Pain management in patients with cancer: focus on opioid analgesics

Development of a Potential-Modulated Electrochemiluminescence Measurement System for Selective and Sensitive Determination of the Controlled Drug Codeine

Codeine is a common analgesic drug that is a pro-drug of morphine. It also has a high risk of abuse as a recreational drug because of its extensive distribution as an OTC drug. Therefore, sensitive and selective screening methods for codeine are crucial in forensic analytical chemistry. To date, a commercial analytical kit has not been developed for dedicated codeine determination, and there is a need for an analytical method to quantify codeine in the field. In the present work, potential modulation was combined with electrochemiluminescence (ECL) for sensitive determination of codeine. The potential modulated technique involved applying a signal to electrodes by superimposing an AC potential on the DC potential. When tris(2,2'-bipyridine)ruthenium(II) ([Ru(bpy)3]2+) was used as an ECL emitter, ECL activity was confirmed for codeine. A detailed investigation of the electrochemical reaction mechanism suggested a characteristic ECL reaction mechanism involving electrochemical oxidation of the opioid framework. Besides the usual ECL reaction derived from the amine framework, selective detection of codeine was possible under the measurement conditions, with clear luminescence observed in an acidic solution. The sensitivity of codeine detection by potential modulated-ECL was one order of magnitude higher than that obtained with the conventional potential sweep method. The proposed method was applied to codeine determination in actual prescription medications and OTC drug samples. Codeine was selectively determined from other compounds in medications and showed good linearity with a low detection limit (150 ng mL-1).

Opioid Use at End-Of-Life Among Nova Scotia Patients With Cancer

Purpose: To determine the factors associated with opioid analgesic prescriptions as measured by community pharmacy dispensations to all Nova Scotia (NS) patients with cancer at end-of-life from 2005 to 2009.

Methods: The NS Cancer Registry and the NS Prescription Monitoring Program (NSPMP) were used to link Nova Scotians who had a cancer diagnosis and received a prescription for opioids in their last year of life (n = 6,186) from 2005 to 2009. The association of factors with opioid dispensations at end-of-life were determined (e.g., patient demographics, type of prescriber, type of cancer, and opioid type, formulation, and dose).

Results: Almost 54% (n = 6,186) of the end-of-life study population with cancer (n = 11,498) was linked to the NSPMP and therefore dispensed opioids. Most prescriptions were written by general practitioners (89%) and were for strong opioids (81%). Immediate-release formulations were more common than modified-release formulations. Although the annual average parenteral morphine equivalents (MEQ) did not change during the study period, the number of opioid prescriptions per patient per year increased from 5.9 in 2006 to 7.0 in 2009 (p < 0.0001). Patients age 80 and over received the fewest prescriptions (mean 3.9/year) and the lowest opioid doses (17.0 MEQ) while patients aged 40–49 received the most prescriptions (mean 14.5/year) and the highest doses of opioid (80.2 MEQ).

Conclusion: Our study examined opioid analgesic use at end-of-life in patients with cancer for a large real-world population and determined factors, trends and patterns associated with type and dose of opioid dispensed. We provide information regarding how general practitioners prescribe opioid therapy to patients at end-of-life. Our data suggest that at the time of this study, there may have been under-prescribing of opioids to patients with cancer at end-of-life. This information can be used to increase awareness among general practitioners, and to inform recommendations from professional regulatory bodies, to aid in managing pain for cancer patients at end-of-life. Future work could address how opioid prescribing has changed over time, and whether efforts to reduce opioid prescribing in response to the opioid crisis have affected patients with cancer at end-of-life in Nova Scotia.

An overview of the use and misuse/abuse of opioid analgesics in different world regions and future perspectives

Opioids are an important therapeutic option for severe resistant chronic pain but, in the absence of proper oversight, their use has risks. The level of prescription opioid misuse/abuse differs among countries, due to differences in healthcare systems and pain management approaches. However, evaluating the true dimension of prescription opioid misuse/abuse is complicated by statistical reporting which often does not differentiate between prescription and illicit opioid use, or between prescription opioid use by patients and nonpatients, highlighting a need for greater uniformity. Parallel efforts to educate patients and the general public about opioid risks, facilitate appropriate analgesic prescribing and identify alternative formulations or options to use instead of or with opioids, may contribute to optimizing prescription opioid use for pain management.

