Tapering off long-term opioid therapy in chronic non-cancer pain patients: A randomized clinical trial

BACKGROUND

The indications for initiating long-term opioid treatment (L-TOT) for chronic non-cancer pain (CNCP) are often unclear and associated with problematic use. This study aimed at evaluating the efficacy of stabilizing opioid therapy followed by a sequential opioid tapering off program in CNCP patients.

METHODS

A randomized clinical trial with a medications stabilization period (Phase 1) was followed by an opioid tapering off program (Phase 2). In Phase 2, patients were randomized to Control Group (stable treatment) or Taper off Group (sequential opioid dose reduction) and assessed at baseline, after stabilization and up to 6 months. Primary outcomes: measures of cognitive function; secondary outcomes: pain, sleep, rest, quality of life, depression, anxiety, opioid misuse and opioid withdrawal symptoms.

RESULTS

In all, 274 patients were screened; 75 were included, out of which 40 dropped out before Phase 2. Those who succeeded Phase 1 (n = 35) had weak/moderate improvements of psychomotor function (p = 0.020), sleeping hours (p = 0.031), opioid withdrawal symptoms (p = 0.019), measures of quality of life (p ≤ 0.043) and opioid misuse scores (p = 0.003). In Phase 2, patients in Taper off Group (n = 15) experienced stable pain intensity and felt significantly more rested at third assessment than the Control Group (n = 20).

CONCLUSIONS

The opioid tapering off program was not successful due to the vast number of dropouts. Phase 1 was associated with weak to moderate improvements on psychomotor function, sleeping, opioid withdrawal symptoms, quality of life and reduced risk of opioid misuse. In the intervention group of Phase 2, pain intensity was stable and patients felt more rested.

SIGNIFICANCE

This trial showed that sequential tapering off L-TOT in CNCP patients may be an unfeasible approach. However, improvements after opioid treatment stabilization were achieved and stable pain intensity in those tapered off may encourage the development of more refined programs.

Development of health-related quality of life and symptoms in patients with advanced cancer in Greenland

A prospective national cohort study assessed the development of health-related quality of life (HRQoL) and symptoms in adult patients undergoing treatment and care for advanced cancer in Greenland. HRQol was examined by EORTC QLQ-C30 version 3.0 questionnaire monthly for 4 months. Changes over time and between-group comparisons were examined. Of 58 patients included in the study, 47% completed the questionnaire four times. Functioning was generally high, and improved social functioning was observed after 1 and 2 months. The highest symptom score was for fatigue followed by pain and nausea/vomiting. A high score for financial problems remained unchanged during the entire period. Patients with higher income had reduced pain intensity (p = .03) and diarrhoea (p = .05) than patients with income below the poverty line. After 1 month, reduction in pain intensity was observed for Nuuk citizens compared with non-Nuuk citizens (p = .05). After 2 months, non-Nuuk citizens reported improved social functioning compared with Nuuk citizens (p = .05). After 3 months, Global Health in Nuuk citizens was improved compared with non-Nuuk citizens (p = .05). An important clinical finding was that patients' needs for support are related to social status, and geographical factors should be taken into account when planning palliative care.

Long-term opioid therapy in Denmark: A disappointing journey

BACKGROUND

Longitudinal population-based studies of long-term opioid therapy (L-TOT) in chronic non-cancer pain (CNCP) patients are sparse. Our study investigated incidence and predictors for initiating L-TOT and changes in self-rated health, pain interference and physical activities in long-term opioid users.

METHODS

Data were obtained from the national representative Danish Health and Morbidity Surveys and The Danish National Prescription Registry. Respondents with no dispensed opioids the year before the survey were followed from 2000 and from 2005 until the end of 2012 (n = 12,145). A nationally representative subsample of individuals (n = 2015) completed the self-administered questionnaire in both 2000 and 2013. Collected information included chronic pain (≥6 months), health behaviour, self-rated health, pain interference with work activities and physical activities. Long-term users were defined as those who were dispensed at least one opioid prescription in six separate months within a year.

RESULTS

The incidence of L-TOT was substantially higher in CNCP patients at baseline than in others (9/1000 vs. 2/1000 person-years). Smoking behaviour and dispensed benzodiazepines were significantly associated with initiation of L-TOT in individuals with CNCP at baseline. During follow-up, L-TOT in CNCP patients increased the likelihood of negative changes in pain interference with work (OR 9.2; 95% CI 1.9-43.6) and in moderate activities (OR 3.7; 95% CI 1.1-12.6). The analysis of all individuals indicated a dose-response relationship between longer treatment duration and the risk of experiencing negative changes.

CONCLUSIONS

Individuals on L-TOT seemed not to achieve the key goals of opioid therapy: pain relief, improved quality of life and functional capacity.

SIGNIFICANCE

Long-term opioid therapy does not seem to provide pain relief, improvement in HRQOL and physical capacity in CNCP patients in a general population.

Characteristics of the case mix, organisation and delivery in cancer palliative care: a challenge for good-quality research

OBJECTIVES

Palliative care (PC) services and patients differ across countries. Data on PC delivery paired with medical and self-reported data are seldom reported. Aims were to describe (1) PC organisation and services in participating centres and (2) characteristics of patients in PC programmes.

METHODS

This was an international prospective multicentre study with a single web-based survey on PC organisation, services and academics and patients' self-reported symptoms collected at baseline and monthly thereafter, with concurrent registrations of medical data by healthcare providers. Participants were patients ≥18 enrolled in a PC programme.

RESULTS

30 centres in 12 countries participated; 24 hospitals, 4 hospices, 1 nursing home, 1 home-care service. 22 centres (73%) had PC in-house teams and inpatient and outpatient services. 20 centres (67%) had integral chemotherapy/radiotherapy services, and most (28/30) had access to general medical or oncology inpatient units. Physicians or nurses were present 24 hours/7 days in 50% and 60% of centres, respectively. 50 centres (50%) had professorships, and 12 centres (40%) had full-time/part-time research staff. Data were available on 1698 patients: 50% females; median age 66 (range 21-97); median Karnofsky score 70 (10-100); 1409 patients (83%) had metastatic/disseminated disease; tiredness and pain in the past 24 hours were most prominent. During follow-up, 1060 patients (62%) died; 450 (44%) <3 months from inclusion and 701 (68%) within 6 months. ANOVA and χ² tests showed that hospice/nursing home patients were significantly older, had poorer performance status and had shorter survival compared with hospital-patients (p<.0.001).

