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ABSTRACT: BACKGROUND: Dealing with cancer pain implies assessing the intensity and other attributes of pain and identifying appropriate outcomes and endpoints to evaluate the effect of treatments. METHODS: In the context of an observational longitudinal prospective study, 1461 painful cancer patients were evaluated at baseline and weekly over 4 weeks. Four pain intensity (PI) measures (worst, average, least and right now: WP, AP, LP, and PRN), pain relief and patients' satisfaction with pain treatments were recorded. Starting from these data, we extrapolated the full responder (FR) subjects, whose PI decreased by ≥2 points, or by ≥30%, or who obtained a final score of ≤5 points, according to criteria previously suggested by literature. The receiver operating characteristics (ROC) curve analysis was used to estimate the predictive accuracy. RESULTS: All the PI measures decreased from the initial to final visit: the reduction was 1.9 as WP, 1.3, 0.8 and 1.2 as AP, LP and PRN, respectively. The proportion of FR differed from 47.8% to 88.3% depending on PI measures and the criterion adopted. ROC analysis showed an acceptable accuracy of all endpoints and confirmed the cut-offs recommended by the literature. The best criterion corresponded to a PI absolute value of ≤4 points when measured as AP. CONCLUSIONS: All measures applied seem able to profile the evolution of pain, with some differences. This implies the need of an appropriate choice of outcomes and endpoints according to the goal and objective of the intervention under evaluation.
European journal of pain (London, England) 12/2012; · 3.37 Impact Factor
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ABSTRACT: Recently, low-dose transdermal buprenorphine (LD-TD-BUP) was introduced for treatment of patients with chronic non-malignant pain. The primary aim of this study was to determine the proportion of patients who were prescribed LD-TD-BUP for non-malignant pain who became long-term users. The secondary aim was to determine the proportion of patients who co-medicated with other opioids or benzodiazepines during treatment with LD-TD-BUP.
Data were drawn from the Norwegian Prescription Database that covers all prescriptions dispensed at pharmacies to the entire Norwegian population (4.7 million inhabitants). The study population consisted of all patients who were dispensed at least one prescription of LD-TD-BUP from its introduction in November 2005 to 31 December 2008. Patients who were dispensed more than 24 patches (≥ 6 months) were defined as long-term users. Reimbursement codes were used to stratify patients as having cancer pain or non-malignant pain.
Among new users of LD-TD-BUP for non-malignant pain (n = 13,451), only 22% became long-term users, while 44% were only dispensed one prescription. Among long-term users who were opioid naive when LD-TD-BUP was initiated, 43% co-medicated with other opioids or benzodiazepines, compared with 82% of those who previously had used opioids.
Three years after introduction, 0.4% of the Norwegian population had been dispensed LD-TD-BUP. Only one-fifth had become long-term users. Those who used opioids before the first dispension of LD-TD-BUP co-medicated with other potentially addictive drugs to a much higher degree compared with those who were opioid naive.
Acta Anaesthesiologica Scandinavica 10/2011; 56(1):88-94. · 2.19 Impact Factor
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ABSTRACT: Cachexia has major impact on cancer patients' morbidity and mortality. Future development of cachexia treatment needs methods for early identification of patients at risk. The aim of the study was to validate nine single-nucleotide polymorphisms (SNPs) previously associated with cachexia, and to explore 182 other candidate SNPs with the potential to be involved in the pathophysiology.
A total of 1797 cancer patients, classified as either having severe cachexia, mild cachexia or no cachexia, were genotyped.
After allowing for multiple testing, there was no statistically significant association between any of the SNPs analysed and the cachexia groups. However, consistent with prior reports, two SNPs from the acylpeptide hydrolase (APEH) gene showed suggestive statistical significance (P=0.02; OR, 0.78).
