The international CHANGE PAIN physician survey: does specialism influence the perception of pain and its treatment?

Fixed Dose Versus Loose Dose: Analgesic Combinations

Combinations of drugs may be fixed (two or more entities in a single product) or loose (two or more agents taken together but as individual agents) to help address multimechanistic pain. The use of opioids plus nonopioids can result in lower opioid consumption without sacrificing analgesic benefits. Drug combinations may offer additive or synergistic benefits. A variety of fixed-dose combination products are available on the market such as diclofenac plus thiocolchicoside, acetaminophen and caffeine, acetaminophen and opioid, ibuprofen and acetaminophen, tramadol and acetaminophen, and others. Fixed-dose combination products offer predictable pharmacokinetics and pharmacodynamics, known adverse events, and can reduce the pill burden. However, they are limited to certain drug combinations and doses; loose dosing allows prescribers the versatility to meet individual patient requirements as well as the ability to titrate as needed. Not all drug combinations offer synergistic benefits, which depend on the drugs and their doses. Certain drugs offer dual mechanisms of action in a single molecule, such as tapentadol, and these may further be used in combination with other analgesics. New technology allows for co-crystal productions of analgesic agents which may further improve drug characteristics, such as bioavailability. Combination analgesics are important additions to the analgesic armamentarium and may offer important benefits at lower doses than monotherapy.

Pathophysiologic Approach to Pain Therapy for Complex Pain Entities: A Narrative Review

Pain management is challenging for both clinicians and patients. In fact, pain patients are frequently undertreated or even completely untreated. Optimal treatment is based on targeting the underlying mechanisms of pain and tailoring the management modality for each patient using a personalized approach. This narrative review deals with pain conditions that have a complex underlying mechanism and need an individualized and frequently multifactorial approach to pain management. The research is based on previously conducted studies, and does not contain any studies with human participants or animals performed by any of the authors. This is not an exhaustive review of the current evidence. However, it provides the clinician with a perspective on pain therapy targeting the underlying pain mechanism(s). When dealing with complex pain conditions, the prudent physician benefits from having a deep knowledge of various underlying pain mechanisms in order to provide a plan for optimal pharmacological pain relief to patients.

The effects of food on opioid-induced nausea and vomiting and pharmacological parameters: a systematic review

Opioids remain the standard of care for treating moderate to severe pain resulting from surgery or injury in cases of acute pain, and are recommended for patients who have not responded to nonopioid analgesics. Effective management of pain has an impact on clinical course and often depends on achieving an acceptable balance between opioid efficacy, safety, and tolerability. Common opioid-related adverse events such as nausea and vomiting are associated with an overall lower achievement of effective pain management and patient satisfaction. However, in practice, clinicians employ various strategies to maximize efficacy, minimize these adverse effects, and ensure the careful, judicious, and evidence-based use of opioids for patients who require them. Typical strategies for management and minimization of these types of adverse events include dose reduction, dose titration, opioid rotation, prescription for an antiemetic, and recommending the patient take opioids with food. Overall, the most straightforward approach that clinicians tend to employ that does not require additional visits or adjustment of prescriptions, is to recommend patients take opioids with food. However, given the current climate with opioids, it is critical and imperative that decisions for use of opioids be grounded in a solid and thorough evidence-base. In fact, several opioids are recommended to be taken explicitly with or without food because of interactions with abuse-deterrent technologies that can cause increased adverse events or inadequate analgesia. Therefore, we sought to review, synthesize, and summarize the literature for randomized, controlled trials and other studies to support the hypothesis that taking opioids with food reduces opioid-related events such as nausea and vomiting. Based on the current evidence we surveyed, the recommendation to take opioids with food does not appear to consistently and unequivocally reduce nausea and vomiting and, in many cases, increases the frequency of these adverse events in the studies we examined.

Chronic Pain Features Relate to Quality of Life More than Physiopathology: A Cross-Sectional Evaluation in Pain Clinics

OBJECTIVE

To compare the impact of chronic pain physiopathology on health-related quality of life (HR-QoL), considering the influence of pain features and psychosocial adjustment (intensity, interference, psychological comorbidities, and sleep quality).

DESIGN

A cross-sectional study involving 1,025 noncancer patients with predominantly neuropathic, nociceptive, or mixed chronic pain conditions was conducted in 88 pain clinics within Spain. The EuroQol-5 Dimensions instrument (EQ-5D) was used to measure HR-QoL. The Brief Pain Inventory (BPI), Hospital Anxiety and Depression Scale (HADS), and sleep scale developed for the MOS study (MOS-SQ) were used to measure pain features and psychosocial adjustment. Multivariate analyses were used to model HR-QoL measures.