CONCLUSIONS

There is a wide variation in PC services and patients across Europe. Detailed characterisation is the first step in improving PC services and research.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov Identifier: NCT01362816.

Chronic non-cancer pain and the epidemic prescription of opioids in the Danish population: trends from 2000 to 2013

BACKGROUND

Chronic pain has serious consequences for individuals and society. In addition, opioid prescription for chronic non-cancer pain (CNCP) has become more frequent. This study aims to examine the trends regarding the prevalence of CNCP, dispensed opioids, and concurrent use of benzodiazepine (BZD)/BZD-related drugs in the Danish population.

METHODS

Data from the cross-sectional national representative Danish Health and Morbidity Surveys (2000, 2005, 2010, and 2013) were combined with The Danish National Prescription Registry at an individual level. The study populations varied between 5000 and 13,000 individuals ≥16 years (response rates: 51-63%). Respondents completed a self-administered questionnaire, which included the analyzed items on identification of chronic pain (≥6 months).

RESULTS

From 2000 to 2013, the prevalence of CNCP increased and subsequently the annual prevalence of opioid use from 4.1% to 5.7% among CNCP individuals. Higher CNCP prevalence was related to female gender, no cohabitation partner, short education, non-Western origin, and overweight/obesity. In addition, women with CNCP, especially >65 years, became more frequent users of opioids and used higher doses than men. Concurrent use of BZD/BZD-related drugs decreased (13%) from 2010 to 2013, still one-third of long-term opioid user were co-medicated with these drugs.

CONCLUSIONS

The use of opioids has increased in Denmark, especially among elderly women. The concurrent use of BZD/BZD-related drugs has decreased from 2010 to 2013, but still one-third of long-term opioid users were co-medicated.

The evidence of neuraxial administration of analgesics for cancer-related pain: a systematic review

BACKGROUND

The present systematic review analysed the existing evidence of analgesic efficacy and side effects of opioids without and with adjuvant analgesics delivered by neuraxial route (epidural and subarachnoid) in adult patients with cancer.

METHODS

Search strategy was elaborated with words related to cancer, pain, neuraxial route, analgesic and side effects. The search was performed in PubMed, EMBASE, and Cochrane for the period until February 2014. Studies were analysed according to methods, results, quality of evidence, and strength of recommendation.

RESULTS

The number of abstracts retrieved was 2147, and 84 articles were selected for full reading. The final selection comprised nine articles regarding randomised controlled trials (RCTs) divided in four groups: neuraxial combinations of opioid and adjuvant analgesic compared with neuraxial administration of opioid alone (n = 4); single neuraxial drug in bolus compared with continuous administration (n = 2); single neuraxial drug compared with neuraxial placebo (n = 1); and neuraxial opioid combined with or without adjuvant analgesic compared with other comprehensive medical management than neuraxial analgesics (n = 2). The RCTs presented clinical and methodological diversity that precluded a meta-analysis. They also presented several limitations, which reduced study internal validity. However, they demonstrated better pain control for all interventions analysed. Side effects were described, but there were few significant differences in favour of the tested interventions.

CONCLUSION

Heterogeneous characteristics and several methodological limitations of the studies resulted in evidence of low quality and a weak recommendation for neuraxial administration of opioids with or without adjuvant analgesics in adult patients with cancer.

Renal function and symptoms/adverse effects in opioid-treated patients with cancer

BACKGROUND

Renal impairment and the risk of toxicity caused by accumulation of opioids and/or active metabolites is an under-investigated issue. This study aimed at analysing if symptoms/adverse effects in opioid-treated patients with cancer were associated with renal function.

METHODS

Cross-sectional multicentre study (European Pharmacogenetic Opioid Study, 2005-2008), in which 1147 adult patients treated exclusively with only one of the most frequently reported opioids (morphine/oxycodone/fentanyl) for at least 3 days were analysed. Fatigue, nausea/vomiting, pain, loss of appetite, constipation and cognitive dysfunction were assessed (EORTC QLQ-C30). Glomerular filtration rate (GFR) was estimated using Cockcroft-Gault (CG), Modification of Diet in Renal Disease (MDRD), and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI Creatinine) equations.

RESULTS

Mild to severe low GFR was observed among 40-54% of patients. CG equation showed that patients with mild and moderate/severe low GFR on morphine treatment had higher odds of having severe constipation (P < 0.01) than patients with normal GFR. In addition, patients with moderate/severe low GFR on morphine treatment were more likely to have loss of appetite (P = 0.04). No other significant associations were found.

CONCLUSION

Only severe constipation and loss of appetite were associated with low GFR in patients treated with morphine. Oxycodone and fentanyl, in relation to the symptoms studied, seem to be safe as used and titrated in routine cancer pain care.

Symptoms and side effects in chronic non-cancer pain patients: clinical implications and development of new assessment tools

OBJECTIVE

To improve a 41-item screening tool evaluated in our previous study by making it more simple and convenient to patients and at the same time maintain the level of information and the sensitivity.

METHODS

In a prospective, two-period questionnaire study, patients suffering from chronic pain of non-cancer origin for more than 6 months, were asked to fill in two questionnaires: QSSE-41 or QSSE-33 and SF-36. The first part of the study (QSSE-41) included an age- and sex-matched control group.

RESULTS

A total of 67 patients were included in QSSE-41 and 60 patients in QSSE-33. In QSSE-41, the mean number of symptoms reported by the patient group (12.3) was significantly higher than those reported by the controls (6.8) (P < 0.001). Out of the total number of symptoms, 40.3% were reported to be side effects caused by analgesics, and out of those 61.3% were reported as acceptable and 38.7% as unacceptable side effects. In the QSSE-33, the mean number of symptoms reported by the patient group was 13.6. Out of the total number of symptoms, 46.3% were reported to be side effects caused by analgesics, and out of those 56.4% were reported as acceptable and 43.6% as unacceptable side effects.

