Is oral morphine still the first choice opioid for moderate to severe cancer pain? A systematic review within the European Palliative Care Research Collaborative guidelines project

Efficacy and safety of hydromorphone for cancer pain: a systematic review and meta-analysis

BACKGROUND

Cancer pain significantly impacts individuals' quality of life, with opioids being employed as the primary means for pain relief. Nevertheless, concerns persist regarding the adverse reactions and effectiveness of opioids such as morphine. Hydromorphone, recognized as a potent opioid, is a viable alternative for managing cancer-related pain. The goal of this systematic review and meta-analysis was to determine the effectiveness and safety characteristics of hydromorphone in comparison to other opioids, as well as different methods of administering this medication within the scope of cancer pain treatment.

METHODS

The PubMed, Embase, Cochrane Library, Scopus, and Web of Science databases were searched on December 25th, 2023. Following the PRISMA guidelines, a systematic investigation of databases was carried out, and suitable studies were chosen according to predetermined criteria (PICO framework). The meta-analyses were performed using a random-effects model.

RESULTS

This review included 18 RCTs with 2271 patients who compared hydromorphone with morphine, oxycodone, or fentanyl, as well as other types of hydromorphone. Hydromorphone demonstrated efficacy similar to that of morphine and oxycodone in reducing cancer pain intensity, decreasing additional analgesic consumption, and improving quality of life. However, morphine showed slight superiority over hydromorphone in reducing breakthrough pain. Adverse events were comparable between hydromorphone and morphine or oxycodone. Patient-controlled and clinician-controlled hydromorphone administration routes yielded similar outcomes.

CONCLUSIONS

The outcomes of this study substantiate the efficacy of hydromorphone in the management of cancer-related pain, demonstrating similar levels of effectiveness and safety as morphine and oxycodone. These findings are consistent with prior comprehensive analyses, suggesting that hydromorphone is a feasible choice for alleviating cancer-associated pain. Additional investigations are warranted to determine its efficacy in distinct patient cohorts and for different modes of administration.

TRIAL REGISTRATION

Prospero registration ID: CRD42024517513. Link: https://www.crd.york.ac.uk/PROSPERO/#recordDetails .

Case report: The lesson from opioid withdrawal symptoms mimicking paraganglioma recurrence during opioid deprescribing in cancer pain

Pain is one of the predominant and troublesome symptoms that burden cancer patients during their whole disease trajectory: adequate pain management is a fundamental component of cancer care. Opioid are the cornerstone of cancer pain relief therapy and their skillful management must be owned by physicians approaching cancer pain patients. In light of the increased survival of cancer patients due to advances in therapy, deprescription should be considered as a part of the opioid prescribing regime, from therapy initiation, dose titration, and changing or adding drugs, to switching or ceasing. In clinical practice, opioid tapering after pain remission could be challenging due to withdrawal symptoms' onset. Animal models and observations in patients with opioid addiction suggested that somatic and motivational symptoms accompanying opioid withdrawal are secondary to the activation of stress-related process (mainly cortisol and catecholamines mediated). In this narrative review, we highlight how the lack of validated guidelines and tools for cancer patients can lead to a lower diagnostic awareness of opioid-related disorders, increasing the risk of developing withdrawal symptoms. We also described an experience-based approach to opioid withdrawal, starting from a case-report of a symptomatic patient with a history of metastatic pheochromocytoma-paraganglioma.

Effectiveness of Opioid Switching in Advanced Cancer Pain: A Prospective Observational Cohort Study

Opioid switching is a common practice of substituting one opioid for another to improve analgesia or adverse effects; however, it has limited evidence. This study aimed to examine the effectiveness of opioid switching in advanced cancer. This multi-center prospective cohort study recruited patients assessed to switch opioids (opioid switch group) or to continue ongoing opioid treatment (control group). Clinical data (demographics, opioids) and validated instruments (pain and adverse effects) were collected over two timepoints seven days apart. Descriptive analyses were utilized. Non-parametric tests were used to determine differences. Fifty-four participants were recruited (23 control group, 31 switch group). At the follow-up, opioid switching reduced pain (worst, average, and now) (p < 0.05), uncontrolled breakthrough pain (3-fold reduction, p = 0.008), and psychological distress (48% to 16%, p < 0.005). The switch group had a ≥25% reduction in the reported frequency of seven moderate-to-severe adverse effects (score ≥ 4), compared to a reduction in only one adverse effect in the control group. The control group experienced no significant pain differences at the follow-up. Opioid switching is effective at reducing pain, adverse effects, and psychological distress in a population with advanced cancer pain, to levels of satisfactory symptom control in most patients within 1 week.

The Stigma Surrounding Opioid Use as a Barrier to Cancer-Pain Management: An Overview of Experiences with Fear, Shame, and Poorly Controlled Pain in the Context of Advanced Cancer

Cancer-related pain affects a majority of patients with advanced cancer and is often undertreated. The treatment of this pain is largely reliant on the use of opioids, which are essential medicines for symptom management and the maintenance of quality of life (QoL) for patients with advanced cancer. While there are cancer-specific guidelines for the treatment of pain, widespread publication and policy changes in response to the opioid epidemic have drastically impacted perceptions of opioid use. This overview therefore aims to investigate how manifestations of opioid stigma impact pain management in cancer settings, with an emphasis on the experiences of patients with advanced cancer. Opioid use has been widely stigmatized in multiple domains, including public, healthcare, and patient populations. Physician hesitancy in prescribing and pharmacist vigilance in dispensing were identified as barriers to optimal pain management, and may contribute to stigma in the context of advanced cancer. Evidence in the literature suggests that opioid stigma may result in patient deviations from prescription instructions, which generally leads to pain undertreatment. Patients reflected on experiencing shame and fear surrounding their prescription opioid use and feeling uncomfortable communicating with their healthcare providers on these topics. Our findings indicate that future work is required to educate patients and providers in order to de-stigmatize opioid use. Through alleviating stigma, patients may be better able to make decisions regarding their pain management which lead to freedom from cancer-related pain and improved QoL.

Oxycodone for cancer-related pain

BACKGROUND

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

OBJECTIVES

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

SEARCH METHODS

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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

Advances in the clinical application of oxycodone in the perioperative period

To review the research progress of pure opioid receptor agonist oxycodone. The research progress of oxycodone in terms of pharmacokinetics, pharmacodynamics, adverse reactions, clinical application, combined medication and new progress in clinical application was summarized by referring to the literature. Oxycodone is a semi-synthetic thebaine derivative of opioid alkaloids, and is a pure opioid μ and κ receptor agonist. The main action sites are the central nervous system and visceral smooth muscle. Due to its advantages of low adverse reactions, good analgesic effects, and a wide range of safe doses, the drug has been widely used in the control of acute and chronic postoperative pain, as well as malignant and non-malignant pain. Since the end of the 20^th century, researchers have begun to formulate antipyretic analgesics, opioid receptor agonists, opioid receptor antagonists, dopamine receptor antagonists and other drugs with oxycodone in different proportions to enhance the analgesic effect. At the same time, it can reduce the dosage of oxycodone and reduce its adverse reactions, so as to achieve the purpose of limiting opioid abuse. With the continuous research on the efficacy and safety of oxycodone in the perioperative period at home and abroad, oxycodone has become the only dual-opioid potent analgesic that can be used in clinical work.

Hydromorphone for cancer pain

BACKGROUND

This is an update of the original Cochrane Review first published in Issue 10, 2016. For people with advanced cancer, the prevalence of pain can be as high as 90%. Cancer pain is a distressing symptom that tends to worsen as the disease progresses. Evidence suggests that opioid pharmacotherapy is the most effective of these therapies. Hydromorphone appears to be an alternative opioid analgesic which may help relieve these symptoms.

OBJECTIVES

To determine the analgesic efficacy of hydromorphone in relieving cancer pain, as well as the incidence and severity of any adverse events.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase and clinical trials registers in November 2020. We applied no language, document type or publication status limitations to the search.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared hydromorphone with placebo, an alternative opioid or another active control, for cancer pain in adults and children. Primary outcomes were participant-reported pain intensity and pain relief; secondary outcomes were specific adverse events, serious adverse events, quality of life, leaving the study early and death.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data. We calculated risk ratio (RR) and 95% confidence intervals (CI) for binary outcomes on an intention-to-treat (ITT) basis. We estimated mean difference (MD) between groups and 95% CI for continuous data. We used a random-effects model and assessed risk of bias for all included studies. We assessed the evidence using GRADE and created three summary of findings tables.