This study failed to detect any significant association between any of the SNPs analysed and cachexia; although two SNPs from the APEH gene had a trend towards significance. The APEH gene encodes the enzyme APEH, postulated to be important in the endpoint of the ubiquitin system and thus the breakdown of proteins into free amino acids. In cachexia, there is an extensive breakdown of muscle proteins and an increase in the production of acute phase proteins in the liver.
British Journal of Cancer 09/2011; 105(8):1244-51. · 5.04 Impact Factor
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ABSTRACT: Opioid switching is a treatment strategy in cancer patients with unacceptable pain and/or adverse effects (AEs). We investigated whether patients switched to methadone by the stop and go (SAG) strategy have lower pain intensity (PI) than the patients switched over three days (3DS), and whether the SAG strategy is as safe as the 3DS strategy.
In this prospective, open, parallel-group, multicentre study, 42 cancer patients on morphine or oxycodone were randomised to the SAG or 3DS switching-strategy to methadone. The methadone dose was calculated using a dose-dependent ratio. PI, AEs and serious adverse events (SAEs) were recorded daily for 14 days. Primary outcome was average PI day 3. Secondary outcomes were PI now and AEs day 3 and 14 and number of SAEs.
Twenty one patients were randomised to each group, 16 (SAG) and 19 (3DS) patients received methadone. The mean preswitch morphine doses were 900 mg/day in SAG and 1330 mg/day in 3DS. No differences between groups were found in mean average PI day 3 (mean difference 0.5 (CI -1.2-2.2); SAG 4.1 (CI 2.3-5.9) and 3DS 3.6 (CI 2.9-4.3) or in PI now. The SAG group had more dropouts and three SAEs (two deaths and one severe sedation). No SAEs were observed in the 3DS group.
The SAG patients reported a trend of more pain, had significantly more dropouts and three SAEs, which indicate that the SAG strategy should not replace the 3DS when switching from high doses of morphine or oxycodone to methadone.
European journal of cancer (Oxford, England: 1990) 07/2011; 47(16):2463-70. · 4.12 Impact Factor
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ABSTRACT: The European Pharmacogenetic Opioid Study (EPOS) of a large series of European cancer patients treated with opioids was carried out to assess the influence of genetics on cancer pain relief. As response to opioid therapy was associated with the patients' country of origin, we tested whether population stratification might represent a confounding factor in the analysis of genetic control of response to opioid therapy. From the whole EPOS series representing 2294 patients' genotypes for 379 single-nucleotide polymorphisms (SNPs), we extracted 117 autosomal SNPs with minor allele frequency>0.28 to obtain highly informative genetic markers, and analyzed the SNPs in 1724 individuals showing <20% missing genotypes. Use of the AWclust program to detect clusters of genetically related individuals in the EPOS series showed that the 117-SNP panel distinguished four main European subgroups statistically associated with ethnicity, but not with country of origin or with the pain relief phenotype. Subethnic European groups of genetically related individuals exist that can be correctly identified using an ∼100-SNP panel. Such genetic clustering may control for admixture in association studies and may allow discrimination between genetic and environmental effects on phenotypes showing association with country of origin, as in the case of pain relief.