CONCLUSIONS

This new and shorter screening tool QSSE-33 may substitute the original QSSE-41 and in clinical use, contribute substantially to a more comprehensive and detailed understanding of symptoms/side effects and may consequently lead to improved therapies.

Evidence of peripheral nerve blocks for cancer-related pain: a systematic review

The European Association for Palliative Care has initiated a comprehensive program to achieve an over-all review of the evidence of multiple cancer pain management strategies in order to extend the current guideline for treatment of cancer pain. The present systematic review analyzed the existing evidence of analgesic efficacy for peripheral nerve blocks in adult patients with cancer. A search strategy was elaborated with words related to cancer, pain, peripheral nerve and block. The search was performed in PubMed, EMBASE, and Cochrane for the period until February 2014. The number of abstracts retrieved was 155. No controlled studies were identified. Sixteen papers presented a total of 79 cases. The blocks applied were paravertebral blocks (10 cases), blocks in the head region (2 cases), plexus blocks (13 cases), intercostal blocks (43 cases) and others (11 cases). In general, most cases reported good pain relief and no side effects. The use of peripheral blocks is based upon anecdotal evidence. However, this review only demonstrates the lack of studies, which does not equal a lack of effectiveness.

Symptoms and side effects in chronic non-cancer pain: patient report vs. systematic assessment

BACKGROUND

relieving distressing symptoms and managing the side effects of analgesics are essential in order to improve quality of life and functional capacity in chronic non-cancer pain patients. A quick, reliable and valid tool for assessing symptoms and side effects is needed in order to optimize treatment. We aimed to investigate the symptoms reported by chronic non-cancer pain patients after open-ended questioning vs. a systematic assessment using a list of symptoms, and to assess whether the patients could distinguish between the symptoms and the side effects induced by analgesics.

METHODS

patients treated with either opioids and/or adjuvant analgesics were asked to report their symptoms spontaneously, followed by a 41-item investigator-developed symptom checklist. A control group also filled in the checklist.

RESULTS

a total of 62 patients and 64 controls participated in the study. The numbers of symptoms reported by the patients (9.9 ± 5.9) were significantly higher than those reported by the controls (3.2 ± 3.9) (P<0.001). In the patient group, the number of spontaneously reported symptoms (1.3 ± 1.4) was significantly lower than the symptoms reported when using the symptom checklist (9.9 ± 5.9) (P<0.001). The six most frequently symptoms reported by the patients were: (1) Fatigue; (2) Memory deficits; (3) Dry mouth; (4) Concentration deficits; (5) Sweating; and (6) Weight gain. Out of the six most frequently reported symptoms, the share of side effects due to analgesics was: (1) Dry mouth (42%); (2) Sweating (34%); (3) Weight gain (29%); (4) Memory deficits (24%); (5) Fatigue (19%); and (6) Concentration deficits (19%).

CONCLUSION

the number of symptoms reported using systematic assessment was eightfold higher than those reported voluntarily. Fatigue, cognitive dysfunction, dry mouth, sweating and weight gain were the most frequently reported. The patients reported the side effects of their analgesics to contribute substantially to the reported symptoms.

Modafinil for attentional and psychomotor dysfunction in advanced cancer: a double-blind, randomised, cross-over trial

Cognitive impairment seems to be highly prevalent in patients with advanced cancer. Modafinil, a novel vigilance and wake-promoting agent, may be an alternative treatment. We wanted to investigate this treatment on attentional and psychomotor dysfunction in cancer patients. 28 cancer patients with a tiredness score of 50 mm or more on a scale of 0 to 10 (0=no tiredness, 10=worst possible tiredness) and Karnofsky Performance Status 40-70 were included. All medications were kept stable during the trial despite short acting opioids for breakthrough pain. On day 1 the patients were randomly assigned to receive 200 mg Modafinil orally or placebo and on day 4 they crossed-over to the alternative treatment. Finger Tapping Test (FTT), Trail Making Test (TMT) and Edmonton Symptom Assessment System (ESAS) were evaluated before tablet intake and again 4, 5 hours after. FTT for the dominant hand as well as TMT were statistically significantly improved on modafinil (p-values=0.006 and 0.042, respectively). On ESAS, depression and drowsiness also improved statistically significantly (p-values=<0.001 and 0.038, respectively). Modafinil in a single dose regimen was significantly superior to placebo regarding two cognitive tests of psychomotor speed and attention. Furthermore subjective scores of depression and drowsiness were significantly improved by modafinil.

The Danish version of the questionnaire on pain communication: preliminary validation in cancer patients

BACKGROUND

The modified version of the patients' Perceived Involvement in Care Scale (M-PICS) is a tool designed to assess cancer patients' perceptions of patient-health care provider pain communication process. The objective of this study was to examine the psychometric properties of the shortened Danish version of the M-PICS (SDM-PICS).

METHODS

The validated English version of the M-PICS was translated into Danish following the repeated back-translation procedure. Cancer patients were recruited for the study from specialized pain management facilities.

RESULTS

Thirty-three patients responded to the SDM-PICS, Danish Barriers Questionnaire II, Hospital Anxiety and Depression Scale, and Brief Pain Inventory Pain Severity Scale. A factor analysis of the SDM-PICS resulted in two factors: Factor one, patient information, consisted of four items assessing the extent to which the patient shared information with his/her health care provider, and Factor two, health care provider information, consisted of four items measuring the degree to which a health care provider was perceived as the one who shares information. Two separate items addressed the perceived level of information exchange between the patient and the health care provider. The SDM-PICS total had an internal consistency of 0.88. The SDM-PICS scores were positively related to pain relief and inversely related to the measures of cognitive pain management barriers, anxiety, and reported pain levels.

CONCLUSION

The SDM-PICS seems to be a reliable and valid measure of perceived patient-health care provider communication in the context of cancer pain.

Chronic pain and other sequelae in long-term breast cancer survivors: nationwide survey in Denmark

OBJECTIVES

To investigate self-reported chronic pain and other sequelae in a nationally representative sample of long-term breast cancer survivors (BCS).

