Single Dose Analgesic Efficacy of Tapentadol in Postsurgical Dental Pain: The Results of a Randomized, Double-Blind, Placebo-Controlled Study

Intranasal Tapentadol Versus Intravenous Paracetamol for Postoperative Analgesia in Lower Limb Orthopaedic Surgeries Under Spinal Anaesthesia: A Single Blind RCT

OBJECTIVE

We aimed to compare the analgesic effectiveness of intranasal tapentadol nasal spray 44.5 mg and intravenous (IV) paracetamol 1 gm during the postoperative period in patients undergoing lower limb orthopedic surgeries under spinal anesthesia.

METHODS

This prospective, randomized, single-blind clinical trial was carried out in a tertiary care teaching hospital. Patients aged between 18 and 60 years of physical status ASA grade 1-3 were included in the study. Postoperative pain scores were measured using the visual analog scale (VAS) in centimeters (cm) every 12 hours in 37 patients per group. The patients were administered either intranasal tapentadol or IV paracetamol every 6 hours for 72 hours, beginning 3 hours after surgery.

RESULTS

There was a significant group by intervention effect favoring intranasal tapentadol, suggesting a greater reduction in VAS pain scores after the intervention at 72 hours (estimate: -1.58 cm; SE:0.2; P<0.001). Group by time effect for all the measured time frames, except for 36 hours, favored intranasal tapentadol with estimated values for greater reduction in VAS pain scores ranging from -0.8 cm to -1.6 cm.

DISCUSSION

The results of the present study suggests that intranasal tapentadol results in a greater reduction of postoperative pain compared with IV paracetamol in lower limb orthopedic surgeries. The ease of administration of tapentadol may make it a preferred option over IV paracetamol in such surgeries.

Novel Opioids in the Setting of Acute Postoperative Pain: A Narrative Review

Although traditional opioids such as morphine and oxycodone are commonly used in the management of acute postoperative pain, novel opioids may play a role as alternatives that provide potent pain relief while minimizing adverse effects. In this review, we discuss the mechanisms of action, findings from preclinical studies and clinical trials, and potential advantages of several novel opioids. The more established include oliceridine (biased ligand activity to activate analgesia and downregulate opioid-related adverse events), tapentadol (mu-opioid agonist and norepinephrine reuptake inhibitor), and cebranopadol (mu-opioid agonist with nociceptin opioid peptide activity)-all of which have demonstrated success in the clinical setting when compared to traditional opioids. On the other hand, dinalbuphine sebacate (DNS; semi-synthetic mu partial antagonist and kappa agonist), dual enkephalinase inhibitors (STR-324, PL37, and PL265), and endomorphin-1 analog (CYT-1010) have shown good efficacy in preclinical studies with future plans for clinical trials. Rather than relying solely on mu-opioid receptor agonism to relieve pain and risk opioid-related adverse events (ORAEs), novel opioids make use of alternative mechanisms of action to treat pain while maintaining a safer side-effect profile, such as lower incidence of nausea, vomiting, sedation, and respiratory depression as well as reduced abuse potential.

Tapentadol Immediate Release (IR) versus Morphine Hydrochloride for Postoperative Analgesia of Patients Undergoing Total Abdominal Hysterectomy-A Prospective Cohort Study

Background and Objectives: This study aimed to examine the efficacy of tapentadol immediate release (IR) and morphine hydrochloride in the treatment of acute postoperative pain after total abdominal hysterectomy, as well as to examine the frequency of opioid-related side effects in observed patients. Materials and Methods: The prospective observational study was conducted over five months, and it included a total number of 100 patients. The two cohorts had different types of postoperative analgesia, and the effects were observed for 24 h postoperatively, by following the pain scores on NRS (Numerical Pain Scale), contentment with analgesia, and opioid-related side effects. Results: Statistical significance was found when assessing pain 24 h after surgery while coughing, where patients in the tapentadol IR group had significantly higher mean pain scores (p < 0.01). The subjective feeling of satisfaction with postoperative analgesia was statistically significant in the tapentadol IR group (p = 0.005). Vertigo appeared significantly more in patients from the morphine group (p = 0.03). Conclusions: Tapentadol IR (immediate release) and morphine hydrochloride are both effective analgesics used in the first 24 h after total transabdominal hysterectomy. Overall satisfaction of patients with analgesia was good. The frequency of side effects was higher in the morphine group, with statistical significance regarding the vertigo.