MAIN RESULTS

With four new identified studies, the review includes a total of eight studies (1283 participants, with data for 1181 participants available for analysis), which compared hydromorphone with oxycodone (four studies), morphine (three studies) or fentanyl (one study). All studies included adults with cancer pain, mean age ranged around 53 to 59 years and the proportion of men ranged from 42% to 67.4%. We judged all the studies at high risk of bias overall because they had at least one domain with high risk of bias. We found no studies including children. We did not complete a meta-analysis for the primary outcome of pain intensity due to skewed data and different comparators investigated across the studies (oxycodone, morphine and fentanyl). Comparison 1: hydromorphone compared with placebo We identified no studies comparing hydromorphone with placebo. Comparison 2: hydromorphone compared with oxycodone Participant-reported pain intensity We found no clear evidence of a difference in pain intensity (measured using a visual analogue scale (VAS)) in people treated with hydromorphone compared with those treated with oxycodone, but the evidence is very uncertain (3 RCTs, 381 participants, very low-certainty evidence). Participant-reported pain relief We found no studies reporting participant-reported pain relief. Specific adverse events We found no clear evidence of a difference in nausea (RR 1.13 95% CI 0.74 to 1.73; 3 RCTs, 622 participants), vomiting (RR 1.18, 95% CI 0.72 to 1.94; 3 RCTs, 622 participants), dizziness (RR 0.91, 95% CI 0.58 to 1.44; 2 RCTs, 441 participants) and constipation (RR 0.92, 95% CI 0.72 to 1.19; 622 participants) (all very low-certainty evidence) in people treated with hydromorphone compared with those treated with oxycodone, but the evidence is very uncertain. Quality of life We found no studies reporting quality of life. Comparison 3: hydromorphone compared with morphine Participant-reported pain intensity We found no clear evidence of a difference in pain intensity (measured using the Brief Pain Inventory (BPI) or VAS)) in people treated with hydromorphone compared with those treated with morphine, but the evidence is very uncertain (2 RCTs, 433 participants; very low-certainty evidence). Participant-reported pain relief We found no clear evidence of a difference in the number of clinically improved participants, defined by 50% or greater pain relief rate, in the hydromorphone group compared with the morphine group, but the evidence is very uncertain (RR 0.99, 95% CI 0.84 to 1.18; 1 RCT, 233 participants; very low-certainty evidence). Specific adverse events At 24 days of treatment, morphine may reduce constipation compared with hydromorphone, but the evidence is very uncertain (RR 1.56, 95% CI 1.12 to 2.17; 1 RCT, 200 participants; very low-certainty evidence). We found no clear evidence of a difference in nausea (RR 0.94, 95% CI 0.66 to 1.30; 1 RCT, 200 participants), vomiting (RR 0.87, 95% CI 0.58 to 1.31; 1 RCT, 200 participants) and dizziness (RR 1.15, 95% CI 0.71 to 1.88; 1 RCT, 200 participants) (all very low-certainty evidence) in people treated with hydromorphone compared with those treated with morphine, but the evidence is very uncertain. Quality of life We found no studies reporting quality of life. Comparison 4: hydromorphone compared with fentanyl Participant-reported pain intensity We found no clear evidence of a difference in pain intensity (measured by numerical rating scale (NRS)) at 60 minutes in people treated with hydromorphone compared with those treated with fentanyl, but the evidence is very uncertain (1 RCT, 82 participants; very low-certainty evidence). Participant-reported pain relief We found no studies reporting participant-reported pain relief. Specific adverse events We found no studies reporting specific adverse events. Quality of life We found no studies reporting quality of life.

AUTHORS' CONCLUSIONS

The evidence of the benefits and harms of hydromorphone compared with other analgesics is very uncertain. The studies reported some adverse events, such as nausea, vomiting, dizziness and constipation, but generally there was no clear evidence of a difference between hydromorphone and morphine, oxycodone or fentanyl for this outcome. There is insufficient evidence to support or refute the use of hydromorphone for cancer pain in comparison with other analgesics on the reported outcomes. Further research with larger sample sizes and more comprehensive outcome data collection is required.

Symptoms During Outpatient Cancer Treatment and Options for Their Management

BACKGROUND

Cancer patients account for a large segment of the German healthcare system, with a 5-year prevalence of around 1.7 million persons. Advances in oncological treatment, now frequently performed on an outpatient basis, are granting many of these individuals a longer life span. At the same time, cancer patients often suffer disease-related symptoms and adverse effects from their tumor treatment, which may strongly impair their quality of life despite the improved techniques for management of side effects.

METHODS

This review is based on a selective literature search of the PubMed and Cochrane Library databases carried out in December 2019 and January 2020. Special attention was paid to guidelines, expert opinions, and recommendations from professional societies.

RESULTS

Alongside decreased well-being, cancer patients often suffer from fatigue (70-100%), loss of appetite (6-53%), pain (30-80 %), and dyspnea (10-70%). The prevalence and severity of the symptoms varies depending on the tumor entity and the patient's sex. A meta-analysis showed that besides causal treatment, physical activity achieves moderately strong effects in tumor-associated fatigue syndrome (Cohen's d = 0.30 [0.25; 0.36]). The WHO recommends early use of opioids in tumor-associated pain. A meta-analysis of randomized trials described symptom relief by means of opioids also in dyspnea (standardized mean difference: -0.32 [-0.53; -0.10]). Increasingly, guidelines are recommending regular palliative medical symptom screening.

CONCLUSION

Regular documentation of symptoms in outpatients offers the opportunity for targeted management of symptoms during treatment with the involvement of various disciplines such as palliative medicine, exercise therapy, and psychotherapy.

End of life experiences of patients with advanced cancer in Myanmar: Results from the APPROACH study

BACKGROUND

Access to palliative care services is essential for attaining universal health coverage for patients with a terminal cancer. Despite this, many patients with advanced cancer in low-income countries, such as Myanmar, suffer at the end of life (EOL) due to little or no access to palliative care. However, actual evidence on EOL experiences of cancer patients in Myanmar is lacking. This paper aims to describe various dimensions of EOL experiences among patients with an advanced cancer from the largest public hospital in Myanmar.

METHODS

We surveyed 195 patients with stage IV cancer seeking care from outpatient oncology clinics to assess their quality of life, pain severity, pain medications taken, quality of communication with doctors, nursing care and health care coordination, and desire to end life sooner. We assessed socioeconomic status (SES) differences in each patient outcome using separate multivariate linear/logistic regressions.

RESULTS

Forty-one percent of the patients in our sample reported that they wish their life would end sooner. Low SES cancer patients had significantly worse quality of life, reported poor health care coordination and were more likely to report severe pain compared to high SES cancer patients visiting the same hospital.

CONCLUSION

To improve quality of life and pain management and to reduce EOL distress among patients with advanced cancer, there is a pressing need to develop and invest in hospital and community-level palliative care services in Myanmar.

Pain Management in Patients with Serious Illness

Managing pain in patients with serious illness can be complex. However, pain is often a prominent symptom in patients with malignant and nonmalignant serious illness and providers have to be adept at balancing effective pain management and safety. Clinicians should start with a standard pain assessment that lays important groundwork for developing a tailored multimodal approach to pain management. It is important to identify physical causes of pain and also existential causes. Opioids are not always appropriate but are still an important tool for managing pain. Basic opioid management and safe practices are essential when managing this population.

Oxycodone versus morphine for cancer pain titration: A systematic review and pharmacoeconomic evaluation

Objective

To evaluate the efficacy, safety and cost-effectiveness of Oxycodone Hydrochloride Controlled-release Tablets (CR oxycodone) and Morphine Sulfate Sustained-release Tablets (SR morphine) for moderate to severe cancer pain titration.