DESIGN

Age-stratified random sample of 2,000 female BCS 5 years after primary surgery without recurrence drawn from the Danish Breast Cancer Cooperative Group register, which is representative regarding long-term BCS in Denmark.

ASSESSMENT

Self-administered questionnaire including questions on sociodemography, chronic pain (6 months), health-related quality of life (HRQOL) and other sequelae related to breast cancer. Associations with treatment were investigated. Report of chronic pain was compared to normative data.

RESULTS

The response rate was 79%. Chronic pain prevalence of 42% was significantly higher in BCS compared to general population women (SRR: 1.32; 95% CI: 1.23-1.42). Sequelae related to breast cancer were paraesthesia 47%, chronic pain 29%, arm/shoulder swelling 25%, phantom sensations 19%, and allodynia 15%. Chronic pain related to breast cancer was significantly associated with poorer HRQOL and higher medicine consumption, and, in multiple logistic regression analysis, with age (<70 years), short education, being single (divorced, widowed, separated), radiotherapy, and time since operation <10 years. Radiotherapy and younger age were significantly associated with most sequelae.

CONCLUSION

Chronic pain was more prevalent in BCS compared to the general population. Significant predictors for sequelae related to breast cancer were radiotherapy and younger age. Future research should therefore prioritize sequelae prevention.

Pain management of opioid-treated cancer patients in hospital settings in Denmark

AIM

To evaluate the performance and quality of cancer pain management in hospital settings.

METHODS

Anaesthesiologists specialised in pain and palliative medicine studied pain management in departments of oncology and surgery. Study days were randomly chosen and patients treated with oral opioids were included. Information regarding pain aetiology and mechanisms, pain medications and opioid side effects were registered from the medical records and by examining patients. Pain intensity was assessed using the Brief Pain Inventory.

RESULTS

In total, 59 cancer patients were included. In 49 (83%) patients pain aetiology was assessed by the physicians of the departments of oncology and surgery. In only 19 (32%) patients they assessed pain mechanisms. The median oral morphine dose was 120 mg/day (range: 10-720 mg/day). Seventy-eight per cent of patients received opioids at adequate regular intervals according to the duration of action. In 88% of the patients supplemental short-acting oral opioids were given on demand and the median supplemental oral dose was 16.5% of the daily dose. Seven patients with neuropathic pain received adjuvant drugs, whereas six patients with non-neuropathic pain received adjuvant drugs. Regarding opioid side effects only constipation and nausea were treated in the majority of the patients. Average pain intensity in the last 24 h for the total number of patients (n=59) < or =5 cm was 88.1% (confidence interval 77.1-95.1).

CONCLUSION

Cancer pain was prevalent in opioid-treated patients in hospital settings: however, focussing on average pain intensity, the outcome seems favourable compared with other countries. Pain mechanisms were seldom examined and adjuvant drugs were not specifically used for neuropathic pain. Opioid dosing intervals and supplemental opioid doses were most often adequate. However, opioid side effects were highly prevalent and most side effects were left untreated.

Pain, sedation and morphine metabolism in cancer patients during long-term treatment with sustained-release morphine

BACKGROUND

Morphine-6-glucuronide (M-6-G) and morphine-3-glucuronide (M-3-G) are the two most important metabolites of morphine. Both are pharmacologically active, however, with different effects. M-6-G has been demonstrated capable of inducing anti-nociception and sedation, and M-3-G may induce behavioural excitation and possibly antagonise anti-nociception. Their impact on pharmacodynamics in patients in long-term treatment with oral morphine remains to be settled.

METHODS

Forty-two cancer patients treated with oral sustained-release (SR) morphine were assessed for pain, sedation and other side effects related to morphine treatment. Blood samples were analysed for morphine, M-3-G and M-6-G by high-performance liquid chromatography (HPLC).

RESULTS

Significant correlations were found between the daily dose of SR morphine and plasma morphine (M) (r = 0.535, P < 0.001), plasma M-6-G (r = 0.868, P < 0.001) and plasma M-3-G (r = 0.865, P < 0.001). There was no relationship between plasma morphine, M-6-G, M-6-G/M and pain and sedation scores. Seventy-nine percent of the patients suffered from dryness of the mouth, which was the most frequent side effect observed. Patients in this group had higher plasma morphine and M-6-G concentrations than patients who did not suffer from this side effect.

CONCLUSION

The plasma concentrations of morphine and its metabolites, M-3-G and M-6-G, are significantly correlated to the daily dose of SR morphine. Although M-6-G has analgesic properties, no associations were found between pain and plasma morphine and morphine metabolites. This may be due to the multitudinous factors affecting the dose-effect relationship. Patients with dryness of the mouth had higher concentrations of morphine and M-6-G than patients without this side effect.

Economic evaluation of multidisciplinary pain management in chronic pain patients: a qualitative systematic review

In this qualitative systematic review, we have evaluated studies of the economic effectiveness of multidisciplinary pain treatment in chronic non-malignant pain patients. Published reports were identified from a systematic search of bibliographic databases (MEDLINE and EMBASE) and reference lists of retrieved reports. Fourteen reports of nine studies of patients suffering from back pain, fibromyalgia, and mixed chronic pain conditions were considered to be appropriate as economic analyses. In the selected studies, we found serious methodological problems in study designs and application of outcome measures. The quality of the cost measurements was characterized by an apparent lack of tradition using economic methodology. This review does not give an answer to whether multidisciplinary pain management in chronic pain patients is cost-effective or not. Application of standard methods of costing and outcome measurement are essential before studies of cost-effectiveness in multidisciplinary pain treatment can be used in decision-making and planning.

[Therapeutic results in chronic, non-malignant pain in patients treated at a Danish multidisciplinary pain center compared with general practice. A randomized controlled clinical trial]

INTRODUCTION

Multidisciplinary pain treatment (MPT) is generally considered to be the most effective treatment of chronic pain, but its long-term effect has not yet been firmly established.

METHODS

This randomised controlled study compared the effect of outpatient MPT with that of treatment by general practitioners after initial supervision by a pain specialist (GP group) and with a six-month waiting list group (WL group). The participants were 189 patients with chronic non-malignant pain. On referral and at three and six months, the patients filled in questionnaires evaluating pain intensity, health-related quality of life (HRQL), and the use of analgesics.

