A Systematic Review of Prospective Studies Reporting Adverse Events of Commonly Used Opioids for Cancer-Related Pain: A Call for the Use of Standardized Outcome Measures

Patient-Controlled Subcutaneous Analgesia with Hydromorphone versus Oral Oxycontin for Opioid Titration of Cancer Pain: A Prospective Multicenter Randomized Trial

Background

Studies have shown that oral oxycontin tablets can be used for opioid titration. The European Society for Medical Oncology (ESMO) guidelines for adult cancer pain recommend opioid titration through the parenteral route, usually the intravenous or subcutaneous route. Patient-controlled subcutaneous analgesia (PCSA) with hydromorphone needs further evaluation for opioid titration. This prospective multicenter study was designed to compare the efficacy and safety of hydromorphone PCSA with oral oxycontin tablets for opioid titration of cancer pain.

Patients and Methods

Eligible patients with cancer pain were randomly assigned in a 1:1 ratio to the PCSA group or the oxycontin group for dose titration. Different titration methods were given in both groups depending on whether the patient had an opioid tolerance. The primary endpoint of this study was time to successful titration (TST).

Results

A total of 256 patients completed this study. The PCSA group had a significantly lower TST compared with the oxycontin group (median [95% confidence interval (CI)], 5.5[95% CI:2.5-11.5] hours vs.16.0 [95% CI:11.5-22.5] hours; p<0.001). The frequency (median; interquartile) of breakthrough pain (Btp) over 24 hours was significantly lower in the PCSA group (2.5;2.0-3.5) than in the oxycontin group.(3.0; 2.5-4.5) (p=0.04). The pain was evaluated by numeric rating scale (NRS) score at 12 hours after the start of titration. The pain score (median; interquartile) was significantly lower in the PCSA versus the oxycontin group (2.5;1.5-3.0) vs 4.5;3.0-6.0) (p=0.02). The equivalent dose of oral morphine (EDOM) for a successful titration was similar in both groups (p=0.29), but there was a significant improvement in quality of life (QoL) in both groups (p=0.03). No between-group difference in the incidence of opioid-related adverse effects was observed (p=0.32).

Conclusion

Compared with oral oxycontin tablet, the use of PCSA with hydromorphone achieved a shorter titration duration for patients with cancer pain (p<0.001), without significantly increasing adverse events (p=0.32).

Comparison of different sustained-release opioids and acute respiratory conditions in patients with cancer and chronic kidney disease

STUDY OBJECTIVE

Few data are available on the association between the use of oxycodone in patients with chronic kidney disease (CKD) and acute respiratory conditions. The aim of this study was to investigate whether oxycodone is associated with an increased risk of acute respiratory conditions in patients with cancer and CKD compared with other opioids.

DESIGN AND SETTING

The data were obtained from a claims database in Japan. Patients with cancer and CKD who had received sustained-release opioids, including oral oxycodone, oral morphine, or transdermal fentanyl, between April 2014 and May 2021 were selected. The primary outcome was defined as an acute respiratory condition. Data for age and sex, morphine equivalent daily dose, concomitant use of specified medications, comorbidities defined based on the modified Charlson comorbidity index, substance use disorder, and lung cancer or metastatic lung cancer were investigated as covariates. Distribution of acute respiratory conditions was compared among the three sustained-release opioid groups using the log-rank test. Estimates of the incidence of acute respiratory conditions were compared among the groups using a Cox proportional hazards model with time-varying variables.

MAIN RESULTS

A significant difference in the distribution of acute respiratory conditions was found among the three groups (p < 0.01). Cox regression analysis showed a significantly higher risk of acute respiratory conditions with morphine (hazard ratio [HR]: 3.04, 95% confidence interval [CI]: 1.07-8.65, p = 0.04) compared with oxycodone but no significant difference in risk with oxycodone (HR 0.67, 95% CI: 0.32-1.38, p = 0.27) compared with fentanyl.

CONCLUSIONS

The findings suggest that the risk of acute respiratory conditions may be lower in patients with CKD who use oxycodone for cancer pain than in those who use morphine. Additionally, no difference in the risk of acute respiratory conditions was found between oxycodone and fentanyl use.

Prevalence of opioid-induced adverse events across opioids commonly used for analgesic treatment in Japan: a multicenter prospective longitudinal study

PURPOSE

Although opioids have been shown to be effective for cancer pain, opioid-induced adverse events (AEs) are common. To date, little is known about the differences in risks of AEs by opioid type. This study was performed to compare the prevalence of AEs across opioids commonly used for analgesic treatment in Japan.

METHODS

This study was conducted as a preplanned secondary analysis of a multicenter prospective longitudinal study of inpatients with cancer pain who received specialized palliative care for cancer pain relief. We assessed daily AEs until termination of follow-up. We rated the severity of AEs based on the Common Terminology Criteria for Adverse Events version 5.0. We computed adjusted odds ratios for each AE (constipation, nausea and vomiting, delirium, and drowsiness) with the following variables: opioid, age, sex, renal dysfunction, and primary cancer site.

RESULTS

In total, 465 patients were analyzed. Based on the descriptive analysis, the top four most commonly used opioids were included in the analysis: oxycodone, hydromorphone, fentanyl, and tramadol. With respect to the prevalence of AEs among all analyzed patients, delirium (n = 25, 6.3%) was the most frequent, followed by drowsiness (n = 21, 5.3%), nausea and vomiting (n = 19, 4.8%), and constipation (n = 28, 4.6%). The multivariate logistic analysis showed that no single opioid was identified as a statistically significant independent predictor of any AE.

CONCLUSION

There was no significant difference in the prevalence of AEs among oxycodone, fentanyl, hydromorphone, and tramadol, which are commonly used for analgesic treatment in Japan.

Oxycodone for cancer-related pain

BACKGROUND

Many people with cancer experience moderate to severe pain that requires treatment with strong opioids, such as oxycodone and morphine. Strong opioids are, however, not effective for pain in all people, neither are they well tolerated by all people. The aim of this review was to assess whether oxycodone is associated with better pain relief and tolerability than other analgesic options for adults with cancer pain. This is an updated Cochrane review previously published in 2017.

OBJECTIVES

To assess the effectiveness and tolerability of oxycodone by any route of administration for pain in adults with cancer.

SEARCH METHODS

For this update, we searched the Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library, MEDLINE and MEDLINE In-Process (Ovid), Embase (Ovid), Science Citation Index, Conference Proceedings Citation Index - Science (ISI Web of Science), BIOSIS (ISI), and PsycINFO (Ovid) to November 2021. We also searched four trial registries, checked the bibliographic references of relevant studies, and contacted the authors of the included studies. We applied no language, date, or publication status restrictions.

SELECTION CRITERIA

We included randomised controlled trials (parallel-group or cross-over) comparing oxycodone (any formulation or route of administration) with placebo or an active drug (including oxycodone) for cancer background pain in adults by examining pain intensity/relief, adverse events, quality of life, and participant preference.

DATA COLLECTION AND ANALYSIS

Two review authors independently sifted the search, extracted data and assessed the included studies using standard Cochrane methodology. We meta-analysed pain intensity data using the generic inverse variance method, and pain relief and adverse events using the Mantel-Haenszel method, or summarised these data narratively along with the quality of life and participant preference data. We assessed the overall certainty of the evidence using GRADE.

