Opioid switching from and to tapentadol extended release in cancer patients: conversion ratio with other opioids

Dual opioid therapy in a cancer patient with myasthenia gravis who developed respiratory depression from codeine

This case report describes a patient who was referred to our unit after an emergency room admission for respiratory depression induced by codeine, and was successfully managed with tapentadol.

Therapeutic alliance impact on analgesic outcomes in a real-world clinical setting: An observational study

A good therapeutic alliance is relevant for healthcare providers exposed to patients' suffering, especially since patients and physicians may understand the painful experience differently. Our aim was to explore the impact of therapeutic alliance on analgesic outcomes in a real-world interdisciplinary pain unit (PU). A cross-sectional observational study was conducted on outpatients (n = 69) using opioids on a long-term basis for the treatment of chronic non-cancer pain, where clinical pharmacologists and pharmacists advised patients about their opioid treatment. Responses to the patient-doctor relationship questionnaire (PDRQ), sociodemographic and clinical information (pain level, quality of life and hospital use) were collected, whereas pharmacology data (analgesic prescription, adverse events, and compliance) were obtained from electronic health records. Patients were predominantly middle-aged (75 % women, 72 % retired), experiencing moderate pain (VAS 40-70 mm) on average, and under a high morphine equianalgesic dosage (95 ± 88 mg per day, mainly tapentadol or fentanyl). Patients with better PDRQ outcomes, and therefore better therapeutic alliance, showed lower pain intensity than patients with worse PDRQ outcomes (pain intensity: high scores 60 ± 47 mm and medium scores 60 ± 45 mm vs. low scores 80 ± 75 mm, p < 0.01). Along with this, pain intensity was lower when patients affirmed that, thanks to the health-care providers, they "gained new insight", "felt better", or "felt content with their doctor's treatment". What´s more, patients who affirmed "I benefit from the treatment" experienced increased pain relief (benefit 40 ± 30 vs. non-benefit 19 ± 26 mm, p = 0.010) and improved quality of life (benefit 33 ± 25 vs. non-benefit 18 ± 16 mm, p = 0.031). However, there was a percentage of patients who did not fully understand the provided information, which is something to be taken into account to improve in clinical routine. Therapeutic alliance supported by pharmacist experts on pain management can be an effective strategy to improve analgesic outcomes. Further efforts are needed to improve communication strategies for pain management. Future directions of research should include the analysis of the role of the pharmacist in poly-professional consultations as related to the advice of patients about their medication, and the mutual trust with the patients.

Sex Differences in Oxycodone/Naloxone vs. Tapentadol in Chronic Non-Cancer Pain: An Observational Real-World Study

Despite the large body of research on sex differences in pain, there is a lack of translation to real-world pain management. Our aim was to analyse the sex differences in the analgesic response to oxycodone/naloxone (OXN) and tapentadol (TAP), in comparison with other opioids (OPO) commonly prescribed for chronic non-cancer pain (CNCP). An observational and cross-sectional study was conducted on ambulatory CNCP patients (n = 571). Sociodemographic, clinical (pain intensity, relief, and quality of life), safety (adverse events (AEs), adverse drug reactions), hospital frequentations and pharmacological (morphine equivalent daily dose (MEDD)) variables were collected. Multiple linear regressions were carried out to assess the association between sex and outcomes. Sex differences were observed, with lower female tolerability and higher hospital frequentation, especially in the OXN group (OR AEs report = 2.8 [1.8−4.4], p < 0.001). Here, females showed higher hospital use (23% hospital admission, 30% prescription change, p < 0.05), requiring a higher MEDD (127 ± 103 mg/day, p < 0.05), compared to OXN men. Regardless of the opioid group, CNCP women were significantly older than men (three years), with significantly higher benzodiazepine use (OR = 1.6 [1.1−2.3]), more constipation (OR = 1.34 [0.93−1.90]) and headache (OR = 1.45 [0.99−2.13]) AEs, than men who were more likely to refer sexual dysfunction (OR = 2.77 [1.53−5.01]), and loss of libido (OR = 1.93 [1.22−3.04]). Sex-differences were found related to poorer female drug tolerability and higher hospital resources, even worst in OXN female users. Other differences related to older female ages and benzodiazepine prescription, need to be further analysed from a gender perspective.