RESULTS

At six months, the patients allocated to MPT (N = 63) reported a reduction in pain intensity (p < 0.001), and an improvement in psychological well-being (p < 0.001), quality of sleep (p < 0.05), and physical functioning (p < 0.05). The WL group (N = 63) had a statistically significant deterioration in most of the HRQL measures. The only effect of treatment found in the GP group was a reduction in the use of short-acting opioids. In the MPT group, the use of opioids administered on demand and short-acting opioids was decreased (p < 0.001). No change in the use of analgesics was seen in the WL group.

DISCUSSION

The study showed that (i) in the MPT group there was a significant reduction in pain intensity and an improvement in HRQL compared to the WL group, and (ii) the mere establishment of a pain diagnosis and management plan by a specialist was not sufficient to enable the referring GP to manage patients with severe chronic pain.

[Sociodemographic predictors of therapeutic results in patients with chronic, non-malignant pain]

INTRODUCTION

Chronic pain is in its nature multidimensional and is most successfully treated by a multidisciplinary approach. Some patients do not benefit from treatment, and psychological and socio-economic factors may play a major role. The present study investigated the ability of sociodemographic variables to predict the short-term effect of multidisciplinary treatment in patients with chronic pain who where referred consecutively to a Danish multidisciplinary pain centre.

METHOD

Pain scores (VAS) and health-related quality of life (HRQL) were assessed. On entry and three and six months later HRQL was evaluated by medical outcome short form (SF-36) and the psychological general well-being scale (PGWB). Sociodemographic variables were: age, gender, educational level, civil status employment status, and disability pension (DP) status.

RESULTS

Of the sociodemographic variables evaluated, only the DP status seemed to be a significant outcome predictor. Patients applying for a DP do not improve. Patients receiving a DP and those who do not achieved moderate improvements, but these were significantly larger. The same pattern was seen for changes in psychological well-being and social functioning. The DP status predicted improvement in pain and social functioning.

DISCUSSION

The present study indicates that the multidimensional problems experienced by patients applying for a DP are dominated by sociodemographic factors. Focus on the solution of these socio-economic problems is important, if patients with chronic pain are to benefit from multidisciplinary pain treatment.

Does the medical record cover the symptoms experienced by cancer patients receiving palliative care? A comparison of the record and patient self-rating

The aim of this study was to investigate the extent to which the symptoms experienced by advanced cancer patients were covered by the medical records. Fifty-eight patients participated in the study. On the day of first encounter with our palliative care department, a medical history was taken, and on this or the following day, the patients completed the EORTC Quality of Life Questionnaire (EORTC QLQ-C30), Edmonton Symptom Assessment System (ESAS), and Hospital Anxiety and Depression Scale (HADS). The symptomatology reported in the patient-completed questionnaires was compared with the symptomatology mentioned by the physician in the medical record. The analysis revealed good concordance concerning pain, but most other symptoms or problems were reported much more often by patients than by their doctors. Reasons for these discrepancies are discussed. It is suggested that the doctor's knowledge of the patient's symptomatology might gain from more systematic screening and transfer of information from patient self-assessment questionnaires to the medical records.

Neuropsychological performance in cancer patients: the role of oral opioids, pain and performance status

The aim of the present study was to evaluate the possible influence of oral opioids, pain and performance status on some aspects of psychomotor function and cognition in cancer patients. One hundred and thirty cancer patients between 40 and 76 years of age were consecutively included in the study. In order to separate the impact of performance status, pain and oral opioids on neuropsychological functioning the patients were allocated in a cross-sectional design to five different groups. Group 1 (N=40), which was considered the control group, was characterized by being in Karnofsky Performance Status (KPS) A ('Able to carry on normal activity and work. No special care is needed'), had no pain and received no oral opioid medication. Group 2 (N=19) was characterized by being in KPS B ('Unable to work. Able to live at home and care for most personal needs. A varying degree of assistance is needed'), had no pain and received no oral opioid medication. Group 3 (N=19) was characterized by being in KPS B, had pain, but received no oral opioid medication. Group 4a (N=31) was characterized by being in KPS B, had pain and received stable doses of oral opioids. Group 4b (N=21) was characterized by being in KPS B, had no pain and received stable doses of opioids. Assessments comprised pain intensity, sedation, opioid doses, time from ingestion of last opioid dose to testing and opioid side effects. The neuropsychological tests used were continuous reaction time (CRT), finger tapping test (FTT) and paced auditory serial addition task (PASAT). Regarding the neuropsychological tests group 1 was compared with each of the other groups and respecting the hierarchy of increasing numbers of stigmatizing factors group 1 was compared with group 2, group 2 with group 3 and so forth. Concerning CRT, group 1 performed statistically significantly faster than groups 2, 4a and 4b. Concerning FTT, group 1 performed statistically significantly faster than groups 3 and 4a. Concerning PASAT, groups 1 and 4b performed statistically significantly better than group 4a. Furthermore, the pain-relieved groups 2 and 4b performed statistically significantly better in PASAT than the pain-suffering groups 3 and 4a. We conclude that in cancer patients the impact of stigmatizing factors (oral opioids, pain and reduced performance status) seems to impair some important aspects of neuropsychological performance, but more specifically our results indicate that (1) the use of long-term oral opioid treatment in cancer patients per se did not affect any of the neuropsychological tests used in the present study, (2) cancer patients being in KPS B had statistically significantly slower CRT than patients being in KPS A and (3) pain itself may deteriorate the performance of PASAT more than oral opioid treatment.