MAIN RESULTS

For this update, we identified 19 new studies (1836 participants) for inclusion. In total, we included 42 studies which enrolled/randomised 4485 participants, with 3945 of these analysed for efficacy and 4176 for safety. The studies examined a number of different drug comparisons. Controlled-release (CR; typically taken every 12 hours) oxycodone versus immediate-release (IR; taken every 4-6 hours) oxycodone Pooled analysis of three of the four studies comparing CR oxycodone to IR oxycodone suggest that there is little to no difference between CR and IR oxycodone in pain intensity (standardised mean difference (SMD) 0.12, 95% confidence interval (CI) -0.1 to 0.34; n = 319; very low-certainty evidence). The evidence is very uncertain about the effect on adverse events, including constipation (RR 0.71, 95% CI 0.45 to 1.13), drowsiness/somnolence (RR 1.03, 95% CI 0.69 to 1.54), nausea (RR 0.85, 95% CI 0.56 to 1.28), and vomiting (RR 0.66, 95% CI 0.38 to 1.15) (very low-certainty evidence). There were no data available for quality of life or participant preference, however, three studies suggested that treatment acceptability may be similar between groups (low-certainty evidence). CR oxycodone versus CR morphine The majority of the 24 studies comparing CR oxycodone to CR morphine reported either pain intensity (continuous variable), pain relief (dichotomous variable), or both. Pooled analysis indicated that pain intensity may be lower (better) after treatment with CR morphine than CR oxycodone (SMD 0.14, 95% CI 0.01 to 0.27; n = 882 in 7 studies; low-certainty evidence). This SMD is equivalent to a difference of 0.27 points on the Brief Pain Inventory scale (0-10 numerical rating scale), which is not clinically significant. Pooled analyses also suggested that there may be little to no difference in the proportion of participants achieving complete or significant pain relief (RR 1.02, 95% CI 0.95 to 1.10; n = 1249 in 13 studies; low-certainty evidence). The RR for constipation (RR 0.75, 95% CI 0.66 to 0.86) may be lower after treatment with CR oxycodone than after CR morphine. Pooled analyses showed that, for most of the adverse events, the CIs were wide, including no effect as well as potential benefit and harm: drowsiness/somnolence (RR 0.88, 95% CI 0.74 to 1.05), nausea (RR 0.93, 95% CI 0.77 to 1.12), and vomiting (RR 0.81, 95% CI 0.63 to 1.04) (low or very low-certainty evidence). No data were available for quality of life. The evidence is very uncertain about the treatment effects on treatment acceptability and participant preference. Other comparisons The remaining studies either compared oxycodone in various formulations or compared oxycodone to different alternative opioids. None found any clear superiority or inferiority of oxycodone for cancer pain, neither as an analgesic agent nor in terms of adverse event rates and treatment acceptability. The certainty of this evidence base was limited by the high or unclear risk of bias of the studies and by imprecision due to low or very low event rates or participant numbers for many outcomes.

AUTHORS' CONCLUSIONS

The conclusions have not changed since the previous version of this review (in 2017). We found low-certainty evidence that there may be little to no difference in pain intensity, pain relief and adverse events between oxycodone and other strong opioids including morphine, commonly considered the gold standard strong opioid. Although we identified a benefit for pain relief in favour of CR morphine over CR oxycodone, this was not clinically significant and did not persist following sensitivity analysis and so we do not consider this important. However, we found that constipation and hallucinations occurred less often with CR oxycodone than with CR morphine; but the certainty of this evidence was either very low or the finding did not persist following sensitivity analysis, so these findings should be treated with utmost caution. Our conclusions are consistent with other reviews and suggest that, while the reliability of the evidence base is low, given the absence of important differences within this analysis, it seems unlikely that larger head-to-head studies of oxycodone versus morphine are justified, although well-designed trials comparing oxycodone to other strong analgesics may well be useful. For clinical purposes, oxycodone or morphine can be used as first-line oral opioids for relief of cancer pain in adults.

Less Well-Known Consequences of the Long-Term Use of Opioid Analgesics: A Comprehensive Literature Review

BACKGROUND

The adverse effects of short-term opioid analgesics are well known and acknowledged; however, the spectrum of the sequelae of long-term use seems less clear. Some effects may remain undetected but still have the potential to cause harm and reduce patients' quality of life.

OBJECTIVE

To review the literature on the adverse effects of long-term opioid therapy.

METHODS

We performed a quasi-systematic search, analyzing articles published in the MEDLINE database between January 2000 and March 2021 that identified adverse effects of opioids used for chronic pain treatment.

RESULTS

Growing evidence indicates that there are multiple serious adverse effects of opioid treatment. Long-term opioid use may have significant effects on the endocrine, immune, cardiovascular, respiratory, gastrointestinal, and neural systems. Studies show that long-term opioid treatment increases the risk of fractures, infections, cardiovascular complications, sleep-disordered breathing, bowel dysfunction, overdose, and mortality. Opioids may potentially affect cancer development. Most consequences of the long-term use of opioids have been identified in studies of patients with non-malignant pain.

CONCLUSION

Studies indicate that long-term use of opioids increases the risk of drug-related events in a significant number of patients. Clinicians should be aware of these complications associated with prescribing opioids, discuss them with patients, prevent complications, if possible, and diagnose them early and manage adequately. More human studies are needed to assess the risk, including trials with individual opioids, because they have different adverse effect profiles.

Opioid Use in Patients With Cervical Cancer at Two Urban Medical Centers

Purpose

Patients with cervical cancer are at high risk for opioid use. This study aimed to characterize opioid prescribing patterns at 2 urban hospitals.

Methods and Materials

Data from patients with cervical cancer treated with curative intent from 2011 to 2018 were retrospectively collected. Women with unrelated chronic opioid use before diagnosis, persistent/recurrent disease at 3 months after initiation of treatment, or initiation of opioids >6 months after treatment were excluded. Demographics, disease characteristics, treatment, and outpatient prescription practices were collected. Endpoints included duration of opioid use ≥6 and ≥12 months.

Results

There were 106 women included, of whom 83% received definitive radiation. Most patients (n = 91, 85.8%) received outpatient opioids. Most common timing of prescriptions were before cancer therapy (35.9%), postprocedure (26.4%), and during radiation therapy (17.0%). Median duration was 3 (interquartile range, 1-11) months; 35.2% of these patients received opioids ≥6 months and 22% received opioids ≥12 months. Greater International Federation of Gynaecology and Obstetrics (FIGO) stage, recurrent/residual disease, initiation of opioids before treatment, history of depression or anxiety, and use of gabapentin or steroids were associated with long-term opioid use.

Conclusions

Most patients were prescribed outpatient opioids, many of whom used opioids for 12 months. Improvement in provider communication and education, increased posttreatment monitoring, and further evaluation of nonopioid therapies are needed in this patient population to reduce long-term opioid use.

Ai-Tong-An-Gao-Ji and Fisetin Inhibit Tumor Cell Growth in Rat CIBP Models by Inhibiting the AKT/HIF-1α Signaling Pathway

BACKGROUND

Ai-Tong-An-Gao-Ji (ATAGJ) has been extensively applied for acute bone cancer pain treatment with a satisfactory efficacy, while the specific mechanisms remain unclear and require further investigation.

METHODS

Overlapped genes of ATAGJ and CIBP obtained from SwissTargetPrediction website and GeneCards database were presented as a Venn diagram. A network diagram of drug-component-target was further established using the Cytoscape 3.6.0 software. The effect of fisetin on Walker 256 cell proliferation was observed by clone formation assay and EDU assay, and the interaction between fisetin and AKT was revealed using the immunoprecipitation assay. Effects of fisetin on AKT/HIF-1α signaling pathway in Walker 256 cells were ultimately detected using Western blot and qPCR assays.

RESULTS

The key component fisetin and core target gene AKT were sorted out using the drug-component-target network with a binding energy between fisetin and AKT less than -5 kcal/mol. Clone formation assay and EDU assay showed that fisetin substantially suppressed the proliferation of Walker 256 cells. Immunoprecipitation assay results revealed that the combination of fisetin and AKT decreased the level of AKT/HIF-1α signaling pathway of Walker 256 cells.

CONCLUSIONS

The fisetin of ATAGJ can markedly suppress Walker 256 cells, and the mechanisms may be intimately associated with the combination of fisetin and AKT. Furthermore, fisetin decreased the level of p-AKT and inhibited the expression of the AKT/HIF-1α signaling pathway.

Translating Evidence to Practice: A Multisite Collaboration to Implement Guidelines and Improve Constipation Management in Patients With Cancer

Despite the high incidence of constipation in people with cancer, there is little research on management strategies for opioid-induced constipation (OIC). This project used the Plan-Do-Study-Act model to examine implementation of the Oncology Nursing Society GuidelinesTM to improve constipation management in patients with cancer. Nurse champions at four sites identified practice gaps, including providing education on OIC for patients who are new to opioids and increasing follow-up assessment. This project demonstrates that multisite, collaborative projects are feasible and may enhance patient quality of life and decrease anticipated complications.

