Is oxycodone efficacy reflected in serum concentrations? A multicenter, cross-sectional study in 456 adult cancer patients

CONTEXT

The relationship between oxycodone and metabolite serum concentrations and clinical effects has not previously been investigated in cancer pain patients.

OBJECTIVES

The aim of this study was to assess whether there is a relationship between oxycodone concentrations and pain intensity, cognitive functioning, nausea, or tiredness in cancer patients. Also, oxymorphone and noroxymorphone contributions to analgesia and the adverse effects of oxycodone were assessed.

METHODS

Four hundred fifty-six cancer patients receiving oxycodone for cancer pain were included. Pain was assessed using the Brief Pain Inventory. The European Organisation for Research and Treatment of Cancer Quality-of-Life Questionnaire-C30 was used to assess the symptoms of tiredness, nausea, constipation, and depression. Cognitive function was assessed using the Mini-Mental State Examination. Associations were examined by multiple linear or ordinal logistic regressions. Whether patients classified as being a "treatment success" or a "treatment failure" had different serum concentrations of oxycodone or metabolites was assessed using Mann-Whitney U-tests.

RESULTS

Serum concentrations of oxycodone and metabolites were not associated with pain intensity, nausea, tiredness, or cognitive function, with the exception that increased pain intensity was associated with higher oxymorphone concentrations. Patients with poor pain control and side effects had higher serum concentrations of the oxycodone metabolites, noroxycodone and noroxymorphone, compared with those with good pain relief and without side effects.

CONCLUSION

This study of patients receiving oxycodone for cancer pain confirms previous observations that there is most likely no association between serum concentrations of opioid analgesics and clinical effects.

Use of opioid analgesics in the treatment of cancer pain: evidence-based recommendations from the EAPC

Here we provide the updated version of the guidelines of the European Association for Palliative Care (EAPC) on the use of opioids for the treatment of cancer pain. The update was undertaken by the European Palliative Care Research Collaborative. Previous EAPC guidelines were reviewed and compared with other currently available guidelines, and consensus recommendations were created by formal international expert panel. The content of the guidelines was defined according to several topics, each of which was assigned to collaborators who developed systematic literature reviews with a common methodology. The recommendations were developed by a writing committee that combined the evidence derived from the systematic reviews with the panellists' evaluations in a co-authored process, and were endorsed by the EAPC Board of Directors. The guidelines are presented as a list of 16 evidence-based recommendations developed according to the Grading of Recommendations Assessment, Development and Evaluation system.

Expert conference on cancer pain assessment and classification--the need for international consensus: working proposals on international standards

An increasing number of cancer patients live longer, and palliative care has become an important part of their treatment. Symptoms are often inadequately assessed and managed. A significant challenge in clinical trials is to control for the variability of the samples being studied. To overcome this problem, classification systems have been developed in order to characterise and stratify patients by grouping them according to major common characteristics. The lack of agreed methods for the assessment and classification of cancer pain has been clearly indicated in clinical trials and in clinical practice and may be one possible explanation for the inadequate treatment of cancer pain. This was the background to an international expert meeting arranged in September 2009 in Milan, Italy. The primary aims were to produce recommendations on how to assess and classify cancer pain and to recommend a strategy for the further development, validation and implementation of an international cancer pain classification and assessment system. The recommendations consisted of two basic working proposals, nine specific working proposals and seven recommendations for the further development of a cancer pain classification system. Examples of specific working proposals were to include pain intensity, pain mechanism, breakthrough pain and psychological distress as the core domains in this classification of cancer pain and to measure pain intensity with a 0-10 numerical rating scale with 'no pain' and 'pain as bad as you can imagine' as anchors. The proposed name for this international standard is Cancer Pain Assessment and Classification System (CPACS).

Is there a genetic cause for cancer cachexia? - a clinical validation study in 1797 patients

BACKGROUND

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.

METHOD

A total of 1797 cancer patients, classified as either having severe cachexia, mild cachexia or no cachexia, were genotyped.

RESULTS

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).

CONCLUSION

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.

How to switch from morphine or oxycodone to methadone in cancer patients? a randomised clinical phase II trial

AIM

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.

METHODS

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.

RESULTS

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.

CONCLUSION

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.