Treatment outcome of chronic non-malignant pain patients managed in a danish multidisciplinary pain centre compared to general practice: a randomised controlled trial

This randomised controlled study investigated the effect of outpatient multidisciplinary pain centre treatment (MPT) compared with treatment by a general practitioner after initial supervision by a pain specialist (GP-group) and with a group of patients waiting for 6 months before treatment was initiated (WL-group). One-hundred-and-eighty-nine chronic non-malignant pain patients were studied. At referral, and after 3 and 6 months patients filled in questionnaires evaluating pain intensity, health related quality of life (HRQL) and use of analgesics. HRQL was evaluated using the Medical Outcome Study-Short Form (SF-36), the Hospital Anxiety and Depression scale (HAD) and the Psychological General Well-being Scale (PGWB). After 6 months patients allocated to MPT (n=63) reported statistically significant reduction in pain intensity (VAS-score, P<0.001), improvement in psychological well-being (PGWB, P<0.001), quality of sleep (P<0.05) and physical functioning (SF-36-Phycical Functioning, P<0.05). No improvements were seen in the GP-group (n=63). In the WL-group (n=63) a statistically significant deterioration was observed in PGWB-scores, HAD-scores and in 6 of 8 SF-36-subscores (P </= 0.05). A reduction in use of opioids administered on demand was obtained in the group receiving MPT (P<0.001). In the MPT- and GP-groups a decrease in the use of short acting opioids was observed (P<0.01). No change in use of analgesics was seen in the WL-group. The study showed that (i) in the MPT-group there was a significant reduction in pain intensity and improvement of HRQL compared to the WL-group, and (ii) the mere establishment of a pain diagnosis and a pain management plan by a pain specialist was not sufficient to enable the referring GP to manage severely chronic pain patients.

Oral glycopyrrolate alleviates drooling in a patient with tongue cancer

Although sialorrhea and drooling are uncommon symptoms in cancer patients, they can cause considerable discomfort, inconvenience and social embarrassment. In this article we describe a patient with tongue cancer who was successfully treated with oral glycopyrrolate 0.4 mg 3 times daily. Glycopyrrolate is a quaternary ammonium compound. In contrast to the recommended treatment with scopolamine, glycopyrrolate is virtually without side effects to the central nervous system because it penetrates the blood-brain barrier poorly. Glycopyrrolate has a slow and erratic absorption from the gastrointestinal system, but even low plasma levels are associated with a distinct and long-lasting antisialogic effect.

Steady-state kinetics and dynamics of morphine in cancer patients: is sedation related to the absorption rate of morphine?

Eighteen patients suffering from chronic pain due to cancer completed a balanced, double-blind, double-dummy, two period cross-over trial comparing the pharmacokinetics (PK) and pharmacodynamics (PD) of morphine and its metabolites, morphine-3-glucuronide and morphine-6-glucuronide, after administration of morphine given as controlled-release (CR) tablets (every 12 h) and immediate-release (IR) tablets (every 6 h). The same total daily dose of morphine was given in both study periods. Patients received both test formulations for 4 days and on the final day of each period, peripheral venous blood samples for analysis of morphine, morphine-3-glucuronide, and morphine-6-glucuronide were obtained. Pain intensity, sedation, and continuous reaction time (CRT) were assessed. No significant differences could be demonstrated in AUC/dose, Cmin, Cmax or fluctuation index values between the two treatments (IR and CR tablets) for either morphine or its metabolites. Tmax for morphine and its metabolites occurred significantly later after administration of CR tablets than after administration of IR tablets. There were no significant differences between the IR and the CR formulation with respect to analgesia and side effects, and there was no difference in the patients' overall impression of the two treatments. More important, there was no difference between the Tmax and the time to peak sedation after administration of IR tablets (P = 0.63). However, due to the relatively small number of patients and the variability in the data, the statistical power of the test was only 0.074. The risk of a type II error is 0.926. These data demonstrate the PK and PD similarities and differences between CR and IR morphine. They suggest that there may be a relationship between Tmax (determined by absorption rate) and sedation, but further evaluation of this potential relationship is needed.

[Pain epidemiology and health-related quality of life in patients with chronic non-malignant pain]

This paper presents the results of a detailed study of the pain epidemiology and health related quality of life (HRQL) in 150 chronic non-malignant pain patients referred to a Danish multidisciplinary pain centre. Mean pain intensity was 71.6 (SD 18.5) on the VAS scale. HRQL was evaluated using the questionnaires: SF-36, HAD and PGWB. Compared with the normal population (NP) both physical, psychological and social well-being was severely reduced, and 58% were found to have a depressive or anxiety disorder. Sixty-three percent of the patients had neurogenic pain conditions. Of these, only 25% were treated with antidepressants or anticonvulsants. At referral 73% were treated with opioids. Mean opioid consumption was 64 mg of morphine per day. Patients had used the health care system five times more often than the NP (p < 0.001). The study showed that HRQL of chronic non-malignant pain patients is among the lowest observed for any medical condition.

Is development of hyperalgesia, allodynia and myoclonus related to morphine metabolism during long-term administration? Six case histories

BACKGROUND

Recently, clinical reports have suggested a relationship between the occurrence of hyperalgesia, allodynia and/or myoclonus and treatment with high doses of morphine in humans. Although few clinical descriptions of these phenomena are available, experimental work supports the notion that high doses of morphine may play a pathogenetic role in the observed behavioural syndrome.

METHODS

Six patients, four with malignant and two with chronic, non-malignant pain conditions, treated with moderate to high doses of oral, continuous intravenous infusion or intrathecal morphine developed hyperalgesia, allodynia and/or myoclonus. When the side-effects occurred, blood or CSF samples were taken and analyzed for contents of morphine, morphine-6-glucuronide (M-6-G) and morphine-3-glucuronide (M-3-G).

RESULTS

When comparing the plasma and CSF concentrations from these patients with data from available literature obtained from patients not suffering from these side-effects, it was demonstrated that the values deviated in five patients. In all six patients, the side-effects disappeared after substituting morphine with other opioid agonists or after lowering the daily dose of morphine.

CONCLUSION

These results may indicate that elevated concentrations of M-3-G in plasma as well as the plasma and CSF M-3-G/M-6-G ratios may play a pathogenetic role in the development of hyperalgesia, allodynia and myoclonus.

[Denmark's first research facility in palliative medicine. Organization and research strategy]

Denmark's first palliative medicine research unit is now being set up at Bispebjerg Hospital, with single-room and two double-room ward. The multidisciplinary team consists of doctors, a psychologist, nurses, a physiotherapist, an ergotherapist, a medical social worker, a priest and a dietician. An out-patient facility is also being established to enable patients to choose between hospitalisation out-patient treatment or home treatment by appropriate staff. Another aspect of palliative medicine is care of the patient's family members. The intervention offered at our facility is led by a psychologist, and consists primarily of counselling. With its limited clinical opacity, the department of palliative medicine is first and foremost a research and development facility. The first chair in palliative medicine in Denmark was conferred upon the department in 1998.