Adverse Drug Reactions in Japanese Patients with End-Stage Heart Failure Receiving Continuous Morphine Infusion: A Single-Center Retrospective Cohort Study

BACKGROUND

Opioids have been reported to be effective for refractory dyspnea in patients with advanced heart failure (HF) in the palliative care setting.

OBJECTIVE

The aim of this study was to evaluate the incidence of adverse drug reactions (ADRs) and their relationship with morphine dose/duration or renal insufficiency in patients with end-stage HF receiving continuous morphine infusion.

METHODS

We retrospectively studied 38 patients with end-stage HF receiving continuous intravenous or subcutaneous morphine infusion for the relief of breathlessness between 2014 and 2019 (mean age 78 years). The endpoints were nausea/vomiting, respiratory depression, and drowsiness, which are common morphine-related ADRs.

RESULTS

Of 38 patients with end-stage HF receiving continuous intravenous/subcutaneous morphine infusion, 14 (37%) experienced ADRs. The median estimated glomerular filtration rate (eGFR) was lower in patients with than in those without ADRs (16 [range 9-48] vs. 41 [range 8-133], respectively; p = 0.011). The ADRs with the highest incidence were drowsiness (n = 13), nausea/vomiting (n =5), and respiratory depression (n =3). There were no differences in the maintenance dose or duration of morphine administration between patients with and without ADRs. A baseline eGFR of 32 mL/min/1.73 m² was a good cutoff value for ADR prediction (sensitivity 86%, specificity 96%). A baseline eGFR < 32 mL/min/1.73 m² was significantly associated with the occurrence of morphine-related ADRs (odds ratio 6.63, 95% confidence interval 1.19-37.01).

CONCLUSIONS

Our results showed that 37% of patients with end-stage HF receiving continuous intravenous/subcutaneous morphine infusion experienced ADRs, especially drowsiness. Patients with eGFR < 32 mL/min/1.73 m² were likely to experience morphine-related ADRs.

Validity and Reliability of the Hindi Version of the Patient Assessment of Constipation Quality of Life Questionnaire in Cancer Patients on Opioids for Pain Management at Tertiary Care Center, India

Background:

Opioid-induced constipation (OIC) causes a significant worsening of quality of life (QOL). The patient assessment of constipation QOL questionnaire (PAC-QOL) is a validated scale in English language to assess the QOL in patients with chronic constipation and guide the management by measuring response to a targeted therapy.

Objective:

The objective of the study was to evaluate the validity and reliability of PAC-QOL questionnaire after translation in Hindi language for Indian cancer patients with OIC.

Materials and Methods:

This was a prospective observational cross-sectional study. Three hundred and thirteen adult cancer patients receiving opioid treatment for pain and experiencing self-reported symptoms of constipation were evaluated. The severity of constipation was assessed at baseline and at an interval of at least 2 weeks by the physician using constipation scoring system (CSS) and self-reported Hindi version of PAC-QOL questionnaire.

Results:

The data obtained from 313 patients were taken for analysis. The internal consistency of the tool was established with the favorable value of Cronbach's alfa coefficient (i.e., >0.70) obtained for all four subgroups and overall score. The intraclass correlation coefficient value of >0.70 also established good correlation between overall and subgroups scores of Hindi version of PAC-QOL, obtained at 1^st and 2^nd visit. It was observed from the result that a significant correlation existed between the overall and subgroups scores of Hindi version of PAC-QOL and CSS, thus establishing concurrent validity.

Conclusion:

It was concluded from the study results that Hindi version of PAC-QOL is both reliable and valid to assess the QOL in patients with OIC.

Opioid-induced constipation in patients with cancer: a "real-world," multicentre, observational study of diagnostic criteria and clinical features

The aim of this study was to investigate opioid-induced constipation (OIC) in a large cohort of "real-world" patients with cancer; the objectives were to determine the prevalence of OIC, the utility of a simple screening question, the accuracy of the Rome IV diagnostic criteria, the clinical features of OIC (physical and psychological), and the impact of OIC (quality of life). One thousand patients with cancer were enrolled in the study, which involved completion of the Rome IV diagnostic criteria for OIC, the Bowel Function Index, the Patient Assessment of Constipation Quality of Life questionnaire, and the Memorial Symptom Assessment Scale-Short Form. Participants also underwent a thorough clinical assessment by an experienced clinician (ie, "gold-standard" assessment of OIC). Fifty-nine percent of patients were clinically assessed as having OIC, 2.5% as having another cause of constipation, and 19% as not having constipation but were taking regular laxatives. The simple screening question produced a number of false-negative results (19% of patients), whereas the Rome IV diagnostic criteria had an accuracy of 81.9%. Patients with OIC had more symptoms overall, higher Memorial Symptom Assessment Scale-Short Form subscale scores (and total score), and higher Patient Assessment of Constipation Quality of Life questionnaire subscale scores (and the overall score). Opioid-induced constipation was not associated with demographic factors, cancer diagnosis, performance status, or opioid equivalent dosage: OIC was associated with opioid analgesic, with patients receiving tramadol and transdermal buprenorphine having less constipation. The study confirms that OIC is common among patients with cancer pain and is associated with a spectrum of physical symptoms, a range of psychological symptoms, and an overall deterioration in the quality of life.

Opioid-induced constipation in patients with cancer pain in Japan (OIC-J study): a post hoc subgroup analysis of patients with lung cancer

OBJECTIVE

To evaluate the opioid-induced constipation burden in the subgroup of patients with lung cancer who participated in the observational Opioid-Induced Constipation in Patients with Cancer Pain in Japan (OIC-J) study.

METHODS

The prospective, observational study, OIC-J, included 212 patients with various tumour types, 33% of whom had lung cancer. The incidence of opioid-induced constipation was evaluated using several diagnostic criteria, as well as the physician's diagnosis and patient's subjective assessment. Following initiation of opioids, patients recorded details of bowel movements (i.e. date/time, Bristol Stool Scale form, sensations of incomplete evacuation or anorectal obstruction/blockage and degree of straining) in a diary for 2 weeks. Relationships between patient characteristics and opioid-induced constipation onset and effects of opioid-induced constipation on quality of life were explored.

RESULTS

In total, 69 patients were included in this post hoc analysis. The incidence of opioid-induced constipation varied (39.1-59.1%) depending on which diagnostic criteria was used. Diagnostic criteria that included a quality component or a patient's feeling of bowel movement as an evaluation item (i.e. Rome IV, physician's diagnosis, Bowel Function Index, patient's assessment) showed higher incidences of opioid-induced constipation than recording the number of spontaneous bowel movements alone. Opioid-induced constipation occurred rapidly after initiating opioids and had a significant impact on Patient Assessment of Constipation Symptoms total score (P = 0.0031). Patient baseline characteristics did not appear to be predictive of opioid-induced constipation onset.

CONCLUSIONS

In patients with lung cancer, opioid-induced constipation can occur quickly after initiating opioids and can negatively impact quality of life. Early management of opioid-induced constipation, with a focus on quality-of-life improvement and patient's assessments of bowel movements, is important for these patients.

Differential alteration in gut microbiome profiles during acquisition, extinction and reinstatement of morphine-induced CPP

Substance addiction is a chronic and complicated disease involving genetic and environmental factors. Coregulated by the above factors, perturbations of the gut microbiome have been shown to have an essential role in the development of many neuropsychiatric disorders, including addiction. However, shifts in the gut microbiome during different stages of morphine addiction remain uncharacterized. In the present study, we harvested fecal samples from mice at the acquisition (both the control and morphine groups), extinction and reinstatement stages of morphine-induced conditioned place preference (CPP). Gut microbiome profiles were detected with 16S ribosomal RNA gene sequencing. We observed an increase in community richness following morphine conditioning, and it decreased after 4 weeks of abstinence. The abundance of Verrucomicrobia increased and Bacteroides decreased at the acquisition of morphine-induced CPP, while a recovery trend was found at the extinction stage. Several discriminative genera were identified for the characterization of different stages of morphine CPP. Functional analysis of taxa with differential abundance between CPP stages was mainly enriched in the pathways of amino acid metabolism. Taken together, our findings will extend the association between dysbiosis of the gut microbiome and the opioid-induced rewarding or reinforcing behaviors.