Methods

Randomized controlled trials meeting the inclusion criteria were searched through Medline, Cochrane Library, Pubmed, EMbase, CNKI,VIP and WanFang database from the data of their establishment to June 2019. The efficacy and safety data were extracted from the included literature. The pain control rate was calculated to eatimate efficacy. Meta-analysis was conducted by Revman5.1.4. A decision tree model was built to simulate cancer pain titration process. The initial dose of CR oxycodone and SR morphine group were 20mg and 30mg respectively. Oral immediate-release morphine was administered to treat break-out pain. The incremental cost-effectiveness ratio was performed with TreeAge Pro 2019.

Results

19 studies (1680 patients)were included in this study. Meta-analysis showed that the pain control rate of CR oxycodone and SR morphine were 86% and 82.98% respectively. The costs of CR oxycodone and SR morphine were $23.27 and $13.31. The incremental cost-effectiveness ratio per unit was approximate $329.76. At the willingness-to-pay threshold of $8836, CR oxycodone was cost-effective, while the corresponding probability of being cost-effective at the willingness-to-pay threshold of $300 was 31.6%. One-way sensitivity analysis confirmed robustness of results.

Conclusions

CR oxycodone could be a cost-effective option compared with SR morphine for moderate to severe cancer pain titration in China, according to the threshold defined by the WHO.

[Drug management of cancer-related peripheral neuropathic pain: A systematic review of the literature]

The objective of the present systematic literature review was to provide an update on medical treatment of neuropathic pain in cancer patients. The number of cancer patients is steadily increasing. Pain is frequent in cancer patients. Few studies have focused on medical treatment of pain, and especially of neuropathic pain, in current or former cancer patients. The present systematic review of all studies published between December 2012 and August 2018 was intended to estimate the scale of this lack. In all, 27 articles were identified on a systematic PubMed search and from the authors' personal knowledge, confirming that scant data have been published. The heterogeneity of cancer patients, of cancer, and of pain go some way toward explaining this scarcity. Guidelines, founded mainly on results from non-cancer patients, recommend tricyclic antidepressants and antiepileptic drugs; local treatments have the advantage of good systemic tolerance. Larger-scale studies taking account of the etiology of neuropathic pain, its characteristics (strictly neuropathic or mixed) and patient characteristics (awaiting treatment, under treatment, recent or non-recent survivor, or in terminal phase) along the care pathway are needed to improve knowledge. The results of the present literature analysis can help future research.

Efficacy, tolerability and acceptability of oxycodone for cancer-related pain in adults: an updated Cochrane systematic review

OBJECTIVES

To assess the efficacy, tolerability and acceptability of oxycodone for cancer pain in adults METHODS: We searched CENTRAL, MEDLINE, MEDLINE In-Process, Embase, SCI, Conference Proceedings Citation Index-Science, BIOSIS, PsycINFO and four trials registries to November 2016.

RESULTS

We included 23 randomised controlled trials with 2144 patients analysed for efficacy and 2363 for safety. Meta-analyses showed no significant differences between controlled-release (CR) and immediate-release oxycodone in pain intensity or adverse events but did show significantly better pain relief after treatment with CR morphine compared with CR oxycodone. However, sensitivity analysis did not corroborate this result. Meta-analyses of the adverse events showed a significantly lower risk of hallucinations after treatment with CR oxycodone compared with CR morphine, but no other differences. The remaining studies either compared oxycodone in various formulations or compared oxycodone to different alternative opioids. None found any clear superiority or inferiority of oxycodone in pain relief or adverse events. The quality of this evidence base was limited by the high/unclear risk of bias of the studies and the low event rates for many outcomes.

CONCLUSIONS

Oxycodone offers similar levels of pain relief and adverse events to other strong opioids. However, hallucinations occurred less with CR oxycodone than with CR morphine, but the quality of this evidence was very low, so this finding should be treated with utmost caution. Our conclusions are consistent with other reviews and suggest that oxycodone can be used first line as an alternative to morphine. However, because it is cheaper, morphine generally remains the first-line opioid of choice.

Oxycodone for cancer-related pain

BACKGROUND

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

OBJECTIVES

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

SEARCH METHODS

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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

Palliative Care of Adult Patients With Cancer

BACKGROUND

In Germany, the annual mortality rate from cancer in the year 2011 was 269.9 deaths per 100 000 persons; every fourth death was due to cancer. A central objective of palliative care is to maintain the best possible quality of life for cancer patients right up to the end of their lives.

METHODS

The PubMed, Embase, and Cochrane Library databases were systematically searched for pertinent publications, and the ones that were selected were assessed as recommended by the Scottish Intercollegiate Guidelines Network. As part of the German Guideline Program in Oncology, recommendations for the S3 Guideline on Palliative Care concerning seven different topics in the management of adult patients with incurable cancer were developed by a representative expert panel employing a consensus process.

RESULTS

Opioids are the drugs of first choice for severe and moderately severe cancer-related pain, and for breathlessness. No clinically relevant respiratory depression was observed in any study. When opioids are used, accompanying medication to prevent constipation is recommended. Drugs other than opioids are ineffective against breathlessness, but clinical experience has shown that benzodiazepines and opioids can be used in combination in advanced stages of disease, or if the patient suffers from marked anxiety. Depression should be treated even in patients with a short life expectancy; psychotherapy is indicated, and antidepressant medication is indicated as well if depression is at least moderately severe. Communication skills, an essential component of palliative care, play a major role in conversations between the physician and the patient about the diagnosis, the prognosis, and the patient's wish to hasten death. When the dying phase begins, tumor-specific treatments should be stopped.

CONCLUSION

Palliative care should be offered to cancer patients with incurable disease. Generalist and specialist palliative care constitute a central component of patient care, with the goal of achieving the best possible quality of life for the patient.

Comparison of the Tolerability Profile of Controlled-Release Oral Morphine and Oxycodone for Cancer Pain Treatment. An Open-Label Randomized Controlled Trial

CONTEXT

Oxycodone and morphine are recommended as first-choice opioids for moderate/severe cancer pain, but evidence about their relative tolerability has significant methodological limitations.

OBJECTIVES

This study was mainly aimed at comparing the risk of developing adverse events (AEs) with controlled-release oral morphine vs. oxycodone; secondary aims were comparing their analgesic efficacy and testing heterogeneity in tolerability across different age and renal function subgroups.

METHODS

An open-label multicenter RCT (EudraCT number: 2006-003151-21) was carried out in patients with moderate/severe cancer pain. At baseline, 7 and 14 days, patients scored on 0-10 rating scales (0-10 numerical rating scale) the intensity of pain and of a list of common opioid side effects. The primary end point was the percentage of patients reporting an AE (a worsening ≥ 2 points on any of the listed side effects); tolerability by subgroups and average follow-up pain intensity were compared through regression models.

RESULTS

One hundred eighty-seven patients were enrolled (47% of originally planned). Intention to treat (ITT) analysis (N = 185, morphine 94, oxycodone 91) did not show any difference in the risk of developing AEs (risk difference -0.6%, 95% CI -11.0% to 9.9%) nor in analgesia (0-10 numerical rating scale pain intensity difference -0.28, 95% CI -0.83 to 0.27). No evidence of heterogeneity of tolerability across age and renal function patient subgroups emerged.

CONCLUSION

This trial failed to show any difference in tolerability and analgesic efficacy of morphine and oxycodone as first-line treatment for moderate/severe cancer pain but results interpretation is difficult due to lack of power, potential bias from open-label design, and concerns about assay sensitivity. These data, however, can significantly contribute to future meta-analyses comparing WHO Step-III opioids and are relevant in designing future randomized studies.

Hydromorphone for cancer pain

BACKGROUND

Cancer pain is an important and distressing symptom that tends to increase in frequency and intensity as the cancer advances. For people with advanced cancer, the prevalence of pain can be as high as 90%. It has been estimated that 30% to 50% of people with cancer categorise their pain as moderate to severe, with between 75% and 90% of people with cancer experiencing pain that they describe as having a major impact on their daily life. Epidemiological studies suggest that approximately 15% of people with cancer pain fail to experience acceptable pain relief with conventional management. Uncontrolled pain can lead to physical and psychological distress and can, consequently, have a drastic effect on people's quality of life.