Management of opioid-induced nausea and vomiting in cancer patients: systematic review and evidence-based recommendations

The objectives were to review the existing literature on management of opioid-induced nausea and vomiting in cancer patients and summarize the findings into evidence-based recommendations. Systematic searches of MEDLINE, EMBASE and the Cochrane Central Register of Controlled Trials were performed, using free text and MeSH/EMTREE search terms. The searches were limited to articles published in English from each database set-up date to 31 July 2009. Reference lists and relevant international conference proceedings were hand-searched. Fifty-five studies were identified, providing data on 5741 patients. The studies were classified into: (A) studies in which treatment of nausea/vomiting was the primary outcome (a total of 18 studies, of which eight studies specifically addressed opioid-induced emesis); and (B) studies in which nausea/vomiting were secondary or tertiary outcomes (37 studies). The existing evidence had several limitations, there was a lack of consistency and the overall quality was grade D. By applying the principles of the Grading of Recommendations Assessment, Development and Evaluations (GRADE) system, three weak recommendations were formulated. The current evidence is too limited to give evidence-based recommendations for the use of antiemetics for opioid-induced nausea or vomiting in cancer patients. The evidence suggests that nausea and vomiting in cancer patients receiving an opioid might be reduced by changing the opioid or opioid administration route. The evidence was also too limited to prioritize between symptomatic treatment and adjustment of the opioid treatment.

Starting step III opioids for moderate to severe pain in cancer patients: dose titration: a systematic review

The European Association for Palliative Care recommendation for starting morphine for cancer pain is dose titration with immediate release (IR) oral morphine given every 4 h with additionally doses for breakthrough pain. As part of a EU 6th framework programme to revise the guidelines we review the evidence regarding starting treatment and dose titration of opioids in adult patients with moderate to severe cancer pain. Relevant papers were identified though a systematic search in Medline for papers published until the end of 2009. We identified 15 relevant papers. Thirteen papers were descriptive papers reporting the results from starting treatment with oral morphine (six studies), starting treatment with intravenous morphine (two studies) and starting treatment with transdermal fentanyl (four studies). All treatment strategies resulted in acceptable pain control and were well tolerated. Two randomized controlled trials were identified. One study compared starting opioid treatment with intravenous morphine versus IR oral morphine and one study compared IR oral morphine versus sustained release oral morphine.

Multiple Loci modulate opioid therapy response for cancer pain

PURPOSE

Patients treated with opioid drugs for cancer pain experience different relief responses, raising the possibility that genetic factors play a role in opioid therapy outcome. In this study, we tested the hypothesis that genetic variations may control individual response to opioid drugs in cancer patients.

EXPERIMENTAL DESIGN

We tested 1 million single-nucleotide polymorphisms (SNP) in European cancer patients, selected in a first series, for extremely poor (pain relief ≤40%; n = 145) or good (pain relief ≥90%; n = 293) responses to opioid therapy using a DNA-pooling approach. Candidate SNPs identified by SNP-array were genotyped in individual samples constituting DNA pools as well as in a second series of 570 patients.

RESULTS

Association analysis in 1,008 cancer patients identified eight SNPs significantly associated with pain relief at a statistical threshold of P < 1.0 × 10⁻³, with rs12948783, upstream of the RHBDF2 gene, showing the best statistical association (P = 8.1 × 10⁻⁹). Functional annotation analysis of SNP-tagged genes suggested the involvement of genes acting on processes of the neurologic system.

CONCLUSION

Our results indicate that the identified SNP panel can modulate the response of cancer patients to opioid therapy and may provide a new tool for personalized therapy of cancer pain.

Prevalence and predictors of cognitive dysfunction in opioid-treated patients with cancer: a multinational study

PURPOSE

To identify prevalence and associated factors of cognitive dysfunction in opioid-treated patients with cancer.

PATIENTS AND METHODS

EPOS (European Pharmacogenetic Opioid Study) is a prospective cross-sectional multicenter study in which adult patients with cancer who received treatment with opioids for moderate or severe pain for at least 3 days were included. Cognitive function was assessed using the Mini-Mental State Examination (MMSE). MMSE scores were categorized into definite cognitive dysfunction (scores < 24), possible cognitive dysfunction (scores 24-26), and no cognitive dysfunction (scores > 26). Factors potentially associated with cognitive dysfunction were assessed. Associations between MMSE and explanatory variables were analyzed by ordinal logistic regression models.