[Epidemiology of cancer pain]

The prevalence of pain in cancer patients is influenced by several factors, for example the cancer disease, stage of disease, metastases present and treatment. However, only very few studies take all these factors in account when presenting the prevalence of pain in cancer patients. Pain may be caused by direct tumour infiltration, but may also be indirectly related to the cancer disease, caused by the cancer treatment or unrelated to the cancer. The most frequent pain quality is somatic pain followed by visceral and neuropathic pain. Pain with certain qualities or characteristics, such as incident pain, tenesmi in the gastrointestinal tract or cramps located to the bladder or rectum are more difficult to relieve than other pains. Other factors, such as major psychological distress, fast increasing doses of opioids and a past history of addictive behaviour may also be predictive of a poor treatment outcome. Besides pain cancer patients may also suffer from other troublesome symptoms such as asthenia, anorexia, constipation, nausea and vomiting and poor quality of sleep. These symptoms have great impact on the patients' well-being and should be treated contemporarily.

[Morphine metabolism--pharmacokinetics and pharmacodynamics]

With the increasing use of morphine, growing interest for the clinical implications of its metabolites, morphine-3-glucuronide (M-3-G) and morphine-6-glucuronide (M-6-G) has emerged in the literature. M-6-G binds to the opioid receptor and has analgesic properties in man. Clinical studies have not delivered strong evidence of significant correlation between the concentration of morphine and its glucuronides in plasma and cerebrospinal fluid and pharmacodynamics such as analgesia. There is no clinical evidence to indicate that M-6-G has a pronounced respiratory depressing effect in man, while the literature contains conflicting reports with regard to other side-effects. M-3-G does not bind to the m-opioid receptor and consequently has no antinociceptive effects. Studies in rodents have shown that morphine, M-6-G and especially M-3-G may induce hyperalgesia, allodynia and myoclonus. It is assumed that these side effects are caused by a spinal antiglycinergic mechanism. The role of M-3-G in morphine antagonism and development of tolerance has not yet been settled. As M-3-G and M-6-G are eliminated by the kidneys, renal insufficiency will lead to accumulation of these. Accordingly dosage should be reduced or other opioids be considered in such cases.

[Malignant bone pain]

Bone pain is one of the most frequent causes of pain in patients with cancer, and the levels of metastases and bone pain are not directly correlated. Nociceptors in the periosteum are probably stimulated by halisteresis or by inflammatory oedema leading to an increase in the intraosseous pressure. Some authors believe that the nociceptors in bone are mediated via intraosseous mechanoreceptors in the bone-matrix. At a low pain level the initial treatment is acetylsalicylic acid, paracetamol or other nonsteroidal antiinflammatory drugs. At increasing pain level initial doses of oral opioids are added. In severe bone pain, where conventional therapy seems difficult, opioids are administered by invasive techniques. In localised bone pain palliative radiation is the first treatment of choice. Corticosteroids induce an analgetic effect indirectly by reducing the inflammatory oedema, inhibiting the synthesis of prostaglandins and may inhibit excitatory nerve fibres. Endocrine treatment, calcitonin and biophosphonates have shown a documented pain-relieving effect in patients with disseminated breast and prostate cancer. Chemotherapy has shown a pain-relieving effect in patients with disseminated breast cancer, surgical intervention is used in stabilizing osteolytic bones before or after a fracture ensuring a reasonable relief of pain.

[Treatment of cancer pain in Denmark. A questionnaire survey]

A questionnaire survey was carried out with the aim of evaluating knowledge about and practice of cancer pain treatment in Denmark. A questionnaire was sent to a 10% random sample of Danish physicians. Of these 1411 physicians, 1068 (76%) returned the questionnaires and after the exclusion of those doctors who never treated cancer patients, 577 (54%) were analyzed. Their knowledge of the principles and practice of cancer pain treatment was evaluated by means of 14 multiple-choice and open questions. Their ability to apply their knowledge in practice was evaluated by analyzing their suggested treatment of three simulated patient cases. Ninety-seven percent of the physicians recognized difficulties in cancer pain treatment, the most frequent being side effects of drugs and inadequate pain relief. It appeared from the proposals for pain treatment of the patient cases that the majority of the physicians could treat both pain from bone metastasis (75%) and visceral pain (78%) satisfactorily, while very few suggested coanalgesics for neuropathic pain (20%). Older physicians performed less satisfactorily than did their younger colleagues. Basic pain treatment skills have been acquired by the Danish physicians. However, in the future emphasis should be placed on the treatment of neuropathic pain with coanalgesics and the management of opioid side-effects.

Psychomotor and cognitive functioning in cancer patients

Psychomotor and cognitive dysfunction in cancer patients can be classified into two main categories according to etiology: disease-induced factors (metabolic disturbances, brain metastasis, pain, etc.) and treatment-related factors (drugs, antineoplastic therapy, etc.). In particular, the effects of chronic opioid administration in cancer patients have been subjected to investigations, and most studies have been engaged in assessment and treatment of the cerebral dysfunction. Early studies found that cancer patients in chronic oral opioid therapy had prolonged continuous reaction times, and that the opioids seemed to be mainly responsible for the prolongation. Significant dose escalations of opioids (> or = 30%) caused transiently impaired psychomotor and cognitive functions in cancer patients. Cancer patients in chronic oral opioid therapy did not achieve any advantages changing to epidural opioid therapy with regard to faster continuous reaction times and less pain. Large doses of opioids are often required to control severe pain in cancer patients. As increased sedation and impaired psychomotor and cognitive functions often occur, a number of studies have investigated the use of amphetamine derivatives to counteract the sedative side-effects of opioid. These drugs seem promising during high-dose opioid therapy and their use may be particularly rewarding in poor opioid-responsive pain conditions such as incident and neuropathic pain.

