Responsible prescribing of opioids for the management of chronic pain

The role of nitric oxide and neuroendocrine system in pain generation

Previous studies have indicated a complex interplay between the nitric oxide (NO) pain signaling pathways and hormonal signaling pathways in the body. This article delineates the role of nitric oxide signaling in neuropathic and inflammatory pain generation and subsequently discusses how the neuroendocrine system is involved in pain generation. Hormonal systems including the hypothalamic-pituitary axis (HPA) generation of cortisol, the renin-angiotensin-aldosterone system, calcitonin, melatonin, and sex hormones could potentially contribute to the generation of nitric oxide involved in the sensation of pain. Further research is necessary to clarify this relationship and may reveal therapeutic targets involving NO signaling that alleviate neuropathic and inflammatory pain.

An observational study of clinical outcome measures in patients treated with cannabis-based medicinal products on the UK Medical Cannabis Registry

INTRODUCTION

While there is increasing evidence of the effects of cannabis-based medicinal products (CBMPs) on health-related quality of life (HRQoL), a major limitation of the current literature is the heterogeneity of studied CBMPs. This study aims to analyze changes in HRQoL in patients prescribed a homogenous selection of CBMPs.

METHODS

Primary outcomes were changes in patient-reported outcomes (PROMs) at 1, 3, 6, and 12 months from baseline. The secondary outcome was an adverse events analysis. Statistical significance was defined as p < 0.050.

RESULTS

1378 patients prescribed Adven® CBMPs (Curaleaf International, Guernsey, UK) were included in the final analysis. 581 (42.16%) participants were current users of cannabis at baseline. 641 (46.51%), 235 (17.05%), and 502 (36.43%) patients were treated with oils, dried flowers, or a combination of the two, respectively. Improvements were found in all PROMs in each route of administration at 1, 3, 6, and 12 months from baseline (p < 0.010). Those prescribed dried flower only or both oils and dried flower experienced greater improvements in GAD-7, SQS, and EQ-5D-5L index values at 12 months (p < 0.050). There was no difference in outcomes between those prescribed dried flower only or dried flower with oils (p > 0.050). 3663 (265.82%) adverse events were reported by 297 (21.55%) patients.

CONCLUSION

There was an associated improvement in self-reported anxiety, sleep quality, and HRQoL in patients treated with the CBMPs. Those prescribed treatment formulations including dried flower were most likely to show a clinical improvement. However, these results must be interpreted with caution given the limitations of study design.

miR-199a-3p suppresses neuroinflammation by directly targeting MyD88 in a mouse model of bone cancer pain

AIMS

Pain is a profoundly debilitating symptom in cancer patients, leading to disability, immobility, and a marked decline in their quality of life. This study aimed to investigate the potential roles of miR-199a-3p in a murine model of bone cancer pain induced by tumor cell implantation in the medullary cavity of the femur.

MATERIALS AND METHODS

We assessed pain-related behaviors, including the paw withdrawal mechanical threshold (PWMT) and the number of spontaneous flinches (NSF). To investigate miRNA expression and its targets in astrocytes, we employed a combination of RNA-seq analysis, qRT-PCR, Western blotting, EdU, TUNEL, ChIP, ELISA, and luciferase reporter assays in mice (C3H/HeJ) with bone cancer pain and control groups.

KEY FINDINGS

On days 10, 14, 21, and 28 post-surgery, we observed significant differences in PWTL, PWMT, and NSF when compared to the sham group (P < 0.001). qRT-PCR assays and miRNA sequencing results confirmed reduced miR-199a-3p expression in astrocytes of mice with bone cancer pain. Gain- and loss-of-function experiments demonstrated that miR-199a-3p suppressed astrocyte activation and the expression of inflammatory cytokines. In vitro investigations revealed that miR-199a-3p mimics reduced the levels of inflammatory factors in astrocytes and MyD88/NF-κB proteins. Furthermore, treatment with a miR-199a-3p agonist resulted in reduced expression of MyD88, TAK1, p-p65, and inflammatory mediators, along with decreased astrocyte activation in the spinal cord.

SIGNIFICANCE

Collectively, these findings demonstrate that upregulation of miR-199a-3p may offer a therapeutic avenue for mitigating bone cancer pain in mice by suppressing neuroinflammation and inhibiting the MyD88/NF-κB signaling pathway.

The effectiveness and safety of the rapid titration strategy of background controlled-release oxycodone hydrochloride for patients with moderate-to-severe cancer pain: A retrospective cohort study

BACKGROUND

Oxycodone hydrochloride is a semisynthetic narcotic analgesic agent. This study aimed to explore optimal titration strategy of controlled-release (CR) oxycodone hydrochloride in patients with cancer pain.

METHODS

258 patients, who used regular strong opioids (morphine and CR oxycodone hydrochloride) for cancer pain across 25 three grade class hospitals in China during January 15th 2017 to April 30th 2017, were retrospectively studied. The patients were divided into 4 groups according to treatment regimens titrated. The pain remission rate and numeric rating scale (NRS) of cancer pain was recorded at 0, 12, 24, 36, 48, 60, 72 h after opioid titration. The incidence of adverse events (AEs) with therapy were also observed.

RESULTS

12 h after treatment, pain remission rate of Group B, C and D was significantly higher (P < 0.001) than Group A. For the complete remission rate, there were also significant differences among the four groups (P < 0.001). No significant difference was found among four groups for pain remission rate at 24, 72 h after treatment. Multiple comparison of NRS scores showed that the both Group B and C varied significantly with Group D (P = 0.028, P = 0.05, respectively), showing superior analgesic effect over Group D. AEs were significantly different among groups (P < 0.01), with the most frequent AEs in Group A, lowest in Group B.

CONCLUSION

The rapid titration strategy of background CR oxycodone hydrochloride was effectiveness and safety in patients with moderate-to-severe cancer pain.

Transformation products of pharmaceuticals in the environment: Their fate, (eco)toxicity and bioaccumulation potential

Nowadays, a huge scientific attention is being paid to the chemicals of emerging concern, which may pose a significant risk to the human and whole ecosystems. Among them, residues of pharmaceuticals are a widely investigated group of chemicals. In recent years it has been repeatedly demonstrated that pharmaceuticals are present in the environment and that some of them can be toxic to organisms as well as accumulate in their tissues. However, even though the knowledge of the presence, fate and possible threats posed by the parent forms of pharmaceuticals is quite extensive, their transformation products (TPs) have been disregarded for long time. Since last few years, this aspect has gained more scientific attention and recently published papers proved their common presence in the environment. Also the interest in terms of their toxicity, bioconcentration and stability in the environment has increased. Therefore, the aim of our paper was to revise and assess the current state of knowledge on the fate and effects resulting from the presence of the pharmaceuticals' transformation drugs in the environment. This review discusses the metabolites of compounds belonging to six major pharmaceutical groups: SSRIs, anticancer drugs, antibiotics, antihistamines, NSAIDs and opioids, additionally discussing other individual compounds for which literature data exist. The data presented in this paper prove that some TPs may be as harmful as their native forms, however for many groups of drugs this data is still insufficient to assess the risk posed by their presence in the environment.