Targeted Therapy for Orofacial Pain: A Novel Perspective for Precision Medicine

Orofacial pain (OFP) is a dental specialty that includes the diagnosis, management and treatment of disorders of the jaw, mouth, face, head and neck. Evidence-based understanding is critical in effectively treating OFPs as the pathophysiology of these conditions is multifactorial. Since OFP impacts the quality of life of the affected individuals, treating patients successfully is of the utmost significance. Despite the therapeutic choices available, treating OFP is still quite challenging, owing to inter-patient variations. The emerging trends in precision medicine could probably lead us to a paradigm shift in effectively managing the untreatable long-standing pain conditions. Precision medicine is designed based on the patient's genetic profile to meet their needs. Several significant relationships have been discovered based on the genetics and genomics of pain in the past, and some of the notable targets are discussed in this review. The scope of this review is to discuss preclinical and clinical trials that include approaches used in targeted therapy for orofacial pain. Future developments in pain medicine should benefit from current trends in research into novel therapeutic approaches.

Tapentadol versus oxycodone analgesia and side effects after laparoscopic hysterectomy: A randomised controlled trial

BACKGROUND

Tapentadol is an opioid, which acts as a μ-opioid receptor agonist and inhibits noradrenaline reuptake in the central nervous system. This dual mechanism of action results in synergistic analgesic effects and potentially less side effects. This has been shown in treatment of chronic pain but postoperative studies are sparse.

OBJECTIVES

The main aim was to compare the analgesic effect of tapentadol with oxycodone after laparoscopic hysterectomy. Opioid side effects were recorded as secondary outcomes.

DESIGN

Randomised, blinded trial.

SETTING

Single-centre, Oslo University Hospital, Norway, December 2017 to February 2019.

PATIENTS

Eighty-six opioid-naïve American Society of Anesthesiologists physical status 1 to 3 women undergoing laparoscopic hysterectomy for nonmalignant conditions.

INTERVENTION

The patients received either oral tapentadol (group T) or oxycodone (group O) as part of multimodal pain treatment. Extended-release study medicine was administered 1 h preoperatively and after 12 h. Immediate-release study medicine was used as rescue analgesia.

MAIN OUTCOME MEASURES

Pain scores, opioid consumption and opioid-induced side effects were evaluated during the first 24 h after surgery.

RESULTS

The groups scored similarly for pain at rest using a numerical rating scale (NRS) 1 h postoperatively (group T 4.4, 95% CI, 3.8 to 5.0, group O 4.6, 95% CI, 3.8 to 5.3). No statistically significant differences were found between the groups for NRS at rest or while coughing during the 24-h follow-up period (P = 0.857 and P = 0.973). Mean dose of oral rescue medicine was similar for the groups (P = 0.914). Group T had significantly lower odds for nausea at 2 and 3 h postoperatively (P = 0.040, P = 0.020) and less need for antiemetics than group O. No differences were found for respiratory depression, vomiting, dizziness, pruritus, headache or sedation.

CONCLUSION

We found tapentadol to be similar in analgesic efficacy to oxycodone during the first 24 h after hysterectomy, but with significantly less nausea.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT03314792.

Tapentadol vs oxycodone for postoperative pain treatment the first 7 days after total knee arthroplasty: a randomized clinical trial

ABSTRACT

Pain after total knee arthroplasty is a prevalent condition. This study compared the effectiveness of tapentadol extended-release (ER) 50 mg × 2, oxycodone controlled-release (CR) 10 mg × 2, and placebo, as added to a multimodal analgesic regime both in-hospital and at home the first week after total knee arthroplasty. The study was randomized and blinded for investigators, staff, outcome assessors, and patients. Follow-up included pain intensity on mobilization, pain at rest, worst pain in the previous 24 hours, and adverse effects measured on 0 to 10 numerical rating scales. A total of 134 patients in 3 study groups received their allocated intervention and were included in the analysis. The primary outcome pain on mobilization the 7 first postoperative days reported as area under the curve was 528.1 (SD 267.5, interquartile range (IQR) 356.6-665.4) for placebo, 427.2 (SD 203.9, IQR 303.6-544.3) for tapentadol ER, and 507.9 (SD 243.7, IQR 292.4-686.8) for oxycodone CR (P = 0.12). With the exception of constipation being less prevalent in the tapentadol ER group (P = 0.02), we found no significant differences between treatment groups for the secondary outcomes. Tapentadol ER as an add-on to multimodal analgesia did not significantly improve pain relief when compared to oxycodone CR or placebo. Constipation was lowest in the tapentadol ER group.

The role of peripheral opioid receptors in orofacial pain

Opioid receptors are widely distributed in the central and peripheral nervous systems and non-neuronal tissues. Numerous researchers have noted the pivotal role of peripheral opioid receptors (PORs) in analgesia. Accumulating evidence has shown the existence of PORs in the trigeminal nerve system, indicating that PORs may be involved in the modulation of orofacial pain. In this review, we summarise the recent evidence for the role of PORs in orofacial pain and discuss the possible cellular mechanisms.

