Green innovation in analytical chemistry: A sustainable densitometric HPTLC approach for the distinctive separation and quantification of structurally related abused drugs - tramadol, tapentadol, and venlafaxine - in seized pharmaceutical dosage forms

An innovative ecofriendly high-performance thin layer chromatographic (HPTLC) method with spectrophotometric detection for simultaneous determination of Tramadol (TMD), Tapentadol (TAP), and Venlafaxine (VEN) in seized dosage forms was presented. Our method was conducted to achieve separation following the optimal conditions: pre-coated silica gel plates using a green mobile phase (heptane: acetone: ammonia, 7:3:0.5 v/v), with absorbance scanning at 272 nm. The validation of the method was done following International Conference on Harmonization (ICH) guidelines, demonstrates linearity, accuracy, precision, selectivity, robustness, and system suitability. Separation was achieved with a detection limit of 0.34, 0.16, and 0.084 (ug/band) for TMD, TAP, and VEN, respectively, the method successfully analyzes seized samples. Trueness is confirmed through a high degree of similarity between HPTLC and gas chromatography results. The study's ecofriendly approach, simplicity, and selectivity position it as a promising method for efficient, on-site monitoring of seized samples.

Increased incidence of mixed drug toxicity deaths involving tapentadol - A forensic study

Tapentadol is a relatively new synthetic opioid analgesic prescribed for the management of moderate to severe pain. While tapentadol has been shown to be more effective than traditional opioid analgesics, it still carries the risk of addiction, abuse, and misuse. In Australia, tapentadol has become one of the top five most commonly prescribed opioid drugs, with prescriptions increasing by approximately 150,000 each year since it first became available. The rapid increase in tapentadol prescriptions has occurred in parallel to an increasing number of post-mortem tapentadol detections in South Australia (SA). While the number of deaths in SA related to tapentadol use was low in the current study, findings suggest that an increasing trend of deaths involving tapentadol will continue in parallel to a rapidly increasing number of prescriptions, mirroring trends associated with traditional opioids in SA. As a comparatively new opioid analgesic, monitoring future trends will be important to determine if additional prescribing education, intervention, or restrictions are required.

Enhanced in vitro and ex vivo transdermal permeation of microemulsion gel of tapentadol hydrochloride

Aim of the current study is to develop a microemulsion gel for transdermal delivery of tapentadol hydrochloride. Microemulsion was developed using phase diagram and subjected to assay, globule size, PDI, zeta potential, TEM and in vitro drug release studies. The optimized microemulsion was converted into gel using carbopol 934 NF and evaluated for viscosity, spreadability, in vitro, ex vivo, FTIR, DSC, stability and skin irritation studies. The mean globule size, PDI, zeta potential and in vitro drug release of microemulsion were found 247.3 nm, 0.298, -17.6 mV and 98.42% respectively. In vitro and ex vivo drug release of gel was found 92.2% and 88.6% in 24 h. Viscosity and spreadability results indicated ease of application and no incompatibility was observed from FTIR studies. The skin irritation studies showed absence of erythema. Key findings from the current research concluded that microemulsion gel was suitable for effective transdermal delivery.

Tapentadol Versus Oxycodone for Opioid-Related Adverse Drug Events and Clinical Outcomes After Inpatient Surgery

Oxycodone is a commonly prescribed opioid for postoperative pain. However, there has been a marked increase in the use of tapentadol over the previous decade due to a perceived superior safety profile of tapentadol compared to oxycodone. There is limited real-world evidence on the safety of tapentadol compared to oxycodone after surgery. The primary objective was to examine the impact of tapentadol compared to oxycodone use on the incidence of opioid-related adverse drug events after surgery. Data for adult surgical patients receiving tapentadol or oxycodone during hospitalization between January 1, 2018, and December 31, 2021, were collected from electronic medical records of 3 tertiary metropolitan hospitals in Australia. The primary outcome was the incidence of opioid-related adverse events. Patients receiving tapentadol or oxycodone were matched using nearest-neighbour propensity score matching. In the matched cohorts (n = 1,530 vs n = 2,775; mean [standard deviation] age 62.3 [17.0] years vs 61.9 [standard deviation 17.9] years; 43% vs 45% male for the tapentadol vs oxycodone groups, respectively), patients given tapentadol experienced a similar incidence of adverse events overall (14.4%, 220/1,530 vs 12.6%, 349/2,775; P = .100; 95% CI -.35% to 3.95%). Secondary outcomes included an increased risk of delirium (2.7%, 41/1,530 vs 1.3%, 37/2,775), arrhythmias (3.4%, 52/1,530 vs 2.2%, 62/2,775), and length of hospital stay (5 [range 1-201] vs 4 [range 1-226] days) compared with oxycodone use. Further real-world studies are warranted to determine the impact of tapentadol use on a broad range of patient outcomes. PERSPECTIVE: This study provides an early signal that tapentadol use may be associated with an increased risk of some adverse events and a longer length of stay. Further research is needed to examine the impact of tapentadol use on a broad range of patient outcomes in clinical practice settings.

Pharmacokinetics of oral tapentadol in cats

To evaluate pharmacokinetics of one dose of tapentadol hydrochloride orally administered to cats. Prospective experimental study. Five healthy adult mixed-breed cats. Each cat received 18.8 ± 1.0 mg/kg tapentadol orally. Venous blood samples were collected at time 0 (immediately prior to administration of tapentadol) 1, 2, 5, 10, 15, 30, 45, 60, 90 min, and 2, 4, 8, 12 to 24 h after drug administration. Plasma tapentadol concentrations and its metabolites were determined using ultra-performance liquid chromatography-tandem mass spectrometry. Geometric mean Tmax of tapentadol, desmethyltapentadol, tapentadol-O-glucuronide, and tapentadol-O-sulfate was 2.3, 7.0, 6.0, and 4.6 h, respectively. Mean Cmax of tapentadol, desmethyltapentadol, tapentadol-O-glucuronide, and tapentadol-O-sulfate was 637, 66, 1134, and 15,757 ng/mL, respectively, after administration. Mean half-life of tapentadol, desmethyltapentadol, tapentadol-O-glucuronide, and tapentadol-O-sulfate was 2.4, 4.7, 2.9, and 10.8 h. The relative exposure of tapentadol and its metabolites were tapentadol 2.65%, desmethyltapentadol 0.54%, tapentadol-O-glucuronide 6.22%, and tapentadol-O-sulfate 90.6%. Tapentadol-O-sulfate was the predominant metabolite following the administration of oral tapentadol in cats. Further studies are warranted to evaluate the association of analgesia with plasma concentrations of tapentadol.

The role of tapentadol in cancer pain pharmacotherapy in patients with metastatic malignant disease

OBJECTIVE

The aim of this study was to establish the effects of prolonged formulation of tapentadol in combination with palliative radiotherapy on bone metastatic changes in oncology patients with primary breast cancer and proven bone metastases.

PATIENTS AND METHODS

The research was conducted as a prospective study at the Clinic for Oncology, University Clinical Center Nis, Nis, Serbia, during a three-month interval of monitoring the patients. The first group comprised 30 patients with mentioned malignancy for which tapentadol was prescribed, and they underwent palliative radiotherapy for bone metastatic changes. The second group comprised 30 patients with the same disease treated only with pain relief radiotherapy to metastatic changes. All the patients were interviewed using the Pain Detect questionnaire.