RESULTS

We included 1,915 patients with cancer from 17 centers. MMSE scores less than 27 were observed in 32.9% of patients. Patients with lung cancer had higher odds (adjusted odds ratio, 1.46; 95% CI, 1.09 to 1.95) for having lower MMSE scores compared with patients with other cancer diagnoses. Patients receiving daily opioid doses of 400 mg or more (oral morphine equivalents) had 1.75 (95% CI, 1.25 to 2.46) times higher odds of having lower MMSE scores compared with those receiving daily doses less than 80 mg. Other risk factors for cognitive dysfunction were older age, low Karnofsky performance status (KPS), time since diagnosis (< 15 months), and absence of breakthrough pain (BTP).

CONCLUSION

One third of opioid-treated patients with cancer had possible or definite cognitive dysfunction. Lung cancer, daily opioid doses of 400 mg or more (oral morphine equivalents), older age, low KPS, shorter time since cancer diagnosis, and absence of BTP were predictors for cognitive dysfunction.

Comparing the effect of hydroxyethyl starch 130/0.4 with balanced crystalloid solution on mortality and kidney failure in patients with severe sepsis (6S--Scandinavian Starch for Severe Sepsis/Septic Shock trial): study protocol, design and rationale for a double-blinded, randomised clinical trial

Background

By tradition colloid solutions have been used to obtain fast circulatory stabilisation in shock, but high molecular weight hydroxyethyl starch (HES) may cause acute kidney failure in patients with severe sepsis. Now lower molecular weight HES 130/0.4 is the preferred colloid in Scandinavian intensive care units (ICUs) and 1^st choice fluid for patients with severe sepsis. However, HES 130/0.4 is largely unstudied in patients with severe sepsis.

Methods/Design

The 6S trial will randomise 800 patients with severe sepsis in 30 Scandinavian ICUs to masked fluid resuscitation using either 6% HES 130/0.4 in Ringer's acetate or Ringer's acetate alone. The composite endpoint of 90-day mortality or end-stage kidney failure is the primary outcome measure. The secondary outcome measures are severe bleeding or allergic reactions, organ failure, acute kidney failure, days alive without renal replacement therapy or ventilator support and 28-day and 1/2- and one-year mortality. The sample size will allow the detection of a 10% absolute difference between the two groups in the composite endpoint with a power of 80%.

Discussion

The 6S trial will provide important safety and efficacy data on the use of HES 130/0.4 in patients with severe sepsis. The effects on mortality, dialysis-dependency, time on ventilator, bleeding and markers of resuscitation, metabolism, kidney failure, and coagulation will be assessed.

Trial Registration

ClinicalTrials.gov: NCT00962156

Influences on the pharmacokinetics of oxycodone: a multicentre cross-sectional study in 439 adult cancer patients

Objective

Oxycodone is widely used for the treatment of cancer pain, but little is known of its pharmacokinetics in cancer pain patients. The aim of this study was to explore the relationships between ordinary patient characteristics and serum concentrations of oxycodone and the ratios noroxycodone or oxymorphone/oxycodone in cancer patients.

Methods

Four hundred and thirty-nine patients using oral oxycodone for cancer pain were included. The patients’ characteristics (sex, age, body mass index [BMI], Karnofsky performance status, “time since starting opioids”, “oxycodone total daily dose”, “time from last oxycodone dose”, use of CYP3A4 inducer/inhibitor, “use of systemic steroids”, “number of medications taken in the last 24 h”, glomerular filtration rate (GFR) and albumin serum concentrations) influence on oxycodone serum concentrations or metabolite/oxycodone ratios were explored by multiple regression analyses.

Results

Sex, CYP3A4 inducers/inhibitors, total daily dose, and “time from last oxycodone dose” predicted oxycodone concentrations. CYP3A4 inducers, total daily dose, and “number of medications taken in the last 24 h” predicted the oxymorphone/oxycodone ratio. Total daily dose, “time from last dose to blood sample”, albumin, sex, CYP3A4 inducers/inhibitors, steroids, BMI and GFR predicted the noroxycodone/oxycodone ratio.

Conclusion

Women had lower oxycodone serum concentrations than men. CYP3A4 inducers/inhibitors should be used with caution as these are predicted to have a significant impact on oxycodone pharmacokinetics. Other characteristics explained only minor parts of the variability of the outcomes.

Content development for EUROPEAN GUIDELINES on the use of opioids for cancer pain: a systematic review and Expert Consensus Study

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.

Health care providers underestimate symptom intensities of cancer patients: a multicenter European study

Background

Many patients with advanced cancer depend upon health care providers for symptom assessment. The extent of agreement between patient and provider symptom assessments and the association of agreement with demographic- and disease-related factors was examined.