Nonsteroidal Anti-Inflammatory Drugs and Opioids in Postsurgical Dental Pain

Postsurgical dental pain is mainly driven by inflammation, particularly through the generation of prostaglandins via the cyclooxygenase system. Thus, it is no surprise that numerous randomized placebo-controlled trials studying acute pain following the surgical extraction of impacted third molars have demonstrated the remarkable efficacy of nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen, naproxen sodium, etodolac, diclofenac, and ketorolac in this prototypic condition of acute inflammatory pain. Combining an optimal dose of an NSAID with an appropriate dose of acetaminophen appears to further enhance analgesic efficacy and potentially reduce the need for opioids. In addition to being on average inferior to NSAIDs as analgesics in postsurgical dental pain, opioids produce a higher incidence of side effects in dental outpatients, including dizziness, drowsiness, psychomotor impairment, nausea/vomiting, and constipation. Unused opioids are also subject to misuse and diversion, and they may cause addiction. Despite these risks, some dental surgical outpatients may benefit from a 1- or 2-d course of opioids added to their NSAID regimen. NSAID use may carry significant risks in certain patient populations, in which a short course of an acetaminophen/opioid combination may provide a more favorable benefit versus risk ratio than an NSAID regimen.

The pharmacological management of dental pain

Introduction: Dental pain is primarily treated by dentists and emergency medicine clinicians and may occur because of insult to the tooth or oral surgery. The dental impaction pain model (DIPM) has been widely used in clinical studies of analgesic agents and is generalizable to many other forms of pain.Areas Covered: The authors discuss the DIPM, which has allowed for important head-to-head studies of analgesic agents, such as acetaminophen, nonsteroidal anti-inflammatory drugs (NSAIDs), opioids, and combinations. Postsurgical dental pain follows a predictable trajectory over the course of one to 3 days. Dental pain may have odontic origin or may be referred pain from other areas of the body.Expert opinion: Pain following oral surgery has sometimes been treated with longer-than-necessary courses of opioid therapy. Postsurgical dental pain may be moderate to severe but typically resolves in a day or two after the extraction. Opioid monotherapy, rarely used in dentistry but combination therapy (opioid plus acetaminophen or an NSAID), was sometimes used as well as nonopioid analgesic monotherapy. The dental impaction pain model has been valuable in the study of analgesics but does not address all painful conditions, for example, pain with a neuropathic component.

A Comparative Study of Oral Analgesics for Postoperative Pain After Minor Oral Surgery

We compared the effects of preoperative administration of diclofenac sodium, celecoxib, and acetaminophen on postoperative pain in patients undergoing minor oral surgery under general anesthesia. One hundred twenty-eight patients were randomly divided into 4 groups preoperatively treated with diclofenac sodium 50 mg, celecoxib 400 mg, acetaminophen 1000 mg, or placebo. Postoperative pain was managed using intravenous patient-controlled infusion of fentanyl. Assessments included levels of postoperative pain by using visual analog scale (VAS) scores at 4, 5, and 6 hours after administration of the test drug; consumption of fentanyl up to each time point; and time to first requirement for fentanyl. Our study demonstrated that, for diclofenac sodium and celecoxib in comparison with placebo, there were significantly lower VAS scores at 4, 5, and 6 hours after oral administration of the study drug; a longer period of time to first requirement for fentanyl after surgery; and less consumption of postoperative fentanyl. A similar analgesic effect versus placebo was noted for acetaminophen but only at the 5- and 6-hour time points. In contrast, no significant differences in VAS scores at 4 hours after administration or time to first requirement for fentanyl were observed between acetaminophen and placebo. Furthermore, no significant differences in measurements were observed between the study drugs at any time point. These findings suggest that oral administration of celecoxib 400 mg is suitable for controlling postoperative pain, and as effective as diclofenac sodium 50 mg. Acetaminophen 1000 mg also exerts analgesic effect with slower onset for postoperative pain.

Ketorolac, Oxymorphone, Tapentadol, and Tramadol: A Comprehensive Review

Pain remains a tremendous burden on patients and for the health care system, with uncontrolled pain being the leading cause of disability in this country. There are a variety of medications that can be used in the treatment of pain, including ketorolac, oxymorphone, tapentadol, and tramadol. Depending on the clinical situation, these drugs can be used as monotherapy or in conjunction with other types of medications in a multimodal approach. A strong appreciation of pharmacologic properties of these agents and potential side effects is warranted for clinicians.

Comparison of anti-inflammatory and analgesic effects of Ginger powder and Ibuprofen in postsurgical pain model: A randomized, double-blind, case-control clinical trial

Background:

Ginger has been used as an herbal drug for a long time for the treatment of chronic inflammatory conditions.

Materials and Methods:

This randomized, double-blind clinical trial was conducted on 67 healthy adults with at least one impacted lower third molar. Participants were randomly allocated into three groups: Ibuprofen, Ginger, and placebo. Evaluation of inflammation was done by measuring cheek swelling, mouth opening ability, serum C-reactive protein (CRP) levels, and visual analog scale (for pain scoring). The number and the time of using rescue medication were recorded too.