Oxycodone/naloxone versus tapentadol in real-world chronic non-cancer pain management: an observational and pharmacogenetic study

Tapentadol (TAP) and oxycodone/naloxone (OXN) potentially offer an improved opioid tolerability. However, real-world studies in chronic non-cancer pain (CNCP) remain scarce. Our aim was to compare effectiveness and security in daily pain practice, together with the influence of pharmacogenetic markers. An observational study was developed with ambulatory test cases under TAP (n = 194) or OXN (n = 175) prescription with controls (prescribed with other opioids (control), n = 216) CNCP patients. Pain intensity and relief, quality of life, morphine equivalent daily doses (MEDD), concomitant analgesic drugs, adverse events (AEs), hospital frequentation and genetic variants of OPRM1 (rs1799971, A118G) and COMT (rs4680, G472A) genes, were analysed. Test CNCP cases evidenced a significantly higher pain relief predictable due to pain intensity and quality of life (R² = 0.3), in front of controls. Here, OXN achieved the greatest pain relief under a 28% higher MEDD, 8–13% higher use of pregabalin and duloxetine, and 23% more prescription change due to pain, compared to TAP. Whilst, TAP yielded a better tolerability due the lower number of 4 [0–6] AEs/patient, in front of OXN. Furthermore, OXN COMT-AA homozygotes evidenced higher rates of erythema and vomiting, especially in females. CNCP real-world patients achieved higher pain relief than other traditional opioids with a better tolerability for TAP. Further research is necessary to clarify the potential influence of COMT and sex on OXN side-effects.

Analysis of Various Factors Associated With Opioid Dose Escalation in Patients With Cancer Pain

Introduction

Pain is one of the most important symptoms in terms of prevalence and a major cause of distress in patients with cancer. Therefore, this study aimed to analyze and identify the factors that influence the worsening of pain in patients with cancer necessitating opioid dose escalation.

Methods

The study was conducted in a single center. This study is a retrospective cohort study of 390 adult cancer patients. The primary endpoint was dose escalation for strong opioids. Adjusted odds ratios (aORs) and their 95% confidence intervals (CIs) were calculated using a logistic regression model to evaluate the relationships of factors with opioid dose escalation for cancer pain.

Results

Polypharmacy was associated with opioid dose escalation (aOR = 2.54, 95% CI = 1.486-4.370, p = 0.001). Conversely, alcohol consumption was associated with a reduced need for dose escalation (aOR = 0.60, 95% CI = 0.376-0.985, p = 0.043).

Conclusion

The results of this study indicate that moderate alcohol consumption does not reduce the efficacy of opioids in patients with cancer pain. Meanwhile, patients receiving polypharmacy may be able to more rapidly alleviate their pain via early opioid dose modification.

Rates and Costs of Dispensing Naloxone to Patients at High Risk for Opioid Overdose in the United States, 2014-2018

INTRODUCTION

Clinical practice guidelines recommend co-prescribing naloxone to patients at high risk of opioid overdose, but few such patients receive naloxone. High costs of naloxone may contribute to limited dispensing.

OBJECTIVE

The aim of this study was to evaluate rates and costs of dispensing naloxone to patients receiving opioid prescriptions and at high risk for opioid overdose.

METHODS

Using claims data from a large US commercial insurance company, we conducted a retrospective cohort study of new opioid initiators between January 2014 and December 2018. We identified patients at high risk for overdose defined as a diagnosis of opioid use disorder, prior overdose, an opioid prescription of ≥ 50 mg morphine equivalents/day for ≥ 90 days, and/or concurrent benzodiazepine prescriptions.

RESULTS

Among 5,292,098 new opioid initiators, 616,444 (12%) met criteria for high risk of overdose during follow-up, and, of those, 3096 (0.5%) were dispensed naloxone. The average copayment was US$24.83 for naloxone (standard deviation [SD] 67.66) versus US$9.74 for the index opioid (SD 19.75). The average deductible was US$6.18 for naloxone (SD 27.32) versus US$3.74 for the index opioid (SD 25.56), with 94% and 88% having deductibles of US$0 for their naloxone and opioid prescriptions, respectively. The average out-of-pocket cost was US$31.01 for naloxone (SD 73.64) versus US$13.48 for the index opioid (SD 34.95).

CONCLUSIONS

Rates of dispensing naloxone to high risk patients were extremely low, and prescription costs varied greatly. Since improving naloxone's affordability may increase access, whether naloxone's high cost is associated with low dispensing rates should be evaluated.

Tapentadol Versus Tramadol: A Narrative and Comparative Review of Their Pharmacological, Efficacy and Safety Profiles in Adult Patients

We conducted a narrative review of the literature to compare the pharmacological, efficacy and safety profiles of tapentadol and tramadol, and to assess the clinical interest of tapentadol in adult patients. Tapentadol and tramadol share a mixed mechanism of action, including both mu-agonist and monoaminergic properties. Tapentadol is approximately two to three times more potent than tramadol and two to three times less potent than morphine. It has no identified analgesically active metabolite and is not significantly metabolised by cytochrome P450 enzymes, thus overcoming some limitations of tramadol, including the potential for pharmacokinetic drug-drug interactions and interindividual variability due to genetic polymorphisms of cytochrome P450 enzymes. The toxicity profiles of tramadol and tapentadol are similar; however tapentadol is likely to result in less exposure to serotoninergic adverse effects (nausea, vomiting, hypoglycaemia) but cause more opioid adverse effects (constipation, respiratory depression, abuse) than tramadol. The safety of tapentadol in real-world conditions remains poorly documented, particularly in at-risk patient subgroups and also in the ability to assess the risk associated with its residual serotonergic activity (serotonin syndrome, seizures). Because of an earlier market introduction, more real-world safety data are available for tramadol, including data from at-risk patient subgroups. The level of evidence on the efficacy of both tramadol and tapentadol for the treatment of chronic pain is globally low. The trials published to date show overall that tapentadol does not provide a clinically significant analgesic improvement compared to existing treatments, for which the safety profile is much better known. In conclusion, tapentadol is not a first-line opioid but represents an additional analgesic in the therapeutic choices, which some patients may benefit from after careful examination of their clinical situation, co-morbidities and co-medications.