OBJECTIVES

To determine the analgesic efficacy of hydromorphone in relieving cancer pain, as well as the incidence and severity of any adverse events.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials, MEDLINE, Embase and clinical trials registers up to April 2016. There were no language, document type or publication status limitations applied in the search.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared hydromorphone with placebo or other active pain medication for cancer pain in both adults and children. The four main outcomes selected have previously been identified as important to people with cancer; pain no worse than mild pain, and the impact of the treatment on consciousness, appetite and thirst. We did not consider physician-, nurse- or carer-reported measures of pain.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data. For binary outcomes, we calculated risk ratio (RR) and its 95% confidence interval (CI), on an intention-to-treat basis. For continuous data, we estimated the mean difference (MD) between groups and its 95% CI. We used a random-effects model and assessed the risk of bias for all included studies. A meta-analysis was not completed on any of the primary outcomes in this review due to the lack of data. We assessed the evidence using GRADE and created two 'Summary of findings' tables.

MAIN RESULTS

We included four studies (604 adult participants), which compared hydromorphone to oxycodone (two studies) or morphine (two studies). Overall, the included studies were at low or unclear risk of bias, rated unclear due to unknown status of blinding of outcome assessment; we rated three studies at high risk of bias for potential conflict of interest. Data for 504 participants were available for analysis. We collected data on endpoint participant-reported pain intensity measured with a visual analogue scale (VAS) (mean ± standard deviation (SD): hydromorphone 28.86 ± 17.08, n = 19; oxycodone 30.30 ± 25.33, n = 12; scale from 0 to 100 with higher score indicating worse pain), and Brief Pain Inventory (BPI) 24 hours worst pain subscale (mean ± SD: hydromorphone 3.5 ± 2.9, n = 99; morphine 4.3 ± 3.0, n = 101, scale from 0 to 10 with higher score indicating worse pain). The data demonstrated a similar effect between groups with both comparisons. The pain intensity data showed that participants in all four trials achieved no worse than mild pain. There were several adverse events: some were the expected opioid adverse effects such as nausea, constipation and vomiting; others were not typical opioid adverse effects (for example, decreased appetite, dizziness and pyrexia, as shown in Table 1 in the main review), but generally showed no difference between groups. There were three deaths in the morphine group during the trial period, considered to be due to disease progression and unrelated to the drug. Three trials had over 10% dropout, but the reason and proportion of dropout was balanced between groups. The overall quality of evidence was very low mainly due to high risk of bias, imprecision of effect estimates and publication bias. There were no data available for children or for several participant-important outcomes, including participant-reported pain relief and treatment impact on consciousness, appetite or thirst.

AUTHORS' CONCLUSIONS

This review indicated little difference between hydromorphone and other opioids in terms of analgesic efficacy. Data gathered in this review showed that hydromorphone had a similar effect on participant-reported pain intensity as reported for oxycodone and morphine. Participants generally achieved no worse than mild pain after taking hydromorphone, which is comparable with the other drugs. It produced a consistent analgesic effect through the night and could be considered for use in people with cancer pain experiencing sleep disturbance. However, the overall quality of evidence was very low mainly due to risk of bias, imprecision of effect estimates and publication bias. This review only included four studies with limited sample size and a range of study designs. Data for some important outcomes, such as impact of the treatment on consciousness, appetite or thirst, were not available. Therefore, we were unable to demonstrate superiority or inferiority of hydromorphone in comparison with other analgesics for these outcomes. We recommend that further research with larger sample sizes and more comprehensive outcome data collection is required.

Oral morphine for cancer pain

BACKGROUND

This is the third updated version of a Cochrane review first published in Issue 4, 2003 of The Cochrane Library and first updated in 2007. Morphine has been used for many years to relieve pain. Oral morphine in either immediate release or modified release form remains the analgesic of choice for moderate or severe cancer pain.

OBJECTIVES

To determine the efficacy of oral morphine in relieving cancer pain, and to assess the incidence and severity of adverse events.

SEARCH METHODS

We searched the following databases: Cochrane Central Register of Controlled Trials (CENTRAL 2015, Issue 9); MEDLINE (1966 to October 2015); and EMBASE (1974 to October 2015). We also searched ClinicalTrials.gov (1 October 2015).

SELECTION CRITERIA

Published randomised controlled trials (RCTs) using placebo or active comparators reporting on the analgesic effect of oral morphine in adults and children with cancer pain. We excluded trials with fewer than 10 participants.

DATA COLLECTION AND ANALYSIS

One review author extracted data, which were checked by another review author. There were insufficient comparable data for meta-analysis to be undertaken or to produce numbers needed to treat (NNTs) for the analgesic effect. We extracted any available data on the number or proportion of participants with 'no worse than mild pain' or treatment success (very satisfied, or very good or excellent on patient global impression scales).

MAIN RESULTS

We identified seven new studies in this update. We excluded six, and one study is ongoing so also not included in this update. This review contains a total of 62 included studies, with 4241 participants. Thirty-six studies used a cross-over design ranging from one to 15 days, with the greatest number (11) for seven days for each arm of the trial. Overall we judged the included studies to be at high risk of bias because the methods of randomisation and allocation concealment were poorly reported. The primary outcomes for this review were participant-reported pain and pain relief.Fifteen studies compared oral morphine modified release (Mm/r) preparations with morphine immediate release (MIR). Fourteen studies compared Mm/r in different strengths; six of these included 24-hour modified release products. Fifteen studies compared Mm/r with other opioids. Six studies compared MIR with other opioids. Two studies compared oral Mm/r with rectal Mm/r. Three studies compared MIR with MIR by a different route of administration. Two studies compared Mm/r with Mm/r at different times and two compared MIR with MIR given at a different time. One study was found comparing each of the following: Mm/r tablet with Mm/r suspension; Mm/r with non-opioids; MIR with non-opioids; and oral morphine with epidural morphine.In the previous update, a standard of 'no worse than mild pain' was set, equivalent to a score of 30/100 mm or less on a visual analogue pain intensity scale (VAS), or the equivalent in other pain scales. Eighteen studies achieved this level of pain relief on average, and no study reported that good levels of pain relief were not attained. Where results were reported for individual participants in 17 studies, 'no worse than mild pain' was achieved by 96% of participants (362/377), and an outcome equivalent to treatment success in 63% (400/638).Morphine is an effective analgesic for cancer pain. Pain relief did not differ between Mm/r and MIR. Modified release versions of morphine were effective for 12- or 24-hour dosing depending on the formulation. Daily doses in studies ranged from 25 mg to 2000 mg with an average of between 100 mg and 250 mg. Dose titration was undertaken with both instant release and modified release products. A small number of participants did not achieve adequate analgesia with morphine. Adverse events were common, predictable, and approximately 6% of participants discontinued treatment with morphine because of intolerable adverse events.The quality of the evidence is generally poor. Studies are old, often small, and were largely carried out for registration purposes and therefore were only designed to show equivalence between different formulations.

AUTHORS' CONCLUSIONS

The conclusions have not changed for this update. The effectiveness of oral morphine has stood the test of time, but the randomised trial literature for morphine is small given the importance of this medicine. Most trials recruited fewer than 100 participants and did not provide appropriate data for meta-analysis. Only a few reported how many people had good pain relief, but where it was reported, over 90% had no worse than mild pain within a reasonably short time period. The review demonstrates the wide dose range of morphine used in studies, and that a small percentage of participants are unable to tolerate oral morphine. The review also shows the wide range of study designs, and inconsistency in cross-over designs. Trial design was frequently based on titration of morphine or comparator to achieve adequate analgesia, then crossing participants over in cross-over design studies. It was not clear if these trials were sufficiently powered to detect any clinical differences between formulations or comparator drugs. New studies added to the review for the previous update reinforced the view that it is possible to use modified release morphine to titrate to analgesic effect. There is qualitative evidence that oral morphine has much the same efficacy as other available opioids.

Efficacy and tolerability of oral oxycodone and oxycodone/naloxone combination in opioid-naïve cancer patients: a propensity analysis

Background

World Health Organization step III opioids are required to relieve moderate-to-severe cancer pain; constipation is one of the most frequent opioid-induced side effects. A fixed combination, prolonged-release oxycodone/naloxone (OXN), was developed with the aim of reducing opioid-related gastrointestinal side effects. The objective of this study was to compare the efficacy and safety of prolonged-release oxycodone (OXY) alone to OXN in opioid-naïve cancer patients with moderate-to-severe pain.