Corticosteroid dosing and opioid use are high in patients with SLE and remain elevated after belimumab initiation: a retrospective claims database analysis

Objectives

To investigate corticosteroid and opioid use among patients with SLE and to examine the impact of belimumab initiation on the use of other SLE therapies.

Methods

We identified adult patients with SLE (International Classification of Diseases, 9th Revision/10th Revision 710.0 and M32) between 1 January 2012 and 31 May 2018 (earliest SLE diagnosis=index date) within MarketScan administrative claims data. Patients were followed from index date for a minimum of 12 months and until the earlier of disenrolment in their health plan or study end (31 May 2018). Corticosteroid utilisation, corticosteroid dose (in prednisone equivalents) and opioid utilisation (overall, by strength (weak, strong) and by duration (chronic use defined as >90 days of cumulative drug supply)) were measured during follow-up. Oral corticosteroid and opioid use were compared in the 6 months before and after initiation of belimumab.

Results

There were 49 413 patients with SLE eligible for analysis (mean (SD) age: 50.1 (14.0) years, 90.2% female). Of these, 68.5% received corticosteroids, and the average number of prescriptions was 4.59 (4.11) over the first 12 months of follow-up. Among patients with oral corticosteroids, average daily dose was 19.4 (14.2) mg and 59.6% had an average daily dose of ≥15 mg. Half (52.6%) had at least one opioid prescription and of these, 34.6% had chronic use over the first 12 months of follow-up. Among patients initiating belimumab during follow-up (n=1710), oral corticosteroid use decreased by 9.1% (p=0.001), and average daily dose decreased from 14.5 (18.4) mg to 11.9 (18.0) mg (p<0.001) in the 6 months after initiation compared with the 6 months prior. Initiation of belimumab had no impact on prevalence of opioid use.

Conclusions

A high proportion of patients with SLE are treated with corticosteroids to control SLE and opioid therapy to manage chronic pain. While there was no change in opioid use, oral corticosteroid use and dose intensity decreased following initiation of belimumab.

Factors related to pain management adequacy in patients receiving palliative care: data from a tertiary hospital in Indonesia

BACKGROUND Adequate pain management must be applied to improve the quality of life, particularly in patients receiving palliative care. Thus, this study aimed to determine the factors related to pain management adequacy in patients receiving palliative care. METHODS This cross-sectional study included all patients sent for consultation to the palliative care team complaining of pain in Cipto Mangunkusumo Hospital, Jakarta, Indonesia from 2016 to 2018. All data such as gender, age, employment status, disease type, primary cancer location, pain intensity, analgesic drug treatment duration, and the presence of anxiety and depression were retrieved from medical records. Pain management adequacy was evaluated using the pain management index. Logistic regression included all variables with p<0.25 related to pain management adequacyin bivariate analysis. RESULTS Out of 175 patients with pain, 85.7% reported having adequate pain management. Pain was more adequately treated in patients with employment (p = 0.001), milder pain intensity (p<0.001), those using opioids (p<0.001), and those who did not experience anxiety (p = 0.05). Factors related to pain management adequacy were opioid use (OR = 3.23, 95% CI = 1.71–6.13) and milder pain (OR = 11.15, 95% CI = 3.89–31.99). CONCLUSIONS Most of the patients received adequate pain management which related to opioid use and milder pain.