Methods

This cross-sectional study included 1933 patient-health care provider dyads, from 11 European countries. Patients reported symptoms by using the four-point scales of the European Organization of Research and Treatment of Cancer Core Quality of Life Questionnaire (EORTC QLQ-C30) version 3, and providers used corresponding four-point categorical scales. Level of agreement was addressed at the group level (Wilcoxon Signed-Rank test), by difference scores (provider score minus patient score), at the individual level (Intraclass Correlation Coefficients, ICCs) and visually by Bland-Altman plots. Absolute numbers and chi-square tests were used to investigate the relationship between agreement and demographic-, as well as disease-related factors.

Results

The prevalence of symptoms assessed as moderate or severe by patients and providers, respectively, were for pain (67 vs.47%), fatigue (71 vs. 54%), generalized weakness (65 vs. 47%), anorexia (47 vs. 25%), depression (31 vs. 17%), constipation (45 vs. 30%), poor sleep (32 vs. 21%), dyspnea (30 vs. 16%), nausea (27 vs. 14%), vomiting (14 vs. 6%) and diarrhea (14 vs. 6%). Symptom scores were identical or differed by only one response category in the majority of patient-provider assessment pairs (79-93%). Providers underestimated the symptom in approximately one of ten patients and overestimated in 1% of patients. Agreement at the individual level was moderate (ICC 0.38 to 0.59). Patients with low Karnofsky Performance Status, high Mini Mental State-score, hospitalized, recently diagnosed or undergoing opioid titration were at increased risk of symptom underestimation by providers (all p < 0.001). Also, the agreement was significantly associated with drug abuse (p = 0.024), provider profession (p < 0.001), cancer diagnosis (p < 0.001) and country (p < 0.001).

Conclusions

Considerable numbers of health care providers underestimated symptom intensities. Clinicians in cancer care should be aware of the factors characterizing patients at risk of symptom underestimation.

Biological pathways and genetic variables involved in pain

PURPOSE

This paper summarizes current knowledge of pain-related and analgesic-related pathways as well as genetic variations involved in pain perception and management.

METHODS

The pain group of the GENEQOL Consortium was given the task of summarizing the current status of research on genetic variations in pain and analgesic efficacy. This review is neither exhaustive nor comprehensive; we focus primarily on single-nucleotide polymorphisms.

RESULTS

Two categories of potential genetic pain-perception pathways were identified: neurotransmission modulators and mechanisms that affect inflammation. Four categories were identified for analgesic efficacy: genes related to receptor interaction, modulation of opioid effects, metabolism, and transport. Various genetic variations involved in these pathways are proposed as candidate genetic markers for pain perception and for individual sensitivity to analgesics.

CONCLUSIONS

Candidate gene association studies have been used to provide evidence for the genetic modulation of pain perception and response to analgesics. However, the nature and range of genetic modulation of pain is not well addressed due to the limited number of patients and the limited number of genes and genetic variants investigated in studies to date. Moreover, personalized analgesic treatments will require a more complete understanding of the effects of genetic variants and gene-gene interactions in response to analgesics.

[Intensive care of patients with acute liver failure]

BACKGROUND

Acute liver failure and acute decompensated chronic liver failure are two diseases that demand extensive knowledge of etiology and triggering factors, pathophysiology, diagnosis, prognosis and recommended guidelines for treatment. The article defines the diseases, discusses etiological factors, treatment strategies, indications for referral to the transplantation unit at Rikshospitalet and prognostic factors of importance.

MATERIAL AND METHODS

The basis for this article is literature identified through a non-systematic search in PubMed and the authors' clinical experience and experimental research within the field.

RESULTS

In the Western world paracetamol poisoning and toxic reactions to other drugs are the most common triggering factors for acute liver poisoning in adults. Patients can quickly develop multi organ failure requiring advanced intensive care. The most common complications are hepatic encephalopathy, acute renal failure and coagulation disturbances. Acute decompensated chronic liver failure strikes patients with known liver disease and is most often triggered by inflammation, infection, gastrointestinal bleeding, drugs, traumas or disturbances in acid/base/electrolyte balance. Early diagnosing of triggering factors and intensive medical supportive treatment is especially important. Acute renal failure indicates a very bad prognosis.