Indian Society for Study of Pain, Cancer Pain Special Interest Group Guidelines on Pharmacological Management of Cancer Pain (Part I)

The Indian Society for Study of Pain (ISSP), Cancer Pain Special Interest Group guidelines on pharmacological management of cancer pain in adults provides a structured, step-wise approach which will help to improve the management of cancer pain and to provide the patients with a minimally acceptable quality of life. The guidelines have been developed based on the available literature and evidence, to suit the needs, patient population, and situations in India. A questionnaire based on the key elements of each sub drafts addressing certain inconclusive areas where evidence was lacking, was made available on the ISSP website, and circulated by E-mail to all the ISSP and Indian Association of Palliative Care (IAPC) members. We recommend that analgesics for cancer pain management should follow the World Health Organization three-step analgesic ladder appropriate for the severity of pain. The use of paracetamol and nonsteroidal anti-inflammatory drugs alone or in combination with opioids for mild-to-moderate pain should be used. For mild-to-moderate pain, weak opioids such as tramadol, tapentadol, and codeine can be given in combination with nonopioid analgesics. We recommend morphine as the opioid of first choice for moderate-to-severe cancer pain.

Tapentadol in the management of cancer pain: current evidence and future perspectives

Thanks to the progress in early diagnosis and treatment of cancer, the life expectancy of cancer patients has now increased. Patients are, therefore, more likely to experience their individual cancer pain as a chronic pain. As a consequence, long-term treatment of cancer-related pain and oncological therapy-related pain are a major need for all patients and a challenge to all healthcare professionals. Tapentadol is a centrally acting analgesic drug characterized by two synergistic mechanisms of action, since it acts at the µ-opioid receptor (MOR) and inhibits noradrenalin re-uptake (NRI). Therefore, tapentadol has been considered the first of a new class of drugs, MOR-NRI. Tapentadol has been tested in different populations of cancer patients (opioid-naive and -pretreated), such as those with pain of mixed etiology, patients with pain from hematological malignancies and patients experiencing pain conditions due to anticancer treatment. According to available evidence, tapentadol prolonged release was well tolerated and effective in cancer pain patients. In randomized, double-blind and active-controlled trials it proved non-inferior to standard opioids like morphine or oxycodone in the management of moderate-to-severe cancer pain, both in opioid-naive and in opioid-pretreated patients. The good analgesic efficacy may be partly due to the action of tapentadol on neuropathic pain components. Together with the low rate of gastrointestinal adverse effects and the overall favorable safety profile, tapentadol can be considered a good option in cancer pain patients, who can suffer frequently from nausea, vomiting, constipation or other events that further reduce their quality of life.

Multiple effectiveness aspects of tapentadol for moderate-severe cancer-pain treatment: an observational prospective study

Background

Previous studies have shown the efficacy of tapentadol (TP) for chronic cancer pain. We evaluated multiple effectiveness aspects of TP prolonged release on moderate–severe cancer-related pain, neuropathic pain (NeP), patient satisfaction, and quality of life.

Methods

An observational prospective study was conducted on 80 cancer patients. Opioid-naïve patients received a starting dose of prolonged-release TP 50 mg twice daily, and opioid-experienced patients were switched to TP, not to exceed 500 mg/day. Treatment response was evaluated at 3, 6, 30–40, and 60–70 days through response rate, numeric rating-scale scoring, survival analysis (time to event for response), pain-intensity difference, TP escalation-index percentage, and effects on NeP. The drug-sparing effect on concomitant therapies was evaluated.

Results

Seventy of 80 patients (88%) were responders to treatment (95% CI 78%–94%). Compared to T₀, pain-intensity reductions were statistically significant for all intervals (P<0.01), with better results at T₃/T₄. NeP was significantly reduced at T₄ (P<0.01). The probability of response was low at the initial stages and increased during the study. Pain-intensity differences decreased during the study, though without significance. Two patients (2.5%) left the study for TP-induced side effects. A significant improvement in quality of life was observed after 30–40 days (P<0.01). The majority of patients were “satisfied”, “very satisfied”, or “extremely satisfied” (T₃–T₄).