Efficacy and safety of opioid therapy guided by pharmacogenetics: a systematic review

Aim: To perform a systematic review to determine the efficacy/safety of PGx-guided opioid therapy for chronic/postoperative pain. Materials & methods: We searched PubMed and other specialized databases. Articles were considered if they compared the efficacy/safety of PGx-guided opioid therapy versus usual care. The risk of bias assessment was performed using Cochrane tools. Results: A total of 3794 records were retrieved. Only five were included for data extraction. A lower requirement of analgesics during postoperative in the PGx-guided intervention arm was reported in two studies. Also, two studies reported significant pain improvement in favor of the PGx-guided therapy when analyzing the subgroup of patients with a high-risk CYP2D6 phenotype. Conclusion: Despite the findings described, information on the efficacy/safety of this intervention is scarce.

Opioid painkiller dependence in a sample of elderly medical inpatients

BACKGROUND

Over the past few years, there has been a growing concern about prescription opioid misuse and dependence in the elderly. Our study aimed to investigate the prevalence of previous and current prescription opioid dependence among elderly medical inpatients recruited from a large German hospital.

METHODS

This cross-sectional study analyzed a cohort of inpatients aged 65 years and older who were assessed with a structured clinical interview. Levels of past and current dependence on opioids benzodiazepines, hypnotics, and non-opioid analgesics were assessed.

RESULTS

Of 2108 elderly inpatients admitted to the hospital during a 6-month period, 400 fulfilled the inclusion criteria and agreed to participate to the survey. Among these 400 subjects, 43 (10.8%) presented with a dependence on opioid analgesics, including 41 with current dependence and 22 (51.2%) with a de novo condition. Addiction severity was considered mild in 65.1% of cases and severe in 11.6% of cases. Tilidine and oxycodone were the most typically reported molecules.

CONCLUSIONS

Further research is warranted, to better understand the possible risk factors of prescription drug misuse, abuse, and addiction in this vulnerable population. Clinicians should be updated and informed regarding both prescription medication misuse potential and safe prescribing practices in the elderly.

Antinociceptive properties of an isoform-selective inhibitor of Nav1.7 derived from saxitoxin in mouse models of pain

ABSTRACT

The voltage-gated sodium channel Nav1.7 is highly expressed in nociceptive afferents and is critically involved in pain signal transmission. Nav1.7 is a genetically validated pain target in humans because loss-of-function mutations cause congenital insensitivity to pain and gain-of-function mutations cause severe pain syndromes. Consequently, pharmacological inhibition has been investigated as an analgesic therapeutic strategy. We describe a small molecule Nav1.7 inhibitor, ST-2530, that is an analog of the naturally occurring sodium channel blocker saxitoxin. When evaluated against human Nav1.7 by patch-clamp electrophysiology using a protocol that favors the resting state, the Kd of ST-2530 was 25 ± 7 nM. ST-2530 exhibited greater than 500-fold selectivity over human voltage-gated sodium channel isoforms Nav1.1-Nav1.6 and Nav1.8. Although ST-2530 had lower affinity against mouse Nav1.7 (Kd = 250 ± 40 nM), potency was sufficient to assess analgesic efficacy in mouse pain models. A 3-mg/kg dose administered subcutaneously was broadly analgesic in acute pain models using noxious thermal, mechanical, and chemical stimuli. ST-2530 also reversed thermal hypersensitivity after a surgical incision on the plantar surface of the hind paw. In the spared nerve injury model of neuropathic pain, ST-2530 transiently reversed mechanical allodynia. These analgesic effects were demonstrated at doses that did not affect locomotion, motor coordination, or olfaction. Collectively, results from this study indicate that pharmacological inhibition of Nav1.7 by a small molecule agent with affinity for the resting state of the channel is sufficient to produce analgesia in a range of preclinical pain models.

Opioids for chronic low back pain management: a Bayesian network meta-analysis

Introduction: Chronic low back pain (LBP) is common, and some patients require opiates therapy. This Bayesian network meta-analysis (NMA) analyzed available randomized clinical trials (RCTs) on the use of opioids for LBP.Methods: All RCTs comparing two or more opioids for chronic LBP and reporting results under the Numeric Rating Scale were included. The following drugs were analyzed: fentanyl, morphine, tapentadol, oxycodone, buprenorphine, oxymorphone, tramadol. The NMA was performed through the STATA routine for Bayesian hierarchical random-effects model analysis, with standardized mean difference (SMD) effect measure. Data regarding the rate of adverse events and different drug formulations were also reported.Results: Data from 2933 patients were obtained, with a mean age of 53.30 ± 6.95 years. The mean duration of symptoms prior to beginning the trial was 95.16 ± 47.29 months. The mean follow-up was 3.29 ± 1.72 months. Among the analyzed compounds, oxymorphone, tapentadol and fentanyl showed the highest efficacy in terms of pain reduction.Conclusion: According to published level I evidence, oxymorphone, tapentadol and fentanyl were the most effective drugs in the treatment of chronic LBP. However, different formulation and pharmacokinetic characteristics need to be taken into consideration when choosing the ideal compound for a given patient.

Anti-inflammatory and analgesic effects of methanol extract of red cultivar Allium cepa bulbs in rats and mice

OBJECTIVES

Several cultivars of Allium cepa L. have been studied for anti-inflammatory and analgesic activities but there is inadequate information on such biological activities of the concentrated extracts of the Nigerian grown red cultivar A. cepa bulb.

METHODS

The anti-inflammatory models used in this study were Carrageenan-induced paw oedema and formalin-induced paw lick in rats, while acetic acid-induced abdominal writhing, hot plate reaction, hot water tail flick tests in mice were the analgesic models.

RESULTS

At 30 min post-induction (pi), the inhibition of paw oedema (62.50%) by 200 mg/kg of methanol extract of red cultivar A. cepa bulb (MERCACB) was significantly (p<0.001) higher than that of indomethacin (15.63%) at 10 mg/kg. The paw oedema inhibition at 60 min pi by MERCACB (76.92%) was significantly higher than that of indomethacin (41.03%). At the early phase of formalin paw-lick test, the pain reaction time (PRT) of rat treated with MERCACB (400 mg/kg) was significantly lower than that of indomethacin and the control groups. The hotplate test revealed that PRT of mice treated with 800 mg/kg of MERCACB were significantly (p<0.01) longer in comparism to indomethacin and control groups. The PRT of mice subjected to thermal pain due to hot water and treated with 800 mg/kg of MERCACB was significantly (p<0.05) longer than that of the control group.

CONCLUSIONS

These findings indicate that MERCACB possesses potent anti-inflammatory and analgesic properties which confirm the traditional use of the plant for the treatment of inflammatory diseases and may be useful as a future therapeutic agent.