Results:

Sixty patients completed the study. In all three groups, there was a significant increase in the mean cheek swelling measures, compared with the baseline, until day 5. The reduction in mouth opening ability was significant in all three groups, compared with the baseline, until day 5. There was no significant difference between ibuprofenand ginger groups in pain scores in all follow-up days. Number of required rescue medication on the day of surgery was significantly more in the placebo group. No significant or strong correlations were found between CRP levels and clinical findings.

Conclusion:

Within the limitations of this study, it can ban be concluded that gingerpowder is as effective as ibuprofenin the management of postsurgical sequelae. Furthermore, CRP levels alone are not suggested for the assessment of anti-inflammatory effects of drugs.

A comparative clinical evaluation of analgesic efficacy of Tapentadol and ketorolac in mandibular third molar surgery

Introduction:

The surgical removal of impacted mandibular third molars is one of the most commonly performed dentoalveolar procedures in oral and maxillofacial surgery and is associated with varying degrees of postoperative discomfort. Pain, trismus, and swelling are the most common postoperative complaints, and these influence a patient's quality of life in the days after surgery.

Materials and Methods:

A comparative study of the 32 patients, 16 were allocated to receive ketorolac and 16 patients were allocated to receive tapentadol. As the data for this study were collected at different time points, analysis for the longitudinal study was done. The main outcome variable, pain level was measured in five-ordered categories. As we had ordinal data in our study, we first checked for marginal homogeneity through Cochran–Mantel–Haenszel test.

Results:

In the present study, the results show that there is no statistically significant difference between the two treatment groups (P = 0.1184). According to results, there is no significant group by time interaction, which means both drugs have shown almost equal efficacy at different time points. Similarly, there is no difference in efficacy of the two drugs across gender level.

Conclusion:

The present findings showed that there is no statistically significant difference between the two treatment groups, although ketorolac is more effective for immediate pain reduction than tapentadol. However, the overall reduction of pain using both groups has no significant difference.

Role of preemptive tapentadol in reduction of postoperative analgesic requirements after laparoscopic cholecystectomy

BACKGROUND AND AIMS

Poorly managed acute postoperative pain may result in prolonged morbidity. Various pharmacotherapies have targeted this, but research on an ideal preemptive analgesic continues, taking into account drug-related side effects. Considering the better tolerability profile of tapentadol, we assessed its role as a preemptive analgesic in the reduction of postoperative analgesic requirements, after laparoscopic cholecystectomy.

MATERIAL AND METHODS

In a prospective-double-blinded fashion, sixty patients posted for above surgery, were randomized to receive tablet tapentadol 75 mg (Group A) or starch tablets (Group B) orally, an hour before induction of general anesthesia. Perioperative analgesic requirement, time to first analgesia, pain, and sedation score were compared for first 24 h during the postoperative period and analyzed by one-way analysis of variance test. A P < 0.05 was considered significant.

RESULTS

Sixty patients were analyzed. The perioperative analgesic requirement was significantly lower in Group A. Verbal numerical score was significantly lower in Group A at the time point, immediately after shifting the patient to the postanesthesia care unit. Ramsay sedation scores were similar between the groups. No major side effects were observed except for nausea and vomiting in 26 cases (10 in Group A, 16 in Group B).

CONCLUSION

Single preemptive oral dose of tapentadol (75 mg) is effective in reducing perioperative analgesic requirements and acute postoperative pain, without added side effects. It could be an appropriate preemptive analgesic, subjected to future trials concentrating upon its dose-response effects.

Comment on controlling dental post-operative pain and the intraoral local delivery of drugs

The results of numerous double-blind, placebo-controlled clinical trials consistently demonstrate that nonsteroidal antiinflammatory drugs should be the first line agents in treating postsurgical dental pain. Additive and potential opioid-sparing effects have also been reported in oral surgery pain by combining an optimal dose of an NSAID with acetaminophen 500 mg. While opioid combination drugs are indicated in some dental postsurgical patients, clinicians can no longer ignore the scourge of prescription opioid abuse in the United States. Other potential opioid sparing strategies include the use of locally delivered antimicrobial/antiinflammatory agents such as Bexident Post or extended duration local anesthetic agents such as liposomal bupivacaine placed directly in or in the vicinity of the extraction socket.

Tapentadol immediate-release for acute postbunionectomy pain: a phase 3, randomized, double-blind, placebo-controlled, parallel-group study in Taiwan

OBJECTIVE

To evaluate the efficacy and safety of tapentadol immediate-release (IR) for treating acute pain following orthopedic bunionectomy surgery in a Taiwanese population.

METHODS

This was a phase 3, randomized, double-blind, placebo-controlled, parallel-group bridging study in which Taiwanese patients (N = 60) with moderate-to-severe pain following bunionectomy were randomized (1:1:1) to receive tapentadol IR 50 or 75 mg or placebo orally every 4-6 hours over a 72 hour period. The primary endpoint was the sum of pain intensity difference over 48 hours (SPID48), analyzed using analysis of variance.