The Pharmacogenomics Journal 07/2011; 12(5):412-6. · 4.54 Impact Factor
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P Klepstad,
T Fladvad,
F Skorpen,
K Bjordal,
A Caraceni,
O Dale,
A Davies,
M Kloke,
S Lundström,
M Maltoni,
L Radbruch,
R Sabatowski,
V Sigurdardottir,
F Strasser,
P M Fayers, S Kaasa
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ABSTRACT: Cancer pain patients need variable opioid doses. Preclinical and clinical studies suggest that opioid efficacy is related to genetic variability. However, the studies have small samples, findings are not replicated, and several candidate genes have not been studied. Therefore, a study of genetic variability with opioid doses in a large population using a confirmatory validation population was warranted. We recruited 2294 adult European patients using a World Health Organization (WHO) step III opioid and analyzed single nucleotide polymorphisms (SNPs) in genes with a putative influence on opioid mechanisms. The patients' mean age was 62.5 years, and the average pain intensity was 3.5. The patients' primary opioids were morphine (n=830), oxycodone (n=446), fentanyl (n=699), or other opioids (n=234). Pain intensity, time on opioids, age, gender, performance status, and bone or CNS metastases predicted opioid dose and were included as covariates. The patients were randomly divided into 1 development sample and 1 validation sample. None of 112 SNPs in the 25 candidate genes OPRM1, OPRD1, OPRK1, ARRB2, GNAZ, HINT1, Stat6, ABCB1, COMT, HRH1, ADRA2A, MC1R, TACR1, GCH1, DRD2, DRD3, HTR3A, HTR3B, HTR2A, HTR3C, HTR3D, HTR3E, HTR1, or CNR1 showed significant associations with opioid dose in both the development and the validation analyzes. These findings do not support the use of pharmacogenetic analyses for the assessed SNPs to guide opioid treatment. The study also demonstrates the importance of validating findings obtained in genetic association studies to avoid reporting spurious associations as valid findings. To elicit knowledge about new genes that influence pain and the need for opioids, strategies other than the candidate gene approach is needed.
Pain 03/2011; 152(5):1139-45. · 5.78 Impact Factor
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ABSTRACT: Workpackage 3.1 (WP 3.1), within the European Palliative Research Collaborative (EPCRC), was aimed at critically revising and updating the European Association for Palliative Care recommendations on cancer pain management. The aim of this paper is to report the results of the first phase in the revision process which consists of a literature review and an expert consensus about the contents to be considered relevant in the development of the new guidelines. A systematic literature search was carried out from 2001 to 2008 through various databases including Medline, Cinahl, Cochrane Database of Systematic Reviews, Embase and Google. Through this process, guideline quality was evaluated, content was compared with EAPC recommendations and a first set of key-points was developed. A modified two-round Delphi method was applied to choose the most relevant topics for future systematic literature reviews. Fourteen guidelines on cancer pain management, published or updated after 2000, were retrieved. A comparison of these guidelines with the EAPC recommendations led to the formulation of 37 key-points, which were submitted to a panel of experts through a Delphi method. Through the responses given by the experts (25 after the first round and 19 after the second) and after a revision by the WP 3.1 local and steering committees, a final list of 22 topics was generated to answer all identified key-points. Each of these topics will be the object of systematic literature reviews. The final version of the "Evidence-based guidelines for the use of opioid analgesics in the treatment of cancer pain: the EAPC recommendations" will be based on the results of the 22 systematic literature reviews.
Minerva anestesiologica 10/2010; 76(10):833-43. · 2.66 Impact Factor
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ABSTRACT: Brief treatments for chronic non-malignant pain patients with problematic opioid use are warranted. The aims of the present study were to investigate (1) whether it is possible to withdraw codeine use in such patients with a brief cognitive-behavioural therapy (CBT), (2) whether this could be done without pain escalation and reduction in quality of life and (3) to explore the effects of codeine reduction on neurocognitive functioning.
Eleven patients using codeine daily corresponding to 40-100 mg morphine were included. Two specifically trained physicians treated the patients with six CBT sessions, tapering codeine gradually within 8 weeks. Codeine use, pain intensity, quality of life and neuropsychological functioning were assessed at pre-treatment to the 3-month follow-up.
Codeine use was significantly reduced from mean 237 mg [standard deviation (SD) 65] pre-treatment to 45 mg (SD 66) post-treatment and to 48 mg (SD 65) at follow-up without significant pain escalation or reductions in quality of life. Moreover, neuropsychological functioning improved significantly on some tests, while others remained unchanged.
The promising findings of codeine reduction in this weaning therapy programme for pain patients with problematic opioid use should be further evaluated in a larger randomized control trial comparing this brief CBT with both another brief treatment and attention placebo condition.