RESULTS

All patients reported very low HR-QoL. The mean EQ-5D index scores were 0.33, 0.36, and 0.37 in the mixed, neuropathic, and nociceptive pain groups, respectively. The differences did not reach statistical significance (P = 0.057). Patients with nociceptive pain had less pain (least pain intensity score: 4.7 vs. 5.2 in the other groups; P = 0.006), less interference with daily activities (BPI average interference score: 6.3 vs. 6.6 and 6.7 in the neuropathic and mixed pain groups, respectively; P = 0.013), less anxiety (HADS score: 8.5 vs. 9.6 and 9.7 in the same respective groups; P = 0.001), and fewer sleep problems (MOS-SQ sleep problems index: 46.8 vs. 52.2 and 50.2 in the same respective groups; P = 0.005). In the adjusted analyses, HR-QoL measures were explained by pain intensity, anxiety, and sleep quality, but not by physiopathological pain type.

CONCLUSIONS

Pain features, particularly intensity, have a greater impact than pain physiopathology on HR-QoL. Distinct physiopathological mechanisms give rise to different pain features that, in turn, may mediate the HR-QoL of patients with chronic pain. This could be used to improve pain management strategies.

Blockade of Serotonin 5-HT2A Receptors Suppresses Behavioral Sensitization and Naloxone-Precipitated Withdrawal Symptoms in Morphine-Treated Mice

The increasing prescription of opioids is fueling an epidemic of addiction and overdose deaths. Morphine is a highly addictive drug characterized by a high relapse rate - even after a long period of abstinence. Serotonin (5-HT) neurotransmission participates in the development of morphine dependence, as well as the expression of morphine withdrawal. In this study, we examined the effect of blockade of 5-HT_2A receptors (5-HT_2ARs) on morphine-induced behavioral sensitization and withdrawal in male mice. 5-HT_2AR antagonist MDL 11,939 (0.5 mg/kg, i.p.) suppressed acute morphine (5.0 mg/kg, s.c.)-induced increase in locomotor activity. Mice received morphine (10 mg/kg, s.c.) twice a day for 3 days and then drug treatment was suspended for 5 days. On day 9, a challenge dose of morphine (10 mg/kg) was administered to induce the expression of behavioral sensitization. MDL 11,939 (0.5 mg/kg, i.p.) pretreatment suppressed the expression of morphine-induced behavioral sensitization. Another cohort of mice received increasing doses of morphine over a 7-day period to induce morphine-dependence. MDL 11,939 (0.5 mg/kg, i.p.) prevented naloxone-precipitated withdrawal in morphine-dependent mice on day 7. Moreover, chronic morphine treatment increased 5-HT_2AR protein level and decreased the phosphorylation of extracellular signal-regulated kinases in the prefrontal cortex. Together, these results by the first time demonstrate that 5-HT_2ARs modulate opioid dependence and blockade of 5-HT_2AR may represent a novel strategy for the treatment of morphine use disorders.

HIGHLIGHTS

(i)Blockade of 5-HT_2A receptors suppresses the expression of morphine-induced behavioral sensitization.(ii)Blockade of 5-HT_2A receptors suppresses naloxone-precipitated withdrawal in morphine-treated mice.(iii)Chronic morphine exposure induces an increase in 5-HT_2A receptor protein level and a decrease in ERK protein phosphorylation in prefrontal cortex.

Tapentadol Prolonged Release for Chronic Pain: A Review of Clinical Trials and 5 Years of Routine Clinical Practice Data