Intranasal Low-Dose Naltrexone Against Opioid Side Effects: A Preclinical Study

Opioids are broad spectrum analgesics that are an integral part of the therapeutic armamentarium to combat pain in the clinical practice. Unfortunately, together with analgesia, a number of adverse effects can occur such as nausea, vomiting, constipation, gastrointestinal alterations and cognitive impairments. Naltrexone is a competitive antagonist of opioid receptors commonly used to treat opioid addiction; its oral use against agonists side effects is limited by the decrease of opioids-therapeutic efficacy and own adverse effects. The intranasal delivery of naltrexone could offer a quick and effective achievement of CNS based on extracellular mechanisms including perineural and perivascular transport. The aim of the study was to test the efficacy of intranasal low-dose naltrexone in reducing intraperitoneal morphine and oxycodone side effects in rodents. In mice, 1 μg naltrexone intranasally administered 30 min before opioids reduced cognitive impairments and motor alteration induced by 10 mg kg^-1 morphine and 60 mg kg^-1 oxycodone in the Passive avoidance and Rota rod tests, respectively. Moreover, naltrexone rebalanced opioid-induced reduction of the intestinal transit and latency of feces expulsion as well as food intake inhibition. Importantly, 1 μg naltrexone instillation did not block analgesia as demonstrated by the Hot plate test. In rats, intranasal naltrexone counteracted the opioid-induced pica phenomenon related to emesis and increased water and palatable food intake. The effects were comparable to that achieved by metoclopramide used as reference drug. Treatments did not influence body weight. Lastly, the safety of the intranasal delivery has been checked by hematoxylin-eosin staining that did not show histological alterations of the nasal cavity. In conclusion, intranasal low-dose naltrexone counteracted morphine and oxycodone induced gastrointestinal and CNS side effects without impairing opioid analgesia. It is a candidate to be a valid clinical strategy deserving deep analysis.

Responsible Prescribing of Opioids for Chronic Non-Cancer Pain: A Scoping Review

Chronic non-cancer pain is common and long-term opioid therapy is frequently used in its management. While opioids can be effective, they are also associated with significant harm and misuse, and clinicians must weigh any expected benefits with potential risks when making decisions around prescribing. This review aimed to summarise controlled trials and systematic reviews that evaluate patient-related, provider-related, and system-related factors supporting responsible opioid prescribing for chronic non-cancer pain. A scoping review methodology was employed, and six databases were searched. Thirteen systematic reviews and nine controlled trials were included for analysis, and clinical guidelines were reviewed to supplement gaps in the literature. The majority of included studies evaluated provider-related factors, including prescribing behaviours and monitoring for misuse. A smaller number of studies evaluated system-level factors such as regulatory measures and models of healthcare delivery. Studies and guidelines emphasise the importance of careful patient selection for opioid therapy, development of a treatment plan, and cautious initiation and dose escalation. Lower doses are associated with reduced risk of harm and can be efficacious, particularly when used in the context of a multimodal interdisciplinary pain management program. Further research is needed around many elements of responsible prescribing, including instruments to monitor for misuse, and the role of policies and programs.

Prescribing Analgesics to Older People: A Challenge for GPs

Background: Due to population aging, there is an increase in the prevalence of chronic diseases, and in particular musculoskeletal diseases. These trends are associated with an increased demand for prescription analgesics and an increased risk of polypharmacy and adverse medication reactions, which constitutes a challenge, especially for general practitioners (GPs), as the providers who are most responsible for the prescription policy. Objectives: To identify patterns of analgesics prescription for older people in the study area and explore associations between a long-term analgesic prescription and comorbidity patterns, as well as the prescription of psychotropic and other common medications in a continuous use. Methods: A retrospective study was conducted in 2015 in eastern Croatia. Patients were GP attenders ≥40 years old (N = 675), who were recruited during their appointments (consecutive patients). They were divided into two groups: those who have been continuously prescribed analgesics (N = 432) and those who have not (N = 243). Data from electronic health records were used to provide information about diagnoses of musculoskeletal and other chronic diseases, as well as prescription rates for analgesics and other medications. Exploratory methods and logistic regression models were used to analyse the data. Results: Analgesics have been continuously prescribed to 64% of the patients, mostly to those in the older age groups (50–79 years) and females, and they were indicated mainly for dorsalgia symptoms and arthrosis. Non-opioid analgesics were most common, with an increasing tendency to prescribe opioid analgesics to older patient groups aged 60–79 years. The study results indicate that there is a high rate of simultaneous prescription of analgesics and psychotropic medications, despite the intention of GPs to avoid prescribing psychotropic medications to patients who use any option with opioid analgesics. In general, receiving prescription analgesics does not exceed the prescription for chronic diseases over the rates that can be found in patients who do not receive prescription analgesics. Conclusion: Based on the analysis of comorbidities and parallel prescribing, the results of this study can improve GPs’ prescription and treatment strategies for musculoskeletal diseases and chronic pain conditions.

Repurposing of Tranilast for Potential Neuropathic Pain Treatment by Inhibition of Sepiapterin Reductase in the BH4 Pathway

Tetrahydrobiopterin (BH₄) is a cofactor in the production of various signaling molecules including nitric oxide, dopamine, adrenaline, and noradrenaline. BH₄ levels are critical for processes associated with cardiovascular function, inflammation, mood, pain, and neurotransmission. Increasing pieces of evidence suggest that BH₄ is upregulated in chronic pain. Sepiapterin reductase (SPR) catalyzes both the reversible reduction of sepiapterin to dihydrobiopterin (BH₂) and 6-pyruvoyl-tetrahydrobiopterin to BH₄ within the BH₄ pathway. Therefore, inhibition of SPR by small molecules can be used to control BH₄ production and ultimately alleviate chronic pain. Here, we have used various in silico and in vitro experiments to show that tranilast, licensed for use in bronchial asthma, can inhibit sepiapterin reduction by SPR. Docking and molecular dynamics simulations suggest that tranilast can bind to human SPR (hSPR) at the same site as sepiapterin including S157, one of the catalytic triad residues of hSPR. Colorimetric assays revealed that tranilast was nearly twice as potent as the known hSPR inhibitor, N-acetyl serotonin. Tranilast was able to inhibit hSPR activity both intracellularly and extracellularly in live cells. Triple quad mass spectrophotometry of cell lysates showed a proportional decrease of BH₄ in cells treated with tranilast. Our results suggest that tranilast can act as a potent hSPR inhibitor and therefore is a valid candidate for drug repurposing in the treatment of chronic pain.

Opioid Analgesics Prescription to End-of-Life Cancer Patients: Characteristics, Attitudes, and Practices of French General Practitioners

Background: Pain management, especially at the end of life, varies depending on the prescriber's characteristics and attitudes. Little is known about the practices of general practitioners (GPs) regarding end-of-life management for patients with cancer. Objectives: To provide an overview of the characteristics associated with GPs' attitudes and practices regarding opioids prescribing and to explore GPs' perceived role and difficulties in managing end-of-life care for patients with cancer. Design: A cross-sectional study (December 2015 to March 2016). Subjects and Analyses: Data were collected from a representative sample of 376 GPs in southeastern France recruited to participate in a survey on medical practices and opinions regarding cancer patient management. Descriptive analyses and multivariate logistic regressions were conducted to study the characteristics, attitudes, and practices associated with GPs' opioids prescribing attitudes. Results: Almost 97% of GPs stated that they prescribe opioids to end-of-life cancer patients. Among these, 77% said that they prescribe opioids on their own initiative, while 23% declared doing so in coordination with a specialist team. Female GPs, GPs working in solo practices, and GPs reporting more difficulties in managing end-of-life cancer patients were significantly less likely to prescribe opioids on their own initiative. Conclusion: Our results suggest that GPs' characteristics and practices influence the prescribing attitudes at the end of life. Given the dearth of studies on this topic, further research is recommended to better understand the impact of GPs' characteristics on their prescriptive attitudes. The possible interactions between patients' and physicians' characteristics-in particular gender-should also be investigated.