RESULTS

Out of 60 patients randomized (mainly women [96.7%]; median age 44 years), 41 (68.3%) completed the treatment. Mean SPID48 values were significantly higher for tapentadol IR (p ≤ 0.006: 50 mg, p ≤ 0.004: 75 mg) compared with placebo. Between-group differences in LS means of SPID48 (vs. placebo) were tapentadol IR 50 mg: 105.6 (95% CI: 32.0; 179.2); tapentadol IR 75 mg: 126.6 (95% CI: 49.5; 203.7). Secondary endpoints including SPID at 12, 24, and 72 hours, time to first use of rescue medication, cumulative distribution of responder rates, total pain relief and sum of total pain relief and sum of pain intensity difference at 12, 24, 48, and 72 hours, and patient global impression of change showed numerically better results supporting that tapentadol IR (50 and 75 mg) was more efficacious than placebo in relieving acute pain. The most frequent treatment emergent adverse events reported in ≥ 10% patients in either group were dizziness, nausea, and vomiting. A limitation of this study may possibly include more controlled patient monitoring through 4-6 hour dosing intervals, which reflects optimal conditions and thus may not approximate real-world clinical practice. However, all treatment groups would be equally affected by such bias of frequent monitoring, if any, since it was a randomized and double-blind study.

CONCLUSIONS

Tapentadol IR treatment significantly relieved acute postoperative pain and was well tolerated in a Taiwanese population. ClinicalTrials.gov identifier: NCT01813890.

Case report of a fatal intoxication by Nucynta

Tapentadol (Nucynta) is a centrally acting opioid analgesic prescribed for the treatment of moderate to severe acute pain. Its efficacy is believed to be due to μ-opioid receptor agonist activity and inhibition of norepinephrine reuptake resulting in increased norepinephrine concentrations. There is only one other case in the literature relating to the toxicity of this agent or report of a fatality. This case report documents a case in which tapentadol was identified as the cause of death. The tapentadol concentration found in the heart blood submitted in this case was more than 20 times the upper limit of the therapeutic range. Possible mechanisms of death include respiratory depression, central nervous system depression, and serotonin syndrome. Based on the scene investigation and autopsy findings in this case, the medical examiner determined that the cause of death was narcotic (Nucynta) intoxication and the manner of death was undetermined.

A Randomized Controlled Trial on the Effect of Tapentadol and Morphine on Conditioned Pain Modulation in Healthy Volunteers

Background

Modulatory descending pathways, originating at supraspinal sites that converge at dorsal horn neurons, influence pain perception in humans. Defects in descending pain control are linked to chronic pain states and its restoration may be a valuable analgesic tool. Conditioned pain modulation (CPM) is a surrogate marker of descending inhibition that reduces the perception of pain from a primary test stimulus during application of a conditioning stimulus. Here the effects of the analgesics tapentadol, a combined mu-opioid receptor agonist and noradrenaline reuptake inhibitor, and morphine, a strong mu-opioid receptor agonist, were tested on CPM in a randomized, double-blind, placebo-controlled crossover trial in 12 healthy pain-free volunteers, to understand possible differences in mechanism of action between these opioids.

Methods and Results

On three occasions CPM responses were obtained 60-90 and 120-150 min following intake of tapentadol (100 mg immediate release tablet), morphine (40 mg immediate release tablet) or placebo. At both time points, CPM was detectable after treatment with placebo and tapentadol (peak pain ratings reduced by 20-30% after application of the conditioning stimulus) but not after morphine. Compared to placebo morphine displayed significantly less CPM: mean treatment difference 18.2% (95% CI 3.4 to 32.9%) at 60-90 min after drug intake and 19.5% (95% CI 5.7 to 33.2%) at 120-150 min after drug intake (p = 0.001). No difference in CPM between placebo and tapentadol was detected: mean treatment difference 1.5% (95% CI -11.6 to 14.6%) at 60-90 min after drug intake and 1.5% (95% CI -16.0 to 18.9%) at 120-150 min after drug intake (p = 0.60).

Conclusions

Our data show that in volunteers morphine affects CPM, while tapentadol was without effect despite identical experimental conditions. These data confirm that tapentadol’s main mechanism of action is distinct from that of morphine and likely related to the effect of adrenergic stimulation on descending controls.

Trial Registration

Netherlands Trial Register NTR2716

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.

Tapentadol hydrochloride: A novel analgesic

Tapentadol is a novel, centrally acting analgesic with dual mechanism of action, combining mu-opioid receptor agonism with noradrenaline reuptake inhibition in the same molecule. It has an improved side effect profile when compared to opioids and nonsteroidal anti-inflammatory drugs. The dual mechanism of action makes Tapentadol a useful analgesic to treat acute, chronic, and neuropathic pain.