Methods

Propensity analysis was utilized in this observational study, which evaluated the efficacy, safety, and quality of life.

Results

Out of the 210 patients recruited, 146 were matched using propensity scores and included in the comparative analysis. In both groups, pain intensity decreased by ≈3 points after 60 days, indicating comparable analgesic efficacy. Responder rates were similar between groups. Analgesia was achieved and maintained with similarly low and stable dosages over time (12.0–20.4 mg/d for OXY and 11.5–22.0 mg/d for OXN). Bowel Function Index (BFI) and laxative use per week improved from baseline at 30 days and 60 days in OXN recipients (−16, P<0.0001 and −3.5, P=0.02, respectively); BFI worsened in the OXY group. The overall incidence of drug-related adverse events was 28.9% in the OXY group and 8.2% in the OXN group (P<0.01); nausea and vomiting were two to five times less frequent with OXN. Quality of life improved to a significantly greater extent in patients receiving OXN compared to OXY (increase in Short Form-36 physical component score of 7.1 points vs 3.2 points, respectively; P<0.001).

Conclusion

In patients with chronic cancer pain, OXN provided analgesic effectiveness that is similar to OXY, with early and sustained benefits in tolerability. The relationship between responsiveness to OXN and clinical characteristics is currently being investigated.

Strong opioids for noncancer pain due to musculoskeletal diseases: Not more effective than acetaminophen or NSAIDs

The classification of morphine as a step III analgesic, based on pharmacological data, creates a strong bias toward a belief in the efficacy of this drug. However, double-blind emergency-room trials showed similar levels of pain relief with intravenous acetaminophen as with intravenous morphine in patients with renal colic, low back pain or acute limb pain. In patients with chronic noncancer low back pain, morphine and other strong opioids in dosages of up to 100mg/day were only slightly more effective than their placebos, no more effective than acetaminophen, and somewhat less effective than nonsteroidal anti-inflammatory drugs (NSAIDs). In patients with osteoarthritis, strong opioids were not more effective than NSAIDs and, in some studies, than placebos. The only randomized controlled trial in patients with sciatica found no difference with the placebo. Chronic use of strong opioids can induce hyperalgesia in some patients. Hyperpathia with increased sensitivity to cold leading the patient to request higher dosages should suggest opioid-induced hyperalgesia. Pain specialists in the US have issued a petition asking that strong opioids be used in dosages no higher than 100mg/day of morphine-equivalent, in an effort to decrease the high rate of mortality due to the misuse and abuse of strong opioids (10,000 deaths/year in the US). Healthcare providers often overestimate the efficacy of step III analgesics, despite pain score decreases of only 0.8 to 1.2 points.

Quality of life and healthcare resource in patients receiving opioids for chronic pain: a review of the place of oxycodone/naloxone

In patients managed with opioids for chronic pain, opioid-induced bowel dysfunction—specifically, opioid-induced constipation (OIC)—is a common side effect, which has a significant impact on quality of life (QoL). The most recent developments for management of OIC are opioid antagonists, including naloxone, a competitive antagonist of peripheral opioid receptors that reverses opioid-induced peripheral gastrointestinal (GI) effects. A prolonged-release formulation of naloxone is available in combination with oxycodone (OXN PR). To review the specific role of OXN PR in the management of chronic pain and OIC and its impact on QoL and healthcare costs, a review of available relevant literature was conducted. Healthcare costs can be up to ten times higher for patients with GI events than for those without. Assessment of QoL in patients with OIC is essential, and multiple tools for its evaluation are available. The Bowel Function Index (BFI), a tool that was specifically developed and validated to measure bowel function in patients with OIC, can be an indication of QoL. In patients with moderate-to-severe chronic pain, randomized trials have demonstrated that OXN PR has equal analgesic efficacy and safety, but results in improved bowel function, compared with prolonged-release oxycodone (Oxy PR) alone. In conclusion, randomized studies using the BFI, as well as real-world clinical practice observations, have demonstrated improved QoL for patients taking OXN PR. This combination should allow more patients to benefit from the analgesic efficacy of opioid therapy and should minimize the side effects of constipation that correspond to improvements in QoL and healthcare offsets.

Oxycodone for cancer-related pain

BACKGROUND

Many patients with cancer experience moderate to severe pain that requires treatment with strong opioids, of which oxycodone and morphine are examples. Strong opioids are, however, not effective for pain in all patients, nor are they well-tolerated by all patients. The aim of this review was to assess whether oxycodone is associated with better pain relief and tolerability than other analgesic options for patients with cancer pain.

OBJECTIVES

To assess the effectiveness and tolerability of oxycodone for pain in adults with cancer.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library, MEDLINE and MEDLINE In-Process (Ovid), EMBASE (Ovid), Science Citation Index, Conference Proceedings Citation Index - Science (ISI Web of Science), BIOSIS (ISI), PsycINFO (Ovid) and PubMed to March 2014. We also searched Clinicaltrials.gov, metaRegister of Controlled Trials (mRCT), EU Clinical Trials Register and World Health Organization International Clinical Trials Registry Platform (ICTRP). We checked the bibliographic references of relevant identified studies and contacted the authors of the included studies to find additional trials not identified by the electronic searches. No language, date or publication status restrictions were applied to the search.

SELECTION CRITERIA

We included randomised controlled trials (parallel-group or cross-over) comparing oxycodone (any formulation or route of administration) with placebo or an active drug (including oxycodone) for cancer background pain in adults.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted study data (study design, participant details, interventions and outcomes) and independently assessed the quality of the included studies according to standard Cochrane methodology. Where possible, we meta-analysed the pain intensity data using the generic inverse variance method, otherwise these data were summarised narratively along with the adverse event and patient preference data. The overall quality of the evidence for each outcome was assessed according to the GRADE approach.

MAIN RESULTS

We included 17 studies which enrolled/randomised 1390 patients with 1110 of these analysed for efficacy and 1170 for safety. The studies examined a number of different drug comparisons. Four studies compared controlled release (CR) oxycodone to immediate release (IR) oxycodone and pooled analysis of three of these studies showed that the effects of CR and IR oxycodone on pain intensity after treatment were similar (standardised mean difference (SMD) 0.1, 95% confidence interval (CI) -0.06 to 0.26; low quality evidence). This was in line with the finding that none of the included studies reported differences in pain intensity between the treatment groups. Three of the four studies also found similar results for treatment acceptability and adverse events in the IR and CR groups; but one study reported that, compared to IR oxycodone, CR oxycodone was associated with significantly fewer adverse events.Six studies compared CR oxycodone to CR morphine and pooled analysis of five of these studies indicated that pain intensity did not differ significantly between the treatments (SMD 0.14, 95% CI -0.04 to 0.32; low quality evidence). There were no marked differences in adverse event rates, treatment acceptability or quality of life ratings.The remaining seven studies either compared oxycodone in various formulations or compared oxycodone to different alternative opioids. None of them found any clear superiority or inferiority of oxycodone for cancer pain, neither as an analgesic agent nor in terms of adverse event rates and treatment acceptability.The quality of this evidence base was limited by the risk of bias of the studies and by small sample sizes for many outcomes. Random sequence generation and allocation concealment were under-reported, and the results were substantially compromised by attrition with data missing from more than 20% of the enrolled/randomised patients for efficacy and from more than 15% for safety.

AUTHORS' CONCLUSIONS

Overall, the data included within this review suggest that oxycodone offers similar levels of pain relief and adverse events to other strong opioids including morphine, which is commonly considered the gold standard strong opioid. Our conclusions are consistent with other recent reviews and suggest that while the reliability of the evidence base is low, given the absence of important differences within this analysis it seems unlikely that larger head to head studies of oxycodone versus morphine will be justified. This means that for clinical purposes oxycodone or morphine can be used as first line oral opioids for relief of cancer pain.

Morphine or oxycodone for cancer-related pain? A randomized, open-label, controlled trial

CONTEXT

There is wide interindividual variation in response to morphine for cancer-related pain; 30% of patients do not have a good therapeutic outcome. Alternative opioids such as oxycodone are increasingly being used, and opioid switching has become common clinical practice.

OBJECTIVES

To compare clinical response to oral morphine vs. oral oxycodone when used as first-line or second-line (after switching) treatment in patients with cancer-related pain.

