Pharmacological rationale for tapentadol therapy: a review of new evidence

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.

Consensus on the preoperative management of patients with chronic moderate to severe shoulder pain to improve postoperative outcomes: Delphi results

BACKGROUND

Appropriate preoperative management of patients with chronic moderate to severe shoulder pain who are candidates for surgery owing to rotator cuff disease or glenohumeral osteoarthritis may improve surgery and patient outcomes, but published evidence in this regard is scarce. Therefore, the availability of recommendations on preoperative interventions based on expert consensus may serve as guidance.

METHODS

A Delphi study was conducted to develop a preoperative management algorithm based on a national expert consensus. A Delphi questionnaire was developed by a scientific committee following a systematic review of the relevant literature published during the past 10 years using PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) criteria. It consisted of 48 statements divided into 5 blocks (block I, assessment and diagnosis of preoperative pain; block II, preoperative function and psychosocial aspects; block III, therapeutic objectives; block IV, treatment; and block V, follow-up and referral), and 28 experienced shoulder surgeons from across the country were invited to answer.

RESULTS

All participants responded to the Delphi questionnaire in the first round, and 25 responded in the second round (89.3% of those invited). Overall, 46 of 49 final statements reached a consensus, on the basis of which a final preoperative management algorithm was defined by the scientific committee. First, surgeons should assess shoulder pain intensity and characteristics, shoulder functionality, and psychosocial aspects using specific validated questionnaires. Preoperative therapeutic objectives should include shoulder pain control, depression and/or nocturnal sleep improvement, opioid consumption adjustment, and substance abuse cessation. Postoperative objectives regarding the degree of shoulder pain reduction or improvement in functionality and/or quality of life should be established in agreement with the patient. Treatment of preoperative chronic moderate to severe shoulder pain should comprise nonpharmacologic as well as pharmacologic interventions. Follow-up of the shoulder pain levels, treatment adherence, and mental health status of these patients may be carried out by the surgical team (surgeon and anesthesiologist) together with the primary care team. Patients with very intense shoulder pain levels may be referred to a pain unit following specific protocols.

CONCLUSION

A preoperative management algorithm for patients with chronic moderate to severe shoulder pain who are candidates for surgery owing to rotator cuff disease or glenohumeral osteoarthritis was defined based on a national expert consensus. Main points include comprehensive patient management starting with an objective assessment of shoulder pain and function, as well as quality of life; establishment of preoperative and postoperative therapeutic targets; prescription of individualized therapeutic interventions; and multidisciplinary patient follow-up. Implementation of these recommendations into clinical practice may result in better preoperative shoulder pain management and more successful surgical outcomes and patient satisfaction.

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 for the management of cancer pain in adults: an update

PURPOSE OF REVIEW

Tapentadol is the first of a new class of analgesics, having synergistic µ-opioid receptor agonist and noradrenaline reuptake inhibitory actions. It has been widely researched in many areas of pain, often in noninferiority studies against potent opioids. This review describes all randomized and recent nonrandomized studies of tapentadol in adults with cancer pain.

RECENT FINDINGS

Tapentadol has been shown to be at least as effective as morphine and oxycodone in five randomized (two of which were multicenter and double-blind) and a range of nonrandomized trials, although caution is needed when interpreting these results. It is effective in both opioid-naive patients and those already taking opioids. By having a lower µ-opioid receptor binding affinity, it has fewer opioid-related toxicities such as constipation and nausea. A recent randomized trial comparing tapentadol to tapentadol plus duloxetine in patients with chemotherapy-induced peripheral neuropathy shows similar improvement in both groups in a range of pain relieving and quality of life measures, with similar adverse effects.

SUMMARY

Tapentadol has been shown in a range of studies to be an effective analgesic and thus should be considered as an alternative to morphine and oxycodone, especially when opioid toxicities are an issue.