Identification of steroid receptors in human adipose tissue

Steroids have the ability to alter adipose tissue distribution. Controversy exists as to whether these effects of sex hormones (oestrogen, progesterone and testosterone) on human adipose tissue are indirect or direct, as only very few studies have focused on steroid receptor status in human adipose tissue. In the present study, we reinvestigated steroid receptor status in human mature adipose tissue and human preadipocytes. Oestrogen, glucocorticoid and androgen receptors were found in human mature adipocytes from both women and men. The receptors were detected by ligand binding. Furthermore, the existence of the receptors was confirmed by demonstrating that adipocytes contained mRNA encoding the receptors. cDNA was generated using reverse transcriptase (RT) followed by polymerase chain reaction (PCR) amplification using specific primers (RT-PCR) for the specific steroid receptors. Adipocytes did not contain mRNA encoding the progesterone receptor (PR), and no progesterone binding was detectable in human adipocytes. Human preadipocytes contained glucocorticoid receptor (GR) mRNA and androgen receptor (AR) mRNA, whereas we were unable to detect oestrogen receptor (ER) mRNA and progesterone mRNA in human preadipocytes. In conclusion, oestrogen glucocorticoid and androgen receptors are present in mature adipocytes from subjects of both sexes, whereas adipocytes do not contain progesterone receptors. In preadipocytes, only glucocorticoid receptors and androgen receptors are present, whereas oestrogen receptors and progesterone receptors are not present.

Stereoselective pharmacokinetics of methadone in chronic pain patients

Ten patients with chronic pain were randomized to an open, balanced, crossover study. Each patients received two different preparations of racemic methadone, i.e., tablets and intravenous infusion. The pharmacokinetic parameters of the R- and S-enantiomers of the racemate are reported. The analgesically active R-methadone has a significantly longer mean elimination half-life than the optical antipode S-methadone (t1/2 = 37.5 and 28.6 h, respectively). The mean total volume of distribution is 496.6 L for R-methadone and 289.1 L for S-methadone. Significant differences in the mean clearance between R- and S-methadone are seen (0.158 and 0.129 L/min, respectively). However, the lagtime after oral administration and the bioavailability did not show differences between the isomers. The data suggest that both enantiomers of methadone should be measured if correlations between pharmacodynamics and kinetics are made due to the stereoselective differences in half-life, total volume of distribution, and clearance.

[Continuous subcutaneous infusion of opioids in cancer patients]

This review article describes pharmacokinetics, pharmaco-dynamics, side effects and the practical use of continuous subcutaneous infusion of opioids in cancer patients with pain. Clinical studies have shown that the analgesic effects of continuous subcutaneous infusion of morphine are comparable to continuous intravenous morphine, and that the treatment modality is associated with a low frequency of side-effects and complications. Continuous subcutaneous infusions of morphine are therefore recommended as the treatment of choice for cancer patients with pain, when oral analgesic treatment is no longer possible.

[Morphine-induced hyperalgesia, allodynia and myoclonus--new side-effects of morphine?]

During the last ten years hyperalgesia (H), allodynia (A) and myoclonia (M) has been reported at an increased frequency in human beings treated with morphine. The side effects are most common in cancer patients treated with high dose morphine, and has been reported for all routes of administration. The mechanisms are unknown, but human cases and experimental works have resulted in the following theories: 1) Morphine and morphine metabolites change the postsynaptic pain-transmission in dorsal horn neurones via non opioid-receptors (glycine and/or N-methyl-D-aspartate). 2) Morphine and morphine metabolites activate other opioid receptor populations. 3) Supplemental drugs in cancer management. 4) An abnormal metabolism of morphine or morphine metabolites. 5) A combination of one or more of the above-mentioned theories. The first mentioned theory is the most likely. The treatment of morphine induced H, A, and M seems to be to discontinue morphine administration and to initiate therapy with other opioids (fentanyl, sufentanyl, methadone or ketobemidone).

Irradiation of bone metastases in breast cancer patients: a randomized study with 1 year follow-up

The results from a prospective randomized trial comparing two different radiation schedules for treatment of painful bone metastases in women with recurrent breast cancer are presented. A total of 217 patients with painful bone metastases were randomized to either 30 Grey (Gy) in ten fractions, five fractions a week (5F/W) or 15 Gy in three fractions 2F/W. The effect of treatment was evaluated by pain assessment, the radiological response and the degree of side-effects. The patients were rated at start of treatment and after 1, 3, 6 and 12 months. No difference between the two radiation regimes was found, neither in achieved pain relief, improvement in level of activity and medication, nor was there any difference in radiological response and side-effects from treatment. Both regimes resulted in a significant improvement in both pain score and level of activity 1 month after treatment, an improvement which persisted during the follow-up period. We conclude that 15 Gy given in three fractions 2F/W is as effective as 30 Gy in ten fractions 5F/W, but more convenient to the patient and of less cost to society.

Continuous reaction time after single dose, long-term oral and epidural opioid administration

Auditory continuous reaction time was studied in three treatment groups. Twenty opioid naive patients received intramuscular morphine 0.15 mg kg-1 bodyweight for premedication. Thirty-one cancer patients were treated with oral opioids, 180 mg morphine per 24 h (median). Twenty-two cancer patients were treated with epidural morphine, 79 mg morphine per 24 h (median). The treatment groups were compared to a control group of 44 healthy persons taking no analgesics. The reaction time was measured using 152 auditory signals and summarized as 10%, 50% and 90% percentiles. Analysing reaction time distributions, the opioid naive patients showed the greatest difference to the control group in the shortest reaction times while chronic opioid users showed the greatest difference for the longest reaction times. There seems to be a qualitative difference in reaction time distribution, between opioid naive individuals treated with single dose morphine and cancer patients in long-term treatment.

Myoclonic spasms during treatment with high doses of intravenous morphine in renal failure

Myoclonic spasms occurred in a patient suffering from renal failure after high doses of continuous intravenous morphine (100 mg/h). The concentrations of morphine, morphine-6-glucuronide and morphine-3-glucuronide (mumol/l) in plasma were: 1.93, 52.06 and 381.8, and in cerebrospinal fluid were: 1.02, 5.86 and 61.82, respectively. The role of morphine and morphine glucuronides in myoclonic spasms is discussed.