Delphi consensus on strategies in the management of opioid-induced constipation in cancer patients

BACKGROUND

Opioid-induced constipation (OIC) is a frequent and bothersome adverse event related with opioid therapy in cancer patients. Despite the high prevalence, medical management of OIC is often uncertain. The current project aimed to investigate expert opinion on OIC management and provide practical recommendations to improve the clinical approach of OIC in cancer patient.

METHODS

A modified Delphi method was conducted involving 46 different physicians experts in OIC. Using a structured questionnaire of 67 items this project intended to seek consensus on aspects related to diagnosis, treatment, and quality of life of cancer patients suffering with OIC.

RESULTS

After two rounds, a consensus was reached in 91% of the items proposed, all in agreement. Agreement was obtained on OIC definition (95.7%). Objective and patient-reported outcomes included in that definition should be assessed routinely in clinical practice. Responsive to symptom changes and easy-to-use assessment tools were recommended (87.2%). Successful diagnosis of OIC requires increase clinicians awareness of OIC and proactivity to discuss symptoms with their patients (100%). Successful management of OIC requires individualization of the treatment (100%), regular revaluation once is established, and keeping it for the duration of opioid treatment (91.5%). Oral Peripherally Acting μ-Opioid Receptor Agonists (PAMORAs), were considered good alternatives for the treatment of OIC in cancer patients (97.9%). This drugs and laxatives can be co-prescribed if OIC coexist with functional constipation.

CONCLUSIONS

The panelists, based on their expert clinical practice, presented a set of recommendations for the management of OIC in cancer patients.

Predicting Opioid Therapy Safety In Pancreatic Cancer Patients

Background — Obligatory use of strong opioids for treating chronic pain syndrome in patients with pancreatic cancer provides the implementation of opioid-associated adverse reactions. Genetic and non-genetic risk factors are predictive of the opioid therapy safety. Contemporary methods of information analysis allow using prognostic risk models for practical application. Objective — Identification of significant risk factors for the development of opioid-associated adverse drug reactions in patients with chronic pain syndrome against the background of pancreatic cancer. Material and Methods — The study included 90 patients with chronic pain against the background of pancreatic cancer, randomized at a ratio of 1: 1. Group 1 received morphine sulfate (MS), group 2 received fentanyl transdermal therapeutic system (FTTS) with standard adjuvant therapy (ketoprofen, diazepam, amitriptyline). To assess pain level, the 10-point Digital Rating Scale, the Visual Analogue Scale and the pain questionnaires were used. The assessment of the treatment safety was conducted by the Naranjo Scale. Assessment of prognostic genetic and non-genetic factors was carried out using ROC analysis with calculation of AUC (the area under the ROC-curve). Results — Prognostic models of good quality were determined with the optimal ratio of sensitivity and specificity for the influence of genetic and non-genetic risk factors on the development of opioid-associated adverse drug reactions (OA-ADRs) in comparison groups. Various prognostic factors, complementing each other, were identified in the comparison groups. Conclusion — The following OA-ADRs predicting factors were identified: for FTTS-associated nausea and vomiting – age and carriage of rs7438135 AG genotype of UGT2B7 gene; for local reactions – the sum of points on the ESAS scale and carriage of rs7438135 AA genotype of UGT2B7 gene; for difficulty urinating – the level of glomerular filtration rate; for neurotoxicity – the level of AST and bilirubin, and the carriage of rs1128503 GG genotype of ABCB1 gene; for pruritus – carriage of rs1045642642 AA genotype of ABCB1 gene. The prognostic factors for the implementation of MS-associated neurotoxicity were age and comorbidity; for dry mouth was predicted best from the sum of points on the MMCE scale; weakness was predicted by the carriage of rs7668258 TT genotype of UGT2B7 gene.

Characterizing Pain Experiences: African American Patients With Multiple Myeloma Taking Around-the-Clock Opioids

BACKGROUND

Despite known disparities by race, studies to date have not focused on pain characterization among African American patients with multiple myeloma.

OBJECTIVES

This study aimed to characterize the pain experience, beliefs about pain and pain control, and additional symptoms among African American patients with multiple myeloma taking around-the-clock opioids.

METHODS

This study employed secondary analysis of baseline data from a completed longitudinal study of opioid adherence. Descriptive statistics were used to characterize the sample, pain experience, beliefs regarding pain and pain control, and related symptoms.

FINDINGS

Participants (N = 34) experienced everyday pain and additional symptoms, and half experienced depression. Pain management barriers included dislike of pills, fear of addiction, and bothersome side effects from pain and medication. Additional larger studies can incorporate multilevel factors contributing to high symptom burden.

Role of the nurse in supporting the safe use of opioids

Opioids are powerful analgesics that are derived from the opium poppy plant. They are recognised as central in the management of acute pain and cancer pain, but concerns about long-term use have resulted in recommendations that they should be used with caution in the management of chronic pain. Opioids have associated side effects and risks, but these may be exaggerated and some healthcare professionals can be unnecessarily cautious and withhold the use of opioids, even in cases where these medicines may be beneficial. It is important that nurses understand the pharmacology, side effects and risks of opioids, so they can ensure these medicines are administered safely.

Analgesic efficacy of nefopam for cancer pain: a randomized controlled study

Background: Nefopam is a non-opioid, non-steroidal, central acting drug used effectively for postoperative pain. The efficacy of nefopam for cancer pain remains unclear. We aimed to evaluate the analgesic efficacy of nefopam for cancer pain in a randomized controlled trial. Methods: Patients with moderate to severe cancer pain (n=40) were randomly divided into two groups. The nefopam group (n=20) received three 20 mg doses of nefopam every 8 hours. The placebo group (n=20) received normal saline. Intravenous patient-controlled analgesia with morphine was given for breakthrough pain for 48 hours. The primary outcome was significant pain reduction. Secondary outcomes were morphine consumption over 48 hours and incidence of side effects. Results: The nefopam group showed pain reduction at 12 hours (65% of patients), 24 hours (80%), 36 hours (85%), and 48 hours (65%). The placebo group showed pain reduction at 12 hours (70%), 24 hours (75%), 36 hours (80%), and 48 hours (60%). However, there were no statistically significant differences between the groups (p>0.05). The median dosage of morphine consumption in 48 hours was lower in the nefopam group (25.5 mg) compared with the placebo group (37 mg), but this was not statistically significant (p=0.499). There were no statistically significant differences in blood pressure and heart rate between the groups. Side effects in both groups were comparable. Conclusions: At dosage of 60 mg in 24 hours, nefopam did not provide significant pain reduction in moderate to severe cancer pain patients. However, there was a trend of reduced opioid consumption. Further studies with larger sample sizes, longer duration, or higher doses of nefopam are warranted. Registration: Thai Clinical Trail Registry (TCTR) ID TCTR20181016001; registered on 12 October 2018.

Identification of genetic polymorphisms modulating nausea and vomiting in two series of opioid-treated cancer patients

Nausea and vomiting are often associated with opioid analgesia in cancer patients; however, only a subset of patients develop such side effects. Here, we tested the hypothesis that the occurrence of nausea and vomiting is modulated by the genetic background of the patients. Whole exome sequencing of DNA pools from patients with either low (n = 937) or high (n = 557) nausea and vomiting intensity, recruited in the European Pharmacogenetic Opioid Study, revealed a preliminary association of 53 polymorphisms. PCR-based genotyping of 45 of these polymorphisms in the individual patients of the same series confirmed the association for six SNPs in AIM1L, CLCC1, MUC16, PDE3A, POM121L2, and ZNF165 genes. Genotyping of the same 45 polymorphisms in 264 patients of the Italian CERP study, also treated with opioids for cancer pain, instead confirmed the association for two SNPs in ZNF568 and PDE3A genes. Only one SNP, rs12305038 in PDE3A, was confirmed in both series, although with opposite effects of the minor allele on the investigated phenotype. Overall, our findings suggest that genetic factors are indeed associated with nausea and vomiting in opioid-treated cancer patients, but the role of individual polymorphisms may be weak.