INTERPRETATION

Patients diagnosed with acute liver failure or acute decompensated chronic liver failure remain a clinical challenge. Optimal treatment requires extensive knowledge of pathophysiological mechanisms and treatment strategies.

Which variables are associated with pain intensity and treatment response in advanced cancer patients?--Implications for a future classification system for cancer pain

BACKGROUND

This study is part of a research program to reach consensus on an international cancer pain classification system. A confirmative and explorative approach was applied to investigate which of the variables identified in the literature, by experts and patients that are associated with pain.

METHODS

Data from an international, multicentre, cross-sectional study of cancer patients treated with opioids were investigated. Dependent variables were: average pain, worst pain, and pain relief (11-point Numerical Rating Scales). Forty-six independent variables were chosen based upon previous studies. Bivariate analyses identified independent variables associated with at least one of the dependent ones; 21 were included in multivariate linear regression analyses.

RESULTS

Two thousand two hundred and seventy-eight patients were investigated; 52% males, mean age 62 years, mean Karnofsky Performance Status 59%, mean daily opioid oral equivalent dose 341 mg. Fifty-eight percent had breakthrough pain. Mean pain scores were: average pain 3.5, worst pain 5.3 and pain relief 74%. Variables most strongly associated with these three dependent variables were: breakthrough pain, psychological distress, sleep, and opioid dose.

CONCLUSIONS

Breakthrough pain and psychological distress were confirmed as key variables of a future classification system. Candidate variables were: sleep, opioid dose, pain mechanism, use of non-opioids, pain localisation, cancer diagnosis, location of metastases, and addiction.

Cognitive dysfunction and health-related quality of life after a cardiac arrest and therapeutic hypothermia

BACKGROUND

Evidence-based treatment protocols including therapeutic hypothermia have increased hospital survival to over 50% in unconscious out-of-hospital cardiac arrest survivors. In this study we estimated the incidence of cognitive dysfunctions in a group of cardiac arrest survivors with a high functional outcome treated with therapeutic hypothermia. Secondarily, we assessed the cardiac arrest group's level of cognitive performance in each tested cognitive domain and investigated the relationship between cognitive function and age, time since cardiac arrest and health-related quality of life (HRQOL).

METHODS

We included 26 patients 13-28 months after a cardiac arrest. All patients were scored using the Cerebral Performance Category scale (CPC) and Mini-Mental State Examination (MMSE). Twenty-five of the patients were tested for cognitive function using the Cambridge Neuropsychological Test Automated Battery (CANTAB). These patients were tested using four cognitive tests: Motor Screening Test, Delayed Matching to Sample, Stockings of Cambridge and Paired Associate Learning from CANTAB. All patients filled in the Short Form-36 for the assessment of HRQOL.

RESULTS

Thirteen of 25 (52%) patients were classified as having a cognitive dysfunction. Compared with the reference population, there was no difference in the performance in motor function and delayed memory but there were significant differences in executive function and episodic memory. We found no associations between cognitive function and age, time since cardiac arrest or HRQOL.

CONCLUSION

Half of the patients had a cognitive dysfunction with reduced performance on executive function and episodic memory, indicating frontal and temporal lobe affection, respectively. Reduced performance did not affect HRQOL.

Chronic pain after cardiac surgery: a prospective study

BACKGROUND

Chronic pain is a complication of several surgical procedures. The prevalence of chronic pain reported after cardiac surgery varies from 18% to 61%. However, most studies are retrospective, do not use validated instruments for pain measurement or include only pain at the sternum site. The aim of the present study was to assess chronic pain and health-related quality of life (HRQOL) after cardiac surgery.

METHODS

In a prospective, population-based study, we included 534 patients (413 males) and assessed chronic pain and HRQOL before, 6 months after, and 12 months after cardiac surgery. Pain was measured by the Brief Pain Inventory, while HRQOL was measured by the Short-Form 36 (SF-36).

RESULTS

Five hundred and twenty-one patients were alive 12 months after surgery; 462 (89%) and 465 (89%) responded after 6 and 12 months, respectively. Chronic pain was reported by 11% of the patients at both measurements. Younger age was associated with chronic pain [odds ratio 0.7 (95% confidence interval: 0.5-0.9)] at 12 months. Patients with chronic pain reported lower scores on seven of eight SF-36 subscales.

DISCUSSION

In conclusion, we observed a lower prevalence of chronic pain after cardiac surgery than in previous studies. Still, more than one out of 10 patients reported chronic pain after cardiac surgery. Chronic pain appears to affect HRQOL. Thus, given the large number of patients subjected to cardiac surgery, this study confirms that chronic pain after cardiac surgery is an important health care issue.