Meta-analysis of clinical trials to assess denosumab over zoledronic acid in bone metastasis

Background Bone metastases-induced skeletal complications result in reduced patient survival, lower quality of life, and an increase in healthcare costs. Previously, zoledronic acid (ZA) was the standard choice of treatment for bone metastases, but another drug, denosumab, has also shown promise. However, the clinical utility of these two drugs requires further exploration. Aim of the review Due to the lack of direct comparisons regarding the efficacy of these drugs in both solid tumors and multiple myeloma (MM), we herein tried to conduct a meta-analysis to compare their efficacy in parallel for bone metastases treatment in both solid tumor and MM patients. Methods Multiple databases including Cochrane Library, MEDLINE, EMBASE, and Web of Science were searched to identify randomized controlled trials (RCTs) reported up to March 2019 directly comparing denosumab with ZA in solid tumors and MM. Information about the following events was primarily searched: time to first on-study skeletal-related event (SRE), time to first and subsequent SREs, and overall survival. Information about secondary outcomes including disease progression, pain, health-related quality of life, and adverse events was also recorded. Results Overall, we analyzed data from four distinct RCTs including 7441 patients, and our analysis revealed that patients in the denosumab group had a significantly delayed incidence to the first and subsequent SREs. In addition, denosumab resulted in a higher incidence of hypocalcemia and osteonecrosis of the jaw (ONJ), and a lower incidence of renal toxicity and acute phase reactions, in comparison to ZA. Conclusion Overall, denosumab showed superiority in delaying the first and subsequent SREs, and hence seems to be a promising choice for managing bone metastases in both solid tumors and MM. However, it can induce a higher incidence of ONJ and hypocalcaemia, but these are preventable and manageable effects.

Topical Ketamine with Other Adjuvants: Underutilized for Refractory Cancer Pain? A Case Series and Suggested Revision of the World Health Organization Stepladder for Cancer Pain

Background: Uncontrolled cancer pain is a significant problem in palliative medicine. Opioids are often first-line treatment that increase risks of analgesic tolerance and hyperalgesia. Topical ketamine with other adjuvant pain medications is an often-overlooked treatment, yet may be most effective in difficult-to-treat cancer pain.

Objective: We report a case series of hospice patients with uncontrolled cancer pain who were suboptimally treated with opioids and nerve blocks, whose symptoms responded to topical ketamine with other adjuvants. We review the pronociceptive properties of opioids and how topical multimodal treatment of cancer pain can be more effective than standard opioids, other topical adjuvant medications, and nerve blocks. We discuss the shortcomings of the World Health Organization (WHO) stepladder for the treatment of cancer pain and suggest an adjuvant treatment algorithm, directing physicians to appropriate adjuvant pain agents based on pain type and distinct receptor actions.

Design: This is a retrospective case series of patients who responded to topical multimodal pain treatment with implementation of findings into an addendum to the WHO stepladder.

Subjects: Subjects were from a case series of community-based hospice patients with previously uncontrolled cancer pain.

Measurement: Measurement was made by self-report of pain levels using the 10-point numeric pain rating scale.

Results: Patients' pain was controlled with topical adjuvant medications with return to previously lost function and prevention of otherwise escalating opioid dosing.

Conclusions: These patient cases reveal how ketamine-based topical treatment for cancer pain can be more effective than standard opioids, other topical adjuvant medications, and nerve blocks with no noted side effects and observed reduction in opioid consumption.

Preparation of bivalent agonists for targeting the mu opioid and cannabinoid receptors

In order to obtain novel pharmacological tools and to investigate a multitargeting analgesic strategy, the CB₁ and CB₂ cannabinoid receptor agonist JWH-018 was conjugated with the opiate analgesic oxycodone or with an enkephalin related tetrapeptide. The opioid and cannabinoid pharmacophores were coupled via spacers of different length and chemical structure. In vitro radioligand binding experiments confirmed that the resulting bivalent compounds bound both to the opioid and to the cannabinoid receptors with moderate to high affinity. The highest affinity bivalent derivatives 11 and 19 exhibited agonist properties in [³⁵S]GTPγS binding assays. These compounds activated MOR and CB (11 mainly CB₂, whereas 19 mainly CB₁) receptor-mediated signaling, as it was revealed by experiments using receptor specific antagonists. In rats both 11 and 19 exhibited antiallodynic effect similar to the parent drugs in 20 μg dose at spinal level. These results support the strategy of multitargeting G-protein coupled receptors to develop lead compounds with antinociceptive properties.