Variation in adverse drug events of opioids in the United States

Background: The United States (US) ranks high, nationally, in opioid consumption. The ongoing increase in the misuse and mortality amid the opioid epidemic has been contributing to its rising cost. The worsening health and economic impact of opioid use disorder in the US warrants further attention. We, therefore, assessed commonly prescribed opioids to determine the opioids that were over-represented versus under-represented for adverse drug events (ADEs) to better understand their distribution patterns using the Food and Drug Administration's Adverse Event Reporting System (FAERS) while correcting for distribution using the Drug Enforcement Administration's Automation of Reports and Consolidated Orders System (ARCOS). Comparing the ratio of the percentage of adverse drug events as reported by the FAERS relative to the percentage of distribution as reported by the ARCOS database is a novel approach to evaluate post-marketing safety surveillance and may inform healthcare policies and providers to better regulate the use of these opioids. Methods: We analyzed the adverse events for 11 prescription opioids, when correcting for distribution, and their ratios for three periods, 2006-2010, 2011-2016, and 2017-2021, in the US. The opioids include buprenorphine, codeine, fentanyl, hydrocodone, hydromorphone, meperidine, methadone, morphine, oxycodone, oxymorphone, and tapentadol. Oral morphine milligram equivalents (MMEs) were calculated by conversions relative to morphine. The relative ADEs of the selected opioids, opioid distributions, and ADEs relative to distribution ratios were analyzed for the 11 opioids. Results: Oxycodone, fentanyl, and morphine accounted for over half of the total number of ADEs (n = 667,969), while meperidine accounted for less than 1%. Opioid distributions were relatively constant over time, with methadone repeatedly accounting for the largest proportions. Many ADE-to-opioid distribution ratios increased over time, with meperidine (60.6), oxymorphone (11.1), tapentadol (10.3), and hydromorphone (7.9) being the most over-represented for ADEs in the most recent period. Methadone was under-represented (<0.20) in all the three periods. Conclusion: The use of the FAERS with the ARCOS provides insights into dynamic changes in ADEs of the selected opioids in the US. There is further need to monitor and address the ADEs of these drugs.

Prescribing trend of tapentadol in a Sydney local health district

AIMS

Tapentadol, an opioid with mu-opioid receptor agonism and noradrenaline reuptake inhibition, has been increasingly used in Australia since 2011. However, data on hospital prescribing trends and indications are scarce. This study aimed to investigate hospital prescribing trends of tapentadol, oxycodone and tramadol in a Sydney local health district (LHD) and the indications for tapentadol hospital prescriptions in an Australian tertiary hospital.

METHODS

We analysed 5-year patient dispensing for tapentadol, oxycodone and tramadol from four hospitals in a Sydney LHD with data expressed as oral morphine equivalents (OME). We also conducted a retrospective review of 140 and 54 patients prescribed tapentadol at a tertiary hospital's surgical and spinal units in 2020.

RESULTS

Over 5 years in the Sydney LHD, there was a 19.5% reduction in total dispensing of these opioids from 1 225 210 to 986 477.5 OME milligrams. Decreases were specifically for oxycodone (-37.8% immediate-release, -65.2% sustained-release) and tramadol (-74.6% immediate-release, -70.1% sustained-release). Contrastingly, hospital prescriptions of tapentadol immediate-release increased by 223.2% between 2018-19 and 2020-21 while sustained-release increased by 17.9% from 2016-17 to 2020-21. By 2020-21, tapentadol overtook oxycodone to become the most prescribed opioid in the Sydney LHD (51.4%). At the hospital's surgical units, 137 (97.9%) patients were prescribed tapentadol for acute post-operative pain with the majority (54.0%) prescribed both immediate-release and sustained-release tapentadol, while 71.1% were prescribed for neuropathic pain in the spinal units.

CONCLUSION

In a Sydney LHD, tapentadol prescriptions increased significantly to become the preferred opioid analgesic. At the hospital's surgical units, off-label prescriptions of tapentadol sustained-release for acute post-operative pain were observed.

A Multimodal Clinical Approach for the Treatment of Bone Metastases in Solid Tumors

Context

Bone metastasis (BM) is a frequent complication of cancer, representing the third most common site of secondary spread in solid cancers behind the lung and liver. Bone metastasis is found in up to 90% of prostate and breast cancer patients. They can cause significant complications, such as pathological fractures and paralysis of the spine, which decrease daily functioning and quality of life (QoL) and worsen prognosis. The growing life expectancy of cancer patients due to improvements in systemic therapies may further increase BM's eventuality and clinical burden in cancer patients.

Evidence Acquisition

Four physicians from five different specialties were interviewed and resumed the most relevant literature of the last 20 years focusing on pain treatment in BM patients.

Results

Treatment for BM ideally involves various types of specialists and assessments. The disease status and patient background should be considered, requiring holistic care and expertise from various medical specialties.

Conclusions

Interventional, nuclear medicine, radiotherapy, and mini-invasive techniques can be safe and effective for relieving pain and modifying health-related QoL in BM patients.