A GTP cyclohydrolase 1 genetic variant delays cancer pain

Pain is a major symptom in 70% of patients with advanced cancer. We analyzed data of 251 cancer patients (142 men and 109 women aged 29-89 years, Karnofsky status 10-90, 65.7+/-13.9) for association of a reduced-function haplotype in the GTP cyclohydrolase 1 (GCH1) gene with cancer pain therapy. The interval between cancer diagnosis and opioid therapy initiation was significantly (p=0.002) longer in homozygous carriers of these genetic variants (78+/-65.2 months) than in heterozygous (37+/-46.5 months) and non-carriers (30.4+/-43.8 months). Thus, reduced GCH1 upregulation, here conferred by non-coding and non-splice site GCH1 variants known to lead to decreased tetrahydrobiopterin expression, delays the need for opioid therapy in cancer. This suggests the future possibility of using partial GCH1 blockade or BH4 inhibition as a prophylactic to prevent or delay the development of cancer pain.

The establishment of the GENEQOL consortium to investigate the genetic disposition of patient-reported quality-of-life outcomes

To our knowledge, no comprehensive, interdisciplinary initiatives have been taken to examine the role of genetic variants on patient-reported quality-of-life outcomes. The overall objective of this paper is to describe the establishment of an international and interdisciplinary consortium, the GENEQOL Consortium, which intends to investigate the genetic disposition of patient-reported quality-of-life outcomes. We have identified five primary patient-reported quality-of-life outcomes as initial targets: negative psychological affect, positive psychological affect, self-rated physical health, pain, and fatigue. The first tangible objective of the GENEQOL Consortium is to develop a list of potential biological pathways, genes and genetic variants involved in these quality-of-life outcomes, by reviewing current genetic knowledge. The second objective is to design a research agenda to investigate and validate those genes and genetic variants of patient-reported quality-of-life outcomes, by creating large datasets. During its first meeting, the Consortium has discussed draft summary documents addressing these questions for each patient-reported quality-of-life outcome. A summary of the primary pathways and robust findings of the genetic variants involved is presented here. The research agenda outlines possible research objectives and approaches to examine these and new quality-of-life domains. Intriguing questions arising from this endeavor are discussed. Insight into the genetic versus environmental components of patient-reported quality-of-life outcomes will ultimately allow us to explore new pathways for improving patient care. If we can identify patients who are susceptible to poor quality of life, we will be able to better target specific clinical interventions to enhance their quality of life and treatment outcomes.

Health-related quality of life three years after coronary surgery: A comparison with the general population

OBJECTIVES

To assess health-related quality of life (HRQOL) in patients three years after coronary artery bypass grafting (CABG) compared to the general Norwegian population, with emphasis on age and gender-differences.

DESIGN

A cross-sectional postal survey of patients who underwent CABG in 2000. HRQOL was assessed using the Short Form 36 (SF-36). Subgroup analyses were performed according to age (<70 versus =70 years) and gender.

RESULTS

Of 233 eligible patients 203 responded (mean age 67.6 years, 17% females). Patients reported better scores on bodily pain than the general population (p=0.008), but did not differ on other subscales of SF-36. Younger patients tended to score lower, older patients higher than the general population on HRQOL. Female patients reported lower HRQOL than the general female population and reported significantly lower scores than male patients on 3 of 8 subscales.

CONCLUSIONS

Three years after CABG the HRQOL is comparable to the general Norwegian population even in older patients. The older patients reported less pain than the general population.

Classification of pain in cancer patients--a systematic literature review

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.

A double-blind, randomized, crossover comparison between single-dose and double-dose immediate-release oral morphine at bedtime in cancer patients