Current state and future perspective of drug repurposing in malignant glioma

Malignant gliomas are still extremely difficult to treat because complete surgical resection is biologically not feasible due to the invasive nature of these diseases and the proximity of tumors to functionally sensitive areas. Moreover, adjuvant therapies are facing a strong therapeutic resistance since the central nervous system is a highly protected environment and the tumor cells display a vast intra-tumoral genetic and epigenetic variation. As a consequence, new therapeutics are urgently needed but the process of developing novel compounds that finally reach clinical application is highly time-consuming and expensive. Drug repurposing is an approach to facilitate and accelerate the discovery of new cancer treatments. In malignant glioma, like in other cancers, pre-existing physiological pathways that regulate cell growth, cell death or cell migration are dysregulated causing malignant transformation. A wide variety of drugs are clinically used to treat non-cancerous diseases interfering with these malignancy-associated pathways. Repurposed drugs have key advantages: They already have approval for clinical use by national regulatory authorities. Moreover, they are for the most part inexpensive and their side effect and safety profiles are well characterized. In this work, we provide an overview on current repurposing strategies for the treatment of malignant glioma.

Incidence of opioid-induced constipation in Japanese patients with cancer pain: A prospective observational cohort study

This multicenter, prospective, observational cohort study assessed opioid induced constipation (OIC) in Japanese patients with cancer. Eligible patients had stable cancer and an ECOG PS of 0-2. OIC incidence based on the Rome IV diagnostic criteria was determined by patient diary entries during the first 14 days of opioid therapy. The proportion of patients with OIC was calculated for each 1-week period and the overall 2-week study period. Secondary measurements of OIC included the Bowel Function Index (BFI) score (patient assessment administered by physician), spontaneous bowel movements (SBMs) per week (patient assessment), and physician assessments. Medication for constipation was allowed. Two hundred and twenty patients were enrolled. The mean morphine-equivalent dose was 22 mg/day. By Rome IV criteria, the cumulative incidence of OIC was 56% (95% CI: 49.2%-62.9%); week 1, 48% (95% CI: 40.8%-54.6%); week 2, 37% (95% CI: 30.1%-43.9%). The cumulative incidence of OIC was lower in patients who received prophylactic agents for constipation (48% [95% CI: 38.1%-57.5%]) than in patients who did not (65% [95% CI: 55.0%-74.2%]). The cumulative incidences of OIC were 59% (95% CI: 51.9%-66.0%), 61% (95% CI: 54.3%-68.1%), and 45% (95% CI: 38.0%-51.8%) based on BFI scores, physician assessments, and SBM frequency, respectively. Frequency of BMs/week before starting opioids was the most influential factor for the occurrence of OIC. Utilization of prophylactic agents for constipation was associated with a modest effect on reducing the incidence of OIC. The incidences of OIC reported were variable depending on the diagnostic tool involved.

Fluoroscopic Characterization of Colonic Dysmotility Associated to Opioid and Cannabinoid Agonists in Conscious Rats

Background/Aims

Gastrointestinal adverse effects have a major impact on health and quality of life in analgesics users. Non-invasive methods to study gastrointestinal motility are of high interest. Fluoroscopy has been previously used to study gastrointestinal motility in small experimental animals, but they were generally anesthetized and anesthesia itself may alter motility. In this study, our aim is to determine, in conscious rats, the effect of increasing doses of 2 opioid (morphine and loperamide) and 1 cannabinoid (WIN 55,212-2) agonists on colonic motility using fluoroscopic recordings and spatio-temporal maps.

Methods

Male Wistar rats received barium sulfate intragastrically, 20–22 hours before fluoroscopy, so that stained fecal pellets could be seen at the time of recording. Animals received an intraperitoneal administration of morphine, loperamide, or WIN 55,212-2 (at 0.1, 1, 5, or 10 mg/kg) or their corresponding vehicles (saline, Cremophor, and Tocrisolve, respectively), 30 minutes before fluoroscopy. Rats were conscious and placed within movement-restrainers for the length of fluoroscopic recordings (120 seconds). Spatio-temporal maps were built, and different parameters were analyzed from the fluoroscopic recordings in a blinded fashion to evaluate colonic propulsion of endogenous fecal pellets.

Results

The analgesic drugs inhibited propulsion of endogenous fecal pellets in a dose-dependent manner.

Conclusions

Fluoroscopy allows studying colonic propulsion of endogenous fecal pellets in conscious rats. Our method may be applied to the noninvasive study of the effect of different drug treatments and pathologies.

Transversus Abdominis Plane Blocks in Microsurgical Breast Reconstruction: Analysis of Pain, Narcotic Consumption, Length of Stay, and Cost

BACKGROUND

Transversus abdominis plane blocks are increasingly being used in microvascular breast reconstruction. The implications of these blocks on specific reconstructive, patient, and institutional outcomes remain to be fully elucidated.

METHODS

Patients undergoing abdominally based microvascular breast reconstruction from 2015 to 2017 were reviewed. Length of stay, complications, narcotic consumption, donor-site pain, and hospital expenses were compared between patients who did and did not receive transversus abdominis plane blocks with liposomal bupivacaine. Outcomes were subsequently compared in patients with elevated body mass index.

RESULTS

Fifty patients (43.9 percent) received blocks [27 (54.0 percent) under ultrasound guidance] and 64 patients (56.1 percent) did not. Patients with the blocks had significantly decreased oral and total narcotic consumption (p = 0.0001 and p < 0.0001, respectively) and significantly less donor-site pain (3.3 versus 4.3; p < 0.0001). There was no significant difference in hospital expenses between the two cohorts ($21,531.53 versus $22,050.15 per patient; p = 0.5659). Patients with a body mass index of 25 kg/m(2) or greater who received a block had a significantly decreased length of stay (3.8 days versus 4.4 days; p = 0.0345) and decreased narcotic consumption and postoperative pain compared with patients without blocks. Patients with a body mass index less than 25 kg/m(2) did not have a significant difference in postoperative pain, narcotic consumption, or length of stay between groups.

CONCLUSIONS

Transversus abdominis plane blocks with liposomal bupivacaine significantly reduce oral and total postoperative narcotic consumption and donor-site pain in all patients after abdominally based microvascular breast reconstruction without increasing hospital expenses. The blocks also significantly decrease length of stay in patients with a body mass index greater than or equal to 25 kg/m(2).

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Opioid switching and variability in response in pain cancer patients

INTRODUCTION

Opioid switching is a possible strategy for inadequate analgesia or unmanageable side effects. Its effectiveness ranges from 50 to 90% and is still debated.

PURPOSE

We analyzed the impact of opioid switching in a cancer pain population treated with strong opioids for pain.

METHODS

This is a post hoc analysis from a multicenter, randomized, four-arm, controlled, phase IV clinical trial. Outcome variables included the percentages of switches, the reasons for the switch, the dose changes before and after the switch, depending on the starting opioid, the response in case of inadequate analgesia, and unmanageable toxicity, and the variability of response among and within patients.

RESULTS

We analyzed 498 patients. The opioid was switched in 79 patients (15.9%) 87 times, mainly for uncontrolled pain (52.3%), adverse opioid reactions (22.1%), both of these (4.8%), and dysphagia (20.8%). The reasons for switching varied depending on the starting opioid. Pain reduction was good after 51.45% of switches and control of opioid side effects was good after 43.5%. The relief of opioid-induced toxicity varied among adverse events and within each patient. The daily doses were higher after switching oral opioids and lower after transdermal drugs.

CONCLUSIONS

Half of the patients who underwent switching experienced improved relief of pain or amelioration of opioid toxicity. The switch can help in the management of some cases but with many limits and uncertainties.