Postoperative pain: a review of emerging therapeutic options

INTRODUCTION

Postoperative pain is often managed by opioid medications, even though they carry a risk of adverse effects such as vomiting, constipation, sedation, respiratory depression and physical dependence. Furthermore, opioid use in the healthcare setting has likely contributed to the epidemic. However, the mismanagement of postoperative pain can result in delayed recovery time, impaired physical function, increased risk of morbidity and mortality, chronic pain, and higher healthcare costs.

AREAS COVERED

This review explores emerging therapeutic options and strategies in the management of acute postoperative pain and focuses on opioid-sparing, multimodal analgesia. This includes regional anesthetic techniques, non opioid pharmacotherapy, novel opioids and non-pharmacologic therapy. We have also discussed examples of novel analgesics and formulations which have potential benefits in reducing postoperative pain and opioid use after surgery.

EXPERT OPINION

The development of novel regional anesthesia techniques allows for opioid minimization in increasing number of surgical procedures. This synergizes with the availability of novel non-opioid analgesic adjucts. In addition, several novel opioid drugs have been developed which may be pathway selective and associated with less adverse effect than conventional opioids.

Tapentadol and oxycodone reduce cingulate glutamate in healthy volunteers

Tapentadol and oxycodone are commonly used analgesics. Preclinical studies have shown that oxycodone modulates brain metabolites related to opioid pathways, whereas tapentadol also affects noradrenergic activity. However, knowledge about the function of the medications in the human brain is limited. The aim was to investigate effects of tapentadol and oxycodone on brain glutamate, the most important neurotransmitter in pain processing. Magnetic resonance spectroscopy was obtained in 21 healthy subjects from the anterior cingulate cortex, prefrontal cortex, and insula at baseline and after 14 days of treatment with either 50 mg tapentadol, 10 mg oxycodone (equipotent dose, both extended release) or placebo twice daily in a randomized double-blind cross-over study. Compared to baseline, decreased glutamate/creatine levels were identified in anterior cingulate cortex after tapentadol (1.26 ± 0.14 vs. 1.35 ± 0.18, P = .04) and oxycodone (1.26 ± 0.10 vs. 1.35 ± 0.12, P = .05) treatments, both with 7% reduction. This indicates that both analgesics modulate the glutamatergic system at the supraspinal level in humans.

Monoaminergic and Opioidergic Modulation of Brainstem Circuits: New Insights Into the Clinical Challenges of Pain Treatment?

The treatment of neuropathic pain remains a clinical challenge. Analgesic drugs and antidepressants are frequently ineffective, and opioids may induce side effects, including hyperalgesia. Recent results on brainstem pain modulatory circuits may explain those clinical challenges. The dual action of noradrenergic (NA) modulation was demonstrated in animal models of neuropathic pain. Besides the well-established antinociception due to spinal effects, the NA system may induce pronociception by directly acting on brainstem pain modulatory circuits, namely, at the locus coeruleus (LC) and medullary dorsal reticular nucleus (DRt). The serotoninergic system also has a dual action depending on the targeted spinal receptor, with an exacerbated activity of the excitatory 5-hydroxytryptamine 3 (5-HT3) receptors in neuropathic pain models. Opioids are involved in the modulation of descending modulatory circuits. During neuropathic pain, the opioidergic modulation of brainstem pain control areas is altered, with the release of enhanced local opioids along with reduced expression and desensitization of μ-opioid receptors (MOR). In the DRt, the installation of neuropathic pain increases the levels of enkephalins (ENKs) and induces desensitization of MOR, which may enhance descending facilitation (DF) from the DRt and impact the efficacy of exogenous opioids. On the whole, the data discussed in this review indicate the high plasticity of brainstem pain control circuits involving monoaminergic and opioidergic control. The data from studies of these neurochemical systems in neuropathic models indicate the importance of designing drugs that target multiple neurochemical systems, namely, maximizing the antinociceptive effects of antidepressants that inhibit the reuptake of serotonin and noradrenaline and preventing desensitization and tolerance of MOR at the brainstem.

Pain reduction induced by tapentadol in patients with musculoskeletal chronic pain fosters better sleep quality

Background

Poor sleep may predict the increase and intensification of pain over time with increased insomnia symptoms being both a predictor and an indicator of worse pain outcomes and physical functioning status over time. However, the impact of different analgesic therapies on quality of life, functional recovery and sleep has been poorly assessed to date, whereas these evaluations may greatly help clinicians in the selection of treatment when dealing with patients with chronic pain (CP).