The European Association for Palliative Care guidelines for treatment of cancer pain recommend a double dose (DD) of immediate-release morphine at bedtime instead of single doses (SD) repeated every four hours throughout the night. A previous open controlled study reported more side effects after DD than after SD. The present study was a randomized, double-blind, crossover study comparison of DD and SD of immediate-release morphine during the night, followed by an open pharmacokinetic study. The primary outcome was average pain intensity during the night, as measured on an 11-point numerical rating scale. Secondary outcomes were morning pain, number of rescue medications, adverse effects (nausea, xerostomia, tiredness, sleep quality, and number of awaking episodes) and patient preference. Morphine and metabolites were quantified by a validated liquid chromatography-tandem mass spectrometry method. Nineteen patients completed the clinical study; 13 participated in the pharmacokinetic follow up. Average pain during the night for DD vs. SD was close to statistical significance (mean 0.8 and 1.4, respectively, P=0.058; mean [95% confidence interval] for the difference was 0.50 [0.02, 1.0]). A similar trend was observed for strongest night pain (P=0.069) and sleep quality (P=0.077). Only two patients required rescue morphine. Four patients had no treatment preference; nine and six favored DD and SD, respectively. DD patients displayed higher area under the curve for morphine and morphine-6-glucuronide during the first part of the night. Although DD tended to perform slightly better than SD, a difference in average pain during the night of 0.50 has little clinical significance, and the two procedures are, therefore, clinically equivalent. It is speculated whether the initial higher exposure to morphine-6-glucuronide may have clinical significance.

Intensity and treatment of symptoms in 3,030 palliative care patients: a cross-sectional survey of the EAPC Research Network

OBJECTIVE

This study aimed to describe intensity and treatment of symptoms other than pain in European palliative care units.

PATIENTS

A total of 3,030 patients, including 2,064 that used an opioid, were included from 143 palliative care centers, in 21 European countries.

RESULTS

Pain was treated with analgesics corresponding to the WHO pain ladder step I (n = 374), II (n = 497), and III (n = 1,567). Frequencies of symptoms observed as moderate or severe were for generalized weakness (50 percent), fatigue (48 percent), anxiety (28 percent), anorexia (26 percent), constipation (18 percent), focal weakness (18 percent), depression (18 percent), and dyspnoea (15 percent). When comparing WHO-groups, cancer diagnoses, metastasis sites, countries, and genders, we found that some of the symptom intensities and treatments differed significantly between subgroups. A majority of patients used drugs for symptom management. Still, more than one-third of patients assessed to have moderate or severe constipation did not receive any treatment. The corresponding numbers for depression, confusion, nausea, vomiting, or anxiety were approaching 40 percent and for poor sleep about 50 percent. Prescription practice of antiemetics, laxatives, and psychotropic drugs varied widely between countries both in terms of preparation and percent of patients receiving a specific treatment.

CONCLUSIONS

This survey shows that clinically relevant symptoms are frequent and that one-third to half of the patients with a symptom observed as moderate or severe do not receive any treatment aimed to reduce the symptom intensity. Several symptoms and treatments differed between WHO-groups, cancer diagnoses, metastasis locations, countries, and genders. Prescription practice varied between countries both in terms of medication administered and percent of patients receiving specific treatment.

Genetic variation in the catechol-O-methyltransferase (COMT) gene and morphine requirements in cancer patients with pain

Background

Genetic variation contributes to differences in pain sensitivity and response to different analgesics. Catecholamines are involved in the modulation of pain and are partly metabolized by the catechol-O-methyltransferase (COMT) enzyme. Genetic variability in the COMT gene may therefore contribute to differences in pain sensitivity and response to analgesics. It is shown that a polymorphism in the COMT gene, Rs4680 (Val158Met), influence pain sensitivity in human experimental pain and the efficacy for morphine in cancer pain treatment. In this study we wanted to investigate if variability in other regions in the COMT gene also contributes to interindividual variability in morphine efficacy.

Results

We genotyped 11 single nucleotide polymorphisms (SNPs) throughout the COMT gene, and constructed haplotypes from these 11 SNPs, which were in Hardy-Weinberg equilibrium. We compared both genotypes and haplotypes against pharmacological, demographical and patient symptoms measurements in a Caucasian cancer patient cohort (n = 197) receiving oral morphine treatment for cancer pain. There were two frequent haplotypes (34.5% and 17.8%) in our cohort. Multivariate analyses showed that patients carrying the most frequent haplotype (34.5%) needed lower morphine doses than patients not carrying the haplotype, with a reduction factor of 0.71 (p = 0.005). On the allele level, carriers of alleles for six of the SNPs show weak associations in respect to morphine dose and the alleles associated with the lowest morphine doses constitute part of the most frequent haplotype.

Conclusion

This study suggests that genetic variability in the COMT gene influence the efficacy of morphine in cancer patients with pain, and that increased understanding of this variability is reached by expanding from analyses of single SNPs to haplotype construction and analyses.