Frequency, Outcomes, and Associated Factors for Opioid-Induced Neurotoxicity in Patients with Advanced Cancer Receiving Opioids in Inpatient Palliative Care

Context: Opioid-induced neurotoxicity (OIN) is an underdiagnosed yet distressing symptom in palliative care patients receiving opioids. However, there have been only a limited number of studies on OIN. Objectives: Our aim was to determine the frequency of and risk factors for OIN in patients receiving opioids during inpatient palliative care. Methods: We randomly selected 390 of 3014 eligible patients who had undergone palliative care consultations from January 2014 to December 2014. Delirium, drowsiness, hallucinations, myoclonus, seizures, and hyperalgesia were defined as OIN and were recorded. The other 10 common symptoms in cancer patients were assessed using the Edmonton Symptom Assessment Scale (ESAS). Patient demographics, morphine equivalent daily dose (MEDD), comorbidities, OIN management, and overall survival (OS) duration were also assessed. The associations between the incidence of OIN and MEDD, the other 10 symptoms, and OS were analyzed. Results: Fifty-seven (15%) patients had OIN. The most common symptom was delirium (n = 27). On multivariate analysis, a high MEDD (p = 0.020), high ESAS pain score (p = 0.043), drowsiness (p = 0.007), and a poor appetite (p = 0.014) were significantly associated with OIN. OIN was not significantly associated with a shorter OS duration (p = 0.80). Conclusions: OIN was seen in 15% of patients receiving opioids as part of inpatient palliative care. Although OIN was not associated with OS, routine monitoring is especially needed in cancer patients.

Effects of smoking and body mass index on the exposure of fentanyl in patients with cancer

The transdermal fentanyl patch is widely used to treat cancer-related pain despite its wide inter- and intrapatient variability in pharmacokinetics. The aim of this study was to investigate whether smoking and body size (i.e. body mass index) influence fentanyl exposure in patients with cancer. These are factors that typically change during treatment and disease trajectories. We performed an explorative cohort study in patients with cancer using transdermal fentanyl patches (Durogesic®), by taking a blood sample for pharmacokinetic analysis one day after applying a patch in patients with a stable fentanyl dose. A total of 88 patients were evaluable. Although no statistically significant difference was found, the plasma concentrations of non-smokers was 28% (95% CI [-14%; +89-%]) higher than those of smokers normalizing for a dose of 25μg/min. Patients with a low BMI (< 20 kg/m2) had almost similar (10% (95% CI [-39%; +97%]) higher) plasma concentrations compared to patients with a high BMI (> 25 kg/m2). A wider variation in fentanyl plasma concentrations was found in this study than anticipated. Due to this variation, studies in larger patient cohorts are needed to further investigate the effect of smoking on plasma concentration of fentanyl and thereby clarify the clinical significance of our findings.

Intravenous Oxycodone versus Intravenous Morphine in Cancer Pain: A Randomized, Open-Label, Parallel-Group, Active-Control Study

Objective

To compare efficacy and safety of intravenous continuous infusion of oxycodone with morphine in patients with cancer pain.

Methods

A 5-day, randomized, open-label, exploratory study at 6 sites in the Republic of Korea. Sixty-six adults aged ≥19 years with moderate-to-severe cancer pain (Numeric Rating Scale [NRS] ≥ 4) were enrolled. The study group received intravenous (IV) oxycodone, and the comparator group received IV morphine which were titrated depending on pain intensity. The efficacy endpoint is change in average NRS score from baseline to Day 5. Other assessments included worst, current, and average pain intensity; patient satisfaction; medication dose; and adverse events.

Results

Both groups achieved >50% reduction in average pain intensity: from “moderate” at baseline (oxycodone versus morphine: 6.0 ± 1.8 versus 5.9 ± 1.4) to “mild” at Day 5 (2.5 ± 1.8 versus 2.8 ± 1.6). While this reduction was similar between groups (3.5 ± 2.2 versus 3.1 ± 1.8, P value = 0.562), oxycodone achieved faster pain relief (average pain: 3.0 ± 1.6 versus 3.9 ± 1.6, P value = 0.020) on Day 2 and significant NRS reductions for worst pain on Day 2 (P value = 0.045) and current pain on Day 2 (P value = 0.035) and Day 5 (P value = 0.020) compared to morphine. Patient satisfaction, adverse events, and adverse drug reactions were similar for both groups.

Conclusions

For Asian patients with cancer pain, IV oxycodone is faster acting and showed similar analgesic efficacy and safety profiles as IV morphine. This trial is registered with Clinicaltrials.gov NCT02660229.

Oxycodone for cancer-related pain

BACKGROUND

Many people with cancer experience moderate to severe pain that requires treatment with strong opioids, such as oxycodone and morphine. Strong opioids are, however, not effective for pain in all people, neither are they well-tolerated by all people. The aim of this review was to assess whether oxycodone is associated with better pain relief and tolerability than other analgesic options for adults with cancer pain. This is an updated version of the original Cochrane review published in 2015, Issue 2 on oxycodone for cancer-related pain.

OBJECTIVES

To assess the effectiveness and tolerability of oxycodone by any route of administration for pain in adults with cancer.

SEARCH METHODS

For this update, we searched the Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library, MEDLINE and MEDLINE In-Process (Ovid), Embase (Ovid), Science Citation Index, Conference Proceedings Citation Index - Science (ISI Web of Science), BIOSIS (ISI), and PsycINFO (Ovid) to November 2016. We also searched four trial registries, checked the bibliographic references of relevant studies, and contacted the authors of the included studies. We applied no language, date, or publication status restrictions.

SELECTION CRITERIA

We included randomised controlled trials (parallel group or cross-over) comparing oxycodone (any formulation or route of administration) with placebo or an active drug (including oxycodone) for cancer background pain in adults by examining pain intensity/relief, adverse events, quality of life, and participant preference.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed the included studies using standard Cochrane methodology. We meta-analysed pain intensity data using the generic inverse variance method, and adverse events using the Mantel-Haenszel method, or summarised these data narratively along with the quality of life and participant preference data. We assessed the overall quality of the evidence using GRADE.

MAIN RESULTS

For this update, we identified six new studies (1258 participants) for inclusion. In total, we included 23 studies which enrolled/randomised 2648 participants, with 2144 of these analysed for efficacy and 2363 for safety. The studies examined a number of different drug comparisons.Pooled analysis of three of the four studies comparing controlled-release (CR) oxycodone to immediate-release (IR) oxycodone showed that the ability of CR and IR oxycodone to provide pain relief were similar (standardised mean difference (SMD) 0.1, 95% confidence interval (CI) -0.06 to 0.26; low quality evidence). Pooled analyses of adverse events showed no significant differences between CR and IR oxycodone for asthenia (risk ratio (RR) 0.58, 95% CI 0.2 to 1.68), confusion (RR 0.78, 95% CI 0.2 to 3.02), constipation (RR 0.71, 95% CI 0.45 to 1.13), dizziness/lightheadedness (RR 0.74, 95% CI 0.4 to 1.37), drowsiness/somnolence (RR 1.03, 95% CI 0.69 to 1.54), dry mouth (RR 1.14, 95% CI 0.48 to 2.75), insomnia (RR 1.04, 95% CI 0.31 to 3.53), nausea (RR 0.85, 95% CI 0.56 to 1.28), nervousness (RR 0.57, 95% CI 0.2 to 1.64), pruritus (RR 1.46, 95% CI 0.65 to 3.25), vomiting (RR 0.66, 95% CI 0.38 to 1.15), and discontinuation due to adverse events (RR 0.6, 95% CI 0.29 to 1.22). The quality of the evidence was very low for all these adverse events. Three of the four studies found similar results for treatment acceptability.Pooled analysis of seven of the nine studies comparing CR oxycodone to CR morphine indicated that pain relief was significantly better after treatment with CR morphine than CR oxycodone (SMD 0.14, 95% CI 0.01 to 0.27; low quality evidence). However, sensitivity analysis did not corroborate this result (SMD 0.12, 95% CI -0.02 to 0.26).Pooled analyses of adverse events showed no significant differences between CR oxycodone and CR morphine for confusion (RR 1.01 95% CI 0.78 to 1.31), constipation (RR 0.98, 95% CI 0.82 to 1.16), dizziness/lightheadedness (RR 0.76, 95% CI 0.33 to 1.76), drowsiness/somnolence (RR 0.9, 95% CI 0.75 to 1.08), dry mouth (RR 1.01, 95% CI 0.8 to 1.26), dysuria (RR 0.71, 95% CI 0.4 to 1.26), nausea (RR 1.02, 95% CI 0.82 to 1.26), pruritus (RR 0.81, 95% CI 0.51 to 1.29), vomiting (RR 0.94, 95% CI 0.68 to 1.29), and discontinuation due to adverse events (RR 1.06, 95% CI 0.43 to 2.6). However, the RR for hallucinations was significantly lower after treatment with CR oxycodone compared to CR morphine (RR 0.52, 95% CI 0.28 to 0.97). The quality of the evidence was very low for all these adverse events. There were no marked differences in treatment acceptability or quality of life ratings.The remaining studies either compared oxycodone in various formulations or compared oxycodone to different alternative opioids. None found any clear superiority or inferiority of oxycodone for cancer pain, neither as an analgesic agent nor in terms of adverse event rates and treatment acceptability.The quality of this evidence base was limited by the high or unclear risk of bias of the studies and by imprecision due to low or very low event rates or participant numbers for many outcomes.