Acta Anaesthesiologica Scandinavica 11/2009; 54(5):571-9. · 2.19 Impact Factor
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ABSTRACT: In a longitudinal study of 297 palliative care patients, 280 patients were followed from inclusion to death. Characteristics and health-related quality of life (HRQL) of the participants and those who later dropped out were compared at inclusion, and 3 and 2 months before their death. At inclusion, the dropouts were older (P = 0.001), had reduced Karnofsky performance score (P < 0.001), received more help from the local authority (P = 0.004) and had reduced HRQL compared with patients who continued in the study and completed the next questionnaire. There were no differences in any of the HRQL parameters between participants and dropouts 3 months before death. Two months before death, differences in HRQL were found, but in favour of the dropouts. Data from patients close to death may be representative of a larger group of patients, whereas initial dropouts may lead to a positive bias of reported HRQL.
Palliative Medicine 04/2009; 23(5):432-40. · 2.38 Impact Factor
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ABSTRACT: One of the aims of the European Palliative Care Research Collaborative (EPCRC) is to achieve consensus on a classification system for cancer pain. We performed a systematic literature review to identify existing classification systems and domains/items used to classify cancer patients with pain. In a systematic search in the databases Medline and Embase, covering 1986-2006, 692 hits were obtained. 92 papers were evaluated to address pain classification. Six standardised classification systems were identified; three of them systematically developed and partially validated. Both pain characteristics and patient characteristics relevant for cancer pain classification were included in the classification systems. All but one of the standardised systems aim at predicting treatment response or adequacy of treatment. Several domains and items used to describe cancer pain but not formally described as part of a classification system were also identified and systematized. The existing approaches to pain classification in cancer patients are different, mostly not thoroughly validated, and none is widely applied. An internationally accepted classification system for cancer pain could improve research and cancer pain management. This systematic review suggests a need for developing an international consensus on how to classify pain in cancer patients.
Palliative Medicine 04/2009; 23(4):295-308. · 2.38 Impact Factor
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ABSTRACT: The aim of the study was to investigate whether the length of informed consent documents (ICDs) for oncological trials have increased from 1987 to 2007 and analyze the content of the ICDs. Design: In total, 87 ICDs from oncological trials approved by the Regional Committee for Medical and Health Research Ethics (REC) in the central region of Norway from 1987 to 2007 were analyzed. A list of 17 basic (fundamental medical and ethical aspects) and 30 formal (juridical aspects, financing, insurance and storage of data) content components was constructed based upon international and REC guidelines for ICDs. The number of words and presence of components were registered for all ICDs.
The mean length of the ICDs increased from 338 (range 276-464) words in 1987-1990 to 1087 words (range 399-2345) in 2005-2007. The number of components increased from nine to 25 during the same period. Basic components increased steadily from seven in 1987-1989 to 14 in 2005-2007 while the components concerning formalities increased substantially from two to 11.
The increased length of the ICDs is explained by an increased complexity of the documents and especially more information about formalities. This development increasingly demands competent readers and might prohibit truly informed consents.
Annals of Oncology 11/2008; 20(2):379-85. · 6.43 Impact Factor
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ABSTRACT: The aims of this study were to describe the pain and use of pain medication in nursing home patients and examine which variables that were associated with pain. Inpatients (n = 307) older than 64 years from nursing homes were included. Pain was measured with a 4-point verbal rating scale in the self-reported group (SRG) and Doloplus-2 in the proxy-rated group (PRG). The mean age was 86 years (SD, 7), and more than two-thirds were female. A total of 128 (60%) patients were able to self-report their pain. Approximately 50% of the SRG reported 'pain now', and of these, nearly 50% reported moderate or severe pain intensity. Better cognitive function was associated with higher pain and receiving more potent pain medication in the SRG. The pain prevalence in the PRG was higher than in the SRG (67.5% vs 51%), but no variable was associated with proxy-rated pain. Nearly 30% in the SRG and 40% in the PRG did not receive pain medication in spite of pain. Pain is still a huge problem in the nursing homes, and more research is needed on pain management in nursing home residents.