Getting Back to Living: Further Evidence for the Efficacy of an Interdisciplinary Pediatric Pain Treatment Program

OBJECTIVE

This study examined key functional outcomes following a 3-week interdisciplinary pediatric pain rehabilitation program for adolescents with chronic pain. Maintenance of gains was evaluated at 3-month follow-up.

METHODS

Participants included 171 adolescents (12 to 18 y of age) with chronic pain who completed a hospital-based outpatient pediatric pain rehabilitation program. Participants completed measures of functional disability, depressive symptoms, pain catastrophizing, opioid use, school attendance, and pain severity at admission, discharge, and at 3-month follow-up.

RESULTS

Similar to other interdisciplinary pediatric pain rehabilitation program outcome studies, significant improvements were observed at the end of the program. These improvements appeared to be maintained or further improved at 3-month follow-up. Nearly 14% of the patients were taking daily opioid medication at admission to the program. All adolescents were completely tapered off of these medications at the end of the 3-week program and remained abstinent at 3-month follow-up.

DISCUSSION

This study adds to the available data supporting interdisciplinary pediatric pain rehabilitation as effective in improving functioning and psychological distress even when discontinuing opioids. Implications for future research and limitations of the study are discussed.

Effectiveness of Percutaneous Celiac Plexus Ablation in the Treatment of Severe Cancer Pain in Upper Abdomen and Evaluation of Health Economics

Objective:

To compare the effectiveness, adverse effects, and cost-effectiveness of percutaneous neurolytic celiac plexus block (NCPB) versus traditional medication strategies for the treatment of patients with advanced cancer having severe upper abdominal cancer pain.

Methods:

This retrospective study included 81 patients with advanced upper abdominal cancer admitted to The Sixth People’s Hospital Affiliated to Shanghai Jiaotong University between January 2013 and July 2014. The patients were divided into percutaneous NCPB (treatment) and medication for pain (control) groups. The outcomes were measured in terms of Numeric Rating Scale (NRS) score and Karnofsky Performance Status (KPS) score before treatment and on the 3rd, 7th, 14th, and 28th days posttreatment. The effectiveness and cost-effectiveness of the therapy were assessed using analysis of the health economics.

Results:

The improvements in NRS score (1.42 ± 1.09 vs 4.03 ± 0.96, P < .01) and KPS score (65.55 ± 9.09 vs 63.03 ± 8.961, P < .01) in the treatment group were significantly superior compared to the control group on the 7th day of treatment, followed by no significant difference between the 2 groups on the 14th and the 28th day of treatment. Health economics evaluation revealed that the medicine-specific costs and total health care costs were significantly reduced in the treatment group compared to the control group ( P < .05), but no significant differences between the 2 groups ( P > .05) were seen in the costs of hospitalization, examinations, and treatment.

Conclusion:

The percutaneous NCPB method shows promising results and better cost-effectiveness for treating patients with advanced cancer having severe upper abdominal pain.

Prescribed opioids in primary care: cross-sectional and longitudinal analyses of influence of patient and practice characteristics

OBJECTIVES

To examine trends in opioid prescribing in primary care, identify patient and general practice characteristics associated with long-term and stronger opioid prescribing, and identify associations with changes in opioid prescribing.

DESIGN

Trend, cross-sectional and longitudinal analyses of routinely recorded patient data.

SETTING

111 primary care practices in Leeds and Bradford, UK.

PARTICIPANTS

We observed 471 828 patient-years in which all patients represented had at least 1 opioid prescription between April 2005 and March 2012. A cross-sectional analysis included 99 847 patients prescribed opioids between April 2011 and March 2012. A longitudinal analysis included 49 065 patient-years between April 2008 and March 2012. We excluded patients with cancer or treated for substance misuse.

MAIN OUTCOME MEASURES

Long-term opioid prescribing (4 or more prescriptions within 12 months), stronger opioid prescribing and stepping up to or down from stronger opioids.