METHODS

In this prospective, open-label, randomized, controlled trial (ISRCTN65155201) with a selected crossover phase, patients with cancer-related pain were randomized to receive either oral morphine or oxycodone as first-line treatment. Dose was individually titrated until the patient reported adequate pain control. Patients who did not respond to the first-line opioid (either because of inadequate analgesia or unacceptable adverse effects) were switched to the alternative opioid.

RESULTS

Two hundred patients were recruited. On intention-to-treat analysis (n = 198, morphine 98, oxycodone 100), there was no significant difference between the numbers of patients responding to morphine (61/98 = 62%) or oxycodone (67/100 = 67%) when used as a first-line opioid. Similarly, there was no significant difference in subsequent response when patients were switched to either morphine (8/12 = 67%) or oxycodone (11/21 = 52%). Per-protocol analysis demonstrated a 95% response rate when both opioids were available. There was no difference in adverse reaction scores between morphine and oxycodone either in first-line responders or nonresponders.

CONCLUSION

In this population, there was no difference between analgesic response or adverse reactions to oral morphine and oxycodone when used as a first- or second-line opioid. These data provide evidence to support opioid switching to improve outcomes.

Assessing the response to opioids in cancer patients: a methodological proposal and the results

PURPOSE

The efficacy of treatment with opioids in cancer pain is variable. To evaluate this variability, we (1) applied two parameters, changes in pain intensity (PI) and opioid daily doses (DDs), to distinguish different responses to opioids. The need to switch to another opioid was recorded. We then (2) evaluated the distribution of the responses depending on these parameters, alone and taken together, in cancer patients with pain.

METHODS

The cutoffs between positive and negative responses related to PI and DD were defined on the basis of the literature. For PI, responders were patients who obtained simultaneously a decrease of 30% or more and a final score ≤4 points (numerical rating scale 0 to 10). For DD changes, we applied the opioid escalation index percentage, a positive response corresponding to a dose increase ≤5%. These criteria were applied to 201 cancer patients treated with WHO step III "strong" opioids for 21 days. The results were mainly analyzed case by case.

RESULTS

Of the patients, 63.7% obtained a positive analgesic response and 80.1% a dose-related positive response. Combining the parameters, the response was double positive in 55.2% of cases, double negative in 11.4%, a good analgesic response with a large dose escalation in 8.5%, and no pain relief with a stable dose in 24.9%. Switches were made 21 times, 15 because of the lack of analgesia.

CONCLUSIONS

Different degrees of response to opioids were observed, PI and DD changes both contributing. Only over half the patients had a full positive response.

Patients with chronic pain and dysphagia (CPD): unmet medical needs and pharmacologic treatment options

BACKGROUND

For properly selected patients experiencing chronic pain, extended-release opioid formulations may represent an appropriate pain management choice. For the many adults, elderly, and children who have medical conditions that make swallowing solid, oral-dose formulations difficult (dysphagia) or painful (odynophagia), this option may be limited. The combination of chronic pain with dysphagia (CPD) presents a challenge to physicians and patients alike when oral opioid analgesia is needed to control pain, but patients are unable to swallow solid, oral dosage forms.

METHODS

A Medline search was performed (1990 to 2013) using the search terms swallowing difficulties, dysphagia, odynophagia, adults, pediatrics, elderly, chronic pain, pain, and opioids. The following websites were searched: American Dysphagia Network, Dysphagia Research Society, World Health Organization, American Pain Society, International Association for the Study of Pain, American Academy of Pain Medicine, and American Society of Interventional Pain Physicians. Chronic pain guidelines from the following professional organizations were searched: American Pain Society, National Comprehensive Cancer Network, American Society of Interventional Pain Physicians, British Geriatric Society, European Society of Medical Oncology, World Health Organization, and the European Association for Palliative Care.

FINDINGS

There is an unmet medical need for greater recognition of dysphagia, awareness of potential problems with medication administration in these patients, recognition of alternative drug formulations that are available for use in CPD, and an appreciation that there are new, solid, oral-dose, opioid formulations in development that can mitigate these issues associated with swallowing difficulty while still providing practical, effective analgesia. Current pharmacologic treatments have limitations; new, prospective opioid formulations in clinical development may offer physicians and patients with CPD effective treatment options while mitigating accidental exposure and abuse liability.

CONCLUSIONS

The number of patients with CPD may be larger than is currently anticipated by healthcare providers. Physicians should proactively include a discussion of dysphagia as part of the patient examination. CPD is an unmet medical need. There are novel opioid formulations in clinical development that address the limitations of current opioid treatments. This manuscript reviews the problems associated with dysphagia on medication administration and adherence, currently available treatment options, and opioid analgesic formulations currently in clinical development.

Long-term safety and efficacy of oxycodone/naloxone prolonged-release tablets in patients with moderate-to-severe chronic cancer pain

Aim

To evaluate the long-term safety and efficacy of prolonged-release oxycodone/naloxone (OXN PR) and its impact on quality of life (QoL), in patients with moderate-to-severe cancer pain.

Methods

This was an open-label extension (OLE) of a 4 week, randomized, double-blind (DB) study in which patients with moderate-to-severe cancer pain had been randomized to OXN PR or oxycodone PR (OxyPR). During the OLE phase, patients were treated with OXN PR capsules (≤20/60 mg/day) for ≤24 weeks. Outcome measures included safety, efficacy and QoL.

Results

One hundred and twenty-eight patients entered the OLE, average pain scores based on the modified Brief Pain Inventory—Short Form were low and stable over the 24-week period. The improvement in bowel function and constipation symptoms as measured by the Bowel Function Index and patient assessment of constipation in patients treated with OXN PR during the 4-week DB study was maintained. In patients treated with OxyPR during the DB phase, bowel function and constipation symptoms were improved during the OLE. In the DB and in the OLE, health status and QoL were similar for patients treated with OXN PR and OxyPR. There were no unexpected safety or tolerability issues.

Conclusions

In patients with moderate-to-severe cancer pain, long-term use of OXN PR is well tolerated and effective, resulting in sustained analgesia, improved bowel function and improved symptoms of constipation.

Management of pain in advanced disease

BACKGROUND

Pain is common in advanced malignancy but also prevalent in other non-malignant life-limiting diseases such as advanced heart disease; end stage renal failure and multiple sclerosis. Patients with renal or liver impairment need specific consideration, as most analgesics rely on either or both for their metabolism and excretion.

SOURCES OF DATA

Recent evidence-based guidelines and the systematic reviews that have informed their recommendations.

AREAS OF AGREEMENT

The principles of the WHO (World Health Organisation) analgesic ladder are commonly endorsed as a structured approach to the management of pain. For neuropathic pain, the efficacy of different agents is similar and choice of drug more guided by side effects, drug interactions and cost.

AREAS OF CONTROVERSY

Evidence supporting the WHO analgesic ladder is disputed and alternatives suggested, but no overwhelming evidence for an alternative approach exists to date.

GROWING POINTS

Alternative approaches to the WHO analgesic ladder, new analgesic agents, e.g. rapid onset oral/intranasal fentanyl.

Management of the acute painful crisis in sickle cell disease- a re-evaluation of the use of opioids in adult patients

Management of the acute painful crisis (APC) of sickle cell disease (SCD) remains unsatisfactory despite advances in the understanding and management of acute pain in other clinical settings. One reason for this is an unsophisticated approach to the use of opioid analgesics for pain management. This applies to haematologists who are responsible for developing acute sickle pain management protocols for their patients, and to health care staff in the acute care setting. The objective of this article is to evaluate the evidence for use of opioids in APC management. We have highlighted the possibilities for improving management by using alternatives to morphine, and intranasal (IN) or transmucosal routes of administration for rapid onset of analgesia in the emergency department (ED). We suggest how experience gained in managing acute sickle pain in children could be extrapolated to adolescents and young adults. We have also questioned whether patients given strong opioids in the acute setting are being safely monitored and what resources are required to ensure efficacy, safety and patient satisfaction. We also identify aspects of care where there are significant differences of opinion, which require further study by randomized controlled trial.