Tapentadol, oxycodone or placebo for acute pain of vertebral compression fractures: a randomized Phase IIIb study

SUMMARY Aim: Tapentadol is a centrally acting analgesic that combines µ-opioid receptor agonism with norepinephrine reuptake inhibition. This study evaluated the efficacy and safety of tapentadol immediate-release (IR), oxycodone IR or placebo in subjects with acute pain from vertebral compression fracture (VCF) associated with osteoporosis. Patients & methods: Study patients were adults with new onset of pain or acute exacerbation of previous pain from VCF associated with osteoporosis, radiographic confirmation of VCF and back pain intensity of 5 or greater on an 11-point scale from 0 (no pain) to 10 (pain as bad as you can imagine). Patients were randomized to treatment with tapentadol IR (50 mg, then 50 or 75 mg), oxycodone IR (5 mg, then 5 or 10 mg) or placebo every 4–6 h as needed for pain, for up to 10 days. Twice daily, subjects recorded pain intensity on the 11-point scale (numeric rating scale), pain relief on a 5-point scale from 0 (none) to 4 (complete), sleep assessments (morning assessment only) and any episodes of vomiting (evening assessment only). Results: The study was designed to include 625 subjects, but was stopped after 14 months due to slow enrollment (44 tapentadol IR, 43 oxycodone IR and 21 placebo subjects) and had insufficient statistical power for comparative efficacy analyses. Discontinuation rates in the tapentadol IR, oxycodone IR and placebo groups were 18.2, 27.9 and 9.5%, respectively, often due to adverse events (4.5, 18.6 and 4.8%, respectively). Treatment-emergent adverse-event rates were 63.6, 81.4 and 38.1%, respectively. Conclusion: In this prematurely terminated study in adults with painful VCF, trends suggested that tapentadol IR was tolerated better than oxycodone IR.

Dental and related infections

Emergency physicians should be comfortable treating most dental and related infections. In this article, we outline recommended techniques to perform a dental examination, explore common pathologies, recommend pain and antibiotic management strategies and review common pitfalls. How to avoid overprescribing opioid analgesics is discussed in depth, along with recent studies to support this strategy.

Three newly approved analgesics: an update

Abstract Since 2008, three new analgesic entities, tapentadol immediate release (Nucynta) diclofenac potassium soft gelatin capsules (Zipsor), and bupivacaine liposome injectable suspension (EXPAREL) were granted US Food and Drug Administration (FDA) approval to treat acute pain. Tapentadol immediate-release is a both a mu-opioid agonist and a norepinephrine reuptake inhibitor, and is indicated for the treatment of moderate to severe pain. Diclofenac potassium soft gelatin capsules are a novel formulation of diclofenac potassium, which is a nonsteroidal anti-inflammatory drug (NSAID), and its putative mechanism of action is through inhibition of cyclooxygenase enzymes. This novel formulation of diclofenac allows for improved absorption at lower doses. Liposomal bupivacaine is a new formulation of bupivacaine intended for single-dose infiltration at the surgical site for postoperative analgesia. Bupivacaine is slowly released from this liposomal vehicle and can provide prolonged analgesia at the surgical site. By utilizing NSAIDs and local anesthetics to decrease the transmission of afferent pain signals, less opioid analgesics are needed to achieve analgesia. Since drug-related adverse events are frequently dose related, lower doses from different drug classes may be employed to reduce the incidence of adverse effects, while producing synergistic analgesia as part of a multimodal analgesic approach to acute pain.

Tapentadol extended-release: a recent addition to our analgesic armamentarium

SUMMARY In the never-ending process of providing therapy with diminishing side effects, pain medicine stands out as an important area of work. Ever since the introduction of opioids and elucidation of their mechanisms pharmaceutical researchers have sought a compound that provides long-term analgesia with none of the side effects that include somnolence, lethargy, tolerance, addiction, gastrointestinal symptoms and so on. This article reviews one of the latest improvements in analgesia, the formulation of tapentadol as an extended-release medication. Despite not claiming to have eliminated all the negatives of narcotics tapentadol extended-release seems to have made inroads to that goal.

A randomised, placebo-controlled trial comparing the effects of tapentadol and oxycodone on gastrointestinal and colonic transit in healthy humans

BACKGROUND

Tapentadol is a mu-opioid receptor agonist and norepinephrine reuptake inhibitor. In clinical trials, tapentadol provided somatic pain relief comparable to mu-opioids such as oxycodone, with significantly less gastrointestinal adverse effects. The acute effects of tapentadol on gastrointestinal and colonic transit are unclear.

AIM

To compare acute effects of oral tapentadol and oxycodone on gastric, small bowel and colonic transit of solids in 38 healthy human subjects.

METHODS

In a randomised, parallel-group, double-blind, placebo-controlled study of the effects of identical-appearing tapentadol immediate release (IR), 75 mg t.d.s., or oxycodone IR, 5 mg t.d.s., for 48 h, we measured gastric (GE), small bowel (SBT measured as colonic filling at 6 h) and colonic transit by validated scintigraphy. Drug was commenced on the evening before the start of the transit test. The primary endpoints were overall colonic transit (geometric centre, GC) at 24 h and GE half-time (t1/2 ). ancova of transit data included gender or BMI as covariates. Adverse effects were summarised.