RESULTS

Opioid prescribing in the adult population almost doubled for weaker opioids over 2005-2012 and rose over sixfold for stronger opioids. There was marked variation among general practices in the odds of patients stepping up to stronger opioids compared with those not stepping up (range 0.31-3.36), unexplained by practice-level variables. Stepping up to stronger opioids was most strongly associated with being underweight (adjusted OR 3.26, 1.49 to 7.17), increasing polypharmacy (4.15, 3.26 to 5.29 for 10 or more repeat prescriptions), increasing numbers of primary care appointments (3.04, 2.48 to 3.73 for over 12 appointments in the year) and referrals to specialist pain services (5.17, 4.37 to 6.12). Compared with women under 50 years, men under 50 were less likely to step down once prescribed stronger opioids (0.53, 0.37 to 0.75).

CONCLUSIONS

While clinicians should be alert to patients at risk of escalated opioid prescribing, much prescribing variation may be attributable to clinical behaviour. Effective strategies targeting clinicians and patients are needed to curb rising prescribing, especially of stronger opioids.

Heterogeneity of tumor cells in the bone microenvironment: Mechanisms and therapeutic targets for bone metastasis of prostate or breast cancer

Bone is the most common target organ of metastasis of prostate and breast cancers. This produces considerable morbidity due to skeletal-related events, SREs, including bone pain, hypercalcemia, pathologic fracture, and compression of the spinal cord. The mechanism of bone metastasis is complex and involves cooperative reciprocal interaction among tumor cells, osteoblasts, osteoclasts, and the mineralized bone matrix. The interaction between the metastatic tumor and bone stromal cells has been commonly referred to as the "vicious cycle". Tumor cells stimulate osteoblasts, which in turn stimulate osteoclasts through the secretion of cytokines such as the TNF family member receptor activator of nuclear κB ligand (RANKL). Activated osteoclasts degrade the bone matrix by producing strong acid and proteinases. Bone degradation by osteoclasts releases TGFβ and other growth factors stored in the bone matrix, that further stimulate tumor cells. Bone modifying agents, targeting osteoclast activity, such as bisphosphonate and RANKL antibodies are considered as the standard of care for reducing SREs of patients with bone metastatic diseases. These agents decrease osteoclast activity and delay worsening of skeletal pain and aggravation of bone metastatic diseases. While the management of SREs by these agents may improve patients' lives, this treatment does not address the specific issues of the patients with bone metastasis such as tumor dormancy, drug resistance, or improvement of survival. Here, we review the mechanisms of bone metastasis formation, tumor heterogeneity in the bone microenvironment, and conventional therapy for bone metastatic diseases and discuss the potential development of new therapies targeting tumor heterogeneity in the bone microenvironment.

Acute and subchronic antinociceptive effects of nociceptin/orphanin FQ receptor agonists infused by intrathecal route in rats

Severe pain occurs in the context of many diseases and conditions and is a leading cause of disability. Nociceptin/orphanin FQ (N/OFQ) is the endogenous ligand of the N/OFQ peptide (NOP) receptor. This peptidergic system controls pain transmission and in particular spinally administered N/OFQ has robust antinociceptive properties. The aim of this study was to investigate the spinal antinociceptive properties of NOP peptide agonists after acute and subchronic treatment in rats. Doses unable to alter motor coordination were selected. UFP-112 (full NOP agonist) and UFP-113 (partial NOP agonist) were administered intrathecally (i.t.) by spinal catheterization. Acute injection of UFP-112 induced antinociceptive response at lower dosages (0.03-1nmol i.t.) compared to morphine and similar to N/OFQ. UFP-113 was effective in a 0.001-1nmol i.t. dose range. The antinociceptive effects of NOP ligands were no longer evident in rats knockout for the NOP gene, while those of morphine were maintained. The continuous spinal infusion (by osmotic pumps) of 0.1nmol/h UFP-112 and UFP-113 showed antinociceptive action comparable to 1-3nmol/h morphine or N/OFQ. The antinociceptive effect of morphine progressively decreased and was no longer significant after 6 days of treatment. Similar results were obtained with N/OFQ, UFP-112, and UFP-113. The acute i.t. injection of morphine in animals tolerant to N/OFQ and UFP-112 evoked analgesic effects. Neither morphine nor N/OFQ induced antinociceptive effects in morphine- and UFP-113-tolerant rats. In conclusion this study highlights the analgesic efficacy and potency of UFP-112 and UFP-113 underlining the relevance of NOP system in analgesia.