RESULTS

Significantly more patients from the first group had severe pain in comparison to patients from the control group (χ2=16.596; p<0.001) at the second measurement and also at the third measurement (χ2=15.357; p<0.001). At the third measurement, pain with a neuropathic component was significantly more present in patients from the control group (χ2=8.541; p=0.014). There was a significant pain reduction in both groups - Tapentadol group (χ2=59.513; p<0.001) and control group (χ2=60.000; p<0.001) - and also a significant reduction of neuropathic pain component: Tapentadol group (χ2=56.267; p<0.001) and control group (χ2=60,000; p<0.001). There was a statistically significant positive correlation between tapentadol dose and pain intensity according to the numerical pain scale at all three measurements.

CONCLUSIONS

Tapentadol prolonged-release formulation is an effective pharmacotherapy solution, along with palliative radiotherapy, for pain relief in patients with skeletal metastatic breast cancer. Palliative radiotherapy in these patients does not provide adequate neuropathic pain component relief.

The transit of oral premedication beyond the stomach in patients undergoing laparoscopic sleeve gastrectomy: a retrospective observational multicentre study

BACKGROUND

Antiemetic and analgesic oral premedications are frequently prescribed preoperatively to enhance recovery after laparoscopic sleeve gastrectomy. However, it is unknown whether these medications transit beyond the stomach or if they remain in the sleeve resection specimen, thereby negating their pharmacological effects.

METHODS

A retrospective cohort study was performed on patients undergoing laparoscopic sleeve gastrectomy and receiving oral premedication (slow-release tapentadol and netupitant/palonosetron) as part of enhanced recovery after bariatric surgery program. Patients were stratified into the Transit group (premedication absent in the resection specimen) and Failure-to-Transit group (premedication present in the resection specimen). Age, sex, body mass index, and presence of diabetes were compared amongst the groups. The premedication lead time (time between premedications' administration and gastric specimen resection), and the premedication presence or absence in the specimen was evaluated.

RESULTS

One hundred consecutive patients were included in the analysis. Ninety-nine patients (99%) were morbidly obese, and 17 patients (17%) had Type 2 diabetes mellitus. One hundred patients (100%) received tapentadol and 89 patients (89%) received netupitant/palonosetron. One or more tablets were discovered in the resected specimens of 38 patients (38%). No statistically significant differences were observed between the groups regarding age, sex, diabetes, or body mass index. The median (Q1‒Q3) premedication lead time was 80 min (57.8‒140.0) in the Failure-to-Transit group and 119.5 min (85.0‒171.3) in the Transit group; P = 0.006. The lead time required to expect complete absorption in 80% of patients was 232 min (95%CI:180‒310).

CONCLUSIONS

Preoperative oral analgesia and antiemetics did not transit beyond the stomach in 38% of patients undergoing laparoscopic sleeve gastrectomy. When given orally in combination, tapentadol and netupitant/palonosetron should be administered at least 4 h before surgery to ensure transition beyond the stomach. Future enhanced recovery after bariatric surgery guidelines may benefit from the standardization of premedication lead times to facilitate increased absorption.

TRIAL REGISTRATION

Australian and New Zealand Clinical Trials Registry; number ACTRN12623000187640; retrospective registered on 22/02/2023.

A systematic analysis and data mining of opioid-related adverse events submitted to the FAERS database

The opioid epidemic has become a serious national crisis in the United States. An indepth systematic analysis of opioid-related adverse events (AEs) can clarify the risks presented by opioid exposure, as well as the individual risk profiles of specific opioid drugs and the potential relationships among the opioids. In this study, 92 opioids were identified from the list of all Food and Drug Administration (FDA)-approved drugs, annotated by RxNorm and were classified into 13 opioid groups: buprenorphine, codeine, dihydrocodeine, fentanyl, hydrocodone, hydromorphone, meperidine, methadone, morphine, oxycodone, oxymorphone, tapentadol, and tramadol. A total of 14,970,399 AE reports were retrieved and downloaded from the FDA Adverse Events Reporting System (FAERS) from 2004, Quarter 1 to 2020, Quarter 3. After data processing, Empirical Bayes Geometric Mean (EBGM) was then applied which identified 3317 pairs of potential risk signals within the 13 opioid groups. Based on these potential safety signals, a comparative analysis was pursued to provide a global overview of opioid-related AEs for all 13 groups of FDA-approved prescription opioids. The top 10 most reported AEs for each opioid class were then presented. Both network analysis and hierarchical clustering analysis were conducted to further explore the relationship between opioids. Results from the network analysis revealed a close association among fentanyl, oxycodone, hydrocodone, and hydromorphone, which shared more than 22 AEs. In addition, much less commonly reported AEs were shared among dihydrocodeine, meperidine, oxymorphone, and tapentadol. On the contrary, the hierarchical clustering analysis further categorized the 13 opioid classes into two groups by comparing the full profiles of presence/absence of AEs. The results of network analysis and hierarchical clustering analysis were not only consistent and cross-validated each other but also provided a better and deeper understanding of the associations and relationships between the 13 opioid groups with respect to their adverse effect profiles.

Abuse of tapentadol compared to other atypical opioids among individuals entering treatment for opioid use disorders

OBJECTIVE

Tapentadol is an atypical opioid analgesic thought to have dual mechanisms of action: µ-receptor agonism and inhibition of norepinephrine reuptake. Unlike other atypical opioids, tapentadol is a schedule II-controlled substance. We compared the prevalence of abuse (use to get high) of tapentadol to other atypical opioids used to treat pain (buprenor-phine and tramadol).

DESIGN

An observational, serial cross-sectional study.

SETTING

Individuals enrolling in treatment programs for opioid use disorder in 2019. Each completed a self-administered, paper questionnaire assessing prescription drug abuse and illegal drug use within 1 week of enrollment.

MAIN OUTCOME MEASURES

Indication of past month abuse of tapentadol or comparator drugs on a self-administered ques-tionnaire.

RESULTS

There were 6,987 respondents. Unadjusted and utilization-adjusted logistic regression models were used to compare odds of endorsement of tapentadol to tramadol and buprenorphine products indicated for the management of pain. Unadjusted abuse prevalence was 0.20 percent for total tapentadol (0.03 percent for NUCYNTA® and 0.06 percent for NUCYNTA ER). Relative to total tapentadol, the odds of abuse of buprenorphine for pain was 2.9 times greater (95 percent CI: 1.6 to 5.3, p < 0.001), and for tramadol, 43.1 times greater (95 percent CI: 25.3 to 73.3, p < 0.001). Adjusting for prescriptions dispensed, differences in odds of abuse were not statistically significant (odds ratio (OR) = 1.6, 95 per-cent CI: 0.9 to 3.0, p = 0.108 for buprenorphine for pain and OR = 0.7, 95 percent CI: 0.4 to 1.2, p = 0.209 for tramadol).

CONCLUSIONS

Tapentadol use to get high is less frequent than other atypical opioids. Findings suggest tapentadol is rarely the primary drug abused by an individual.

Physical activity in the first postoperative week in 132 knee arthroplasty patients randomized to 3 different analgesic regimens

BACKGROUND

The aim of this study was to investigate whether objectively recorded physical activity in the first week after surgery in total knee arthroplasty patients differed between patients allocated to 3 different analgesic regimens.

METHODS

A total of 132 total knee arthroplasty patients wore activity monitors 24 hours a day from day 1 after surgery for 6 consecutive days. The time mobilized (stepping/standing) and the number of steps were recorded. This study was a sub-study of a randomized controlled study comparing tapentadol extended-release (ER), oxycodone controlled-release (CR), or a non-opioid placebo analgesic regimen.