Conclusion

TP was effective in terms of drug-sparing effect, response rate, TP escalation-index percentage, and NeP management. By comparing data from the survival analysis with the response rate and time to response (numeric rating scale from T₀ to T₄), we found that although TP induced a quick response, a longer period of therapy and higher doses were needed to improve the positive result.

[Opioid switch and change of route of administration in cancer patients treated by morphine]

This paper reviewed the 2002 guidelines established by the National Federation of Cancer Centres. A group of experts nominated by the 3 French Societies involved in the treatment of cancer pain (AFSOS, SFAP, SFETD), established new guidelines ratios for morphine switching and/or changing of route of administration, in patients for whom either pain was not adequatly managed or adverse effects were unbearable. After a rapid reminder of the pharmacokinetics and metabolism properties of morphine, experts explained why the theory of opioid rotation (oxycodone, hydromorphone, fentanyl, methadone, tapentadol) using fixed equianalgesic ratios is not any more appropriate for a secure clinical practice. In the light of recent publications enhancing our knowledge on the efficacy of new drug switching ratios and for changing the route of administration of morphine, the group of experts recommended to use reconsidered switching ratios favoring security upon efficacy, to minimize overdosing and adverse effects. Consequently, after the new conversion ratio (using slow release opioids) was applied, a second titration should be done by means of normal release rescue formulations for breakthrough pain episodes. A smartphone App. OpioConvert^® will be available for rapid and secure dose conversions.

Opioid Rotation in Cancer Pain Treatment

BACKGROUND

Rotating several different WHO level III opioid drugs is a therapeutic option for patients with chronic cancer-related pain who suffer from inadequate analgesia and/or intolerable side effects. The evidence favoring opioid rotation is controversial, and the current guidelines in Germany and other countries contain only weak recommendations for it.

METHODS

This review is based on pertinent publications retrieved by a systematic review of the literature on opioid rotation for adult patients with chronic cancerrelated pain who are regularly taking WHO level III opioids by the oral or trans - dermal route.

RESULTS

9 individual studies involving a total of 725 patients were included in the analysis, and 3 previous systematic reviews of studies involving a total of 2296 patients were also analyzed. Morphine, oxycodone, fentanyl, hydromorphone, and buprenorphine were used as first-line opioid drugs, and hydromorphone, bupre - norphine, tapentadol, fentanyl, morphine, oxymorphone, and methadone were used as second-line opioid drugs. In all of the studies, pain control was achieved for 14 days after each rotation. In most of them, the dose of the new drug introduced in each rotation needed to be increased above the dose initially calculated from a rotation ratio, with the exception of rotations to methadone. The frequency of side effects was only rarely lessened, but patients largely considered the result of opioid rotation to be positive. No particular opioid drug was found to be best.

CONCLUSION

Opioid rotation can improve analgesia and patient satisfaction. The success of opioid rotation appears to depend on the magnitude of the initial dose, among other factors. Tables of equianalgesic doses should be considered no more than a rough guide for determining the dose of the new drug. Rotations to methadone should be carried out under clinical supervision in experienced hands.

Efficacy and Safety of Oral and Transdermal Opioid Analgesics for Musculoskeletal Pain in Older Adults: A Systematic Review of Randomized, Placebo-Controlled Trials

This systematic review with meta-analysis was performed to evaluate the efficacy and safety of using opioid analgesics in older adults with musculoskeletal pain. We searched Cochrane Library, MEDLINE, EMBASE, Web of Science, AMED, CINAHL, and LILACS for randomized controlled trials with mean population age of 60 years or older, comparing the efficacy and safety of opioid analgesics with placebo for musculoskeletal pain conditions. Reviewers extracted data, assessed risk of bias, and evaluated the quality of evidence using the Grading of Recommendations Assessment, Development and Evaluation approach. Random effects models were used to calculate standardized mean differences (when different scales were used across trials), mean differences and odds ratios with respective 95% confidence intervals (CIs). Meta-regressions were carried out to assess the influence of opioid analgesic daily dose and treatment duration on our main outcomes. We included 23 randomized placebo-controlled trials in the meta-analysis. Opioid analgesics had a small effect on decreasing pain intensity (standardized mean difference = -.27; 95% CI = -.33 to -.20) and improving function (standardized mean difference = -.27, 95% CI = -.36 to -.18), which was not associated with daily dose or treatment duration. The odds of adverse events were 3 times higher (odds ratio = 2.94; 95% CI = 2.33-3.72) and the odds of treatment discontinuation due to adverse events 4 times higher (odds ratio = 4.04; 95% CI = 3.10-5.25) in patients treated with opioid analgesics. The results show that in older adults suffering from musculoskeletal pain, using opioid analgesics had only a small effect on pain and function at the cost of a higher odds of adverse events and treatment discontinuation. For this specific population, the opioid-related risks may outweigh the benefits.

