A systematic review of the use of opioid medication for those with moderate to severe cancer pain and renal impairment: a European Palliative Care Research Collaborative opioid guidelines project

Inappropriate Prescription and Renal Function Among Older Patients with Cognitive Impairment

BACKGROUND

Older people are more sensitive to drugs and adverse drug reactions than younger people because of age-related physiological changes such as impaired renal function. As people with dementia are particularly vulnerable to the effects of drugs, it is especially important to evaluate the dosages of renally cleared medications in this group.

OBJECTIVE

The aim of this study was to estimate the prevalence of impaired renal function and inappropriate prescriptions on the basis of renal function among older patients with dementia or cognitive impairment.

METHODS

The medical records of 428 patients aged ≥65 years who were admitted to two hospitals in northern Sweden were reviewed and renally cleared medications were identified. The Cockcroft-Gault equation was used to evaluate renal function. Doses were evaluated according to the Geriatric Dosage Handbook.

RESULTS

Renal function was impaired (estimated glomerular filtration rate <60 ml/min) in 65.4 % of the study population. Impaired renal function was associated with increasing age. Among 547 prescriptions identified as renally cleared medications, 9.1 % were inappropriate based on the patient's renal function; 13.5 % of the 326 patients prescribed renally cleared medications had inappropriate prescriptions. Inappropriate prescriptions were more common among patients living in nursing homes.

CONCLUSIONS

Impaired renal function is common and inappropriate prescription is prevalent among old people with cognitive impairment in northern Sweden. Continuous consideration of renal function is important when prescribing medications to this group.

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.

Dialyzability of Oxycodone and Its Metabolites in Chronic Noncancer Pain Patients with End-Stage Renal Disease

OBJECTIVES

Opioids are the preferred analgesic drugs to treat severe chronic pain conditions among dialysis patients; however, knowledge about their dialyzability features is limited. Oxycodone is increasingly used for the treatment of chronic pain conditions as oral controlled release (CR) tablets; however, evidence about this drug and its metabolites' dialyzability is lacking.

METHODS

We assessed, during 4-hour dialysis sessions, the effect of standard hemodialysis (HD) and online hemodiafiltration (HDF) methods on the plasma concentration of oxycodone and its metabolites in n = 20 chronic pain patients with end-stage renal disease who were stably treated with oral CR oxycodone. Chromatographic techniques were used to evaluate the studied compounds' plasma concentrations at three different time points during dialysis.

RESULTS

Mean plasma concentrations of oxycodone and noroxycodone in the sample showed an overall reduction trend over time, but it was less enhanced for noroxycodone. Mean reduction in oxycodone and noroxycodone arterial concentrations was significant and higher with HDF (54% and 27%, respectively) than with HD (22% and 17%, respectively). Analysis of the regression of these compounds' clearance on their increasing arterial concentration showed a more stable and linear clearance prediction with HDF (roughly 85 mL/min); with HD, for increasing arterial concentration, clearance of oxycodone decreased while noroxycodone clearance increased.

DISCUSSION

While no oxymorphone or noroxymorphone metabolites were detected, limited dialyzability of oxycodone and noroxycodone was documented along with insignificant postdialysis pain increment. This evidence will contribute toward considerations as to the safety of the use of oxycodone in dialysis patients in the future.

Clinical Pharmacology Studies in Critically Ill Children

Developmental and physiological changes in children contribute to variation in drug disposition with age. Additionally, critically ill children suffer from various life-threatening conditions that can lead to pathophysiological alterations that further affect pharmacokinetics (PK). Some factors that can alter PK in this patient population include variability in tissue distribution caused by protein binding changes and fluid shifts, altered drug elimination due to organ dysfunction, and use of medical interventions that can affect drug disposition (e.g., extracorporeal membrane oxygenation and continuous renal replacement therapy). Performing clinical studies in critically ill children is challenging because there is large inter-subject variability in the severity and time course of organ dysfunction; some critical illnesses are rare, which can affect subject enrollment; and critically ill children usually have multiple organ failure, necessitating careful selection of a study design. As a result, drug dosing in critically ill children is often based on extrapolations from adults or non-critically ill children. Dedicated clinical studies in critically ill children are urgently needed to identify optimal dosing of drugs in this vulnerable population. This review will summarize the effect of critical illness on pediatric PK, the challenges associated with performing studies in this vulnerable subpopulation, and the clinical PK studies performed to date for commonly used drugs.