RESULTS

The placebo group spent significantly more time mobilized than the tapentadol ER and the oxycodone CR groups (P = .016 and .042, respectively), but no statistically significant differences were found between the groups in the number of steps taken. The activity levels of patients in all groups increased in the first week after surgery.

CONCLUSION

Patients in the non-opioid placebo group spent more time mobilized the first week after surgery than those in the tapentadol ER and the oxycodone CR groups, while the number of steps was not different between the groups.

Opioid dispensing 2008-18: a Queensland perspective

ObjectiveThis study provides an overview of opioid dispensing in Queensland from 2008 to 2018 by recipient age, drug, oral morphine equivalent and remoteness.MethodsData were obtained from the Queensland Monitoring of Drugs of Dependence System database for 2008-18 and analysed using data from the Australian Bureau of Statistics to account for population growth. Opioid dispensing by age, drug, oral morphine equivalent and remoteness were assessed.ResultsThe number of prescriptions for Schedule 8 opioid medicines dispensed in Queensland increased from 190 to 430 per 1000 population over the study period (2.3-fold increase). Oxycodone had the largest increase in dispensing over the study period of 3.1-fold, with tapentadol increasing rapidly since initial Pharmaceutical Benefits Scheme listing in 2013 to the third most dispensed opioid by 2018. By 2018, opioid dispensing among the oldest Queenslanders, those aged 85+ years, occurred at triple the rate for those aged 65-84 years. When adjusted to report oral morphine equivalents (OME) in milligrams (mg), there has been an increase of approximately 1.9-fold over the study period. Results were also presented by geographical area, including a heatmap and analysis by remoteness. Prescriptions dispensed per 1000 population were 416 for major cities, 551 for inner regional and 445 for outer regional, and highlight that inner and outer regional areas have higher rates of prescriptions when compared to major cities (32 and 7% higher, respectively).ConclusionThis study highlights changes in opioid prescription dispensing by drug and OME, as well as the variation in dispensing rates when accounting for remoteness. Further studies to link statewide databases, and to better understand drivers for differences in dispensing by location, will provide valuable insights to further inform policy and service provision.

Effects of Different Opioid Drugs on Oxidative Status and Proteasome Activity in SH-SY5Y Cells

Opioids are the most effective drugs used for the management of moderate to severe pain; however, their chronic use is often associated with numerous adverse effects. Some results indicate the involvement of oxidative stress as well as of proteasome function in the development of some opioid-related side effects including analgesic tolerance, opioid-induced hyperalgesia (OIH) and dependence. Based on the evidence, this study investigated the impact of morphine, buprenorphine or tapentadol on intracellular reactive oxygen species levels (ROS), superoxide dismutase activity/gene expression, as well as β2 and β5 subunit proteasome activity/biosynthesis in SH-SY5Y cells. Results showed that tested opioids differently altered ROS production and SOD activity/biosynthesis. Indeed, the increase in ROS production and the reduction in SOD function elicited by morphine were not shared by the other opioids. Moreover, tested drugs produced distinct changes in β2(trypsin-like) and β5(chymotrypsin-like) proteasome activity and biosynthesis. In fact, while prolonged morphine exposure significantly increased the proteolytic activity of both subunits and β5 mRNA levels, buprenorphine and tapentadol either reduced or did not alter these parameters. These results, showing different actions of the selected opioid drugs on the investigated parameters, suggest that a low µ receptor intrinsic efficacy could be related to a smaller oxidative stress and proteasome activation and could be useful to shed more light on the role of the investigated cellular processes in the occurrence of these opioid drug side effects.

A Comparison of Institutional Opioid Equianalgesia Tools: A National Study

Context: Equianalgesic tools are commonly utilized to guide dose of analgesic therapy, but there is no national consensus on equianalgesic calculations in the United States. Objectives: To propose a summary of current opioid equianalgesic data that include variations and trends among national institutions. Methods: Opioid equianalgesic tools were obtained between May and September 2021. For meperidine, tramadol, codeine, hydrocodone, morphine, oxycodone, oxymorphone, hydromorphone, levorphanol, fentanyl, and tapentadol, details of adjustment for incomplete tolerance, opioid equianalgesic ratios, and formulation types were collected and analyzed. Baseline opioid pharmaco kinetic data were obtained through manufacturer labels on FDA databases, including half-life (T1/2), volume of distribution (Vd), clearance (Cl), area under the curve (AUC), max concentration (Cmax), and time to max concentration (Tmax). Results: Thirty-two institutions' equianalgesic tools were included with each study opioid appearing on an average of 23 institutions' tools. Few tools contained guidance on levorphanol or tapentadol; or included minimum and maximum recommended doses. All tools included guidance on fentanyl, hydromorphone, oxycodone, morphine, and hydrocodone. A minority of tools included guidance on cross-tolerance considerations (n = 12, 37.5%). Oral-tramadol-to-oral-morphine and oral-hydromorphone-to-intravenous (IV)-hydromorphone had the largest variances across equianalgesic tools (6.7 ± 2.8 and 4.06 ± 1.2 mg, respectively). Conclusion: Opioid equianalgesia tools from across the United States demonstrated significant variation in their inclusion of guidance on adjustment for incomplete cross-tolerance, oral-to-IV, and oral-to-oral opioid equianalgesic ratios, and which opioids and formulations were listed. Tramadol and hydromorphone had the most variation in their equianalgesic guidance among the opioids.

Clinical role and safety of tapentadol in patients with cancer: A single-center experience

OBJECTIVE

To evaluate real-world data on the use of tapentadol (TAP) in cancer patients.

DESIGN

Single-center retrospective study.

SETTING

Curative/palliative.

PATIENTS, PARTICIPANTS

Patients who started TAP between October 2014 and December 2018 at our institution.

MAIN OUTCOME MEASURE(S)

The primary outcome was the reason for TAP initiation. Secondary outcomes included prescription duration, TAP cessation rate, reason for cessation, and adverse events (AEs). Since the palliative care team (PCT) tended to prescribe to cancer patients with intractable pain more often than patients in usual care, and also tended to prescribe opioids based on their characteristics, we decided to compare patients with and without PCT intervention.

RESULTS

There were 175 patients who first received TAP during the study period, of whom 81 patients (46.3 percent) were male. The median age was 60 years. TAP was prescribed for opioid-naive patients in 45 (26 percent) cases and opioid switch in 130 (74 percent) cases. When comparing the PCT group (n = 121) and the non-PCT group (n = 54) using univariate analysis, the PCT group had a higher opioid switch rate (81.8 percent vs 57.4 percent, p < .001), higher proportion of patients with neuropathic pain (NP) (65.3 percent vs 16.7 percent, p < .001), and a higher proportion of patients with a history of nausea (41.3 percent vs 18.5 percent, p < .01). The cessation rate due to AEs was 8 percent overall.

CONCLUSIONS

Palliative care physicians prescribed TAP for patients with NP or a history of nausea. Opioid-naive patients were preferred by oncologists. TAP has good tolerability in both groups, with a low dropout rate due to AEs.