Cancer patients' barriers to pain management and psychometric properties of the Norwegian version of the Barriers Questionnaire II

The Barriers Questionnaire II (BQ-II) was developed to assess barriers to effective pain management. The purpose of this study was to evaluate the psychometric properties of the BQ-II in a sample of Norwegian cancer patients. The BQ-II was translated into Norwegian and pilot tested with eight oncology outpatients. Then, a convenience sample of 321 cancer patients from two different sites was recruited to maximize the number of questionnaires available for the psychometric analyses. Patients were included if they: were >18 years of age; had a diagnosis of cancer; and self-reported pain and/or use of analgesics. Construct validity of the Norwegian version of the BQ II (NBQ-II) was evaluated using an exploratory factor analysis. A seven-factor solution was found that was more consistent with the original version of the BQ. Construct validity of the NBQ-II was demonstrated through positive correlations between most of the subscale and total scores on the NBQ-II and pain intensity and pain interference scores. Finally, Cronbach's α coefficients of ≥0.7 for six of the seven subscales and 0.89 for the total scale demonstrated acceptable levels of internal consistency. In conclusion, the NBQ-II demonstrated adequate psychometric properties. However, further revision and testing of the questionnaire should be performed to confirm the factor structure that was identified in this study.

Process of foregoing life-sustaining treatment: a survey among Scandinavian intensivists

BACKGROUND

How ethical issues are dealt with varies considerably depending on the geographic and religious background of individuals. The views of Scandinavian physicians on end-of-life care were studied using a survey. The aim of this study was to clarify the actual processes of foregoing life-sustaining treatment in Scandinavia.

METHODS

A questionnaire was developed and sent to 78 intensive care physicians working in Denmark, Finland, Norway and Sweden.

RESULTS

Forty-four responses were obtained (13 from Denmark, eight from Finland, 12 from Norway and 11 from Sweden); 89% of the respondents were from University Hospitals. Withholding and withdrawing of treatment were practiced in all intensive care units (ICUs) concerned, but written guidelines on end-of-life care existed in only one ICU. End-of-life care is usually arranged in the ICU. Religious support is available in most hospitals during office hours, but lacking in 26% of ICUs outside office hours. Vasoactive medication, renal replacement therapy, and artificial nutrition are among the therapies most likely to be discontinued during withdrawal of life support. Certain types of monitoring and organ support are still continued in many centers during end-of-life care.

CONCLUSION

Local written guidelines on end-of-life care are scarce in Scandinavian ICUs, which may explain the observed variability in the practices. Development of guidelines and monitoring how these instructions are carried out may help to improve the quality of care of dying ICU patients.

A controlled comparison between single doses of intravenous and intramuscular morphine with respect to analgesic effects and patient safety

BACKGROUND AND AIM OF INVESTIGATION: Intramuscular (IM) administration has been considered to be safer than intravenous (IV) for opioids on wards, but a comparative knowledge of patient safety and analgesic potency following a single dose of IV and IM administration is lacking. This study was carried out to compare patient safety and analgesic efficacy of a single and high dose of morphine given IM or IV for post-operative pain management.

MATERIALS AND METHODS

Thirty-eight patients with post-operative pain following hip replacement surgery were given IM or IV morphine 10 mg at a specified pain level. The study was randomized and double blinded. Time to onset of analgesic effect (11-point numeric rating scale), respiratory function (p(a)CO2, p(a)O2, and respiratory rate), level of sedation (5-point verbal rating scale), and hemodynamic function were recorded.

RESULTS

In the IV group there was a slight but significant increase in p(a)CO2 after 5, 10, and 15 min compared with the IM group (5.2 vs. 4.8, 5.4, vs. 5.0 and 5.5 vs. 5.1 kPa, respectively). The IV group had a significantly faster onset of analgesic effect than the IM group (5 vs. 20 min). Between 5 and 25 min after morphine administration, pain status in the IV group was significantly improved compared with the IM group. Patients in the IV group were slightly more sedated than the IM group 5 and 10 min after morphine.

CONCLUSION

A 10 mg bolus dose of IV morphine given to patients with moderate pain after surgery does not cause severe respiratory depression, but provides more rapid and better initial analgesia than 10 mg given IM. IV morphine even at a dose as high as 10 mg IV is well tolerated if there is a certain level of pain at its administration. The safety of IV morphine on the general ward needs to be further explored in adequately controlled studies.

Variable response to opioid treatment: any genetic predictors within sight?

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.