Emerging therapies for patients with symptoms of opioid-induced bowel dysfunction

Opioid-induced bowel dysfunction (OIBD) comprises gastrointestinal (GI) symptoms, including dry mouth, nausea, vomiting, gastric stasis, bloating, abdominal pain, and opioid-induced constipation, which significantly impair patients’ quality of life and may lead to undertreatment of pain. Traditional laxatives are often prescribed for OIBD symptoms, although they display limited efficacy and exert adverse effects. Other strategies include prokinetics and change of opioids or their administration route. However, these approaches do not address underlying causes of OIBD associated with opioid effects on mostly peripheral opioid receptors located in the GI tract. Targeted management of OIBD comprises purely peripherally acting opioid receptor antagonists and a combination of opioid receptor agonist and antagonist. Methylnaltrexone induces laxation in 50%–60% of patients with advanced diseases and OIBD who do not respond to traditional oral laxatives without inducing opioid withdrawal symptoms with similar response (45%–50%) after an oral administration of naloxegol. A combination of prolonged-release oxycodone with prolonged-release naloxone (OXN) in one tablet (a ratio of 2:1) provides analgesia with limited negative effect on the bowel function, as oxycodone displays high oral bioavailability and naloxone demonstrates local antagonist effect on opioid receptors in the GI tract and is totally inactivated in the liver. OXN in daily doses of up to 80 mg/40 mg provides equally effective analgesia with improved bowel function compared to oxycodone administered alone in patients with chronic non-malignant and cancer-related pain. OIBD is a common complication of long-term opioid therapy and may lead to quality of life deterioration and undertreatment of pain. Thus, a complex assessment and management that addresses underlying causes and patomechanisms of OIBD is recommended. Newer strategies comprise methylnaltrexone or OXN administration in the management of OIBD, and OXN may be also considered as a preventive measure of OIBD development in patients who require opioid administration.

Palliative strategies for the management of primary and metastatic spinal tumors

BACKGROUND

Technological advances during the last few decades have improved the success rate of surgery for the treatment of malignant spinal tumors. Nonetheless, many patients present with widespread tumor burden and minimal life expectancy, which excludes them from being surgical candidates. For these patients, palliative management is recommended.

METHODS

The authors reviewed prospective and retrospective clinical studies as well as case series regarding palliative treatments for primary and metastatic spinal tumors.

RESULTS

Analgesics, ranging from nonopioids to strong opioids, may be used depending on the degree of pain. Steroids may also improve pain relief, although they are associated with a number of adverse events. Vertebroplasty and kyphoplasty are conservative treatments with high rates of pain relief and vertebral body stabilization. Radiotherapy is the gold standard for palliative management, with approximately 60% of patients experiencing a decrease in tumor-related spinal pain and up to 35% experiencing complete relief. Stereotactic radiosurgery delivers high doses of radiation to patients to provide pain relief while also sparing delicate anatomical structures.

CONCLUSION

Palliative management of spinal tumors is diverse. Analgesics may be used in conjunction with radiotherapy and/or kyphoplasty or vertebroplasty to offer pain relief.

Pain management of the cancer patient

INTRODUCTION

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

AREAS COVERED

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

EXPERT OPINION

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

Fixed ratio (2:1) prolonged-release oxycodone/naloxone combination improves bowel function in patients with moderate-to-severe pain and opioid-induced constipation refractory to at least two classes of laxatives

OBJECTIVE

The effects of combined oxycodone/naloxone prolonged release tablets (OXN PR) were investigated in patients with moderate-to-severe chronic cancer-related or non-cancer pain. All patients had opioid-induced constipation (OIC) which persisted despite substantial laxative therapy.