Comparing opioid types in the persistence of opioid use following surgical admission: a study protocol for a retrospective observational linkage study comparing tapentadol and oxycodone in Australia

INTRODUCTION

Each year, an estimated two million Australians commence opioids, with 50 000 developing longer-term (persistent) opioid use. An estimated 3%-10% of opioid-naïve patients prescribed opioids following surgery develop persistent opioid use. This study will compare rates of persistent opioid use between two commonly used postoperative opioids, oxycodone and tapentadol, to understand if initial postoperative opioid type is important in determining longer-term outcomes.

METHODS AND ANALYSIS

A retrospective data linkage study that analyses administrative data from hospital and community pharmacies. Data will be obtained from at least four pharmacies that service large hospitals with comparable supplies of oxycodone and tapentadol. The study will include at least 6000 patients who have been dispensed a supply of oxycodone or tapentadol to take home following their discharge from a surgical ward. The primary outcome measure will be persistent opioid use at 3 months postdischarge for opioid naïve people who receive either immediate release tapentadol or immediate release oxycodone. Hierarchical logistic regression models will be used to predict persistent opioid use, controlling for covariates including comorbidities.

ETHICS AND DISSEMINATION

Ethics approval has been obtained through the Monash University Human Research Ethics Committee (29977). We will present project findings in a peer-reviewed journal article, in accordance with the REporting of studies Conducted using Observational Routinely-collected health Data statement.

Cost-effectiveness of tapentadol immediate release versus oxycodone immediate release for acute post-operative pain after major hip surgeries

OBJECTIVE

To evaluate the cost-effectiveness of tapentadol immediate-release (IR) versus oxycodone IR for post-operative pain after a major hip surgery.

METHODS

This study has been conducted using an Australian societal perspective, focusing on adult patients after a major hip surgery. A cost-effectiveness analysis was conducted using a decision-analytic model. The model incorporated drug and other resource costs, the probability of opioid-related adverse events, and quality-adjusted life months (QALM) in each treatment arm. A willingness to pay (WTP) threshold of AU$2500 was used per QALM gained. A probabilistic sensitivity analysis was conducted to examine the uncertainty of the assumptions. The primary outcome was the incremental cost-effectiveness ratio (ICER) of tapentadol IR versus oxycodone IR, expressed as Australian dollars (AU$) per QALM gained.

RESULTS

Tapentadol IR dominated oxycodone IR, with a cost savings of AU$201 and an increase in QALM by 0.014. The ICER was -13,946 AU$/QALM (negative value attributed to numerator). In the probabilistic sensitivity analysis, 84.2% of the simulations were in favour of tapentadol IR at the WTP threshold.

CONCLUSIONS

Tapentadol IR may be more cost-effective than oxycodone IR for the treatment of acute postoperative pain after major hip surgeries.

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.

[Monoaminergic opioids: which one should we choose?]

Tapentadol shares with tramadol a mixed mechanism of action. It has no identified analgesically active metabolite and is not significantly metabolised by CYP450, thus overcoming some limitations of tramadol, including potential for pharmacokinetic drug-drug interactions and inter-individual variability due to genetic polymorphisms of CYP450. It is likely to expose less to serotoninergic adverse effects (nausea, vomiting, hypoglycaemia) and more to opioid adverse effects (constipation, respiratory depression, abuse) than tramadol. The level of evidence on the efficacy of both tramadol and tapentadol for the treatment of chronic pain is globally low. As a conclusion, tapentadol represents an additional analgesic which some patients may benefit from after careful examination of their clinical situation, comorbidities and comedications.

[Efficacy of Tapentadol for Neuropathic Pain in Cancer]

Neuropathic pain in patients with cancer often do not respond to both opioid and non-opioid analgesics. Tapentadol has two medical effects: action on the μ opioid receptor and inhibition of noradrenaline reuptake; thus, it is expected to be effective for neuropathic pain. We investigated its effect on neuropathic pain in 40 patients with cancer who received tapentadol between June 2017 and May 2020 at the Japanese Red Cross Nagoya Daini Hospital. We compared the level of neuropathic pain using an NRS before and after tapentadol administration. The NRS score(median)decreased from 7 to 4.5 within 15 days after first administration or dose increase(p<0.05). Twenty-two patients(55%)showed more than 33% improvement in the NRS score. These results suggest that tapentadol may contribute to a reduction in neuropathic pain.

Gastrointestinal Adverse Events in Hospitalized Patients Following Orthopedic Surgery: Tapentadol Immediate Release Versus Oxycodone Immediate Release

BACKGROUND

Tapentadol has relatively less effect on mu-opioid receptors compared with other opioids. This has the potential to reduce the occurrence of gastrointestinal (GI) adverse drug events (ADEs).

OBJECTIVES

To compare the GI ADEs during hospitalization between tapentadol immediate release (IR) and oxycodone IR following orthopedic surgeries.

STUDY DESIGN

Retrospective cohort study.

SETTING

A major metropolitan tertiary referral hospital in Australia.

METHODS

Data for adult orthopedic surgery patients receiving postoperative tapentadol IR or oxycodone IR during hospitalization between January 1, 2018 and June 30, 2019, were collected from electronic medical records. The primary outcome was the occurrence of postoperative GI ADEs occurring during hospitalization. This was defined as a composite of nausea, vomiting, or constipation.

RESULTS

The study cohort included 199 patients. Of these, 99 patients received tapentadol IR and 100 patients received oxycodone IR for postoperative pain during hospitalization. The mean age was 66 ± 12 years, and 111 patients (56%) were women. There was no significant difference between groups on the occurrence of GI ADEs (53% in oxycodone group and 51% in tapentadol group, difference 2%, 95% confidence interval [CI], -11% to 16%; P = 0.777). After adjusting for potential confounders, the use of tapentadol IR was not associated with a significant reduction of GI ADEs (odds ratio, 0.62; 95% CI, 0.32-1.20; P = 0.154).

LIMITATIONS

This was a single-center study and should be extrapolated with caution. As this was a retrospective study, the accuracy and availability of data were dependent on documentation in electronic medical records.

CONCLUSIONS

Tapentadol IR is associated with similar GI ADE occurrence compared with oxycodone IR in patients with orthopedic postoperative pain during hospitalization.

Tapentadol is the least common opioid found in admission urine drug-test results at an intensive outpatient opioid-use disorder treat-ment program in Ohio: A brief report

BACKGROUND

Previous data suggest that tapentadol, an atypical opioid with a putative dual mechanism of action, has relatively low rates of abuse. A better understanding of the rates of abuse among different prescription opioids may help clinicians when considering their potential risks and benefits. The results of urine drug tests (UDTs) may provide a unique opportunity to help answer this question.

METHOD

To investigate different rates of prescription-opioid abuse in this retrospective study, we examined urine drug test results from patients seeking treatment at four facilities of an opioid-use-disorder (OUD) treatment program in Ohio. Urine specimens were collected on admission, one from each patient, in the regular course of care. The opioids reviewed in the present study were tapentadol, hydrocodone, oxycodone, hydromorphone, oxymorphone, and tramadol. Drug dispensing data, including morphine-milligram equivalents (MME) dispensed, were examined to adjust for the relative prevalence of each opioid being examined.

RESULTS

Data from 4,162 patients were examined. Tapentadol was the least common finding in UDT results in this cohort and remained so after adjusting for drug availability. The percentage of specimens positive for a given opioid ranged from 0.12 percent (tapentadol) to 7.04 percent (oxycodone). The availability and MME adjustments resulted in a change of rank order, with tapentadol remaining the lowest but tramadol replacing oxycodone as the prescription opioid with the highest rate of abuse.