RESULTS

At the doses tested, oxycodone and tapentadol significantly delayed GE t1/2 and SBT, but not overall colonic transit, compared to placebo. Transit profiles in all regions were not significantly different between oxycodone and tapentadol at the doses tested. Both oxycodone and tapentadol were associated with nausea and central effects attributable to central opiate effects.

CONCLUSIONS

Tapentadol significantly delayed gastric emptying t1/2 and small bowel transit, similar to oxycodone. These data suggest that acute administration of tapentadol may not have significant advantages over standard mu-opioids, in terms of the potential to avoid upper gastrointestinal motor dysfunction.

Efficacy and safety of additional 200-mg dose of celecoxib in adult patients with postoperative pain following extraction of impacted third mandibular molar: a multicenter, randomized, double-blind, placebo-controlled, phase II study in Japan

BACKGROUND

Although third mandibular molar extraction is a widely used and validated model of acute pain for evaluating analgesic efficacy, a large proportion of patients experience moderate or severe pain following this procedure and require analgesia. Current treatment options have been associated with safety concerns and alternative therapies are sought.

OBJECTIVE

Our aim was to assess the efficacy and safety of an additional 200-mg dose of celecoxib, administered 5 to 12 hours after an initial 400-mg dose of the drug for the treatment of moderate or severe acute pain following extraction of an impacted third mandibular molar.

METHODS

This was a multicenter, randomized, double-blind, placebo-controlled, Phase II study. Patients experiencing moderate or severe pain within 1 to 2 hours following extraction of an impacted third mandibular molar received an initial 400-mg dose of celecoxib. Patients requiring additional analgesia were subsequently randomized to receive either an additional 200-mg dose of celecoxib or placebo 5 to 12 hours after the initial dose. The study was designed and conducted by Pfizer Inc. for approval of celecoxib in Japan for the indication of acute pain. The primary end point was the patient's impression of efficacy (4-category global evaluation scale). Secondary efficacy end points included pain intensity on a 4-category pain intensity scale, pain intensity on a 100-mm visual analog scale (VAS), and the pain intensity difference (100-mm VAS). In an exploratory analysis, use of rescue medication was evaluated. Primary and secondary end points were analyzed using the full analysis set. Assessment of the safety profile included a physical examination, measurement of pulse rate and blood pressure, standard 12-lead ECG, and laboratory tests.

RESULTS

A total of 69 patients (celecoxib, 42/64 [65.6%]; placebo, 27/58 [46.6%]) received the additional dose of study medication; all completed the study without the need for rescue medication. A significantly higher proportion of patients in the celecoxib 200 mg group (41/64 [64.1%]) compared with the placebo group (15/58 [25.9%]) rated the study medication as "good" or "excellent" ≥ 2 hours after the additional dose (P < 0.0001). Pain intensity (VAS) 2 hours after the additional dose was significantly higher in the placebo group than in the celecoxib 200 mg group (P = 0.0003). The reduction in pain intensity from baseline to 2 hours after the additional dose of study medication was also significantly greater in the celecoxib 200 mg group than in the placebo group (P < 0.0001). The incidence of treatment-related, all-cause adverse events was slightly lower in patients receiving celecoxib 200 mg (20.3%) compared with placebo (31.0%).

CONCLUSIONS

Overall, an additional 200-mg dose of celecoxib was well tolerated and efficacious in reducing the pain associated with extraction of an impacted third mandibular molar in the study population. ClinicalTrials.gov identifier: NCT01062113.

Double-blind, placebo-controlled, randomized pilot study of cerebral blood flow patterns employing SPECT imaging in dental postsurgical pain patients with and without pain relief

BACKGROUND

Single-photon emission computed tomography (SPECT) has been employed in the study of altered regional cerebral blood flow (CBF) in experimental and chronic pain. CBF patterns have not been evaluated in patients with acute postoperative pain.

OBJECTIVE

The purpose of this pilot study was to employ SPECT to measure CBF distribution associated with postoperative dental pain and to compare these CBF patterns to subsequent images in the same patients who were experiencing pain relief versus continued or worsening pain who had received active or placebo analgesic interventions. The primary outcome measure was the percentage change in blood flow in various regions of interest.

