for the treatment of mild to moderate acute pain. ClinicalTrials. gov identifier: NCT00366444.

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 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.

A randomized, double-blind, phase III study comparing multiple doses of tapentadol IR, oxycodone IR, and placebo for postoperative (bunionectomy) pain

OBJECTIVE

This study evaluated tapentadol immediate release (IR) for pain relief following orthopedic bunionectomy surgery.

METHODS

This randomized, double-blind, placebo- and active-controlled, phase III study included patients with moderate-to-severe pain following bunionectomy. Randomized patients (N = 603) received tapentadol IR 50, 75, or 100 mg; oxycodone HCl IR 15 mg; or placebo orally every 4-6 hours over a 72-hour period following bunionectomy. The primary endpoint was the sum of pain intensity difference (SPID) over 48 hours. Secondary endpoints included SPID over 12, 24, and 72 hours; total pain relief, and sum of total pain relief and sum of pain intensity difference (SPRID) over 12, 24, 48, and 72 hours; use of rescue medication; patient global impression of change; and onset of action assessment. Possible limitations of this study were that the intense dose monitoring and thorough nursing care were unlikely to represent actual use situations and could introduce similar bias across all treatment groups.

CLINICAL TRIAL REGISTRATION

NCT00364247.

RESULTS

Mean SPID(48) values were significantly higher for tapentadol IR (50, 75, and 100 mg) and oxycodone HCl IR 15 mg compared with placebo (all p <or= 0.001). The overall incidence of adverse events was 70% for tapentadol IR 50 mg, 75% for tapentadol IR 75 mg, 85% for tapentadol IR 100 mg, 87% for oxycodone HCl IR 15 mg, and 41% for placebo. Post hoc analyses showed that tapentadol IR 100 mg and oxycodone HCl IR 15 mg provided equivalent analgesia, yet tapentadol IR 100 mg had a significantly lower incidence of nausea and/or vomiting (53% vs 70%, respectively, nominal p = 0.007).

CONCLUSIONS

Multiple doses of tapentadol IR (50, 75, and 100 mg) significantly relieve acute pain after orthopedic surgery compared with placebo. These data suggest that at doses providing comparable efficacy, tapentadol IR 100 mg has improved gastrointestinal tolerability compared with oxycodone HCl IR 15 mg.

The efficacy and tolerability of multiple-dose tapentadol immediate release for the relief of acute pain following orthopedic (bunionectomy) surgery

OBJECTIVE

Tapentadol is a new, centrally acting analgesic with two mechanisms of action, combining μ-opioid agonism and norepinephrine reuptake inhibition in a single molecule. This study assessed tapentadol immediate release (IR) in patients with postsurgical orthopedic pain.

METHODS

This randomized, double-blind, phase II study involved patients with moderate-to-severe pain after bunionectomy surgery (first metatarsal with osteotomy). Patients (N = 269) were randomly assigned to receive tapentadol IR 50 or 100 mg, oxycodone HCl IR 10 mg, or placebo; the study drug was taken every 4-6 h, over a 72-h period starting 1 day after surgery (Evaluation Day 2). The primary endpoint was the sum of pain intensity over 24 h (SPI-24) on the second day after randomization (Evaluation Day 3). Potential limitations of this study included the use of rescue medication and the fact that it was not powered to statistically compare between-group differences in tolerability measures.

RESULTS

Mean (standard deviation [SD]) SPI-24 values on Evaluation Day 3 were significantly lower for tapentadol IR (50 mg: 33.6 [19.7], p = 0.0133; 100 mg: 29.2 [15.2], p = 0.0001) and oxycodone HCl IR 10 mg (35.7 [17.2]; nominal p = 0.0365) compared with placebo (41.9 [17.7]). The most common treatment-emergent adverse events for all treatment groups were characteristic of drugs with μ-opioid agonist activity. While providing similar analgesic efficacy, tapentadol IR 50 mg was associated with lower rates of nausea (46.3% vs. 71.6% for oxycodone HCl IR 10 mg), dizziness (32.8% vs. 56.7%), vomiting (16.4% vs. 38.8%), and constipation (6.0% vs. 17.9%), and a similar rate of somnolence (28.4% vs. 26.9%) compared with oxycodone HCl IR 10 mg.