CONCLUSIONS

In this sample of UDT results from patients seeking treatment at an OUD program in Ohio, tapentadol was the least frequent finding among the opioids examined, and this remained true when adjusting for dispensing data. Factors potentially contributing to this difference may include pharmacological properties unique to tapentadol. Several important limitations notwithstanding, these findings are consistent with previous real-world evidence and warrant an ongoing line of inquiry.

Effectiveness of tapentadol hydrochloride for treatment of orthopedic pain in dogs: A pilot study

This pilot study evaluated the short-term analgesic effect of oral tapentadol hydrochloride (tapentadol) in dogs with unilateral hind limb lameness secondary to naturally occurring cranial cruciate ligament rupture. Baseline data including pharmacodynamic parameters, sedation scores, lameness scores, and objective gait analyses were collected. Tapentadol was administered orally (30 mg/kg body weight). Four hours following administration of tapentadol all data were collected again. Plasma concentrations of tapentadol 4 hours after administration were assessed using high performance liquid chromatography tandem mass spectrometry. No significant side effects were noted. All dogs had measurable plasma concentrations of tapentadol (mean concentration: 18.9 ng/mL). There were no significant differences in pharmacodynamic parameters or sedation over time. Subjective lameness scores were significantly lower than baseline at 4 hours post-drug administration. No significant improvement was seen in objective gait analysis. Further studies are needed to assess dosing regimens which may lead to effective treatment of acute pain and long-term use.

[Clinical Effects of Opioid Switching to Tapentadol - Retrospective Analysis of Efficacy and Adverse Effects]

The objective of our study was to evaluate the efficacy and adverse effects of opioid switching to tapentadol(TP). It was a retrospective survey carried out at the Kitasato University Hospital outpatient clinic between September 2014 and May 2016. We evaluated pain intensity using the visual analogue scale and the occurrence of adverse effects before switching, at the first evaluation after switching, and during the steady state of TP administration. We included 10 patients; of these, 3 patients discontinued TP owing to uncontrolled pain. The conversion ratio of the previously administered opioids to TP was 1.17 at the time of the first evaluation after switching and 1.42 during the steady state. The mean(±SD)pain intensity was 4.2±2.2 before opioid switching and 4.6±2.2 at the time of the first evaluation after switching. The mean(±SD)pain intensity in the 7 patients excluding the 3 patients who discontinued TP was 4.3±2.0 before opioid switching and 2.7±1.9 during the steady state. Somnolence improved in 5 patients and constipation improved in 2 patients when a stable dose was achieved. Opioid switching to TP was appropriately accomplished using the conversion ratio. Furthermore, pain, sleepiness, and constipation improved following successful titration. These data suggest that TP can be useful in the treatment of cancer pain, in addition to the currently used opioid preparations.

Opioid use and harms associated with a sustained-release tapentadol formulation: a postmarketing study protocol

INTRODUCTION

It has been argued that tapentadol may pharmacologically have lower abuse potential than other pharmaceutical opioids currently available. However, there has been no comprehensive triangulation of data regarding use and harms associated with this formulation. A sustained-release formulation (SRF) of tapentadol (Palexia) was released in Australia in 2011 and listed for public subsidy in 2013. We summarise here the methods of a postmarketing study which will measure postintroduction: (1) population level availability, (2) extramedical use and diversion, (3) attractiveness for extramedical use and (4) associated harms, of tapentadol compared against other pharmaceutical opioids.

METHODS AND ANALYSIS

We evaluated key sources on pharmaceutical use and harms in Australia. This review indicateddata from four sources that disaggregate pharmaceutical opioid formulations and capture tapentadol SRF could be triangulated. These data sources comprised: (1) national pharmaceutical opioid community sales data from 2011 to 2017, (2) national pharmaceutical opioid poisonings reported to Poison Information Centres (PICs) from 2011 to 2017, (3) number of vendors on online marketplaces listing pharmaceutical opioids for sale and (4) data on pharmaceutical opioid extramedical use, attractiveness and harms from interviews with people who regularly inject drugs in Australia.

ETHICS AND DISSEMINATION

Ethics approval is not required for use of pharmaceutical sales data. Ethics approval has been obtained for use of national pharmaceutical opioid poisonings reported to PICs (LNR/16/SCHN/44) and for use of online marketplace data and interview data from people who inject drugs (HC12086). Key findings will be published mid-2018 in a peer-reviewed academic journal, and presented at various conferences and professional meetings.

[New Opioid Options in Japan - Methadone, Tapentadol and Hydromorphone]

In 2010s, several opioids became available in Japan, including methadone, tapentadol and hydromorphone. Methadone was approved in September 2012 by Japanese regulatory authority. Since methadone is positioned as so-calledstep 4 opioidin Japan, it must be prescribed as alternative opioid switched from another of 60mg/day or greater equivalent dose of oral morphine. Diversity of pharmacokinetics among individuals and various drug interactions require close monitoring of adverse events. In spite of these cautions, unique characteristics such as inhibiting N-methyl-D-aspartate(NMDA)and in- ducing internalization/degradation of mu-delta opioid receptor heterodimers underline the value of methadone in opioid switching. Tapentadol, a dual-acting opioid which inhibits noradrenaline(norepinephrine)reuptake, was approved in Japan in March 2014. In a double-blind randomized study comparing with oxycodone, tapentadol showed relatively better tolerability. Advantages such as having no active metabolites and minimal drug interactions also ease the administration of tapentadol to the patients with comorbidities. Hydromorphone, approved in March 2017, has a profile similar to morphine. Higher potency than morphine lead to less production of 3-glucronide metabolite(H3G)which accumulates in patients with renal failure and causes neurotoxicity. Because there is no concluding evidence about effect of hydromorphone on dyspnea or tolerability in patients with renal insufficiency, organized studies are still needed. We expect these "new in Japan" opioids contribute to long-term, stable pain control for patients with cancer.

Tapentadol Prolonged Release Reduces the Severe Chronic Ischaemic Pain and Improves the Quality of Life in Patients with Type 2 Diabetes

This study has been performed in diabetic type 2 patients with pain due to peripheral artery disease (PAD) in order to evaluate the efficacy and tolerability of tapentadol prolonged release (PR). Methods. 25 patients with type 2 diabetes (13 F and 12 M) were admitted in the study. The evaluation of the analgesic efficacy of tapentadol PR was based on both the assessment of the intensity of the pain (NRS scale from 0 to 10) and the nature of the pain (DN4 questionnaire) and on assessment of the patient's quality of life and state of health (SF-12 Health Survey). Study duration was 3 months: a baseline visit and follow-up included visits after 1 week, 1 month, 2 months, and 3 months. Results. At the beginning of the study, the mean intensity of the pain was 7.88 ± 1.17 on the NRS scale and at visit 2 it reduced in a statistically significant way; at the end of the treatment with tapentadol PR, the mean intensity was 2.84 points on the NRS scale. Conclusion. In type 2 diabetic patients with chronic severe pain due to PAD, tapentadol PR reduced pain intensity, improving the quality of life.