PERSPECTIVE

The systematic review shows that, in older adults suffering from musculoskeletal conditions, opioid analgesics have only a small effect on pain and disability. Conversely, this population is at higher risk of adverse events. The results may reflect age-related physiological changes in pain processing, pharmacokinetics, and pharmacodynamics.

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.

Risk of neonatal drug withdrawal after intrauterine co-exposure to opioids and psychotropic medications: cohort study

Objectives To assess the impact of in utero co-exposure to psychotropic medications and opioids on the incidence and severity of neonatal drug withdrawal.Design Observational cohort study.Setting Nationwide sample of pregnancies in publicly insured women in the US, nested in the Medicaid Analytic eXtract (2000-10).Participants 201 275 pregnant women with public insurance who were exposed to opioids around the time of delivery and their liveborn infants.Interventions In utero exposure to psychotropic medications, in particular antidepressants, atypical antipsychotics, benzodiazepines, gabapentin, and non-benzodiazepine hypnotics (Z drugs), with prescriptions filled within the same time window as prescriptions for opioids.Main outcome measure Diagnosis of neonatal drug withdrawal in infants exposed in utero to opioids and psychotropic medications compared with opioids alone.Results The absolute risk for neonatal drug withdrawal ranged from 1.0% in infants exposed in utero to prescription opioids alone to 11.4% for those exposed to opioids co-prescribed with gabapentin. Among neonates exposed in utero to prescription opioids, the relative risk adjusted for propensity score was 1.34 (95% confidence interval 1.22 to 1.47) with concomitant exposure to antidepressants, 1.49 (1.35 to 1.63) with benzodiazepines, 1.61 (1.26 to 2.06) with gabapentin, 1.20 (0.95 to 1.51) with antipsychotics, and 1.01 (0.88 to 1.15) with Z drugs. In utero exposure to two or more psychotropic medications along with opioids was associated with a twofold increased risk of withdrawal (2.05, 1.77 to 2.37). The severity of the withdrawal seemed increased in neonates exposed to both opioids and psychotropic medications compared with opioids alone.Conclusions During pregnancy, the use of psychotropic medications in addition to prescription opioids is common, despite a lack of safety data. The current findings suggest that these drugs could further increase the risk and severity of neonatal drug withdrawal.

A synthesis of oral morphine equivalents (OME) for opioid utilisation studies

PURPOSE

Oral Morphine Equivalent (OME) doses are increasingly being used as a metric to represent opioid use. Driven by a growing need from pharmacoepidemiological studies, the objective of this study was to develop a comprehensive OME conversion table that can be used by researchers to calculate OMEs in a consistent and systematic way.

METHODS

Clinical guidelines and literature sources were collated and synthesised to develop recommended OME conversion factors that can be used for research studies on opioids (including different formulations and routes of administration) currently available internationally including Australia, the United Kingdom, Europe, the United States and Canada.

RESULTS

No single resource includes all opioids that are currently available. Although there was some variation in conversion factors reported in different sources, overall, suggested conversion factors were mostly consistent across national and international sources.

CONCLUSIONS

The use of the OME metric appears optimal for opioid utilisation studies as it facilities both interpretation and comparison between opioids and geographical locations. We have presented a synthesis of published OME conversion factors that can be applied to pharmacoepidemiological studies of opioids, in addition to a discussion of the considerations and caveats in using OME as a metric for opioid use. Copyright © 2015 John Wiley & Sons, Ltd.

Impact of Perioperative Epidural Placement on Postdischarge Opioid Use in Patients Undergoing Abdominal Surgery

BACKGROUND

Opioids play a crucial role in providing analgesia throughout the perioperative period; however, patients may become persistent users of these medications months after surgery. Epidurals have been posited to prevent the development of persistent pain, but there are little data on the effect of epidurals on persistent opioid use.

METHODS

This study was conducted using a claims database of a large, nationwide commercial health insurer. Opioid-naive patients who underwent open abdominal surgery from January 2004 to December 2013 were included in the study. Propensity scores for epidural placement were calculated accounting for demographic characteristics, resource utilization, and comorbid conditions (including medical, psychiatric, and pain conditions). Time-to-event analysis was used with the primary outcome defined as 30 days without filling an opioid prescription after discharge. In addition, total morphine equivalents dispensed within 90 days of discharge were also calculated for each patient.

RESULTS

A total of 6,432 patients were included in the final propensity score-matched cohort. The Cox proportional hazards ratio was 0.96 (95% CI, 0.91 to 1.01; P = 0.0910) for the relation between epidural placement and time till a 30-day gap without filling an opioid prescription. There was no difference in the total morphine equivalents dispensed within 90 days of discharge between the groups (P = 0.7670).

CONCLUSIONS

Epidural placement was not protective against persistent opioid use in a large cohort of opioid-naive patients undergoing abdominal surgery. This finding does not detract from the other potential benefits of epidural placement. More research is needed to understand the mechanism of persistent opioid use after surgery and its prevention.