Tapentadol prolonged release (PR) for the treatment of moderate to severe chronic pain combines 2 modes of action. These are μ-opioid receptor agonism and noradrenaline reuptake inhibition in a single molecule that allow higher analgesic potency through modulation of different pharmacological targets within the pain transmitting systems. At the same time, this can also serve as a clue for modulation of different pain-generating mechanisms according to nociceptive, neuropathic, or mixed pain conditions. Tapentadol PR has now been on the market for 5 years, with over 4.6 million people treated worldwide. A panel of pain specialists convened in Germany to review the clinical program and to discuss the role of tapentadol PR in the management of chronic pain. The clinical study program demonstrated effective and generally well-tolerated treatment for up to 2 years in a broad range of chronic pain conditions, including those with neuropathic pain components. This was confirmed in routine clinical practice observations. Head-to-head studies with World Health Organization (WHO) III opioids such as oxycodone controlled release and oxycodone/naloxone PR showed at least comparable pain relief in the treatment of moderate-to-severe musculoskeletal pain. Rotation from poorly tolerated WHO III opioids to tapentadol PR provided effective pain relief and better symptom control for musculoskeletal pain compared to previous medication. Functionality, health status and quality of life also improved under tapentadol PR treatment. The gastrointestinal tolerability profile was more favorable compared to other tested WHO III opioids. Tapentadol PR has a good safety profile and no evidence of acquired tolerance from the long-term data so far collected. Overall, tapentadol PR represents an effective and generally well-tolerated alternative to "classical" opioidergic drugs.

Economic and clinical burden of opioid-induced nausea and vomiting

Opioids are the standard of care for treating moderate-to-severe pain; however, their efficacy can be limited by adverse events (AEs), including nausea and vomiting. Opioid-induced nausea and vomiting (OINV) is an inherent adverse effect of opioid treatment, exerting effects centrally and peripherally. Opioid-related AEs can impact treatment adherence and discontinuation, which can result in inadequate pain management. OINV may persist long-term, negatively affecting patient functional outcomes, physical and mental health, patient satisfaction, and overall costs of treatment. Multiple factors may contribute to OINV, including activation of opioid receptors in the chemoreceptor trigger zone, vestibular apparatus, and gastrointestinal tract. Prophylactic or early treatment with antiemetics may be appropriate for patients who are at high risk for OINV.

Health Care Utilization and Costs Associated with Nausea and Vomiting in Patients Receiving Oral Immediate-Release Opioids for Outpatient Acute Pain Management

Introduction

Nausea and vomiting (NV) are common side effects of opioid use and limiting factors in pain management. This study sought to quantify the frequency of antiemetic prescribing and the impact of NV on health care resource utilization and costs in outpatients prescribed opioids for acute pain. The perspective was that of a commercial health plan.

Methods

Medical and pharmacy claims from IMS PharMetrics Plus were used to identify patients initiating opioid therapy with a prescription for an oxycodone-, hydrocodone- or codeine-containing immediate-release product for acute use (≤15-day supply) between October 1, 2013 and September 30, 2014. Patients with a medical claim for NV (International Classification of Diseases, Ninth Revision, Clinical Modification codes 787.0x), with or without an antiemetic prescription fill, were compared with patients with no NV claim or antiemetic prescription fill to assess differences in all-cause health care utilization and costs over 1 month. Propensity score matching (PSM) was used to adjust for between-group differences in baseline patient characteristics.

Results

The co-prescribing of opioids with antiemetic agents was 10.2%. After PSM (n = 45,790 per group), patients with NV claims had significantly more hospitalizations (11.5% vs 4.2%), emergency department visits (65.0% vs 12.1%), and physician office visits (85.2% vs 64.5%) compared with patients with no NV claims (all P < 0.0001). Mean total health care costs were higher among patients with a NV claim versus those without evidence of the side effect ($6290 vs $2309; P < 0.0001). Among patients with a recent hospitalization, patients with NV claims had higher rates of 30-day rehospitalization than those with no NV claims (24.4% vs 3.0%; P < 0.0001).

Conclusions

Among outpatients prescribed opioids for management of acute pain, co-prescribing with antiemetics was low, and the economic burden associated with NV was high. Efforts to prevent NV in patients receiving opioid therapy may improve patient outcomes and provide cost savings to the health care system.

Funding

Daiichi Sankyo, Inc.

Electronic supplementary material

The online version of this article (doi:10.1007/s40122-016-0057-y) contains supplementary material, which is available to authorized users.

Estimation of minimal clinically important change of the Japanese version of EQ-5D in patients with chronic noncancer pain: a retrospective research using real-world data

Background

Quality of life (QoL) is routinely assessed and evaluated in medical research. However, in Japan, there is a lack of solid cutoff criteria for evaluating QoL improvement in chronic noncancer pain management. The present study was conducted to identify the minimal clinically important change (MCIC) of the Japanese version of EuroQol-5D 3L(EQ-5D) utility score and numeric rating scale (NRS) with an emphasis on chronic noncancer pain.