AUTHORS' CONCLUSIONS

The conclusions have not changed since the previous version of this review. The data suggest that oxycodone offers similar levels of pain relief and overall adverse events to other strong opioids including morphine. Although we identified a clinically insignificant benefit on pain relief in favour of CR morphine over CR oxycodone, this did not persist following sensitivity analysis and so we do not consider this important. However, in this updated analysis, we found that hallucinations occurred less often with CR oxycodone than with CR morphine, but the quality of this evidence was very low so this finding should be treated with utmost caution. Our conclusions are consistent with other reviews and suggest that while the reliability of the evidence base is low, given the absence of important differences within this analysis it seems unlikely that larger head to head studies of oxycodone versus morphine are justified, although well-designed trials comparing oxycodone to other strong analgesics may well be useful. For clinical purposes, oxycodone or morphine can be used as first-line oral opioids for relief of cancer pain in adults.

Adverse events in a chiropractic spinal manipulative therapy single-blinded, placebo, randomized controlled trial for migraineurs

BACKGROUND

Unlike pharmacological randomized controlled trials (RCTs), manual-therapy RCTs do not always report adverse events (AEs). The few manual-therapy RCTs that provide information on AEs are frequently without details, such as the type and-, severity of the AE and reason for withdrawal.

OBJECTIVE

To prospectively report all AEs in a chiropractic spinal manipulative therapy (CSMT) RCT.

DESIGN

A prospective 3-armed, single-blinded, placebo, RCT.

METHODS

Seventy migraineurs were randomized to the CSMT or a placebo, with 12 intervention sessions over three months. The recommendations by CONSORT and the International Headache Society's Task Force on AEs in migraine RCTs were followed. A standardized reporting scheme designed for pharmacological RCTs was used, and the AEs were described as frequencies and percentages within each group. The 95% confidence intervals (CIs) for the percentages (absolute risk) of AEs in each group were calculated when possible. Attributable risk (%) and relative risk were calculated with the corresponding 95% CIs.

RESULTS

AEs were assessed in 703 sessions, with 355 in the CSMT group and 348 in the placebo group. Local tenderness was the most common AE, reported by 11.3% and 6.9% of the CSMT group and the placebo group, respectively, and tiredness on the intervention day was reported by 8.5% and 1.4% of CSMT group and the placebo group, respectively. The highest attributable risk was for tiredness on the treatment day, 7.0% (CI 3.9-10.2%) which presented a relative risk of 5.9 (CI 2.3-15.0).

CONCLUSIONS

AEs were mild and transient, and severe or serious AEs were not observed.

A review of factors explaining variability in fentanyl pharmacokinetics; focus on implications for cancer patients

Fentanyl is a strong opioid that is available for various administration routes, and which is widely used to treat cancer-related pain. Many factors influence the fentanyl pharmacokinetics leading to a wide inter- and intrapatient variability. This systematic review summarizes multiple studied factors that potentially influence fentanyl pharmacokinetics with a focus on implications for cancer patients. The use of CYP3A4 inhibitors and inducers, impaired liver function, and heating of the patch potentially influence fentanyl pharmacokinetics in a clinically relevant way. In elderly patients, current data suggest that we should carefully dose fentanyl due to alterations in absorption and metabolism. The influence of BMI and gender on fentanyl pharmacokinetics is questionable, most probably due to a large heterogeneity in the published studies. Pharmacogenetics, e.g. the CYP3A5*3 gene polymorphism, may influence fentanyl pharmacokinetics as well, although further study is warranted. Several other factors have been studied but did not show significant and clinically relevant effects on fentanyl pharmacokinetics. Unfortunately, most of the published papers that studied factors influencing fentanyl pharmacokinetics describe healthy volunteers instead of cancer patients. Results from the studies in volunteers may not be simply extrapolated to cancer patients because of multiple confounding factors. To handle fentanyl treatment in a population of cancer patients, it is essential that physicians recognize factors that influence fentanyl pharmacokinetics, thereby preventing potential side-effects and increasing its efficacy.

The rare Arg181Cys mutation in the μ opioid receptor can abolish opioid responses

BACKGROUND

Genetic variability contributes to variable clinical response to opioids. This study emerged from the observation of three Norwegian patients who showed no or extraordinary poor response to very high doses of opioids. We suspected a genetic defect and applied a 'most likely candidate gene' approach to investigate this possibility.

METHODS

DNA sequencing was used to search for mutations in coding regions of the OPRM1 gene, encoding the μ opioid receptor (hMOR), in one patient. The remaining two patients, and two cohorts comprising 2158 European cancer pain patients and 600 Norwegian healthy volunteers, respectively, were genotyped using a custom-made TaqMan SNP allelic discrimination assay.

RESULTS

DNA sequencing disclosed a homozygous, inactivating Arg181Cys mutation in hMOR in the patient who showed no effects from opioids. The two patients with poor effect from very high doses of opioids were both heterozygous for the mutation. Six heterozygous patients identified among the European cancer patients all used high doses of opioids and/or reported inferior effect on their pain. About one in every 100 Norwegians is heterozygous for the mutation.

CONCLUSIONS

The Arg181Cys mutation occurs at clinically relevant frequencies and produces a signaling dead hMOR which may abolish or significantly reduce opioid effects in affected individuals. Anesthesiologists and practitioners in pain medicine should be aware of this mutation as a possible explanation for inefficiency of opioids and consider genotyping in relevant cases. Individuals homozygous for the mutation may need a highly personalized approach to pain therapy.

Treatment with methylnaltrexone is associated with increased survival in patients with advanced cancer

BACKGROUND

Methylnaltrexone (MNTX), a peripherally acting μ-opioid receptor (MOR) antagonist, is FDA-approved for treatment of opioid-induced constipation (OIC). Preclinical data suggest that MOR activation can play a role in cancer progression and can be a target for anticancer therapy.

PATIENTS AND METHODS

Pooled data from advanced end-stage cancer patients with OIC, despite laxatives, treated in two randomized (phase III and IV), placebo-controlled trials with MNTX were analyzed for overall survival (OS) in an unplanned post hoc analysis. MNTX or placebo was given subcutaneously during the double-blinded phase, which was followed by the open-label phase, allowing MNTX treatment irrespective of initial randomization.

RESULTS

In two randomized, controlled trials, 229 cancer patients were randomized to MNTX (117, 51%) or placebo (112, 49%). Distribution of patients' characteristics and major tumor types did not significantly differ between arms. Treatment with MNTX compared with placebo [76 days, 95% confidence interval (CI) 43-109 versus 56 days, 95% CI 43-69; P = 0.033] and response (laxation) to treatment compared with no response (118 days, 95% CI 59-177 versus 55 days, 95% CI 40-70; P < 0.001) had a longer median OS, despite 56 (50%) of 112 patients ultimately crossing over from placebo to MNTX. Multivariable analysis demonstrated that response to therapy [hazard ratio (HR) 0.47, 95% CI 0.29-0.76; P = 0.002) and albumin ≥3.5 (HR 0.46, 95% CI 0.30-0.69; P < 0.001) were independent prognostic factors for increased OS. Of interest, there was no difference in OS between MNTX and placebo in 134 patients with advanced illness other than cancer treated in these randomized studies (P = 0.88).