Tapentadol versus tramadol in the management of low back pain in the emergency department: Impact of use on the need for reassessments

Nontraumatic musculoskeletal disorders are the main reason for presentation to the emergency department (ED), with rachialgia (back pain) being the most common reason to request medical assessment among them. This also generates the highest demand for reassessments due to poor pain control or onset of adverse reactions to the treatment prescribed in the initial assessment.A retrospective observational study based on usual clinical practice was conducted in patients attending the ED due to low back pain during a period of 24 months. The primary objective was to determine the demand for reassessments in the ED by these patients in the following 30 days, according to the type of therapeutic approach used in the initial assessment.A total of 732 patients who requested medical assessment due to back pain in the ED of our hospital were analyzed, 91 of whom were treated with tapentadol whereas 641 received another treatment. In the first month after the initial assessment, reassessments were less common in the tapentadol group; this difference was significant from days 8 to 15 (P = 0.001, odds ratio [OR] 0.252 with 95% confidence interval [CI] 0.100-0.635) and days 15 to 30 (P < 10, OR 0.277 with 95% CI 0.136-0.563). Patients who received tapentadol also had a better clinical evolution of pain compared to those who did not receive it (P < 10) and to those who received tramadol (P < 10).In this study in patients with back pain, tapentadol shows clear advantages over the other analgesics analyzed, in terms of pain control and less need for reassessments.

The role of tapentadol as a strong opioid in cancer pain management: a systematic and critical review

AIM

The aim of this review was to assess the role of tapentadol given at medium-high doses in opioid-tolerant patients for cancer pain management in place of step-3 analgesics.

METHODS AND RESULTS

A systematic literature search was performed out of which six studies and one secondary analysis provided data regarding tapentadol used as a step-3 analgesic for this review. Tapentadol, when used at ≥60 mg of oral morphine equivalents in opioid-tolerant patients with cancer pain, or passing from step-2 doses to ≥60 mg of oral morphine equivalents, was well tolerated and effective and could be considered as a flexible drug to be used for the management of moderate-to-severe cancer pain. The limited occurrence of gastrointestinal adverse effects may be a great advantage in the context of a disease like cancer, where multiple causes contribute to nausea, vomiting, or constipation; however, studies of tapentadol given at doses equivalent to step-3 level have some weaknesses, as data from prospective observational studies are poorly generalizable due to a small number of participants, controlled studies do not clearly show a superiority of tapentadol with respect to other opioids, and the sample size is often small.

CONCLUSIONS

More studies are necessary to confirm the role of tapentadol in cancer patients requiring strong opioids for their pain.

Tapentadol prolonged-release for moderate-to-severe chronic osteoarthritis knee pain: a double-blind, randomized, placebo- and oxycodone controlled release-controlled study

OBJECTIVE

To assess efficacy and safety of tapentadol prolonged release (PR) for moderate-to-severe chronic osteoarthritis knee pain.

METHODS

Patients (n = 990) were randomized (1:1:1) to tapentadol PR, oxycodone controlled release (CR; reference compound for assay sensitivity), or placebo for a double-blind 3-week titration and 12-week maintenance period. Primary efficacy end-points were change from baseline in average pain intensity at week 12 of maintenance (US end-point) and over the entire maintenance period (non-US end-point) with "last observation carried forward" as imputation method for missing scores.

RESULTS

Both primary end-points were not significantly different for tapentadol PR nor for oxycodone CR vs placebo at week 12 (least squares [LS] mean difference = -0.3 [95% CI = -0.61-0.09]; p = 0.152 and 0.2 [95% CI = -0.16-0.54]; p = 0.279, respectively) and over the maintenance period (LS mean difference = -0.2 [95% CI = -0.55-0.07]; p = 0.135 and 0.1 [95% CI = -0.18-0.44]; p = 0.421, respectively). Considerably more patients receiving tapentadol PR than oxycodone CR completed the trial (58.3% vs 36.6%). This is consistent with better results with tapentadol PR on the overall health status (PGIC) compared to oxycodone CR. Indeed, respectively, 56% and 42.5% rated at least "much improved" at the end of treatment. Incidences of gastrointestinal adverse events were higher for both active treatments compared to placebo. Tapentadol PR was associated with a better gastrointestinal tolerability profile with incidences of constipation (17.9% vs 35%) and of the composite of nausea and/or vomiting (23.8% vs 46.8%) significantly lower vs oxycodone CR (p < 0.001).

CONCLUSIONS

The study did not demonstrate assay sensitivity. The finding that both primary end-points for tapentadol PR were not met can, thus, not be interpreted. Tapentadol PR was better tolerated than oxycodone CR, largely due to fewer gastrointestinal side-effects.

Efficacy and safety of tapentadol prolonged release for moderate-to-severe chronic osteoarthritis knee pain: a pooled analysis of two double-blind, randomized, placebo- and oxycodone controlled release-controlled studies

OBJECTIVE

To compare efficacy and safety of tapentadol prolonged-release (PR) and oxycodone-controlled release (CR) in moderate-to-severe chronic osteoarthritis knee pain.

METHODS

Data from two double-blind, randomized, placebo- and oxycodone CR-controlled phase 3 studies with a 3-week titration period and 12-week controlled dose adjustment maintenance period were pooled. Primary efficacy end-points were change from baseline in average pain intensity at week 12 (US end-point) and over the entire maintenance period (non-US end-point).

RESULTS

A total of 2,010 patients were assessed. For both primary end-points, tapentadol PR was significantly more effective than oxycodone CR (LS mean difference of -0.41 [95% CI = -0.65, -0.16; p = 0.001] at week 12 and -0.35 [95% CI = -0.58, -0.12; p = 0.003] over 12 weeks of maintenance [last observation carried forward]). Significantly better outcomes than for oxycodone CR were also observed for patient global impression of change, both Short Form-36 component scores, and EuroQoL-5Dimensions health status index (all p < 0.001). Relative risk for vomiting, constipation, nausea, somnolence, and pruritus was lower for tapentadol PR than for oxycodone CR. A higher proportion of oxycodone CR patients discontinued treatment (64% vs 42.2% for tapentadol PR); time to treatment discontinuation due to an adverse event was significantly shorter for oxycodone CR (p < 0.001).

CONCLUSIONS

The analyses suggest that tapentadol PR provided superior pain relief and a more improved overall health status than oxycodone CR in a large patient population with moderate-to-severe chronic osteoarthritis pain. Compared to oxycodone CR, tapentadol PR showed a more favorable tolerability profile with better gastrointestinal tolerability.

Tapentadol in neuropathic pain cancer patients: a prospective open label study

Many chemotherapy treatments induce peripheral neuropathy (CIPN). These patients often experience neuropathic pain (NP) that reduces the quality of life. The aim of this prospective, open label study was to evaluate the efficacy and tolerability of tapentadol (TP) in patients affected by CIPN. CIPN were consecutively enrolled in a prospective open label study at the Neuro-Oncology Unit of the Regina Elena National Cancer Institute in Rome. During the titration phase, each patient initially received doses of TP 50 mg twice a day. All patients underwent pain intensity (NRS) and DN4. For evaluation of quality of life, patients underwent EORTC QLQ-C30 and EORTC QLQ-CIPN2 QLQ-CIPN20. We enrolled 31 patients, 19 were females with a median age of 60 years. After 3 months of treatment with TP, 22 patients completed the statistical package for social sciences (SPSS). Nineteen patients out of 22 showed a response to treatment (86%). We also observed that TP reduced the NRS and DN4 values from baseline to the last visit in a significant way (p < 0.001, respectively). Seven patients (22.5%) discontinued the TP therapy after the first week of occurrence of side effects. Furthermore, we observed that TP improved also the global health status measured by EORT QLQ-C30. TP is well tolerated and efficacy in the treatment of NP. The important reduction of neuropathic pain, the improvement in NRS and QoL scores after therapy with TP makes it a candidate in the management of patients suffering from neuropathic pain of CIPN also as a first line of therapy.