Endogenous opiates and behavior: 2014

This paper is the thirty-seventh consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2014 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior (endogenous opioids and receptors), and the roles of these opioid peptides and receptors in pain and analgesia (pain and analgesia); stress and social status (human studies); tolerance and dependence (opioid mediation of other analgesic responses); learning and memory (stress and social status); eating and drinking (stress-induced analgesia); alcohol and drugs of abuse (emotional responses in opioid-mediated behaviors); sexual activity and hormones, pregnancy, development and endocrinology (opioid involvement in stress response regulation); mental illness and mood (tolerance and dependence); seizures and neurologic disorders (learning and memory); electrical-related activity and neurophysiology (opiates and conditioned place preferences (CPP)); general activity and locomotion (eating and drinking); gastrointestinal, renal and hepatic functions (alcohol and drugs of abuse); cardiovascular responses (opiates and ethanol); respiration and thermoregulation (opiates and THC); and immunological responses (opiates and stimulants). This paper is the thirty-seventh consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2014 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior (endogenous opioids and receptors), and the roles of these opioid peptides and receptors in pain and analgesia (pain and analgesia); stress and social status (human studies); tolerance and dependence (opioid mediation of other analgesic responses); learning and memory (stress and social status); eating and drinking (stress-induced analgesia); alcohol and drugs of abuse (emotional responses in opioid-mediated behaviors); sexual activity and hormones, pregnancy, development and endocrinology (opioid involvement in stress response regulation); mental illness and mood (tolerance and dependence); seizures and neurologic disorders (learning and memory); electrical-related activity and neurophysiology (opiates and conditioned place preferences (CPP)); general activity and locomotion (eating and drinking); gastrointestinal, renal and hepatic functions (alcohol and drugs of abuse); cardiovascular responses (opiates and ethanol); respiration and thermoregulation (opiates and THC); and immunological responses (opiates and stimulants).

Worldwide research productivity on tramadol: a bibliometric analysis

BACKGROUND

Pain management and safe use of analgesics is an important medical issue. Tramadol is an old analgesic with controversial properties. Evaluation of worldwide scientific output on tramadol has not been explored. Therefore, the main objective of this study was to give a bibliometric overview of global research productivity on tramadol.

METHODS

SciVerse Scopus was used to retrieve and quantitatively and qualitatively analyze worldwide publications on tramadol.

RESULTS

A total of 2059 original and review research articles on tramadol were retrieved from Scopus. Forty-six documents (2.23 %) were published in Anesthesia and Analgesia Journal whereas 30 (1.46 %) were published in Arzneimittel Forschung Drug Research Journal. Retrieved tramadol documents were published from 71 countries and appeared in 160 peer reviewed journals. Although the United States of America (259; 12.86 %) had the largest contribution to tramadol publications; the contribution by other countries like Turkey (232; 11.27) India (189; 8.09 %) and Germany (176; 8.56 % was not far away from that of USA. The most productive institution was Grunenthal, Germany (47; 2.28 %) followed by Tehran University of Medical Sciences, Iran (29; 1.41 %), and, Ortho-McNeil Pharmaceutical Incorporated, USA (25; 1.21 %). Of the 2059 documents, there were 370 documents about dependence. The leading institution in documents pertaining to tramadol dependence was Grunenthal GmbH (18; 4.86 %) followed by Ortho-McNeil Pharmaceutical Incorporated (17; 4.59 %).

CONCLUSIONS

The current study showed that there is an obvious interest in tramadol research. More efforts are needed to clarify the abuse potential and safety profile of tramadol to help in determining the legal status of tramadol. Collaboration among pharmaceutical industry, clinical researchers and academic institutions can improve research quantity and quality on tramadol.

Tapentadol prolonged release for patients with multiple myeloma suffering from moderate-to-severe cancer pain due to bone disease

Context

Myeloma bone disease (MBD) is a devastating complication of multiple myeloma that leads to severe pain.

Objectives

The aim of this study was to evaluate the efficacy and tolerability of tapentadol prolonged release (PR) in the management of patients with MBD suffering from moderate-to-severe cancer pain.

Methods

A 12-week prospective study was carried out in 25 opioid-naïve MBD patients. Patients initially received twice-daily doses of tapentadol PR 50 mg. Doses were then managed to maintain adequate relief or dose-limiting toxicity. The following parameters were recorded at weekly intervals for 4 weeks, and then at weeks 8 and 12: pain, opioid-related adverse effects, use of other analgesics, DN4 (Douleur Neuropathique 4) score. Quality of life (SF-36 [36-item short-form health survey]) was measured at baseline and at final evaluation.