The impact of therapeutic opioid agonists on driving-related psychomotor skills assessed by a driving simulator or an on-road driving task: A systematic review

BACKGROUND

Driving cessation is associated with poor health-related outcomes. People with chronic diseases are often prescribed long-term opioid agonists that have the potential to impair driving. Studies evaluating the impact of opioids on driving-related psychomotor skills report contradictory results likely due to heterogeneous designs, assessment tools and study populations. A better understanding of the effects of regular therapeutic opioid agonists on driving can help to inform the balance between individual's independence and community safety.

AIM

To identify the literature assessing the impact of regular therapeutic opioid agonists on driving-related psychomotor skills for people with chronic pain or chronic breathlessness.

DESIGN

Systematic review reported in accordance with the Preferred Reporting Items for Systematic Review and Meta-analysis statement; PROSPERO Registration CRD42017055909.

DATA SOURCES

Six electronic databases and grey literature were systematically searched up to January, 2017. Inclusion criteria were as follows: (1) empirical studies reporting data on driving simulation, on-the-road driving tasks or driving outcomes; (2) people with chronic pain or chronic breathlessness; and (3) taking regular therapeutic opioid agonists. Critical appraisal used the National Institutes of Health's quality assessment tools.

RESULTS

From 3809 records screened, three studies matched the inclusion criteria. All reported data on people with chronic non-malignant pain. No significant impact of regular therapeutic opioid agonists on people's driving-related psychomotor skills was reported. One study reported more intense pain significantly worsened driving performance.

CONCLUSION

This systematic review does not identify impaired simulated driving performance when people take regular therapeutic opioid agonists for symptom control, although more prospective studies are needed.

Use of Acupuncture in the United States Military Healthcare System

Objectives: The Military Healthcare System (MHS) shows increasing interest in acupuncture as an alternative to opioids for pain control. However, specific factors associated with this procedure in the MHS are not well-described in literature. This study examines usage within the MHS to determine patterns among the diagnoses, provider types, and facilities associated with acupuncture. Materials and Methods: Acupuncture-treated patients were identified from TRICARE claims data in the MHS Data Repository as having at least one acupuncture treatment in fiscal year (FY) 2014. Bivariate analysis was performed to determine demographics, diagnoses, and number of visits, for both active-duty and nonactive-duty personnel. Descriptive statistics were used to show associated provider and facility types. Results: A total of 15,761 people received acupuncture in the MHS in FY 2014. Use of acupuncture was greater for Army service, white race, and senior enlisted rank overall, and for males ages 26-35 among active-duty and females ages 46-64 among nonactive-duty beneficiaries. A cumulative 76% of diagnoses were for musculoskeletal or nerve and system issues. Approximately 60% of patients received acupuncture from physicians, 16% from physical therapists or chiropractors, and 9.7% from physician extenders. Specific acupuncture techniques (traditional, auricular, etc.) could not be determined from the data set. Conclusions: The most common diagnoses associated with acupuncture are consistent with pain management. However, full analysis is hampered by inconsistent coding and lack of granularity regarding specific techniques. Given the popularity of acupuncture in the MHS, further research is necessary to explore the full scope of this intervention.

Opioid Reduction Following Interventional Procedures for Chronic Pain: A Synthesis of the Evidence

The past decade has witnessed the tremendous growth of procedures to treat chronic pain, which has resulted in increased third-party scrutiny. Although most of these procedures appear to be associated with significant pain relief, at least in the short and intermediate term, their ability to improve secondary outcome measures, including function and work status is less clear-cut. One of these secondary outcome measures that has garnered substantial interest in the pain and general medical communities is whether interventions can reduce opioid intake, which is associated with significant risks that in most cases outweigh the benefits in the long term. In the article, we examine whether procedural interventions for chronic pain can reduce opioid intake. Most studies that have examined analgesic reduction as a secondary outcome measure have not separated opioid and nonopioid analgesics, and, among those studies that have, few have demonstrated between-group differences. Reasons for failure to demonstrate opioid reduction can be broadly classified into procedural, design-related, clinical, psychosocial, biological, and pharmacological categories, all of which are discussed. In the future, clinical trials in which this outcome is examined should be designed to evaluate this, at least on a preliminary basis.

Efficacy of Prophylactic Treatment for Oxycodone-Induced Nausea and Vomiting Among Patients with Cancer Pain (POINT): A Randomized, Placebo-Controlled, Double-Blind Trial

BACKGROUND

Although opioid-induced nausea and vomiting (OINV) often result in analgesic undertreatment in patients with cancer, no randomized controlled trials have evaluated the efficacy of prophylactic antiemetics for preventing OINV. We conducted this randomized, placebo-controlled, double-blind trial to evaluate the efficacy and safety of prophylactic treatment with prochlorperazine for preventing OINV.

MATERIALS AND METHODS

Cancer patients who started to receive oral oxycodone were randomly assigned in a 1:1 ratio to receive either prochlorperazine 5 mg or placebo prophylactically, given three times daily for 5 days. The primary endpoint was the proportion of patients who had a complete response (CR) during the 120 hours of oxycodone treatment. CR was defined as no emetic episode and no use of rescue medication for nausea and vomiting during 5 days. Key secondary endpoints were the proportion of patients with emetic episodes, proportion of patients with moderate or severe nausea, quality of life, and proportion of treatment withdrawal.

RESULTS

From November 2013 through February 2016, a total of 120 patients were assigned to receive prochlorperazine (n = 60) or placebo (n = 60). There was no significant difference in CR rates (69.5% vs. 63.3%; p = .47) or any secondary endpoint between the groups. Patients who received prochlorperazine were more likely to experience severe somnolence (p = .048).

CONCLUSION

Routine use of prochlorperazine as a prophylactic antiemetic at the initiation of treatment with opioids is not recommended. Further research is needed to evaluate whether other antiemetics would be effective in preventing OINV in specific patient populations.

IMPLICATIONS FOR PRACTICE

Prophylactic prochlorperazine seems to be ineffective in preventing opioid-induced nausea and vomiting (OINV) and may cause adverse events such as somnolence. Routine use of prophylactic prochlorperazine at the initiation of treatment with opioids is not recommended. Further research is needed to evaluate whether other antiemetics would be effective in preventing OINV in specific patient populations.

Looking beyond the intervertebral disc: the need for behavioral assays in models of discogenic pain

Orthopedic research into chronic discogenic back pain has commonly focused on aging- and degeneration-related changes in intervertebral disc structure, biomechanics, and biology. However, the primary spine-related reason for physician office visits is pain. The ambiguous nature of the human condition of discogenic low back pain motivates the use of animal models to better understand the pathophysiology. Discogenic back pain models must consider both emergent behavioral changes following pain induction and changes in the nervous system that mediate such behavior. Looking beyond the intervertebral disc, we describe the different ways to classify pain in human patients and animal models. We describe several behavioral assays that can be used in rodent models to augment disc degeneration measurements and characterize different types of pain. We review rodent models of discogenic pain that employed behavioral pain assays and highlight a need to better integrate neuroscience and orthopedic science methods to extend current understanding of the complex and multifactorial pathophysiology of discogenic back pain.

Comparison of In Vitro Effects of Opioid Analgesics on Spontaneous Proximal and Distal Colon Contractions in Healthy Rats and Rats with Peritonitis

Objective

The goal of this study was to investigate and compare the effects of opioids on proximal and distal colon contractions in normal rats and rats with peritonitis, with and without the presence of naloxone in the environment.