Opioids for cancer pain - an overview of Cochrane reviews

BACKGROUND

Pain is a common symptom with cancer, and 30% to 50% of all people with cancer will experience moderate to severe pain that can have a major negative impact on their quality of life. Opioid (morphine-like) drugs are commonly used to treat moderate or severe cancer pain, and are recommended for this purpose in the World Health Organization (WHO) pain treatment ladder. The most commonly-used opioid drugs are buprenorphine, codeine, fentanyl, hydrocodone, hydromorphone, methadone, morphine, oxycodone, tramadol, and tapentadol.

OBJECTIVES

To provide an overview of the analgesic efficacy of opioids in cancer pain, and to report on adverse events associated with their use.

METHODS

We identified systematic reviews examining any opioid for cancer pain published to 4 May 2017 in the Cochrane Database of Systematic Reviews in the Cochrane Library. The primary outcomes were no or mild pain within 14 days of starting treatment, withdrawals due to adverse events, and serious adverse events.

MAIN RESULTS

We included nine reviews with 152 included studies and 13,524 participants, but because some studies appeared in more than one review the number of unique studies and participants was smaller than this. Most participants had moderate or severe pain associated with a range of different types of cancer. Studies in the reviews typically compared one type of opioid or formulation with either a different formulation of the same opioid, or a different opioid; few included a placebo control. Typically the reviews titrated dose to effect, a balance between pain relief and adverse events. Various routes of administration of opioids were considered in the reviews; oral with most opioids, but transdermal administration with fentanyl, and buprenorphine. No review included studies of subcutaneous opioid administration. Pain outcomes reported were varied and inconsistent. The average size of included studies varied considerably between reviews: studies of older opioids, such as codeine, morphine, and methadone, had low average study sizes while those involving newer drugs tended to have larger study sizes.Six reviews reported a GRADE assessment (buprenorphine, codeine, hydromorphone, methadone, oxycodone, and tramadol), but not necessarily for all comparisons or outcomes. No comparative analyses were possible because there was no consistent placebo or active control. Cohort outcomes for opioids are therefore reported, as absolute numbers or percentages, or both.Reviews on buprenorphine, codeine with or without paracetamol, hydromorphone, methadone, tramadol with or without paracetamol, tapentadol, and oxycodone did not have information about the primary outcome of mild or no pain at 14 days, although that on oxycodone indicated that average pain scores were within that range. Two reviews, on oral morphine and transdermal fentanyl, reported that 96% of 850 participants achieved that goal.Adverse event withdrawal was reported by five reviews, at rates of between 6% and 19%. Participants with at least one adverse event were reported by three reviews, at rates of between 11% and 77%.Our GRADE assessment of evidence quality was very low for all outcomes, because many studies in the reviews were at high risk of bias from several sources, including small study size.

AUTHORS' CONCLUSIONS

The amount and quality of evidence around the use of opioids for treating cancer pain is disappointingly low, although the evidence we have indicates that around 19 out of 20 people with moderate or severe pain who are given opioids and can tolerate them should have that pain reduced to mild or no pain within 14 days. This accords with the clinical experience in treating many people with cancer pain, but overstates to some extent the effectiveness found for the WHO pain ladder. Most people will experience adverse events, and help may be needed to manage the more common undesirable adverse effects such as constipation and nausea. Perhaps between 1 in 10 and 2 in 10 people treated with opioids will find these adverse events intolerable, leading to a change in treatment.

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.

From acute to chronic pain: tapentadol in the progressive stages of this disease entity

OBJECTIVE

Chronic pain is now recognized as a neural disease, which results from a maladaptive functional and structural transformation process occurring over time. In its chronic phase, pain is not just a symptom but also a disease entity. Therefore, pain must be properly addressed, as many patients still report unsatisfactory pain control despite on-going treatment. The selection of the therapy - taking into account the pathophysiological mechanisms of pain - and the right timing can result in a successful analgesic outcome. This review will present the functional and structural modifications leading to chronification of pain, focusing on the role of tapentadol in this setting.

MATERIALS AND METHODS

For inclusion in this review, research studies were retrieved via a keyword-based query of multiple databases (MEDLINE, Embase, Cochrane). The search was last updated in November 2016; no limitations were applied.

RESULTS

Functional and structural abnormalities of the nervous system associated with pain chronification have been reported in several conditions, including osteoarthritis, chronic back pain, chronic pelvic pain and fibromyalgia. Correct identification and treatment of pain in recurrent/progressive stage is crucial to prevent chronification and related changes in neural structures. Among analgesic drugs, tapentadol, with its dual mechanism of action (opioid agonist and noradrenaline reuptake blocker), has recently resulted active in pain control at both central and spinal level.

CONCLUSIONS

Tapentadol represents a suitable candidate for patients at early progressive stage of pain who have developed neuroplasticity with modification of pain pathways. The availability of different doses of tapentadol may help clinicians to tailor treatment based on the individual need of each patient, with the aim to enhance therapeutic appropriateness in the treatment of musculoskeletal and neuropathic pain.

The Antinociceptive Effect of a Tapentadol-Ketorolac Combination in a Mouse Model of Trigeminal Pain is Mediated by Opioid Receptors and ATP-Sensitive K+ Channels

Preclinical Research The aim of the present study was to evaluate the antinoceptive interaction between the opioid analgesic, tapentadol, and the NSAID, ketorolac, in the mouse orofacial formalin test. Tapentadol or ketorolac were administered ip 15 min before orofacial formalin injection. The effect of the individual drugs was used to calculate their ED₅₀ values and different proportions (tapentadol-ketorolac in 1:1, 3:1, and 1:3) were assayed in the orofacial test using isobolographic analysis and interaction index to evaluate the interaction between the drugs. The combination showed antinociceptive synergistic and additive effects in the first and second phase of the orofacial formalin test. Naloxone and glibenclamide were used to evaluate the possible mechanisms of action and both partially reversed the antinociception produced by the tapentadol-ketorolac combination. These data suggest that the mixture of tapentadol and ketorolac produces additive or synergistic interactions via opioid receptors and ATP-sensitive K⁺ channels in the orofacial formalin-induced nociception model in mice. Drug Dev Res 78 : 63-70, 2017. © 2016 Wiley Periodicals, Inc.

Treating Painful Diabetic Peripheral Neuropathy: An Update

Painful diabetic peripheral neuropathy occurs in approximately 25% of patients with diabetes mellitus who are treated in the office setting and significantly affects quality of life. It typically causes burning pain, paresthesias, and numbness in a stocking-glove pattern that progresses proximally from the feet and hands. Clinicians should carefully consider the patient's goals and functional status and potential adverse effects of medication when choosing a treatment for painful diabetic peripheral neuropathy. Pregabalin and duloxetine are the only medications approved by the U.S. Food and Drug Administration for treating this disorder. Based on current practice guidelines, these medications, with gabapentin and amitriptyline, should be considered for the initial treatment. Second-line therapy includes opioid-like medications (tramadol and tapentadol), venlafaxine, desvenlafaxine, and topical agents (lidocaine patches and capsaicin cream). Isosorbide dinitrate spray and transcutaneous electrical nerve stimulation may provide relief in some patients and can be considered at any point during therapy. Opioids and selective serotonin reuptake inhibitors are optional third-line medications. Acupuncture, traditional Chinese medicine, alpha lipoic acid, acetyl-l-carnitine, primrose oil, and electromagnetic field application lack high-quality evidence to support their use.