[Chronic non-cancer-related pain. Long-term treatment with rapid-release and short-acting opioids in the context of misuse and dependency]

Annually published data show a continual increase in the volume of opioid prescriptions in Germany, thus indicating an intensification of opioid therapy. The majority of opioids are prescribed to treat chronic non-cancer-related pain. On the basis of current guidelines, as well as in terms of the lack of data regarding long-term use of opioids and their effectiveness beyond a period of 3 months, this development must be viewed critically. With reference to four case reports, we discuss and evaluate opioid therapy in relation to medication misuse and the development of drug dependency. Particular emphasis is placed on the administration of rapid-release and short-acting opioid preparations, which we consider to be particularly problematic.

[Observational and cross-sectional study of prevalence and severity of the opioid-induced bowel dysfunction]

Objetivo

Analizar la prevalencia y severidad de los síntomas de disfunción intestinal inducida por opioides (DIO).

Diseño

Estudio epidemiológico, observacional y transversal.

Emplazamiento

Seis hospitales españoles.

Participantes

Trescientos diecisiete pacientes en régimen ambulatorio con diagnóstico de dolor oncológico o dolor crónico no oncológico tratados con un único opioide mayor.

Mediciones principales

La prevalencia de los síntomas de DIO y su severidad se midió usando una escala visual analógica (EVA: 0-100) y el estreñimiento se valoró también mediante el índice de función intestinal (BFI). Se registró el tratamiento para los síntomas gastrointestinales y se comparó su frecuencia según el tratamiento opioide. Finalmente, se estudió la calidad de vida.

Resultados

La tasa de prevalencia de al menos un trastorno gastrointestinal potencialmente relacionado con la DIO fue del 94,6%, siendo el estreñimiento el síntoma más frecuente (BFI: 91,6%; EVA: 90,2%) y casi la mitad de los pacientes (49,8%) presentaron 3 o más síntomas con un EVA ≥ 4. No se detectaron diferencias significativas en la prevalencia de los síntomas entre los distintos tratamientos opioides. Se detectó una afectación en la calidad de vida de los pacientes relacionada con la presencia de síntomas gastrointestinales de moderada a severa.

Conclusiones

En pacientes con tratamiento opioide se constata una elevada frecuencia de trastornos gastrointestinales posiblemente relacionados con la DIO, lo que subraya la necesidad de nuevas estrategias para su tratamiento.

Efficacy and gastrointestinal tolerability of oral oxycodone/naloxone combination for chronic pain in outpatients with cancer: an observational study

Combination opioid agonist/antagonist therapy has been shown to preserve bowel function in patients with chronic cancer pain. This retrospective study evaluated the efficacy and tolerability of prolonged-released fixed-dose oxycodone-naloxone (PR OXN) in consecutive outpatients with chronic cancer pain. Of 206 patients prescribed PR OXN (mean age 61.3 ± 12.9 years; 52.9% female), 31.5% were opioid naïve. PR OXN was associated with a significant decrease in pain score measured on a visual analogue scale over 28 days (P < .0001), without adverse effects on bowel function, nor change in laxative use. PR OXN efficacy and tolerability were similar in opioid-naïve and -experienced patients, and among age-stratified subgroups. No severe side effects occurred. In a real-life outpatient setting, PR OXN provided analgesia without bowel dysfunction in patients with chronic cancer pain.

Versatility of different pharmaceutical formulations of hydromorphone in the management of severe cancer pain and pain in palliative care

SUMMARY The management of severe pain situations requires therapeutic expertise in dealing with changes in pain intensity, analgesic limitations and individual patient needs. Opioids are the treatment of choice in severe pain. The availability of a broad range of opioids and formulations refined the options for improved pain treatment with a specific substance. These may include oral formulations, injectables and other applications suitable for different patient needs. Moreover, variable drug concentrations are most useful in clinical practice. This article briefly reviews the versatility of different hydromorphone formulations in the management of severe pain in palliative care and cancer. Limiting strong opioid treatment with one opioid substance in different formulations (adjuvants if necessary), according to varying requirements of patients, would be eligible for achieving a well-tolerated and effective pain therapy. Its versatility renders hydromorphone suitable for consistent opioid administration with predictable substance release, and may thus contribute to reducing the need for opioid change.

Oral morphine for cancer pain

BACKGROUND

This is the second updated version of a Cochrane review first published in Issue 4, 2003 of The Cochrane Library and first updated in 2007. Morphine has been used for many years to relieve pain. Oral morphine in either immediate release or modified release form remains the analgesic of choice for moderate or severe cancer pain.

OBJECTIVES

To determine the efficacy of oral morphine in relieving cancer pain, and assess the incidence and severity of adverse effects.

SEARCH METHODS

We searched the following databases: Cochrane Pain, Palliative and Supportive Care Group Trials Register (June 2013); Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2013, Issue 5, May); MEDLINE (1966 to June 2013); and EMBASE (1974 to June 2013).

SELECTION CRITERIA

Published randomised controlled trials (RCTs) using placebo or active comparators reporting on the analgesic effect of oral morphine in adults and children with cancer pain. Trials with fewer than ten participants were excluded.

DATA COLLECTION AND ANALYSIS

One review author extracted data, which were checked by another review author. There were insufficient comparable data for meta-analysis to be undertaken or to produce numbers needed to treat (NNTs) for the analgesic effect. We extracted any available data on the number or proportion of participants with 'no worse than mild pain' or treatment success (very satisfied, or very good or excellent on patient global impression scales).

MAIN RESULTS

Ten new studies (638 participants) were identified for this update, bringing the total of included studies to 62, with 4241 participants. Thirty-six studies used a cross-over design ranging from one to 15 days, with the greatest number (11) for seven days for each arm of the trial.Fifteen studies compared oral morphine modified release (Mm/r) preparations with morphine immediate release (MIR). Fourteen studies compared Mm/r in different strengths; six of these included 24-hour modified release products. Fifteen studies compared Mm/r with other opioids. Six studies compared MIR with other opioids. Two studies compared oral Mm/r with rectal Mm/r. Three studies compared MIR with MIR by a different route of administration. Two studies compared Mm/r with Mm/r at different times and two compared MIR with MIR given at a different time. One study was found comparing each of the following: Mm/r tablet with Mm/r suspension; Mm/r with non-opioids; MIR with non-opioids; and oral morphine with epidural morphine.In this update a standard of 'no worse than mild pain' was set equivalent to a score of 30/100 mm or less on a visual analogue pain intensity scale (VAS), or the equivalent in other pain scales. Eighteen studies achieved this level of pain relief on average, and no study reported that good levels of pain relief were not attained. Where results were reported for individual participants in 17 studies, 'no worse than mild pain' was achieved by 96% of participants (362/377), and an outcome equivalent to treatment success in 63% (400/638).Morphine is an effective analgesic for cancer pain. Pain relief did not differ between Mm/r and MIR. Modified release versions of morphine were effective for 12- or 24-hour dosing depending on the formulation. Daily doses in studies ranged from 25 mg to 2000 mg with an average of between 100 mg and 250 mg. Dose titration was undertaken with both instant release and modified release products. A small number of participants did not achieve adequate analgesia with morphine. Adverse effects were common and approximately 6% of participants discontinued treatment because of intolerable adverse effects.

AUTHORS' CONCLUSIONS

The effectiveness of oral morphine has stood the test of time, but the randomised trial literature for morphine is small given the importance of this medicine. Most trials recruited fewer than 100 participants and did not provide appropriate data for meta-analysis. Only a few reported how many people had good pain relief, but where it was reported, over 90% had no worse than mild pain within a reasonably short time period. The review demonstrates the wide dose range of morphine used in studies, and that a small percentage of participants are unable to tolerate oral morphine. The review also shows the wide range of study designs, and inconsistency in cross-over designs. Trial design was frequently based on titration of morphine or comparator to achieve adequate analgesia, then crossing participants over in cross-over design studies. It was not clear if these trials are sufficiently powered to detect any clinical differences between formulations or comparator drugs. New studies added to the review reinforce the view that it is possible to use modified release morphine to titrate to analgesic effect. There is qualitative evidence that oral morphine has much the same efficacy as other available opioids.