Methods

The study was approved by Cumhuriyet University Ethics committee. In this study, 16 Wistar Albino male rats were used. Rats were divided into two groups. Peritonitis was induced using a cecum ligation and perforation method, 24 h before the tissues of rats in the peritonitis group were collected, and sham surgery was performed 24 h before the tissues of rats in the control group were collected. Twenty-four hours after the surgery, rats' organs were harvested and hung in organ baths. Concentration-dependent inhibitory effects of morphine and meperidine on spontaneous intestinal movements were observed. Any differences between the groups were tested using the Kruskal-Wallis test, and any differences between the groups were tested using the Tukey test.

Results

No significant difference was observed between the proximal and distal colon smooth muscle contraction responses in both groups after 80 mM Potassium Chloride (KCl) injection (p>0.005). In the peritonitis group, amplitudes and frequencies of spontaneous contractions in proximal and distal colon significantly increased (p<0.05). Drugs decreased the amplitude and frequency responses in the control group (p<0.05). In the peritonitis group, whereas morphine decreased the amplitude and frequency responses in comparison with the control group (p<0.05), meperidine did not cause any significant changes (p>0.05). In both groups, adding naloxone to the organ baths before adding opioids completely blocked the morphine's inhibitory effect on the amplitude and frequency (p<0.05), but it could not completely block the inhibition caused by meperidine.

Conclusion

Morphine and meperidine exhibit an inhibitory effect on the intestinal motility in both groups. This effect can be blocked by naloxone completely in morphine, and partially in meperidine.

Opioids Resistance in Chronic Pain Management

Chronic pain management represents a serious healthcare problem worldwide. Chronic pain affects approximately 20% of the adult European population and is more frequent in women and older people. Unfortunately, its management in the community remains generally unsatisfactory and rarely under the control of currently available analgesics. Opioids have been used as analgesics for a long history and are among the most used drugs; however, while there is no debate over their short term use for pain management, limited evidence supports their efficacy of long-term treatment for chronic non-cancer pain. Therapy with opioids is hampered by inter-individual variability and serious side effects and some opioids often result ineffective in the treatment of chronic pain and their use is controversial. Accordingly, for a better control of chronic pain a deeper knowledge of the molecular mechanisms underlying resistance to opiates is mandatory.

Guidance on opioids prescribing for the management of persistent non-cancer pain in older adults

Many older adults suffer from persistent pain but prevalence studies consistently showed high levels of untreated or under-treated pain in old population. Both persistent pain and pain under-treatment adversely affect independence and quality of life in geriatric patients. Pain management is challenging in this age-group because of the declining organ function, the presence of concurrent diseases and polypharmacy. For all the above reasons, persistent pain in the elderly should be considered a geriatric syndrome per se and effective approaches are warranted. Current guidelines and consensus statements recommend opioid therapy for older adults with moderate-to-severe persistent pain or functional impairment and diminished quality of life due to pain. However clinicians and patients themselves have some concerns about opioids use. Age-related decline in organs functions and warnings about risk of addiction and drug misuse/abuse also in geriatric patients need particular attention for safe prescribing. On the basis of clinical evidence, these practical recommendations will help to improve the competence on opioid role in persistent pain management and the likelihood of a successful analgesic trial in older patients.

Lidocaine Infusion: A Promising Therapeutic Approach for Chronic Pain

Opioid abuse is a national epidemic in the United States, where it is estimated that a prescription drug overdose death occurs every 19 minutes. While opioids are highly effective in acute and subacute pain control, their use for treatment of chronic pain is controversial. Chronic opioids use is associated with tolerance, dependency, hyperalgesia. Although there are new strategies and practice guidelines to reduce opioid dependence and opioid prescription drug overdose, there has been little focus on development of opioid-sparing therapeutic approaches. Lidocaine infusion has been shown to be successful in controlling pain where other agents have failed. The opioid sparing properties of lidocaine infusion added to its analgesic and antihyperalgesic properties make lidocaine infusion a viable option for pain control in opioid dependent patients. In this review, we provide an overview of the opioid abuse epidemic, and we outline current evidence supporting the potential use of lidocaine infusion as an adjuvant therapeutic approach for management of chronic pain.

Acute Pain Management

Acute pain management is improving steadily over the past few years, but training and professional education are still lacking in many professions. Untreated or undertreated acute pain could have detrimental effects on the patient in terms of comfort and recovery from trauma or surgery. Acute undertreated pain can decrease a patient's vascular perfusion, increase oxygen demand, suppress the immune system, and possibly risk increased incidence of venous thrombosis. Although acute postoperative pain needs to be managed aggressively, patients are most vulnerable during this period for developing adverse effects, and therefore, patient assessment and careful drug therapy evaluation are necessary processes in therapeutic planning. Acute pain management requires careful and thorough initial assessment and follow-up reassessment in addition to frequent dosage adjustments, and managing analgesic induced side effects. Analgesic selection and dosing must be based on the patient's past and recent analgesic exposure. There is no single acute pain management regimen that is suitable for all patients. Analgesics must be tailored to the individual patient.

Self-Reported Cognitive Concerns in People With Lower Limb Loss

OBJECTIVES

To investigate differences between self-reported cognitive concerns in people with lower limb loss (LLL) and normative data derived from the U.S. general population, and secondarily to determine whether there were cognitive differences based on amputation etiology or age.

DESIGN

Survey.

SETTING

General community.

PARTICIPANTS

A volunteer sample of persons with LLL (N=1086) resulting from trauma or dysvascular complications who regularly use a prosthetic limb.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURE

The Quality of Life in Neurological Disorders Applied Cognition-General Concerns Short Form version 1.0 (Neuro-QoL ACGC), an 8-item self-report measure of general cognitive concerns.

RESULTS

People with LLL reported significantly more cognitive concerns than the Quality of Life in Neurological Disorders normative sample. Mean Neuro-QoL ACGC scores were significantly lower than normative values (P<.001) across subgroups defined by age (ie, <40, 40-49, 50-59, 60-69, and 70+ years) and subgroups defined by etiology (ie, traumatic and dysvascular LLL). However, there were no significant differences in cognitive concerns among age subgroups (P=.84) or between the etiology subgroups (P=.58).

CONCLUSIONS

When compared with the Quality of Life in Neurological Disorders normative sample, individuals with LLL report greater concerns with cognitive health. Cognitive concerns were not differentially affected by age or cause of amputation. The presence of cognitive concerns in people with LLL suggests a need to assess perceived cognitive function in order to tailor education and training in prosthetic use and care.

Sublethal effects induced by morphine to the freshwater biological model Dreissena polymorpha

Opioids are considered as emerging contaminants in aquatic ecosystems, mainly due to their large illicit consume worldwide. Morphine (MOR) is the main opiate and it was commonly found at measurable concentrations in freshwaters. Even though its occurrence is well documented, just limited information is available regarding its hazard to nontarget organisms. The aim of this study was of the evaluation of sublethal effects induced by MOR to the freshwater bivalve Dreissena polymorpha. We exposed mussels to two MOR concentrations (0.05 µg/L and 0.5 µg/L) for 14 days and we investigated the sublethal effects by a suite of biomarkers. The Neutral Red Retention Assay (NRRA) was used as a test of cytotoxicity, while the oxidative stress was evaluated by the activity of antioxidant and detoxifying enzymes, namely catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx) and glutathione-S-transferase (GST), and by measuring the levels of lipid peroxidation (LPO) and protein carbonylation (PCC). The genetic damage was assessed by the Single Cell Gel Electrophoresis (SCGE) assay, the DNA diffusion assay and the micronucleus test (MN test). Finally, the filtration rate of D. polymorpha was evaluated in order to investigate possible physiological effects. Both tested concentrations reduced the lysosome membrane stability of bivalves, but only the highest MOR concentration induced significant changes in the activity of antioxidant enzymes (SOD, CAT, and GPx) and increase in lipid peroxidation levels. Slight increase in primary DNA fragmentation was noticed, while no fixed genetic damage and alterations of the filtering rate were found.