Methods

To explore whether tapentadol-induced pain relief may drive improved sleep quality, we carried out a pooled analysis of real-world data collected from 487 patients with CP (mean age, 68.3 years; 57.7% women) suffering from a wide range of chronic musculoskeletal pain conditions and treated with tapentadol.

Results

Following tapentadol treatment, patients experienced an 80% reduction in the frequency of very disturbed sleep as well as a 50% reduction in the predominant sleep complaint reported by patients with CP - that is, nocturnal awakenings. A significantly greater proportion of patients reported good/restful sleep at the end of the study period compared to baseline (72.4% versus 25.3%; p<0.01). This benefit was observed regardless of the clinical setting, treatment duration, posology or patient age and was associated with a higher proportion of patients reporting an improved global health status and good tolerability.

Conclusion

The reduction in pain intensity provided by tapentadol fosters sleep quality and favours a better quality of life. Therefore, our findings provide the rationale for addressing sleep quality as a relevant outcome, complementary to pain relief in CP management.

Perioperative Pain Management and Opioid Stewardship: A Practical Guide

Surgical procedures are key drivers of pain development and opioid utilization globally. Various organizations have generated guidance on postoperative pain management, enhanced recovery strategies, multimodal analgesic and anesthetic techniques, and postoperative opioid prescribing. Still, comprehensive integration of these recommendations into standard practice at the institutional level remains elusive, and persistent postoperative pain and opioid use pose significant societal burdens. The multitude of guidance publications, many different healthcare providers involved in executing them, evolution of surgical technique, and complexities of perioperative care transitions all represent challenges to process improvement. This review seeks to summarize and integrate key recommendations into a "roadmap" for institutional adoption of perioperative analgesic and opioid optimization strategies. We present a brief review of applicable statistics and definitions as impetus for prioritizing both analgesia and opioid exposure in surgical quality improvement. We then review recommended modalities at each phase of perioperative care. We showcase the value of interprofessional collaboration in implementing and sustaining perioperative performance measures related to pain management and analgesic exposure, including those from the patient perspective. Surgery centers across the globe should adopt an integrated, collaborative approach to the twin goals of optimal pain management and opioid stewardship across the care continuum.

Tapentadol Prolonged Release for Long-Term Treatment of Pain in Children

Purpose

Investigation of the efficacy and safety of tapentadol prolonged release (PR) compared with morphine PR for long-term treatment of pain in children.

Patients and Methods

Children aged 6 to <18 years requiring long-term treatment with opioids were studied in a 12-month, 2-part, multi-center trial: Part 1, 14-day open-label, randomized, active-controlled, parallel group non-inferiority trial comparing twice daily tapentadol PR with morphine PR; Part 2, open-label treatment with tapentadol PR for up to 12 months or no treatment “safety observation period”. Pain intensity was rated with visual analogue scale or Faces Pain Scale-Revised, and non-inferiority was assessed by comparison of “treatment responders” (those completing the 14-day treatment period and showing pre-defined changes in pain rating) in each group.

Results

Twenty-three of 48 centers enrolled 73 patients. In Part 1, 45 and 24 patients received tapentadol or morphine, respectively, of which 40 and 22 completed 14-day treatment. In Part 2, thirty-six and 58 patients entered the tapentadol PR or observation periods, respectively, with 20/36 completing at least 12 weeks of treatment; 10 of the 36 had received morphine in Part 1. Forty-four of the 58 patients in the safety observation period had received tapentadol. Tapentadol PR was non-inferior to morphine PR (lower limit of confidence interval above negative non-inferiority margin of −0.2) in Part 1. Rates of adverse events were as expected with nausea (22.2%) and constipation (15.6%) in the tapentadol PR group, and with vomiting (33.3%), nausea and constipation (each 16.7%) in the morphine PR group. No new safety issues were identified; the safety profile of tapentadol over the 12 months treatment and observation periods was comparable to that established in subjects >18 years old.

Conclusion

Tapentadol PR was well tolerated and equivalent to morphine PR for both efficacy and safety in children (6 to <18 years old) requiring long-term treatment with opioids.