RESEARCH DESIGN AND METHODS

This pooled analysis included 75 patients with OIC at study entry that was refractory to at least two laxatives with different modes of action. Patients completed randomized, double-blind treatment with OXN PR 20-120 mg/day for either 12 weeks (OXN 9001: non-cancer pain study) or 4 weeks (OXN 2001: cancer-related pain study). Analgesia and bowel function were assessed using the Brief Pain Inventory Short Form and Bowel Function Index (BFI), respectively. Use of laxative medication and safety were assessed throughout the studies.

CLINICAL TRIAL REGISTRATION

NCT00513656, EudraCT 2005-002398-57, EudraCT 2005-003510-15.

RESULTS

Statistically and clinically significant improvements in bowel function were observed following double-blind treatment with OXN PR. Mean (SD) reduction in BFI score was 21.2 (28.8) and comparable in patients with cancer-related (19.0 [28.9]) and non-cancer pain (23.3.[29.0]; P ≤ 0.0002). Furthermore, the proportion of patients with a BFI score within normal range (≤28.8) increased from 9.5% at screening to 43.1% at Day 15 of OXN PR. While all patients used ≥2 laxatives of different classes at screening, during study treatment 36% stopped using laxatives (P < 0.001). OXN PR provided effective analgesia, evidenced by stable pain scores during study treatment, and there were no unanticipated adverse events.

CONCLUSIONS

OXN PR significantly improved bowel function and reduced the use of laxatives in patients with OIC, previously unresponsive to at least two different classes of laxatives. OXN also provided effective analgesia for patients with moderate-to-severe cancer-related pain and non-cancer-related pain.

Pattern of QTc prolongation in Methadone Maintenance Therapy (MMT) subjects receiving different methadone dosages: A prospective cohort study

Objectives: This study aimed to compare the QTc interval between low and high dose methadone groups and evaluate the pattern of QTc variation.

Methods: This is a prospective cohort study conducted from December 2010 till August 2011 at Malaysian University of Science’s Hospital. Forty six subjects, grouped in high dose (>80mg) and low dose (<80mg) oral methadone, were followed-up at 4-weekly for QTc measurements. Relevant demographic and biochemical profiles were taken at intervals with concurrent QTc measurements.

Results: No significant QTc differences between methadone dosage groups were found at Week 0 (434ms vs 444ms, p = 0.166) and week 8 (446.5ms vs 459ms, p = 0.076), but not at week 4(435ms vs 450ms, p = 0.029). However, there were significant associations between the groups with QT_c prolongation at week 0 and 4 (OR 4.29(95% CI 1.01, 18.72) p=0.044 and OR 5.18 (95% CI 1.34, 20.06) p =0.013, respectively) but not at week 8 (OR 2.44 (95% CI 0.74, 8.01) p=0.139). On multivariate analysis, dose group was the sole significant factor for QT_c prolongation for week 0 and 4 (p values 0.047 and 0.017, respectively), but not at week 8.

Conclusion: High-dose methadone group is more likely to develop prolonged QTc than low-dose group. However, such effects were inconsistent and occurred even during chronic methadone therapy, mandating judicious QTc and serum methadone monitoring.

Morphine sensitivity of spinal neurons in the chronic constriction injury neuropathic rat pain model

Opioid analgesia involves suppression of neuronal activity in central sensory pathways. We show that the classic opioid morphine reduces spinal neuronal spontaneous and evoked activity after induction of neuropathy by chronic constriction injury of the sciatic nerve in rats. The minimal effective dose of morphine was 0.3 mg/kg for most response parameters tested. Morphine sensitivity of spinal cord neurons is similar across neuropathic pain models. We therefore conclude that nerve damage per se rather than the experimental model determines the effectiveness of opioids in general and investigate several pain measurement endpoints which might be important to clinically determine morphine's efficacy in neuropathic pain.