Tolerability, Safety, and Quality of Life with Tapentadol Prolonged Release (PR) Compared with Oxycodone/Naloxone PR in Patients with Severe Chronic Low Back Pain with a Neuropathic Component: A Randomized, Controlled, Open-label, Phase 3b/4 Trial

OBJECTIVE

To evaluate tolerability, safety, and quality-of-life outcomes in non-opioid-pretreated patients with severe chronic low back pain with a neuropathic component receiving tapentadol PR vs. oxycodone/naloxone PR.

METHODS

Eligible patients (average pain intensity [numerical rating scale] ≥ 6; painDETECT positive/unclear ratings) were randomized to twice-daily tapentadol PR 50 mg or oxycodone/naloxone PR 10 mg/5 mg. After a 21-day titration (maximum twice-daily doses: tapentadol PR 250 mg, or oxycodone/naloxone PR 40 mg/20 mg plus oxycodone PR 10 mg), target doses were continued for 9 weeks. Change in the Patient Assessment of Constipation Symptoms (PAC-SYM) total score from baseline to final evaluation was a primary endpoint.

RESULTS

For the primary tolerability-related endpoint, the 97.5% exact repeated confidence interval for tapentadol PR minus oxycodone/naloxone PR for the PAC-SYM total score was [-0.259, 0.121], showing noninferiority (upper limit < 0.7). Incidences of constipation and vomiting were significantly lower with tapentadol PR than oxycodone/naloxone PR (P ≤ 0.045). Confirmatory superiority based on formal noninferiority was shown for the primary effectiveness endpoint (change from baseline to final evaluation in pain intensity) for tapentadol PR vs. oxycodone/naloxone PR (presented separately). Improvements in the Short Form-12 physical component summary and EuroQol-5 Dimension health status index and health state assessment were significantly greater with tapentadol PR vs. oxycodone/naloxone PR (P ≤ 0.024).

CONCLUSIONS

Tapentadol PR had a minimal impact on bowel function (noninferior to oxycodone/naloxone PR) and, along with superior effectiveness (presented separately), was associated with significantly lower incidences of constipation and vomiting and significant improvements in quality-of-life measures vs. oxycodone/naloxone PR.

Scientific Evaluation of Pharmacological Treatment of Osteoarthritis in the Canon of Medicine

Osteoarthritis is the most common articular disease worldwide. Nonetheless, common osteoarthritis treatments are either not effective or associated with side effects. Now the materials derived from plants have found a relevant place in drug discovery. Until the mid-18th century, osteoarthritis in all medical schools worldwide had been managed as general arthritis. Avicenna, the famous scholar of Iranian traditional medicine has provided a long list of herbs that have been used traditionally to treat arthritis. To gain this worthy list, we searched his most famous medical masterpiece: Canon of Medicine. Some of these materials are investigated and employed by modern medicine. However, it is difficult to ignore that still more of these naturally occurring materials could be of use in modern medicine not only to prevent osteoarthritis progression but also osteoarthritis management as natural anti-inflammatory drugs.

Prophylactic Use of Antiemetics for Prevention of Opioid-Induced Nausea and Vomiting: A Questionnaire Survey among Japanese Physicians

BACKGROUND

Antiemetics are being used both for the treatment and prophylaxis of opioid-induced nausea and vomiting (OINV) in clinical practice, despite the lack of evidence for the prophylactic benefit. Data regarding the actual status of prophylactic antiemetic use for OINV remain to be elucidated.

OBJECTIVE

The objective of this study was to evaluate the practice among Japanese physicians of the prophylactic use of antiemetics when starting opioids prescription for the prevention of opioid-induced nausea and vomiting.

METHODS

This questionnaire survey was targeted among physicians experienced in cancer pain treatment at two institutions of Japan (Nagoya University Hospital and Ichinomiya City Municipal Hospital). The questionnaire assessed the physicians' practice and beliefs regarding the prophylactic antiemetics prescription when they start opioids in patients with cancer pain.

RESULTS

Questionnaires were filled in and received from 112 physicians from two institutions. Eighty-two percent of physicians prescribed prophylactic antiemetics at the beginning of opioid prescription, and the most commonly prescribed drug for this purpose was prochlorperazine (88%).

CONCLUSION

Despite the lack of evidence, Japanese physicians commonly prescribe prophylactic antiemetics, most commonly prochlorperazine, for OINV. Prospective clinical trials are necessary to evaluate the efficacy of this practice.

Tapentadol extended release in the management of peripheral diabetic neuropathic pain

Tapentadol, a μ-opioid agonist and norepinephrine reuptake inhibitor, has been found to be an effective medication for a wide variety of chronic pain conditions, including back pain, cancer-related pain, and arthritic pain. It has also been found to have fewer gastrointestinal side effects than more traditional opioid-based therapies. More recently, tapentadol extended release has been demonstrated to be effective in the management of painful diabetic neuropathy, an often debilitating condition affecting approximately one-third of all patients with diabetes. This review highlights the most up-to-date basic and clinical studies by focusing on the mechanisms of action of tapentadol and its clinical efficacy, especially with regard to painful diabetic neuropathy.

Nauclea latifolia Smith (Rubiaceae) exerts antinociceptive effects in neuropathic pain induced by chronic constriction injury of the sciatic nerve

ETHNOPHARMACOLOGICAL RELEVANCE

The roots of Nauclea latifolia Smith (Rubiaceae) popularly known as "koumkouma" is used in traditional Cameroonian medicine as neuropathic pain remedy and for the treatment of headache, inflammatory pain and convulsion. This study was conducted to evaluate the antinociceptive effects of the alkaloid fraction isolated from Nauclea latifolia in neuropathic pain induced by chronic constriction injury (CCI) of the sciatic nerve in rat.

MATERIALS AND METHODS

Bioactive-guided fractionation of the root extracts of Nauclea latifolia using the Von Frey in a rat model of neuropathic pain (Benett model), afforded a potent anti-hyperalgesic fraction IV. Further fractionation of this fraction was performed by high-performance liquid chromatography (HPLC), yielded eight sub-fractions (F1-F8) which were tested for antinociceptive effects. The alkaloid fraction (F3) collected by HPLC, exhibited potent antinociceptive effects, and the anti-allodynic and anti-hyperalgesic effects of this fraction (8, 16, 40 and 80 mg/kg) were determined using the von Frey and acetone tests respectively in a rat model of neuropathic pain. Rota-rod performance and catalepsy tests were used for the assessment of motor coordination.