Palliative Medicine 11/2008; 23(1):8-16. · 2.38 Impact Factor
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ABSTRACT: At present, there is no universally accepted cancer pain assessment tool for use in palliative care (PC). The European Palliative Care Research Collaborative (EPCRC), therefore, aims to develop an international consensus-based computerised pain assessment tool. As part of this process, we have performed (1) a literature review on pain assessment tools for use in the PC and (2) an international expert survey to gain information on the relevant dimensions for pain assessment in PC. 230 publications were identified, only six met the inclusion criteria. Three further articles were identified through manual searching, totalling 11 different pain assessment tools. Nine tools were multidimensional. Pain intensity was assessed in seven, using various numerical/verbal rating scales (NRS/VRS); five tools focused on pain management. Three publications did not identify the rationale for the need to develop a new tool, and the selection procedure for items/dimensions was not described in six tools. Patient and/or professional expert groups were involved in the development of five tools and only two tools were extensively validated or cross-culturally tested. Thirty-two experts (71%) completed the expert survey and identified 'intensity', 'temporal pattern', 'relief/exacerbation', 'pain quality' and 'location' as the five most relevant dimensions. Most preferred assessment of 'pain intensity' was by NRS rather than VRS. Time windows extending 24 h were regarded as less relevant. Development of PC pain assessment tools seems to be a continuous process, which does not adhere to systematic guidelines, thus does not contribute to a universally accepted tool. No tool contained all relevant dimensions as defined by the experts. Many tools focused on particular dimensions, suggesting that specific research interests may drive the tool development process. Extensive literature reviews, expert and patient input and clinical studies are a needed approach in the development of a new consensus-based pain assessment tool.
Palliative Medicine 10/2008; 22(8):895-903. · 2.38 Impact Factor
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ABSTRACT: The aim of this literature review is to summarize and discuss the available evidence for a relationship between polymorphisms in human genes and variability in opioid analgesia and side effects among patients treated for moderate or severe pain. The evidence supporting a role of certain alleles, genotypes or haplotypes in modulation of opioid analgesia is derived from a limited number of studies, a limited number of genes and a limited number of opioids. Although several interesting candidates have emerged as potentially relevant factors, only for one polymorphism, the prevalent 118A>G of the micro-opioid receptor, the accumulated evidence is sufficient to suggest a clinically relevant effect for an opioid used for moderate or severe pain. Still the data are valid only at the group level and cannot be used to predict treatment outcome in individual patients. Only a few of the symptoms often seen as opioid adverse effects in palliative care, such as nausea, vomiting, constipation and sedation, have been associated with genetic variants in various genes, but the results have been based on case reports, healthy volunteers or post-operative patients. So far, there is no clear evidence that genetic markers can be used to predict opioid efficacy or adverse effects in palliative care patients. This reflects the general lack of studies performed in the context of palliative care, the lack of sufficiently scaled studies and the lack of international standards for the assessment of subjective symptoms.
Palliative Medicine 06/2008; 22(4):310-27. · 2.38 Impact Factor
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ABSTRACT: This topical review addresses methadone's pharmacology, its application in malignant and non-malignant pain conditions, practical issues related to methadone for the treatment of pain and its influence on QTc time.
Relevant papers were identified in PubMed and EMBASE.
Methadone is advocated by experts as a second line opioid when first line opioids fail to provide a satisfactory balance between pain control and side effects (opioid switching). Although randomized-controlled studies are lacking, current evidence suggests that switching to methadone in this situation reduces pain intensity. However, interindividual variability in its pharmacokinetics make its application challenging and metabolism by CYP 3A4 and 2B6 implies a substantial risk of drug-drug interactions. Several ways of switching to methadone have been presented, with a gradual switch during 3 days or 'stop and go' as the dominating strategies. Episodes of torsade de pointes arrhythmia during methadone treatment have been reported in patients with other risk factors for arrhythmia, while small prospective studies have reported a small, lasting and stable increase in QTc time. The extensive use of methadone for opioid replacement in addicts has added additional patient barriers to its use for pain control.