Results

Of 25 patients, 22 completed the study. Pain intensity significantly decreased from baseline to all the week intervals (P<0.01). Quality of life significantly improved with respect to all SF-36 subscale parameters (P<0.01), and so did both the physical and mental status (P<0.01). Tapentadol PR significantly reduced DN4 mean value (P<0.01) and the number of patients with neuropathic component (DN4 ≥4) (P<0.01). After 8 weeks of treatment, all patients were negative for the DN4 score. Tapentadol PR was well tolerated, and the use of other analgesics was reduced during the study period.

Conclusion

Tapentadol PR started in doses of 100 mg/day was effective and well tolerated in opioid-naïve MBD patients with moderate-to-severe pain. Tapentadol PR can be considered a first-choice opioid in cancer patients suffering from mixed pain with a neuropathic component.

Ready conversion of patients with well-controlled, moderate to severe, chronic malignant tumor-related pain on other opioids to tapentadol extended release

Background and Objectives

The effectiveness and tolerability of tapentadol extended release (ER), a centrally acting analgesic with μ-opioid receptor agonist and norepinephrine (noradrenaline) reuptake inhibitor activities, have been demonstrated in patients with chronic pain, including those switching directly from prior opioid therapy. The objective of the current study was to evaluate the effectiveness and safety of conversion to oral tapentadol ER (50–250 mg twice daily) from previous around-the-clock strong opioid therapy in patients with moderate to severe, chronic malignant tumor–related cancer pain that was well-controlled.

Methods

This randomized, open-label, phase III study, which was conducted in Japan, included a 1- to 2-week screening period (on previous opioid) and an 8-week, open-label treatment period. Eligible patients, who were taking a strong opioid analgesic and had a mean pain intensity score <4 during the 3 days prior to randomization (adequate pain control on previous strong opioid), were randomized (1:1) to receive twice-daily treatment with tapentadol ER (100–500 mg/day) or morphine sustained release (SR; 20–140 mg/day; reference for assay sensitivity). Initial doses were estimated based on the conversion ratio of tapentadol ER:oxycodone:morphine:fentanyl = 10:2:3:0.03. The primary effectiveness endpoint was the proportion of patients who maintained pain control [change from baseline in mean pain intensity (11-point numerical rating scale) less than +1.5 for 3 consecutive days and no more than two doses of rescue medication per day for 3 consecutive days) during the first week of open-label treatment.

Results

In the tapentadol ER group (n = 50), 84.0 % of patients (42/50; 95 % CI, 70.89–92.83) maintained pain control during Week 1. On the Patient Global Impression of Change, 2.1 % (1/48), 2.1 % (1/48), 22.9 % (11/48), and 50.0 % (24/48) of patients in the tapentadol ER group reported that their overall condition was “very much improved,” “much improved,” “minimally improved,” and “not changed,” respectively, at Week 1 compared with 0 %, 10.7 % (3/28), 28.6 % (8/28), and 53.6 % (15/28) reporting these ratings at Week 8. The sensitivity of effectiveness analyses was validated based on results using morphine SR; 98.0 % (49/50; 95 % CI, 89.35–99.95) of patients in the morphine SR group maintained pain control after 1 week of treatment. The overall safety profile was similar to that demonstrated in previous studies; tapentadol ER was associated with a lower incidence of gastrointestinal treatment-emergent adverse events than morphine SR [38.0 % (19/50) vs. 54.0 % (27/50)], including constipation [12.0 % (6/50) vs. 20.0 % (10/50)] and vomiting [6.0 % (3/50) vs. 26.0 % (13/50)].

Conclusions

Overall, results indicate that conversion from previous strong opioids to tapentadol ER (50–250 mg twice daily) was successful and resulted in safe and effective pain control with improved gastrointestinal tolerability versus morphine SR in patients with moderate to severe cancer-related pain that was well-controlled on their previous opioid.

Electronic supplementary material

The online version of this article (doi:10.1007/s40261-014-0204-3) contains supplementary material, which is available to authorized users.

Pain management of the cancer patient

INTRODUCTION

Cancer pain is one of the most important symptoms of malignant disease, which has a major impact on the quality of life of cancer patients. Therefore, it needs to be treated appropriately after a careful assessment of the types and causes of pain.

AREAS COVERED

The mainstay of cancer pain management is systemic pharmacotherapy. This is, in principle, still based on the WHO guidelines initially published in 1986. Although these have been validated, they are not evidence-based. The principles are a stepladder approach using non-opioids, weak and then strong opioids. In addition, adjuvants can be added at any step to address specific situations such as bone or neuropathic pain. Patients, even if they are on long-acting opioids, need to be provided with immediate-release opioids for breakthrough pain. In case of inefficacy or severe adverse effects of one opioid, rotation to another opioid is recommended.

EXPERT OPINION

There is a major need for more and better randomized controlled trials in the setting of cancer pain as the lack of evidence is hampering the improvement of current treatment guidelines.

The use of opioids for treatment of cancer pain

INTRODUCTION

Pain is commonly experienced by patients with cancer, particularly those with advanced disease. Alleviating pain is an important goal of cancer treatment. Opioids are the cornerstone of the analgesic treatment.