Methods

The data source for this post hoc research was the post-marketing surveillance (PMS) data for a tramadol/acetaminophen combination tablet, which was previously conducted in real-world settings. The parameters extracted from the PMS data were sociodemographic characteristics, NRS, EQ-5D, and dichotomous physician’s global impression of treatment effectiveness (PGI). The optimal cutoff points of MCIC for EQ-5D utility and NRS scores were evaluated using receiver operating characteristics (ROC) analysis. An anchor-based approach using PGI was applied.

Results

Data of 710 patients with chronic noncancer pain were extracted from the PMS database. The NRS score decreased by 2.7 (standard deviation, 2.3) points, whereas the EQ-5D score increased by 0.16 (0.20) points at 4 weeks from baseline. The changes from baseline in NRS and EQ-5D were significantly correlated (r = 0.53, p < 0.001). The estimated optimal cutoff points of MCIC for EQ-5D and NRS were 0.10 and −2.0 points, respectively. The area under the curve of ROC was > 0.80 in both analyses.

Conclusion

These results demonstrated novel cutoff criteria for the Japanese version of EQ-5D, focusing on patients with chronic noncancer pain. The obtained criteria were fairly consistent and can be confidently utilized as an evaluation tool in medical research on chronic noncancer pain in Japan, with additional functionality and usability for QoL assessment in pain management practice.

Trial registration

The data source of this post hoc research was a PMS study with the identifier number UMIN000015901 at umin.ac.jp, UMIN clinical trial registry (UMIN-CTR).

Noninterventional study of transdermal fentanyl (fentavera) matrix patches in chronic pain patients: analgesic and quality of life effects

Fentanyl is considered to be an effective, transdermal treatment of chronic, cancer, and noncancer pain. This noninterventional, clinical practice-based study, on 426 patients attending 42 practices, assessed a proprietary, Aloe vera-containing, transdermal fentanyl matrix patch (Fentavera), for its analgesic effects, patients' quality of life (QoL) effects, tolerability, and adhesiveness. Study outcomes were mean changes from baseline of patient (11-point scales) and physician (5-point scales) ratings. After 1 and 2 months treatment, there were significant (P < 0.0001) decreases in patients' ratings of pain intensity, and impairment of walking, general activity, sleep quality, and QoL. For each parameter, the patient response rate was >30% at 2 months (response = 2-point decrease on 11-point rating scale). In a large majority of patients, the physicians rated the matrix patch as good or very good for analgesic effect, systemic and local tolerance, and adhesiveness. There were 30 adverse events in 4.2% of patients and analgesic comedications were reduced during treatment compared to before treatment. It is concluded, from this population-based data, that the proprietary, transdermal fentanyl matrix patch is effective and safe for chronic pain management in clinical practice, with significant positive analgesic and QoL effects, while being well tolerated and exhibiting good or very good adhesiveness.

Effectiveness and Safety of Tapentadol Prolonged Release (PR) Versus a Combination of Tapentadol PR and Pregabalin for the Management of Severe, Chronic Low Back Pain With a Neuropathic Component: A Randomized, Double-blind, Phase 3b Study

OBJECTIVE

To evaluate the effectiveness and tolerability of tapentadol PR monotherapy versus tapentadol PR/pregabalin combination therapy for severe, chronic low back pain with a neuropathic component.

METHODS

Eligible patients had painDETECT "unclear" or "positive" ratings and average pain intensity ≥ 6 (11-point NRS-3 [average 3-day pain intensity]) at baseline. Patients were titrated to tapentadol PR 300 mg/day over 3 weeks. Patients with ≥ 1-point decrease in pain intensity and average pain intensity ≥ 4 were randomized to tapentadol PR (500 mg/day) or tapentadol PR (300 mg/day)/pregabalin (300 mg/day) during an 8-week comparative period.

RESULTS

In the per-protocol population (n = 288), the effectiveness of tapentadol PR was clinically and statistically comparable to tapentadol PR/pregabalin based on the change in pain intensity from randomization to final evaluation (LOCF; LSMD [95% CI], -0.066 [-0.57, 0.43]; P < 0.0001 for noninferiority). Neuropathic pain and quality-of-life measures improved significantly in both groups. Tolerability was good in both groups, in line with prior trials in the high dose range of 500 mg/day for tapentadol PR monotherapy, and favorable compared with historical combination trials of strong opioids and anticonvulsants for combination therapy. The incidence of the composite of dizziness and/or somnolence was significantly lower with tapentadol PR (16.9%) than tapentadol PR/pregabalin (27.0%; P = 0.0302).