CONCLUSION

This unplanned post hoc analysis of two randomized trials demonstrates that treatment with MNTX and, even more so, response to MNTX are associated with increased OS, which supports the preclinical hypothesis that MOR can play a role in cancer progression. Targeting MOR with MNTX warrants further investigation in cancer therapy.

CLINICAL TRIALS NUMBER

NCT00401362, NCT00672477.

Opioid treatment failure in cancer patients: the role of clinical and genetic factors

AIM

To identify clinical and genetic factors associated with outcome of opioid treatment.

PATIENTS & METHODS

We performed an exploratory analysis in a cohort of 353 patients treated with fentanyl, morphine, oxycodone and/or hydromorphone for cancer-related pain, exploring selected clinical and pharmacogenetic factors for a correlation with treatment failure for all and per type of opioid.

RESULTS

Use of adjuvant pain medication, intensity of pain at rest and age were associated with treatment failure in the various cohorts. Only the genetic variants rs12948783 (RHBDF2) and rs7016778 (OPRK1) correlated statistically significant in univariate, but not in multivariable analysis.

CONCLUSION

Several clinical and genetic factors were identified that warrant further study to clarify their role and use in opioid treatment.

Effects of microRNA‑338‑3p on morphine‑induced apoptosis and its underlying mechanisms

The aim of the present study was to investigate the effects of microRNA-338-3p (miR-338-3p) on morphine (MP)-induced apoptosis, and its underlying mechanisms. Freshly‑isolated mouse peritoneal macrophages were cultured in vitro and treated with MP following transfection with miR‑338‑3p mimic, inhibitor or controls. miR‑338‑3p expression levels increased significantly following MP treatment (P<0.01). This increase was enhanced following transfection with miR‑338‑3p mimic (P<0.05) and abrogated following transfection with miR‑338‑3p inhibitor (P<0.05). The apoptotic rate increased significantly in groups treated with MP (P<0.05); however, this increase was abrogated by transfection with miR‑338‑3p inhibitor (P<0.05). Bioinformatics software predicted that sex determining region Y‑box 4 (SOX4) was the target gene of miR‑338‑3p and this was verified using a dual‑luciferase reporter gene system. SOX4 mRNA and protein expression levels decreased significantly following MP treatment (P<0.05); however, this decrease was abrogated following transfection with miR‑338‑3p inhibitor (P<0.05). Caspase‑3 protein expression levels increased markedly following MP treatment (P<0.05); however, this increase was inhibited by transfection with miR‑338‑3p inhibitor (P<0.05). Therefore, decreased expression of miR‑338‑3p may suppress MP‑induced apoptosis, potentially via the upregulation of SOX4 expression and the caspase‑3‑dependent apoptotic signaling pathway.

The protective effect of hydromorphone to ischemia in rat glial cells

BACKGROUND

Ischemic insults during operation can cause ischemic-reperfusion injuries in brain as well as memory impairments. Total intravenous anesthesia (TIVA) is the preferred anesthetic method in brain surgery, as it utilizes motor evoked potential monitoring. And the use of opioids is common in TIVA. However there are few studies about ischemic protective effect of opioids to glial cells.

METHODS

We used mixed cultures of rat glial cells, which were harvested from the brain of 1-day old rat. We divided the experimental groups according to their hydromorphone conditioning period: (a) pre-culture, (b) per-culture, or (c) pre- and per-culture. We measured the levels of the reactive oxygen species (ROS) induced by tert-butyl hydroperoxide (TBH) using flow cytometry. The ROS levels in the glial cells were also measured after the administration of 100 nM hydromorphone and selective opioid receptor antagonists.

RESULTS

The ROS levels were reduced in the hydromorphone-treated group, as compared to the control group (only TBH treated). There were no differences between pre-conditioned and per-conditioned groups. However, the ROS levels were more reduced in pre- and per-conditioned group compared to pre-conditioned or per-conditioned only groups. Furthermore, selective antagonists for the delta, kappa, or mu opioid receptor partially negated the hydromorphone effect.

CONCLUSION

This study demonstrated that hydromorphone can have additional protective effects on oxidative stress when pre- and per-conditioning is combined. Furthermore we proved that μ, δ, κ opioid receptors participate in protective mechanism of hydromorphone to glial cells.

The Adverse Events of Oxycodone in Cancer-Related Pain: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

The adverse events (AEs) of oxycodone in cancer-related pain were controversial, so we conducted a meta-analysis to determine it. PubMed, Embase, CBM, CNKI, WanFang database, The Cochrane library, Web of Science, and the reference of included studies were searched to recognize pertinent studies. Relative risk (RR) with 95% confidence intervals (CIs) for all AEs were all extracted. The fixed-effects model was used to calculate pooled RRs and 95% CIs. Power calculation was performed using macro embedded in SAS software after all syntheses were completed. We identified 11 eligible trials involving 1211 patients: 604 patients included in oxycodone group and 607 patients involved in control group. Our quantitative analysis included 8 AEs, and the pooled analyses indicated that oxycodone compared with other opioids in cancer-related pain were not significantly decreased RRs of all AEs (dizziness RR = 0.94, 95% CI: 0.69-1.30, Z = 0.35, P = 0.72; nausea RR = 0.88, 95% CI: 0.72-1.07, Z = 1.26, P = 0.21; vomiting RR = 0.89, 95% CI: 0.70-1.15, Z = 0.9, P = 0.37; sleepiness RR = 0.86, 95% CI: 0.38-1.36, Z = 0.36, P = 0.72; constipation RR = 0.98, 95% CI: 0.81-1.19, Z = 0.21, P = 0.83; anorexia RR = 0.97, 95% CI = 0.58-1.62, Z = 0.11, P = 0.91; pruritus RR = 0.76, 95% CI: 0.44-1.30, Z = 1.01, P = 0.31; dysuria RR = 0.33, 95% CI: 0.07-1.62, Z = 1.36, P = 0.1)]. The subgroup analysis shown that Ox controlled-release (CR) had less sleepiness compared with MS-contin (Mc) CR (RR = 0.47, 95% CI: 0.25-0.90, P = 0.02). The power analysis suggests that all AEs have low statistical power. The present meta-analysis detected that no statistically significant difference were found among oxycodone and other opioids in all AEs, but Ox CR may had less sleepiness compared with Mc CR when subgroup analysis were conducted.

Acute toxicity in comprehensive head and neck radiation for nasopharynx and paranasal sinus cancers: cohort comparison of 3D conformal proton therapy and intensity modulated radiation therapy

BACKGROUND

To evaluate acute toxicity endpoints in a cohort of patients receiving head and neck radiation with proton therapy or intensity modulated radiation therapy (IMRT).

METHODS

Forty patients received comprehensive head and neck radiation including bilateral cervical nodal radiation, given with or without chemotherapy, for tumors of the nasopharynx, nasal cavity or paranasal sinuses, any T stage, N0-2. Fourteen received comprehensive treatment with proton therapy, and 26 were treated with IMRT, either comprehensively or matched to proton therapy delivered to the primary tumor site. Toxicity endpoints assessed included g-tube dependence at the completion of radiation and at 3 months after radiation, opioid pain medication requirement compared to pretreatment normalized as equivalent morphine dose (EMD) at completion of treatment, and at 1 and 3 months after radiation.

RESULTS

In a multivariable model including confounding variables of concurrent chemotherapy and involved nodal disease, comprehensive head and neck radiation therapy using proton therapy was associated with a lower opioid pain requirement at the completion of radiation and a lower rate of gastrostomy tube dependence by the completion of radiation therapy and at 3 months after radiation compared to IMRT. Proton therapy was associated with statistically significant lower mean doses to the oral cavity, esophagus, larynx, and parotid glands. In subgroup analysis of 32 patients receiving concurrent chemotherapy, there was a statistically significant correlation with a greater opioid pain medication requirement at the completion of radiation and both increasing mean dose to the oral cavity and to the esophagus.

CONCLUSIONS

Proton therapy was associated with significantly reduced radiation dose to assessed non-target normal tissues and a reduced rate of gastrostomy tube dependence and opioid pain medication requirements. This warrants further evaluation in larger studies, ideally with patient-reported toxicity outcomes and quality of life endpoints.