The Role of Opioid Analgesics in Geriatric Pain Management

When possible, chronic noncancer pain (CNCP) in older adults should be managed by nonpharmacologic modalities in conjunction with nonopioid analgesics. If moderate-to-severe pain persists despite these approaches, however, nonparenteral opioids may be considered as adjunctive therapy. This article reviews the epidemiology of opioid use and their effectiveness for CNCP in older adults and summarizes important age-related changes in opioid pharmacokinetics and pharmacodynamics that increase the risks of adverse effects in the elderly. Finally, to assist clinicians with selecting appropriate therapy, the article concludes with an evidence-based approach to optimize opioid prescribing in older adults with CNCP.

The Application of Failure Modes and Effects Analysis Methodology to Intrathecal Drug Delivery for Pain Management

Objective

This study aimed to utilize failure modes and effects analysis (FMEA) to transform clinical insights into a risk mitigation plan for intrathecal (IT) drug delivery in pain management.

Methods

The FMEA methodology, which has been used for quality improvement, was adapted to assess risks (i.e., failure modes) associated with IT therapy. Ten experienced pain physicians scored 37 failure modes in the following categories: patient selection for therapy initiation (efficacy and safety concerns), patient safety during IT therapy, and product selection for IT therapy. Participants assigned severity, probability, and detection scores for each failure mode, from which a risk priority number (RPN) was calculated. Failure modes with the highest RPNs (i.e., most problematic) were discussed, and strategies were proposed to mitigate risks.

Results

Strategic discussions focused on 17 failure modes with the most severe outcomes, the highest probabilities of occurrence, and the most challenging detection. The topic of the highest‐ranked failure mode (RPN = 144) was manufactured monotherapy versus compounded combination products. Addressing failure modes associated with appropriate patient and product selection was predicted to be clinically important for the success of IT therapy.

Conclusions

The methodology of FMEA offers a systematic approach to prioritizing risks in a complex environment such as IT therapy. Unmet needs and information gaps are highlighted through the process. Risk mitigation and strategic planning to prevent and manage critical failure modes can contribute to therapeutic success.

Evidence for Neurotoxicity Due to Morphine or Hydromorphone Use in Renal Impairment: A Systematic Review

BACKGROUND

Opioids are the mainstay of pain control for patients with chronic pain. Often, opioids with reported active metabolites, such as morphine and hydromorphone, are thought to increase the risk of neurotoxicity in renal impairment.

OBJECTIVES

To identify and assess the quality of evidence for neurotoxic effects in patients with renal impairment receiving morphine or hydromorphone.

METHODS

Systematic searches were conducted of the following databases from inception to December 2015: MEDLINE, CINAHL, EMBASE, in addition to hand-searching relevant review articles' citations. Studies were included if they reported neurotoxic effects of either morphine or hydromorphone for chronic or malignant pain in patients with renal impairment. Review articles and case reports were excluded. Narrative review was undertaken. The Grading of Recommendations, Assessment, Development and Evaluation approach was used to assess study quality.

RESULTS

Six original articles, three prospective and three retrospective studies were identified and assessed. No relevant randomized clinical trials were identified.

CONCLUSIONS

Although morphine and hydromorphone use may be associated with neurotoxic effects in patients with renal impairment, current evidence consists of very low-quality studies with conflicting findings. Clinicians may consider using either morphine or hydromorphone in mild-to-moderate renal impairment, while closely monitoring for neurotoxic effects, particularly when used in high doses and for extended duration.

Musculoskeletal pain in patients with chronic kidney disease

INTRODUCTION

Chronic musculoskeletal pain (CMP) is a very common symptom in patients with chronic kidney disease (CKD), and is associated with a significant deterioration in quality of life.

AIMS

To determine the prevalence and clinical characteristics associated with CMP in patients with advanced CKD not on dialysis, and to analyse their relation with other uraemic symptoms and their prognosis significance.

MATERIAL AND METHODS

Cross-sectional study to analyse the uraemic symptoms of an unselected cohort of patients with CKD stage 4-5 pre-dialysis. In order to characterise patients with CMP, demographic and anthropometric data were collected, as well as data on comorbidities and kidney function. In addition, inflammatory parameters, uric parameters, bone mineral metabolism including 25-hydroxycholecalciferol (25-OHCC), creatine kinase and drugs of potential interest including allopurinol, statins and erythropoiesis-stimulating agents were recorded.