In spite of challenges related to the variable pharmacokinetics and concerns regarding increase in QTc time, current evidence indicates that opioid switching to methadone improves pain control in a substantial proportion of patients who are candidates for opioid switching. Measures must be instituted to secure that patients receiving methadone for pain are not considered opioid addicts.
Acta Anaesthesiologica Scandinavica 04/2008; 52(7):879-89. · 2.19 Impact Factor
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ABSTRACT: Patients with chronic non-malignant pain (CNMP) conditions are known to report reduced health-related quality of life (HRQoL). The objective of this exploratory study was to compare HRQoL between patients admitted to a multidisciplinary pain centre, palliative cancer (PC) patients and national norms.
HRQoL data from 288 patients with CNMP admitted to the multidisciplinary pain centre at Trondheim University Hospital were compared with 434 patients with advanced cancer included in a trial of comprehensive palliative care in the hospital palliative medicine unit and national norms. HRQoL was assessed using the EORTC QLQ-C30. Age- and gender-adjusted norm data were calculated and compared between the two groups.
Scores from both groups deviated from adjusted norm data on all scales, with poorer functioning and more symptoms. Compared with PC patients, CNMP patients reported a larger deviation (worse scores) on global quality of life, cognitive functioning, pain, sleep disturbances and financial difficulties. Deviations from norm data were similar for physical, social and emotional functioning, diarrhoea, dyspnoea and fatigue. PC patients reported worse scores on role functioning, nausea/vomiting, loss of appetite and constipation.
CNMP patients admitted to multidisciplinary pain centres report significantly reduced HRQoL, in addition to severe pain. They consider their HRQoL to be as poor as HRQoL reported from dying cancer patients and substantially poorer than national norms. Factors other than the biological severity of the disease seem to be of major importance for self-reported HRQoL.
Acta Anaesthesiologica Scandinavica 02/2008; 52(1):143-8. · 2.19 Impact Factor
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ABSTRACT: Missing data is a common problem in palliative care research due to the special characteristics (deteriorating condition, fatigue and cachexia) of the population. Using data from a palliative study, we illustrate the problems that missing data can cause and show some approaches for dealing with it. Reasons for missing data and ways to deal with missing data (including complete case analysis, imputation and modelling procedures) are explored. Possible mechanisms behind the missing data are: missing completely at random, missing at random or missing not at random. In the example study, data are shown to be missing at random. Imputation of missing data is commonly used (including last value carried forward, regression procedures and simple mean). Imputation affects subsequent summary statistics and analyses, and can have a substantial impact on estimated group means and standard deviations. The choice of imputation method should be carried out with caution and the effects reported.
Palliative Medicine 01/2007; 20(8):791-8. · 2.38 Impact Factor
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Qual Life Res. 01/2007;
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Qual Life Res. 01/2006;
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ABSTRACT: The individual variability of opioid pharmacology suggests that the patients' genetic disposition influences the response to opioids. Given the complexity of morphine pharmacology, variability may be caused by several genes. We review data which shows that variability in genes coding the enzyme metabolizing morphine (UGT2B7 gene), mu-opioid receptors (OPRM gene) and blood-brain barrier (BBB) transport of morphine by multidrug resistance transporters (MDR1 gene) influences the clinical efficacy of morphine. Furthermore, variability in an enzyme degrading catecholamines (COMT gene) alters the efficacy of morphine demonstrating that genetic variability in non-opioid systems may indirectly influence the clinical efficacy from morphine. Thus, results obtained so far strongly argue that opioid efficacy is partly related to inborn properties caused by genetic variability.
Acta Anaesthesiologica Scandinavica 09/2005; 49(7):902-8. · 2.19 Impact Factor