RESULTS

The alkaloid fraction (80 mg/kg) administered intraperitoneally induced a completely decreased hyperalgesia 90 min post-dosing. In the acetone test, the Nauclea latifolia fraction at 80mg/kg showed its maximal anti-allodynic effects 120 min post-injection. The areas under the curve (AUC) of the anti-allodynic or anti-hyperalgesic effects produced by the alkaloid fraction at 80 mg/kg were significantly (p<0.001) greater than the AUC of effects produced by vehicle in CCI rats. The alkaloid fraction did not exhibit any significant effects on the spontaneous locomotor activity of the mice in rota-rod performance and no sign of catalepsy was observed.

CONCLUSION

The analysis of the effects, expressed as the time course of AUC, supports the traditional use of Nauclea latifolia in neuropathic pain therapy. The pharmacological and chemical studies are continuing in order to characterize the mechanism(s) responsible for this anti-hyperalgesic and anti-allodynic action and also to identify the active substances present in the roots extracts of Nauclea latifolia.

A randomized, double-blind, placebo-controlled, parallel-group study to evaluate the efficacy and safety of the extended-release tramadol hydrochloride/acetaminophen fixed-dose combination tablet for the treatment of chronic low back pain

BACKGROUND

Chronic low back pain is a common condition that is often difficult to treat. The combination of tramadol hydrochloride and acetaminophen in an extended-release formulation has been shown to provide rapid and long-lasting analgesic effects resulting from the synergistic activity of these 2 active ingredients.

OBJECTIVE

The goal of this study was to evaluate the efficacy and safety of extended-release tramadol hydrochloride 75-mg/acetaminophen 650-mg fixed-dose combination tablets (TA-ER) for the treatment of chronic low back pain.

METHODS

This Phase III, double-blind, placebo-controlled, parallel-group study enrolled 245 patients with moderate to severe (≥4 cm on a 10-cm visual analog scale) chronic (≥3 months') low back pain insufficiently controlled by previous NSAIDs or cyclooxygenase-2-selective inhibitors and randomly assigned them to receive 4 weeks of either TA-ER or placebo. The primary efficacy end point was the percentage of patients with a pain intensity change rate ≥30% from baseline to final evaluation. Secondary end points included quality of life (Korean Short Form-36), functionality (Korean Oswestry Disability Index), and adverse events.

RESULTS

The percentage of patients with a pain intensity change rate ≥30% was significantly higher (P < 0.05) in the TA-ER group than in the placebo group for both the full analysis set and the per-protocol population. Pain relief success rate from baseline was significantly higher with TA-ER versus placebo at days 8 and 15 but not at the final visit. Patients in the TA-ER group had significant improvements versus placebo in role-physical, general health, and reported health transition domains of the Korean Short Form-36 and significantly higher functional improvements in the personal care section of the Korean Oswestry Disability Index. Patient assessment of overall pain control as "very good" was also significantly higher with TA-ER than with placebo. Adverse events were reported more frequently with TA-ER than with placebo; the most common adverse events reported were nausea, dizziness, constipation, and vomiting.

CONCLUSIONS

TA-ER was significantly more effective than placebo in providing pain relief, functional improvements, and improved quality of life. It exhibited a predictable safety profile in patients with chronic low back pain. ClinicalTrials.gov identifier: NCT01112267.

The management of chronic pain in important patient subgroups

Chronic pain is a major healthcare issue in Europe and globally, and inadequate or undertreated pain significantly reduces the ability of many patients to participate in ordinary daily activities, adversely affects their employment status and contributes to a substantial rate of depression and anxiety in patients with chronic pain. There is a broad distinction of chronic pain into chronic non-cancer pain and chronic cancer pain, and important subgroups of these include patients with rheumatic and/or orthopaedic diseases, pain syndromes caused by cancer itself and caused by cancer treatment. Despite comprising the majority of non-cancer pain in Europe, chronic non-cancer pain associated with rheumatic diseases and/or orthopaedic conditions is often inadequately managed. Although paracetamol and non-steroidal anti-inflammatory drugs (NSAIDs) play a continuing role in the treatment of chronic rheumatic diseases, accumulating evidence of potential toxicity with both traditional non-selective NSAIDs and selective cyclooxygenase 2 inhibitors has prompted a reassessment of their use. This has particular resonance for the elderly, who are more likely to have significant pain issues than younger patients and are at high risk of NSAID-related adverse events. The use of mild opioids, such as codeine and tramadol, and strong opioids, such as morphine, hydromorphone and oxycodone, may be appropriate where paracetamol and other non-opioid analgesics are ineffective in chronic non-cancer pain. Cancer pain, either related to the underlying disease or caused by cancer treatment, is also a common cause of chronic pain in the elderly. An understanding of individual needs is essential in providing adequate pain relief, which is a central goal of care in all patients with chronic pain.

Treatment of chronic pain in older people: evidence-based choice of strong-acting opioids

In the treatment of chronic malignant and non-malignant pain, opioids are used as strong analgesics. Frail elderly patients often have multiple co-morbidities and use multiple medicines, leading to an increased risk of clinically relevant drug-drug and drug-disease interactions. Age-related changes and increased frailty may lead to a less predictable drug response, increased drug sensitivity, and potential harmful drug effects. As a result, physicians face a complex task in prescribing medication to elderly patients. In this review, the appropriateness of the strong-acting opioids buprenorphine, fentanyl, hydromorphone, methadone, morphine, oxycodone and tapentadol is determined for use in elderly patients. Evidence-based recommendations for prescribing strong opioids to the frail elderly are presented. A literature search was performed for all individual drugs, using a validated and published set of 23 criteria concerning effectiveness, safety, pharmacokinetics and pharmacodynamics, experience, and convenience in elderly patients. First, information on the criteria was obtained from pharmaceutical reference books and a MEDLINE search. The information obtained on the individual drugs in the class of opioids was compared with the reference drug morphine. Evidence-based recommendations were formulated on the basis of the pros and cons for the frail elderly. Using the set of 23 criteria, no differentiation can be made between the appropriateness of buprenorphine, fentanyl, hydromorphone, morphine and oxycodone for use in elderly patients. Methadone has strong negative considerations in the treatment of chronic pain in the frail elderly. Methadone has a high drug-drug interaction potential and is associated with prolongation of the QT interval and a potential risk of accumulation due to a long elimination half-life. In addition, methadone is difficult to titrate because of its large inter-individual variability in pharmacokinetics, particularly in the frail elderly. Because of a lack of empiric knowledge, the use of tapentadol is not recommended in frail elderly persons. Nevertheless, tapentadol may prove to be a useful analgesic for the treatment of chronic pain in frail elderly persons because of its possible better gastrointestinal tolerability. In the treatment of chronic pain in the frail elderly, the opioids of first choice are buprenorphine, fentanyl, hydromorphone, morphine and oxycodone. In order to improve the convenience for elderly patients, the controlled-release oral dosage forms and transdermal formulations are preferred.

Will abuse-deterrent formulations of opioid analgesics be successful in achieving their purpose?