Peripherally acting opioid analgesics and peripherally-induced analgesia

The management of pain, particularly chronic pain, is still an area of medical need. In this context, opioids remain a gold standard for the treatment of pain. However, significant side effects, mainly of central origin, limit their clinical use. Here, we review recent progress to improve the therapeutic and safety profiles of opioids for pain management. Characterization of peripheral opioid-mediated pain mechanisms have been a key component of this process. Several studies identified peripheral µ, δ, and κ opioid receptors (MOR, DOR, and KOR, respectively) and nociceptin/orphanin FQ (NOP) receptors as significant players of opioid-mediated antinociception, able to achieve clinically significant effects independently of any central action. Following this, particularly from a medicinal chemistry point of view, main efforts have been directed towards the peripheralization of opioid receptor agonists with the objective of optimizing receptor activity and minimizing central exposure and the associated undesired effects. These activities have allowed the characterization of a great variety of compounds and investigational drugs that show low central nervous system (CNS) penetration (and therefore a reduced side effect profile) yet maintaining the desired opioid-related peripheral antinociceptive activity. These include highly hydrophilic/amphiphilic and massive molecules unable to easily cross lipid membranes, substrates of glycoprotein P (a extrusion pump that avoids CNS penetration), nanocarriers that release the analgesic agent at the site of inflammation and pain, and pH-sensitive opioid agonists that selectively activate at those sites (and represent a new pharmacodynamic paradigm). Hopefully, patients with pain will benefit soon from the incorporation of these new entities.

Cyclizing Painkillers: Development of Backbone-Cyclic TAPS Analogs

Painkillers are commonly used medications. Native peptide painkillers suffer from various pharmacological disadvantages, while small molecule painkillers like morphine are highly addictive. We present a general approach aimed to use backbone-cyclization to develop a peptidomimetic painkiller. Backbone-cyclization was applied to transform the linear peptide Tyr-Arg-Phe-Sar (TAPS) into an active backbone-cyclic peptide with improved drug properties. We designed and synthesized a focused backbone-cyclic TAPS library with conformational diversity, in which the members of the library have the generic name TAPS c(n-m) where n and m represent the lengths of the alkyl chains on the nitrogens of Gly and Arg, respectively. We used a combined screening approach to evaluate the pharmacological properties and the potency of the TAPS c(n-m) library. We focused on an in vivo active compound, TAPS c(2-6), which is metabolically stable and has the potential to become a peripheral painkiller being a full μ opioid receptor functional agonist. To prepare a large quantity of TAPS c(2-6), we optimized the conditions of the on-resin reductive alkylation step to increase the efficiency of its SPPS. NMR was used to determine the solution conformation of the peptide lead TAPS c(2-6).

Tapentadol is effective in the management of moderate-to-severe cancer-related pain in opioid-naïve and opioid-tolerant patients: a retrospective study

Purpose

Tapentadol is a dual-acting mu-opioid receptor agonist and noradrenaline reuptake inhibitor with non-inferior analgesic efficacy to oxycodone and better gastrointestinal tolerability than full mu-opioid receptor agonists. Tapentadol is approved for cancer pain in Japan; however, real-world evidence on tapentadol’s effectiveness and safety for cancer-related pain in Japan is limited.

Methods

This retrospective study evaluated the effectiveness, safety, and tolerability of tapentadol (by patient type—opioid-naïve and opioid-tolerant) in 84 patients with moderate-to-severe cancer pain at Ichikawa General Hospital between September 2014 and August 2016.

Results

Almost 93% of patients achieved clinically relevant pain relief within 4 days (median). Over 90% of patients with neuropathic pain or mixed pain and all patients with nociceptive pain were responders. Pain intensity significantly decreased from baseline through to the end of maintenance period in opioid-naïve and opioid-tolerant patients. No patients discontinued tapentadol due to serious adverse events. No opioid-naïve patients experienced nausea or vomiting during tapentadol treatment. Only three opioid-tolerant patients experienced nausea which was considered to be related to tapentadol.

Conclusion

Tapentadol is effective and well tolerated in opioid-naïve and opioid-tolerant patients with cancer pain of varying pathophysiology, including those with nociceptive and/or neuropathic components. Tapentadol may be considered for first-line use in moderate-to-severe cancer-related pain.

Modulation of sensitization processes in the management of pain and the importance of descending pathways: a role for tapentadol?