METHODS

Twenty-two healthy individuals (10 males and 12 females, age range 20-29 years) who underwent the removal of ≥1 partial or full bony impacted mandibular third molars were evaluated for pain intensity as the local anesthesia dissipated, employing a 0 to10 numeric rating scale (0 = no pain; 10 = worst imaginable). When the subjects' pain level reached ≥4/10, they were injected intravenously with 260 MBq of technetium Tc 99m bicisate (ethyl cysteinate dimer). Under double-blind conditions and 10 minutes before being placed in the SPECT scanner, the first 10 subjects were randomized to receive intravenous ketorolac 15 mg or saline while the remaining 12 subjects were randomized to receive by mouth either ibuprofen 400 mg, ibuprofen 200 mg, acetaminophen 1000 mg, or placebo. One hour after drug administration, subjects were reevaluated for pain, injected with 925 MBq of technetium Tc 99m bicisate, given rescue medication if required, and then rescanned. CBF ratios were obtained for regions of interest and by normalizing to average whole brain activity.

RESULTS

Subjects generally had a moderate degree (mean [SD], 7.3% [4.0%]) of thalamic asymmetry on initial scans with pain; after treatment, subjects reporting worsening pain regardless of the intervention had higher thalamic asymmetry (8.1% vs 2.8%) than those reporting relief of pain. Subjects who reported reduced pain after the intervention had significantly different (P < 0.05) mean CBF changes compared with those reporting worsening pain in the left prefrontal cortex, left sensorimotor area, right anterior cingulate, and right caudate.

CONCLUSIONS

Acute postoperative dental pain was associated with moderate thalamic asymmetry that improved following successful pain management. Sustained or worsening pain was associated with increased CBF in brain regions associated with pain pathways, whereas pain relief was associated with decreased activity in the same areas.

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.

Tapentadol extended-release for treatment of chronic pain: a review

Tapentadol is a centrally acting analgesic with a dual mechanism of action of mu receptor agonism and norepinephrine reuptake inhibition. Tapentadol immediate-release is approved by the US Food and Drug Administration for the management of moderate-to-severe acute pain. It was developed to decrease the intolerability issue associated with opioids. Tapentadol extended-release has a 12-hour duration of effect, and has recently been evaluated for pain in patients with chronic osteoarthritis, low back pain, and pain associated with diabetic peripheral neuropathy. Tapentadol extended-release was found to provide safe and highly effective analgesia for the treatment of chronic pain conditions, including moderate-to-severe chronic osteoarthritis pain and low back pain. Initial trials demonstrating efficacy in neuropathic pain suggest that tapentadol has comparable analgesic effectiveness and better gastrointestinal tolerability than opioid comparators, and demonstrates effectiveness in settings of inflammatory, somatic, and neuropathic pain. Gastrointestinal intolerance and central nervous system effects were the major adverse events noted. Tapentadol will need to be rigorously tested in chronic neuropathic pain, cancer-related pain, and cancer-related neuropathic pain.

An update on analgesics

Recent introduction of new analgesics into the clinic is best described as a slow process with activity classified into two main areas: improving analgesic efficacy/potency and reducing side-effect profile. This review article describes some of the recent advances with an emphasis on use in the acute setting. In this respect, opioids continue to be the mainstay (but not the only) analgesic and there have been important improvements in their clinical effect profile. For example, tapentadol has been introduced as a mixed opioid and norepinephrine uptake inhibitor which, unlike tramadol, does not require metabolic activation and does not suffer from isomer-dependent pharmacodynamics. Opioid antagonists have received much attention recently either used alone, methylnaltrexone (s.c) or alvimopan (p.o), or in combination, Targinact (oxycodone/naloxone), and appear to be effective in reducing opioid side-effects such as those in the gastrointestinal tract. Other agents where there has been recent development include the use of gabapentin, methylxanthines, and local anaesthetics. An interesting area of translation of basic research is in the inhibition of breakdown of endogenous opioids with opiorphin, targeting of the endocannabinoid system, and the use of ampakines to obtund opioid-induced side-effects. It is clear that there is still much work to be done, but the need for highly efficacious analgesics with good side-effect profile remains.

Tapentadol in pain management: a μ-opioid receptor agonist and noradrenaline reuptake inhibitor

Several mechanisms can be proposed to explain an apparent synergistic analgesic action between μ-opioid and α(2)-adrenergic receptor agonists. Combining both effects in a single molecule eliminates the potential for drug-drug interactions inherent in multiple drug therapy. Tapentadol is the first US FDA-approved centrally acting analgesic having both μ-opioid receptor agonist and noradrenaline (norepinephrine) reuptake inhibition activity with minimal serotonin reuptake inhibition. This dual mode of action may make tapentadol particularly useful in the treatment of neuropathic pain. Having limited protein binding, no active metabolites and no significant microsomal enzyme induction or inhibition, tapentadol has a limited potential for drug-drug interactions. Clinical trial evidence in acute and chronic non-cancer pain and neuropathic pain supports an opioid-sparing effect that reduces some of the typical opioid-related adverse effects. Specifically, the reduction in treatment-emergent gastrointestinal adverse effects for tapentadol compared with equianalgesic pure μ-opioid receptor agonists results in improved tolerability and adherence to therapy for both the immediate- and extended-release formulations of tapentadol.