AREAS COVERED

Pharmacology, characteristics, and use of opioids in clinical practice are presented.

EXPERT OPINION

Although the use of opioids is largely accepted as a fundamental step for controlling cancer pain, existing data supporting this statement are poor. All opioids provide analgesia and are effective in controlling cancer pain. New drugs have been developed and experience is accumulating among clinicians. Despite these drugs having different pharmacokinetic and chemical properties, there is no proof that one opioid is better than another one. Thus, the optimum benefit depends on the experience of the users. Clinicians should weight evidence, clinical experience, patient preferences, and treatment costs when choosing the optimal treatment for an individual patient with cancer pain. New opioids with specific receptor activities are under investigation.

Tapentadol at medium to high doses in patients previously receiving strong opioids for the management of cancer pain

OBJECTIVE

The aim of this study was to assess the efficacy and tolerability of tapentadol (TP) for a period of 4 weeks in patients who were already treated by opioids.

METHODS

A convenience sample of 30 patients was selected for a prospective observational cohort study. Cancer patients who were receiving at least 60 mg of oral morphine equivalents were selected. Patients discontinued their previous opioid analgesics before starting TP, in doses calculated according the previous opioid consumption (1:3.3 ratio with oral morphine equivalents). The subsequent doses were changed according to the patients' needs for a period of 4 weeks. Oral morphine was offered as a breakthrough pain medication. Pain and symptom intensity were recorded at weekly intervals. Distress score (DS) was calculated from the sum of symptom intensities. TP opioid escalation indexes (TPEI) for the study period were calculated.

RESULTS

Nineteen patients were male, and the mean age was 63.5 years (±11.5). The mean Karnofsky status was 62.9 (±10). The mean dose of oral morphine equivalents before switching to TP was 112 mg (±57) and the initial mean dose of TP was 343 mg (±150). Pain intensity significantly decreased. Tapentadol escalation index in percentage was 1.26 (TPEI% ± 2.6) and Tapentadol escalation index in mg was 2.76 (TPEImg ± 4.96). No significant relationships were found with primary tumor (TPEI%, p = 0.204; TPEImg, p = 0.180), pain mechanism (TPEI%, p = 0.863; TPEImg, p = 0.846), age (TPEI%, p = 0.882; TPEImg, p = 0.884), or gender (TPEI%, p = 0.287; TPEImg, p = 0.325). DS decreased, but non-significantly (p = 0.1). Ten patients did not complete the study period: five patients discontinued TP for uncontrolled pain, despite increasing doses of TP over 600 mg/day. Two patients discontinued TP for adverse effects and three patients dropped out, one patient for poor compliance and two patients for unrecorded reasons.

CONCLUSION

In our sample, TP used in doses of 350-450 mg/day was well tolerated and effective in opioid tolerant patients with cancer pain and could be considered as a flexible drug to be used for the management of moderate to severe cancer pain. Like most studies in patients with cancer pain, it was limited by its open-label, uncontrolled design, the number of patients lost in follow-up, and discontinuation of the treatment for several reasons. Further studies in a large number of patients should confirm these preliminary results.

Principles of Opioid Use in Cancer Pain

The management of pain is an essential aspect of comprehensive cancer care. Positive outcomes can be achieved in most patients with widely available therapies. There is a broad consensus that opioid-based pharmacotherapy is the first-line strategy for the treatment of moderate or severe chronic pain in populations with active disease, and treatment guidelines have been developed from the known pharmacology of these drugs, extant data, and extensive clinical experience. This article describes the major opioid analgesics available for the treatment of cancer-related pain and reviews the key elements for safe and effective prescribing, including selection of the best drug and route, approaches to titration and long-term administration of baseline and supplemental doses, rotation from one drug to another in poorly responsive patients, and management of opioid risks.

New opioids

Despite the skilled use of opioid analgesics, which is crucial to the relief of cancer pain, there is a lack of evidence to support many aspects of current clinical practice. Therefore, there is a significant need for more effective treatment options. New opioids have been marketed in the past years, including hydrocodone and oxymorphone. Moreover, mixed opioids with combined mechanisms of action have been developed; one such agent, tapentadol, is a centrally acting oral analgesic that possesses a combined mechanism of action: μ-opioid receptor activation with norepinephrine reuptake inhibition. Drug development strategies involving naloxone have been initiated to reduce peripheral opioid-related adverse effects. The rationale is based on the local antagonist activity of naloxone in intestinal opioid receptors and the negligible oral bioavailability of naloxone, particularly in a prolonged-release formulation. New delivery systems have been developed to provide rapid analgesia with potent opioid drugs such as fentanyl. Despite the upcoming availability of these new drugs and technologies that will add to existing types of opioid medication, their benefits and liabilities will ultimately need to be determined by the individual physician and individual patient experiencing pain.