During the last 2 decades, there has been a dramatic increase in the use of strong opioids for chronic non-cancer pain. This increase has been accompanied by a steep increase in abuse, misuse, and both fatal and non-fatal overdoses involving prescription opioids. The situation is already alarming in the US. Prescription opioid-related harm is a complex, multifactorial issue that requires a multifaceted solution. In this respect, formulations of opioid analgesics designed to resist or deter abuse may be a useful component of a comprehensive opioid risk minimization programme. Such formulations have or are being developed. Abuse-resistant opioids include those that use some kind of physical barrier to prevent tampering with the formulation. Abuse-deterrent opioids are not necessarily resistant to tampering, but contain substances that are designed to make the formulation less attractive to abusers. This article focuses on two products intended to deter abuse that were reviewed by the US Food and Drug Administration (FDA). The first (Embeda®) consists of extended-release morphine with sequestered naltrexone, an opioid antagonist that is released if the tablet is compromised by chewing or crushing. Although Embeda® exhibited abuse-deterrent features, its label warns that it can be abused in a manner similar to other opioid agonists. Furthermore, tampering with Embeda® will result in the release of naltrexone, which may precipitate withdrawal in opioid-tolerant individuals. In March 2011, all dosage forms of Embeda® were recalled because the product failed to meet routine stability standards, and its return date to the market is currently unknown. The second product (Acurox®) was intended to be both tamper resistant and abuse deterrent. It consisted of an immediate-release oxycodone tablet with subtherapeutic niacin as an aversive agent and used a gel-forming ingredient designed to inhibit inhalation and prevent extraction of the drug for injection. The new drug application for Acurox® was rejected in 2010 by the FDA because of concerns about the potential abuse-deterrent benefits of niacin. While acknowledging that no one formulation can be expected to deter all types of opioid-abusive behaviours and no product is likely to be abuse proof in the hands of clear and determined abusers, the reductions in abuse these new products would provide may be an incremental step towards safer prescription opioids.

Clinical benefit in patients with metastatic bone disease: results of a phase 3 study of denosumab versus zoledronic acid

BACKGROUND

Patients with metastatic bone disease are living longer in the metastatic stage due to improvements in cancer therapy, making strategies to prevent the aggravation of bone disease and its complications, such as skeletal-related events (SREs) and pain, increasingly important.

PATIENTS AND RESULTS

In this phase 3 trial in patients with advanced cancer (excluding breast and prostate cancer) or multiple myeloma, denosumab reduced the risk of radiation to bone by 22% relative to zoledronic acid (P = 0.026), prevented worsening of pain and pain interference (2-point increase in Brief Pain Inventory score; P < 0.05 versus zoledronic acid), and reduced the frequency of a shift from no/weak opioid analgesic use to strong opioids (P < 0.05 versus zoledronic acid at months 3-5). Denosumab delayed the time to moderate-to-severe pain compared with zoledronic acid in patients with mild or no pain at the baseline (P = 0.04), supporting early treatment. Health-related quality-of-life scores were similar in both groups. The number needed to treat to avoid one SRE for denosumab was 3 patient-years versus placebo and 10 patient-years versus zoledronic acid.

CONCLUSION

The use of denosumab was associated with better prevention of the complications of metastatic bone disease secondary to solid tumors or multiple myeloma versus zoledronic acid.

Heterogeneity of chronic pain

Chronic pain is a widespread public health issue that has many effects on physical, emotional and cognitive functions. An estimated 10-55% of all adults are thought to have chronic pain. Chronic pain is a multifactorial condition, caused by the complex interplay of nociceptive, neuropathic or mixed pathogenic mechanisms. Chronic pain is associated with specific and non-specific medical conditions such as cancer, HIV/AIDS, rheumatoid arthritis, fibromyalgia, osteoarthritis, low back pain or spinal stenosis and is broadly categorized as cancer pain and non-cancer pain. Evaluation of chronic pain requires a clear understanding of the nature of the pain and its underlying pathophysiology. Adequate assessment of pain, using validated tools, is an essential prerequisite of successful pain management. Unidimensional scales are useful for the measurement of pain intensity, while multidimensional scales measure both pain intensity and the extent to which pain interferes with life activity and emotional functioning. Patients should be reassessed and followed up in order to monitor progress and measure improvements in pain.

Barriers to pain management: focus on opioid therapy

Despite the availability of effective pain treatments, there are numerous barriers to effective management resulting in a large proportion of patients not achieving optimal pain control. Chronic pain is inadequately treated because of a combination of cultural, societal, educational, political and religious constraints. The consequences of inadequately treated pain are physiological and psychological effects on the patient, as well as socioeconomic implications. Unreasonable failure to treat pain is viewed as unethical and an infringement of basic human rights. The numerous barriers to the clinical management of pain vary depending on whether they are viewed from the standpoint of the patient, the physician, or the institution. Identification and acknowledgement of the barriers involved are the first steps to overcoming them. Successful initiatives to overcome patient, physician and institutional barriers need to be multifaceted in their approach. Multidisciplinary initiatives to improve pain management include dissemination of community-based information, education and awareness programmes to attempt to change attitudes towards pain treatment. A better awareness and insight into the problems caused by unrelieved pain and greater knowledge about the efficacy and tolerability of available pain management options should enable physicians to seek out and adhere to treatment guidelines, and participate in interventional and educational programmes designed to improve pain management, and for institutions to implement the initiatives required. Although much work is underway to identify and resolve the issues in pain management, many patients still receive inadequate treatment. Continued effort is required to overcome the known barriers to effective pain management.

Outcomes associated with a cognitive-behavioral chronic pain management program implemented in three public HIV primary care clinics

In patients with HIV/AIDS, chronic pain is common and analgesics pose serious risks. Cognitive-behavioral therapies (CBT) provide an alternative. This study evaluated feasibility and impact of a CBT-based pain management program in three public primary care clinics for HIV patients. The program included a workbook and 12-weeks of group CBT sessions. HIV-positive patients with chronic moderate to severe pain were invited to participate in the program and were assessed at enrollment, 6, 12, and 24 weeks. Despite only moderate group attendance, program enrollment was associated with significant improvements in pain intensity, pain-related functioning, anxiety and acceptance, and mental health. At 24 weeks, effect sizes for pain outcomes were -0.83 for pain intensity and -0.43 for functioning. The pattern of change in outcomes was consistent with predictions based on cognitive-behavioral theory. Effects were observed at all clinics. Adding CBT-based pain management into primary care may provide important benefits for patients with HIV/AIDS.

Controlled release formulation of oxycodone in patients with moderate to severe chronic osteoarthritis: a critical review of the literature

Osteoarthritis (OA) is a physically and emotionally debilitating disease that predominantly affects the aging adult population. Current pharmacologic treatment options primarily consist of nonsteroidal anti-inflammatory drugs and/or acetaminophen, but associated side effects, analgesic limitations, especially in the elderly, and the need for around-the-clock analgesia have led physicians to search for alternative analgesics. Opioids have shown effectiveness at mitigating both chronic cancer and noncancer pain, and their ability to be placed into controlled release (CR) formulations suggests that they may prove efficacious for OA patients. One formulation, oxycodone CR, has shown effectiveness in cancer pain patients and in some trials of noncancer low back pain. In this review, the objective was to synthesize the reported findings by researchers in this field and present an up-to-date look at the efficacy, safety, and tolerability of oxycodone CR in OA patients. Public literature databases were searched using specific keywords (eg, oxycodone CR) for studies assessing the efficacy and safety profile of oxycodone CR and its use in patients with OA. A total of eleven articles that matched the criteria were identified, which included three placebo-controlled trials, six comparative trials, one pharmacokinetic study in the elderly, and one long-term safety trial. Analysis of the studies revealed that oxycodone CR is reasonably efficacious, safe, and tolerable when used to manage moderate to severe chronic OA pain, with similar side effects to that of other opioids.