The place of oxycodone/naloxone in chronic pain management

Opioid analgesics are usually effective in the management of severe chronic pain. However, symptoms of opioid-induced bowel dysfunction (OIBD) are common during opioid therapy. Opioid-induced bowel dysfunction is often unsuccessfully managed due to limited effectiveness and numerous adverse effects of traditional laxatives. Newer treatment possibilities directed at the pathomechanism of OIBD comprise combined prolonged-release oxycodone with prolonged-release naloxone (oxycodone/naloxone) tablets. Oxycodone/naloxone provides effective analgesia with limited impact on bowel function as oxycodone displays high oral bioavailability and naloxone act as local antagonist on opioid receptors in the gastrointestinal tract due to nearly complete inactivation in the liver. Oxycodone/naloxone is administered to opioid-naive patients with severe pain and those unsuccessfully treated with weak opioids. Oxycodone/naloxone may be also administered to patients treated with strong opioids who experience intense symptoms of OIBD. Studies conducted to date indicate that oxycodone/naloxone is an important drug in chronic pain management, prevention and treatment of OIBD.

Pain treatment in patients infected with human immunodeficiency virus in later stages: pharmacological aspects

Pain is a common and debilitating symptom of human immunodeficiency virus (HIV) disease, although it is often underestimated and undertreated, especially in HIV-infected intravenous drug users. It is more likely to occur in the later stages of the HIV disease, where it assumes particular significance, especially in terminally ill patients. However, its successful management is possible, though the goal of effective therapy is hampered by the side effects of highly active antiretroviral therapy and drug-drug interactions. In order to appraise these issues, a search in MEDLINE database was conducted. Book reviews and a search on relevant Web sites were also included. Treatment of HIV is itself very complex and becomes even more difficult when palliative therapy is added. Protease inhibitors, mainly ritonavir, and nonnucleoside reverse transcriptase inhibitors have higher interaction potential, due to their inducer or inhibitory actions on cytochrome P450, posing a risk when coadministered with palliative treatments; so, better outcomes can be achieved with knowledge of pharmacological aspects.

Quality of life and supportive care for patients with metastatic renal cell carcinoma

In recent years, a key issue in the management of patients with metastatic renal cell carcinoma (mRCC) has been the assessment of health-related quality of life (HRQoL), particularly following the introduction of targeted therapies that have brought significant improvements in progression-free survival and quality of life in these patients. HRQoL is becoming one of the main factors influencing choice of therapy, and HRQoL experienced during first-line treatment may affect the choice of the second-line therapy. Consequently, several trials have been conducted to evaluate the impact of approved targeted therapies for mRCC on HRQoL, and this measure is being introduced with increasing frequency in the trial design. With respect to agents used after progression on cytokines, sunitinib and temsirolimus have yielded better HRQoL scores, and sorafenib and pazopanib have shown stable HRQoL scores compared with placebo. Regarding targeted agents approved for patients who progress on a first-line tyrosine kinase inhibitor, everolimus has shown to delay and reduce the degree of Karnofsky performance status deterioration compared with placebo. Moreover, evidence obtained from these trials shows that tumor response and delay in disease progression affect HRQoL. In this article, we review the different HRQoL scales used to evaluate patients with mRCC along with the results obtained in clinical trials. Given that HRQoL is determined not only by treatment-related effects but also by mRCC symptoms and its clinical complications, the characteristics and appropriate treatment of the most commonly experienced symptoms, including anorexia, fatigue, pain, anemia, and venous thromboembolism, are also reviewed.

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.

The role of corticosteroids in the treatment of pain in cancer patients

Pain is one of the most frequent and most distressing symptoms in the course of cancer. The management of pain in cancer patients is based on the concept of the World Health Organization (WHO) analgesic ladder and was recently updated with the EAPC (European Association for Palliative Care) recommendations. Cancer pain may be relieved effectively with opioids administered alone or in combination with adjuvant analgesics. Corticosteroids are commonly used adjuvant analgesics and play an important role in neuropathic and bone pain treatment. However, in spite of the common use of corticosteroids, there is limited scientific evidence demonstrating their efficacy in cancer patients with pain. The use of corticosteroids in spinal cord compression, superior vena cava obstruction, raised intracranial pressure, and bowel obstruction is better established than in other nonspecific indications. This review aims to present the role of steroids in pain and management of other symptoms in cancer patients according to the available data, and discusses practical aspects of steroid use.