Effectiveness of opioid analgesics in chronic noncancer pain

BACKGROUND

There is general agreement about the need to perform a screening test to assess the risk of opioid misuse prior to starting a long-term opioid treatment for chronic noncancer pain. The evidence supporting the effectiveness of opioid long-term treatment is weak, and no predictors of its usefulness have been assessed.

OBJECTIVE

The aim of this study was to assess the effect on pain and quality of life of chronic opioid treatment, and detect the possible predictors of its effectiveness.

METHODS

This observational, prospective study was conducted in 2 Italian Pain Relief Units on 77 patients affected by intractable chronic pain. Patients were submitted to psycho-logical tests, investigating the individual pain experience, risk of opioid misuse, mood states, quality of life, and personality characteristics prior to starting treatment and at 2,4, and 6-month follow-up.

RESULTS

Both maximum and habitual pain, as measured with VAS, underwent a statistically significant reduction at 2, 4, and 6-month follow-up. In multivariate analysis, lower scores in the Pain Medication Questionnaire (PMQ) were predictive of a major reduction in maximum VAS (P = 0.005). Both low PMQ and MMPI-cynicism scores were predictive of habitual VAS decrease (P = 0.012 and P = 0.028, respectively).

CONCLUSION

The results indicate that pain relief significantly improved over a 6-month period of opioid treatment, together with quality of life. The outcome was better in patients with a pretreatment low risk of opioid misuse, low scores in the Cynicism scale of MMPI-2, and no aberrant drug behaviors at follow-up. Therefore, a psychological screening and support is crucial for a good outcome of opioid therapy for chronic noncancer pain patients.

Effectiveness and tolerability of tapentadol sustained release in the Australian setting

OBJECTIVE

To assess the effectiveness and tolerability of tapentadol sustained release (SR) following its introduction to the Australian private market.

DESIGN

A retrospective audit of routine clinical practice with data collection beginning 2 months after the first tapentadol SR prescription.

SETTING

A multidisciplinary Australian pain clinic.

PATIENTS

Fifty patients who were prescribed tapentadol SR as part of routine clinical management at the pain clinic.

INTERVENTIONS

Trial of tapentadol SR with subsequent dose titration if the patient was satisfied with or tolerant of the medication.

MAIN OUTCOME MEASURES

Patient-reported pain outcome, side effects, medication adherence, and concomitant analgesic medications.

RESULTS

Sixty-eight percent of patients reported major reductions in pain. Seventy-two percent of patients tolerated and adhered to treatment and 76 percent reported no side effects. Pain outcome was independent of pain type and prior opioid exposure; however, patients taking tapentadol in combination were more likely to report a positive outcome (Pearson χ(2) = 9.867, n = 46, p = 0.0072).

CONCLUSIONS

Tapentadol was effective and generally well tolerated in the majority of patients for neuropathic, nociceptive and mixed pain types and this was regardless of prior opioid use.

[A simple method for quantification of tapentadol in dog plasma by liquid chromatography-tandem mass spectrometry and evaluation of the effects of conjugated metabolites on tapentadol]

Tapentadol is a novel drug of opioid pain reliever, which is extensively metabolized primarily through conjugation. Tapentadol glucuronide and tapentadol sulfate are major drug-related metabolites in circulation. The objectives of this study were to develop a simple and rapid method to determine tapentadol and evaluate the effects of conjugated metabolites on tapentadol quantification using liquid chromatography with tandem mass spectrometry in dog plasma. The analyte and tramadol（IS） were extracted from plasma by protein precipitation with methanol, and chromatographied on a XDB C(18)（50 mm × 4.6 mm, 1.8 μm） column using a mobile phase of methanol and 5 mmol·L(-1) ammonium acetate（0.01% ammonia）. Mass spectrometric detection was performed using the m/z 222 → 121 transition for tapentadol and the m/z 264 → 58 transition for the internal standard tramadol, the m/z 398 → m/z 121 transition for glucuronides conjugate and the m/z 302 → m/z 222 transition for sulfate conjugate. Conjugated metabolites could undergo in-source conversion to generate an ion that interfered the quantification of tapentadol. Chromatographic separation was achieved to elimination interferences due to in-source conversion of the conjugated metabolites. The standard curves were demonstrated to be linear in the range of 0.100 to 20.0 ng·m L(-1) for tapentadol. The intra- and inter-day precisions were within 5.1%, and accuracy ranged from -3.2% to 0. This method was successfully applied to the pharmacokinetics of tapentadol hydrochloride sustained release tablets in Beagle dogs.

Tapentadol PR for Pain Syndromes in Real Life Patients with Hematological Malignancy

BACKGROUND

More than 50% of oncohematological patients suffer from pain syndrome, mostly originating from the bone, which often include nociceptive and neuropathic complaints. Tapentadol, a recently available treatment option for cancer pain, exerts a dual analgesic mechanisms (opioid and noradrenergic), allowing for a high clinical efficacy as well as for a reduction in adverse events compared to traditional opioids.

AIM

To explore the safety and efficacy of tapentadol as a suitable agent for the pain management in the setting of oncohematology.

METHODS

Our observational study included 36 patients with basal pain intensity (NRS) ranging from 5 to 10. Tapentadol prolonged release (PR) was given at the initial dose of 50 mg BID and careful titrated according to the achieved pain control.

RESULTS

Tapentadol PR was given at the dosages ranging from 200 and 260 mg/day after a careful titration, allowed for a clinically (-7 points NRS) remarkable reduction of pain intensity without any significant side effects.

CONCLUSION

In oncohematological patients on pain, tapentadol PR was effective and well tolerated, so representing a suitable treatment option in this difficult setting.

[Clinical Utility of Tapentadol]

Tapentadol(TP)is a new strong opioid analgesicthat has both m-opioid receptor(MOR)effects and norepinephrine reuptake inhibitor(NRI)effects. In comparison with the existing strong opioid analgesics, the mechanism of action suitable for palliation of neuropathic pain is expected to be better for TP. The analgesic effect and side effects of this drug were tested in 10 cases of exacerbation of neuropathic pain at our hospital, and the sedative response rate was 70%. The main side effects were somnolence 44.4%, nausea 33.4%, and constipation 11.1%. The side effects on the digestive system were considered minimal. Although it is speculated that opioids would be useful as an outpatient treatment, few case reports are available regarding their use for cancer pain; therefore, further investigation is necessary. Generally, numerous social issues that would increase the likelihood of drug adherence failure must be addressed in order to expand the use of strong opioid analgesics such as TP. Both the patients and the healthcare worker should be involved when addressing these issues in Japan, and the measures should include instructions for appropriate reporting and for using such drugs.

[Sustained-release Opioids: Morphine, Oxycodone and Tapentadol]

Opioid analgesics are widely used for managing moderate to severe pain. In cancer pain management sustained-release opioids are used for continuous pain as well as immediate-release opioids for breakthrough pain. Sustained-release drugs have the advantage of stabilizing the blood concentration, although it takes some time to exert their effects. In Japan, the currently available oral sustained-release opioids include six types of sustained-release morphine (three are once-a-day formulations, while the rest are twice-a-day), one type of oxycodone and tapentadol. In this article, we will discuss the pharmacokinetic properties of MS Contin, Morphes, Kadian, P guard and Pacif as sustained-release morphine, Oxycontin as sustained-release oxycodone and Tapenta as sustained-release tapentadol.