Morphine is a substrate of the organic cation transporter OCT1 and polymorphisms in OCT1 gene affect morphine pharmacokinetics after codeine administration

We investigated whether morphine and its pro-drug codeine are substrates of the highly genetically polymorphic organic cation transporter OCT1 and whether OCT1 polymorphisms may affect morphine and codeine pharmacokinetics in humans. Morphine showed low transporter-independent membrane permeability (0.5 × 10⁻⁶ cm/s). Morphine uptake was increased up to 4-fold in HEK293 cells overexpressing human OCT1. The increase was concentration-dependent and followed Michaelis-Menten kinetics (KM = 3.4 μM, VMAX = 27 pmol/min/mg protein). OCT1-mediated morphine uptake was abolished by common loss-of-function polymorphisms in the OCT1 gene and was strongly inhibited by drug-drug interactions with irinotecan, verapamil and ondansetron. Morphine uptake in primary human hepatocytes was strongly reduced by MPP⁺, an inhibitor of organic cation transporters, and morphine was not a substrate of OCT3, the other organic cation transporter expressed in human hepatocytes. In concordance with the in vitro data, morphine plasma concentrations in healthy volunteers were significantly dependent on OCT1 polymorphisms. After codeine administration, the mean AUC of morphine was 56% higher in carriers of loss-of-function OCT1 polymorphisms compared to non-carriers (P = 0.005). The difference remained significant after adjustment for CYP2D6 genotype (P = 0.03). Codeine itself had high transporter-independent membrane permeability (8.2 × 10⁻⁶ cm/s). Codeine uptake in HEK293 cells was not affected by OCT1 overexpression and OCT1 polymorphisms did not affect codeine AUCs. In conclusion, OCT1 plays an important role in the hepatocellular uptake of morphine. Carriers of loss-of-function OCT1 polymorphisms may be at higher risk of adverse effects after codeine administration, especially if they are also ultra-rapid CYP2D6 metabolizers.

Does the pharmacology of oxycodone justify its increasing use as an analgesic?

Oxycodone is a semisynthetic opioid analgesic that is increasingly used for the treatment of acute, cancer, and chronic non-malignant pain. Oxycodone was synthesized in 1917 but its pharmacological properties were not thoroughly studied until recently. Oxycodone is a fairly selective μ-opioid receptor agonist, but there is a striking discrepancy between the relatively low binding potential and G protein activation by oxycodone and its analgesic efficacy. It has been claimed that this is because of active metabolites and enhanced passage to the central nervous system by active transport. We critically review studies on the basic pharmacology of oxycodone and on its pharmacokinetics and pharmacodynamics in humans. In particular, the role of pharmacogenomics and population pharmacokinetics in understanding the properties of oxycodone is discussed in detail. We compare oxycodone with morphine, the standard opioid in clinical use.

Increase in opiate prescription in Germany between 2000 and 2010: a study based on insurance data

BACKGROUND

Insufficient data have been available to date on the prevalence of opioid treatment in Germany, physicians' prescribing habits, and the percentages of cancer patients and non-cancer patients among those receiving opioids for an evaluation of the quality of care and an assessment of possible underuse or misuse.

METHODS

The data analyzed in this study were derived from the statutory health insurance sample of the AOK health insurance company in the German state of Hesse / ASHIP Hesse for the years 2000-2010. For the purpose of this study, prevalence was defined as the percentage of insurees who received at least one outpatient prescription of an opioid (ATC N02A, excluding codeine, levomethadone and methadone). In order to control for population aging, the prevalence was standardized to the German population on December 31(st) of the preceding year and to the age-structure of the population as it was in 1999. Opioid prescribing for cancer was assumed when a cancer diagnosis was documented in the same year in which the opioid prescription was issued.

RESULTS

The percentage of insurees receiving at least one opioid prescription rose over the period of the study from 3.31% in 2000 to 4.53% in 2010, a relative gain of 37%. Opioids were mostly prescribed to patients with non-cancer pain (2010: about 77% of opioid recipients). The percentage of non-cancer patients receiving long-term opioid treatment has also increased over the period of the study.

CONCLUSION

As opioids are frequently prescribed for non-cancer pain, it cannot be inferred from the observed increase in opioid prescribing that cancer patients are now receiving better opioid treatment than they were before. Further issues of concern are the observed increases in the prescribing of potent immediate release opioids and in the long-term opioid treatment for non-cancer patients, the benefit of which is currently debated.

Opioid Prescribing for Cancer Pain During the Last 3 Months of Life: Associated Factors and 9-Year Trends in a Nationwide United Kingdom Cohort Study

Purpose

To determine time trends and characteristics associated with opioid analgesic prescribing to patients with cancer who are approaching the end of life.

Patients and Methods

This population-based cohort study used data on 29,825 patients diagnosed with five common cancers—lung (34.2%), colorectal (19.9%), female breast (21.6%), prostate (19.1%), and head and neck (5.2%)—in the United Kingdom General Practice Research Database (GPRD) who died between 2000 and 2008. Opioid prescription rates in the last 3 months of life were described. Characteristics associated with opioid prescribing were investigated by using generalized estimation equation models.

Results

In the last 3 months of life, 43.6% (95% CI, 43.0% to 44.2%) of patients received at least one prescription of opioids: morphine (33.4%; 95% CI, 32.8% to 33.9%), diamorphine (11.6%; 95% CI, 11.2% to 11.9%), and fentanyl family (10.2%; 95% CI, 9.8% to 10.5%). Over time, prescription rates increased for opioids predominant during specific time periods, especially oxycodone. Older patients (age > 60 years) had significantly lower chances of receiving opioids than their younger (age < 50 years) peers (prevalence ratio [PR] range, 0.14 to 0.78), even adjusted for comorbidity. Women were slightly more likely than men to receive any type of opioid (PR,1.07; 95% CI, 1.04 to 1.11). Morphine and diamorphine (PR range, 1.14 to 1.56) were more commonly prescribed for lung and colorectal cancers and fentanyl family for head and neck cancers (PR, 1.39; 95% CI, 1.19 to 1.62) compared with for prostate cancers.

Conclusion

Morphine and diamorphine remain the stronghold for treating cancer pain in the United Kingdom. Opioid prescription rates are increasing over time. Prescription rates are lower for older people for all opioids, suggesting that this group needs attention.

Opioid genetics: the key to personalized pain control?

There are now several strong opioids available to choose from for the relief of moderate to severe pain. On a population level, there is no difference in terms of analgesic efficacy or adverse reactions between these drugs; however, on an individual level there is marked variation in response to a given opioid. The genetic influences to this variation are complex, and although current research has shown some promising results, these have not been replicated across larger studies and as such the ultimate aim of personalized prescribing remains elusive. If personalized prescribing could be achieved this would have a major impact at an individual level to facilitate safe, effective and rapid symptom control. This review presents some of the recent positive advances in opioid pharmacogenetic studies, focusing on associations between candidate genes and the three main elements of opioid response: analgesic, upper gastrointestinal and central adverse reactions.

[Cancer pain in palliative medicine]

During the course of cancer progression up to 90% of the patients suffer from pain of nociceptive, neuropathic or mixed nociceptive/neuropathic origin. Psychological, social or existential factors may additionally affect the intensity of pain (concept of "total pain"). The WHO "analgesic ladder" provides a large variety of effective drugs that can be used according to the specific pain type. Parenteral or peridural opioid therapy as well as neurodestructive methods can effectively support the analgesic treatment in selected cases.

Opioid genetics in the context of opioid switching

PURPOSE OF REVIEW

On a population level, there is no difference in terms of efficacy or side-effects between any of the strong opioids. On an individual level, however, there is marked variation in response to opioids. This review presents some of the recent advances in opioid pharmacogenetic studies.

RECENT FINDINGS

A growing number of genes have been studied in a number of different patient populations. Most data have come from candidate-gene studies. There have been two genome-wide association studies in pain and opioid response. The clinical and genetic complexity of response to opioids has limited the clinical applicability of the genetic results. Currently, interindividual variation in opioid response is managed clinically through a process known as opioid switching. The evidence supporting the efficacy of opioid switching is poor, mainly because randomized controlled trials in this area are lacking.

SUMMARY

Adequately powered studies to allow identification of genetic variants with small effect size and exploration of gene-gene interaction are needed. Integration of genetic analysis in clinical studies with carefully defined outcome measures will increase the likelihood of identifying clinical and genetic factors which can be used to predict opioid response.

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.