CONCLUSIONS

Tapentadol IR 50 and 100 mg and oxycodone HCl IR 10 mg were effective in this study for the relief of acute postoperative pain following bunionectomy. The study results suggest improved gastrointestinal tolerability of tapentadol IR 50 mg compared with oxycodone at a dose showing comparable efficacy.

Clinical pain management peri-operative scenarios

This article reinforces the clinical points of emphasis that have been stressed throughout this issue in a case scenario format. Common situations dealt with by physicians are examined to highlight the underlying physiology of the specific complaints and treatment interventions. The goal of this article is to present an evidenced-based review of pain management interventions in a format that allows for reader incorporation.

Peri-operative pain management

Surgery is a circumstance in which we know that we will cause pain. Although most of our perioperative pain management interventions are symptomatic, several strategies can reduce and even prevent pain in the perioperative setting. Because the physiologic mechanisms of postoperative pain are understood, it is possible to interrupt these mechanisms before the patient actually becomes symptomatic. This article reviews the literature and presents these strategies with the hope of implementation of the readers.

The efficacy of rofecoxib 50 mg and hydrocodone/acetaminophen 7.5/750 mg in patients with post-arthroscopic pain

OBJECTIVE

To compare the efficacy and tolerability of rofecoxib, hydrocodone/acetaminophen 7.5 mg/750 mg (H/A) and placebo in treating pain after arthroscopy of the knee.

METHODS

A randomized, double-blind, placebo-controlled, single dose study enrolling patients experiencing moderate or severe pain after knee arthroscopy. Patients with moderate-to-severe postoperative pain received either rofecoxib 50 mg (n = 151), H/A (n = 145), or placebo (n = 147). Pain was measured over 24 h. The primary endpoint was total pain relief at 6 h for rofecoxib 50 mg compared with placebo.

RESULTS

H/A (p = 0.003), but not rofecoxib (p = 0.256) was significantly more effective than placebo for total pain relief at 6 h (TOPAR6). Although analgesic onset and peak were significantly better for H/A than for both rofecoxib (p < 0.01, p < 0.05, respectively) and placebo (p < 0.05, p < 0.001, respectively), rofecoxib patients used significantly less rescue analgesia (p < 0.001) over 24 h. Rofecoxib also provided better Brief Pain Inventory Severity (p = 0.008) and Interference Domain (p = 0.045) scores at 24 h compared to placebo and had lower 24-h Pain Severity scores than H/A (p < 0.05). Treatments were generally well tolerated, with no significant difference in the frequency of patient-reported adverse events between groups.

CONCLUSIONS

Rofecoxib 50 mg did not provide significantly different pain relief than placebo at 6 h, and the primary endpoint TOPAR was not attained, although it did show several efficacy benefits at 24 h, including a significant opioid-sparing effect. All treatments were well tolerated, with no significant differences observed. The limited efficacy of rofecoxib in this study contrasts to the results of previous surgical studies evaluating rofecoxib, and may be partially explained by the postoperative dosing in this arthroscopic surgical model.

Calotropis procera latex-induced inflammatory hyperalgesia--effect of antiinflammatory drugs

The milky white latex of plant Calotropis procera produces inflammation of the skin and mucous membranes on accidental exposure. It produces edema on local administration due to the release of histamine and prostaglandins and is associated with hyperalgesia. In the present study we have evaluated the antiedematous and analgesic activity of antiinflammatory drugs against inflammatory response induced by dried latex (DL) of C procera in rat paw edema model. An aqueous extract of DL of C procera was injected into the subplantar surface of the rat paw and the paw volume was measured by a plethysmometer at 0, 1, 2, 6, 12, and 24 hours. Concomitantly the hyperalgesic response was also evaluated by motility test, stair climbing ability test, dorsal flexion pain test, compression test, and observing the grooming behavior. The inhibitory effect of diclofenac and rofecoxib on edema formation and hyperalgesic response was compared with cyproheptadine (CPH). DL-induced edema formation was maximum at 2 hours that was associated with decreased pain threshold, functional impairment, and grooming. Treatment with antiinflammatory drugs and CPH significantly attenuated the edematous response and grooming, increased the pain threshold, and improved functional parameters. Both antiinflammatory and antiserotonergic drugs significantly inhibited the hyperalgesia associated with DL-induced paw edema. Rofecoxib was found to be superior than diclofenac and was as effective as CPH in ameliorating the hyperalgesia. However, it was found to be less effective than CPH in attenuating edema formation.