Objective: This paper presents and discusses recent evidence on the pathophysiological mechanisms of pain. The role of tapentadol - an opioid characterized by an innovative mechanism of action (i.e. µ-opioid receptor [MOR] agonism and inhibition of noradrenaline [NA] reuptake [NRI]) - in the modulation of pain, and the most recent pharmacological evidence on this molecule (e.g. the µ-load concept) are also presented and commented upon.Methods: Narrative review.Results: Solid evidence has highlighted the importance of central sensitization in the transition from acute to chronic pain. In particular, the noradrenergic system holds a major role in limiting central sensitization and the progression to chronic pain. Therefore, pharmacological modulation of the noradrenergic system appears to be a well-grounded strategy for the control of chronic pain. Tapentadol is characterized by a to-date-unique mechanism of action, since it acts both as a MOR agonist and as an inhibitor of NA reuptake. The synergistic interaction of these two mechanisms allows a strong analgesic effect by acting on both ascending and descending pathways. Of note, the reduced µ-load of tapentadol limits the risk of opioid-related adverse events, such as gastrointestinal disturbances. Moreover, the NA component becomes predominant, at least, in some types of pain, with consequent specific clinical efficacy in the treatment of neuropathic and chronic pain.Conclusions: According to these characteristics, tapentadol appears suitable in the treatment of severe uncontrolled chronic pain characterized by both a nociceptive and a neuropathic component, such as osteoarthritis or back pain.

Modulation of sensitization processes in the management of pain and the importance of descending pathways: a role for tapentadol?

Objective: This paper presents and discusses recent evidence on the pathophysiological mechanisms of pain. The role of tapentadol - an analgesic molecule characterized by an innovative mechanism of action (i.e. µ-opioid receptor [MOR] agonism and inhibition of noradrenaline [NA] reuptake [NRI]) - in the modulation of pain, and the most recent pharmacological evidence on this molecule (e.g. the µ-load concept) are also presented and commented upon.Methods: Narrative review.Results: Solid evidence has highlighted the importance of central sensitization in the transition from acute to chronic pain. In particular, the noradrenergic system holds a major role in limiting central sensitization and the progression to chronic pain. Therefore, pharmacological modulation of the noradrenergic system appears to be a well-grounded strategy for the control of chronic pain. Tapentadol is characterized by a to-date-unique mechanism of action since it acts both as a MOR agonist and as an inhibitor of NA reuptake. The synergistic interaction of these two mechanisms allows a strong analgesic effect by acting on both ascending and descending pathways. Of note, the reduced µ-load of tapentadol has two important consequences: first, it limits the risk of opioid-related adverse events, as well as the risk of dependence; second, the NA component becomes predominant at least in some types of pain with consequent specific clinical efficacy in the treatment of neuropathic and chronic pain.Conclusions: According to these characteristics, tapentadol appears suitable in the treatment of chronic pain conditions characterized by both a nociceptive and a neuropathic component, such as osteoarthritis or back pain.

Sublingual delivery of chondroitin sulfate conjugated tapentadol loaded nanovesicles for the treatment of osteoarthritis

Recent treatment approaches of osteoarthritis (OA) face a number of obstacles due to the progressive multitude of pain generators, nociceptive mechanisms, first pass mechanism, less efficacy and compromised safety. The present study was aimed to bring a novel approach for the effective management of OA, by developing sublingual targeted nanovesicles (NVs) bearing tapentadol HCl (TAP), surface modified with chondroitin sulfate (CS). Optimized nontargeted nanovesicle formulation (MB-NV) was developed by an ultrasound method, characterized as spherical in shape, nanometric in size (around 150 nm) with narrow size distribution (polydispersity index <0.5), and good entrapment efficiency (around 50%). MB-NV conjugated with CS which was confirmed by IR and ¹H NMR spectroscopy. C-MB-NV showed improved pharmacokinetics parameters i.e. increased t_1/2 (9.7 h), AUC (159.725 μg/mL*h), and MRT (14.99 h) of TAP than nontargeted formulation and plain drug soln. C-MB-NV in in vitro release studies proved sustained drug release pattern for more than 24 h following Higuchi model kinetics with Fickian diffusion (n ≤ 0.5).Targeted nanovesicles exhibited an improved bioavailability and enhanced analgesic activity in a disease-induced Wistar rat model which indicated the superior targeting potential of C-MB-NV exploiting CD44 receptors as mediators, overexpressed at the affected joints in the OA model. It could be a propitious approach to accustomed therapies for methodical and efficient management in advanced OA therapy.

Novel insights on the management of pain: highlights from the ‘Science of Relief’ meeting

The ‘Science of Relief’ event, held in Milan on 10–11 May 2019, was aimed at promoting dialog between different stakeholders among scientific associations, pharma industry, healthcare services and related institutions. The goal was to renew interest and attention on the management of pain, sharing new solutions in order to bring the patients and their quality of life to the center of attention. An international group of scientists and clinicians presented and discussed new and known evidence in the field of chronic pain, from physiopathology and diagnosis to the choice of appropriate and timely pharmacological treatments. This paper reports the highlights of those presentations.