CONCLUSIONS

Tapentadol PR 500 mg is associated with comparable improvements in pain intensity and quality-of-life measures to tapentadol PR 300 mg/pregabalin 300 mg, with improved central nervous system tolerability, suggesting that tapentadol PR monotherapy may offer a favorable treatment option for severe low back pain with a neuropathic component.

Survey of European patients assessing their own noncancer chronic pain: results from Spain

OBJECTIVE

As part of the CHANGE PAIN international health campaign to improve pain management, patient surveys are being undertaken to explore how patients perceive their noncancer chronic pain and how they deal with it.

RESEARCH DESIGN AND METHODS

In Spain, 8695 patients completed this survey. The cross-sectional data were provided during routine visits to 893 physicians from different specialties. Pain intensity was assessed on two scales: a 5-point verbal rating scale (VRS) and an 11-point numerical rating scale (NRS).

RESULTS

Most patients were women (57%) in their late adulthood (45-64 years; 34%) or elderly (65 years or older; 53%). Pain duration of one year or longer was frequent (65%). Combined pharmacological treatment (51%) was more common than monotherapy (33%). The most frequently prescribed agents were nonsteroidal anti-inflammatory drugs, to be taken alone (18%) or together with weak opioids (15%), followed by weak (7%) or potent (6%) opioids in monotherapy; but there were many different treatments prescribed. Most patients had moderate (47%) or severe/extreme (34%) VRS rated pain. The mean intensity in the NRS was of 5.7 over 10. Many patients had pain above the level they could tolerate (38%) and most (55%) were not satisfied with their therapy. Their main goals were pain relief and reduction of side effects.

KEY LIMITATIONS

Causal inductions are not possible in a cross-sectional research like this. Other clinically meaningful outcome measures in patients with chronic pain, such as patients' quality of life, were not gathered.

CONCLUSIONS

Chronic noncancer pain management is poor. The uncoupling of VRS and NRS pain ratings reveals the high subjectivity of the pain experience, whilst the wide variation in treatment choices indicates that an optimal management strategy remains to be defined. Advances might be attained by boosting communication to tailor treatments to individual patients' perceptions.

Tapentadol prolonged release versus strong opioids for severe, chronic low back pain: results of an open-label, phase 3b study

INTRODUCTION

This open-label, phase 3b study evaluated the effectiveness and tolerability of oral tapentadol prolonged release (PR; 50-250 mg twice daily [b.i.d.]) for managing severe, chronic low back pain in patients responding to World Health Organization (WHO) step III opioids but tolerating treatment poorly. Equianalgesic ratios for tapentadol to prior strong opioids were calculated.

METHODS

Patients rotated directly from prior WHO step III opioids to tapentadol. Patients received tapentadol PR (50-250 mg b.i.d.) during 5-week titration and 7-week maintenance periods. Tapentadol immediate release (IR) 50 mg (≤ twice/day, ≥ 4 h apart) was allowed (total daily dose of tapentadol PR and IR ≤ 500 mg/day). The primary endpoint was responder rate 1 at week 6 (percentage of patients with the same or less pain intensity [11-point numerical rating scale (NRS; 3-day average)] vs week -1).

RESULTS

Responder rate 1 at week 6 (last observation carried forward [LOCF]) was 80.9% (76/94; P < 0.0001 vs. the null responder hypothesis rate [<60%]), resulting in a positive trial despite premature termination (136 recruited of 180 planned). Significant improvements from baseline in pain intensity and neuropathic pain symptoms were observed at weeks 6 and 12 with tapentadol PR (P < 0.05). Equianalgesic ratios were calculated for PR formulations alone and for PR and IR formulations combined for tapentadol to oxycodone, buprenorphine, fentanyl, morphine, and hydromorphone. The prevalences of adverse events reported as the reason for switching to tapentadol (most commonly constipation and nausea) decreased over time.

CONCLUSIONS

Tapentadol PR (50-250 mg b.i.d.) provided at least comparable pain relief and improved tolerability versus prior strong opioids in patients with severe, chronic low back pain responding to WHO step III therapy. Conversion from strong opioids to tapentadol PR, with its two mechanisms of action, went smoothly considering overall effectiveness and tolerability outcomes. Equianalgesic ratios of tapentadol to oxycodone and other strong opioids were in line with other phase 3/3b studies.