RESULTS

The study group consisted of 1169 patients (mean age 65±15 years, 54% male). A total of 38% of patients complained of CMP, and this symptom was more prevalent in women than in men (49 vs. 28%; P<.0001). Muscle weakness, pruritus, muscle cramps, ecchymosis, insomnia, oedema and dyspnoea were the most common symptoms associated with CMP. There were no significant associations between serum levels of creatine kinase, 25-OHCC, treatment with allopurinol, statins or erythropoiesis-stimulating agents and CMP. The female gender, elderly age, obesity, comorbidity (mainly diabetes, heart failure or COPD), and elevated levels of inflammatory markers (C-reactive protein and non-neutrophilic leukocytes) were the best determinants of CMP. While patients with CMP showed a worse survival rate, a multivariate analysis adjusted for demographic data ruled out the independent association of CMP with mortality.

CONCLUSIONS

CMP is highly prevalent in patients with advanced CKD and is associated with other common symptoms of chronic uraemia. As with the general population, elderly age, the female gender, obesity and some comorbid conditions are the best determinants of CMP. Increased inflammatory markers commonly observed in patients with CMP may have a relevant role in its pathogenesis.

The role of drugs in bone pain

Painful symptomatology in the skeletal system can be found in various pathological conditions and can be either localised or diffused. Bone tenderness is common in those who are of an elderly age.

TREATMENT STRATEGY

Patients should be informed of the possible causes of their pain and the different therapies that could alleviate it; furthermore they should be encouraged to have an active role in their therapy. It is necessary to prevent the onset of the pain (by the clock) by considering the biological half-life, the bioavailability and the duration of action of the therapy. According to the World Health Organization (WHO), pain treatment is based on a three-step ladder.

ADJUVANT THERAPIES

Adjuvant therapies are often associated with the drugs in the WHO three step ladder. This heterogeneous group of non-analgesic drugs is used in the treatment of bone pain by bettering the analgesia or reducing the side effects brought on by analgesics.

CONCLUSION

In the daily struggle that doctors face to treat their patients, pain management should not be disregarded. Among the various types of pain, bone pain, must not be underestimated but be fought against by using all means available. Patients need to be treated depending on the severity of their pain, NSAIDs should be the preferred choice of treatment for acute pain but not for that of chronic pain. In the case of chronic pain opioids should be used in their most recent fomulations as they can guarantee fewer side effects. Patients should also be prescribed adjuvant drugs as well as being given psychological support in order to ensure successful treatment.

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

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

Future Directions in Pain Management: Integrating Anatomically Selective Delivery Techniques With Novel Molecularly Selective Agents

Treatment for chronic, locoregional pain ranks among the most prevalent unmet medical needs. The failure of systemic analgesic drugs, such as opioids, is often due to their off-target toxicity, development of tolerance, and abuse potential. Interventional pain procedures provide target specificity but lack pharmacologically selective agents with long-term efficacy. Gene therapy vectors are a new tool for the development of molecularly selective pain therapies, which have already been proved to provide durable analgesia in preclinical models. Taken together, advances in image-guided delivery and gene therapy may lead to a new class of dual selective analgesic treatments integrating the molecular selectivity of analgesic genes with the anatomic selectivity of interventional delivery techniques.

[Good clinical practice guide for opioids in pain management: the three Ts - titration (trial), tweaking (tailoring), transition (tapering)]

BACKGROUND AND OBJECTIVES

Achieving good clinical practice in the use of opioids as part of a comprehensive pain management regimen can face significant challenges. Despite guidelines from governmental and pain society/organization sources, there are still significant hurdles. A review of some basic tenets of opioid analgesia based on current published knowledge and experiences about this important healthcare imperative is warranted.

CONTENT

Consistent with guidelines, the literature supports using the lowest total opioid dose that provides adequate pain control with the fewest adverse effects. Titration (or trial) during opioid initiation is a way of starting low and going slow (and assessing the appropriateness of a specific opioid and formulation). Recognizing that multiple factors contribute to an individual's personal experience of pain, the physical, psychological, social, cultural, spiritual, pharmacogenomic, and behavioral factors of the individual patient should be taken into account (tweaking, or tailoring). Finally, for those patients for whom transition (tapering) from opioid is desired, doing so too rapidly can have negative consequences and minimization of problems during this step can be achieved by proper tapering.

CONCLUSION

We conclude that a simultaneously aggressive, yet conservative, approach is advocated in the literature in which opioid therapy is divided into three key steps (the 3 T's): titration (or trial), tweaking (or tailoring), and transition (or tapering). Establishment of the 3 T's along with the application of other appropriate good medical practice and clinical experience/judgment, including non-pharmacologic approaches, can assist healthcare providers in the effort to achieve optimal management of pain.

Fentanyl Enhances Hepatotoxicity of Paclitaxel via Inhibition of CYP3A4 and ABCB1 Transport Activity in Mice

Fentanyl, a potent opioid analgesic that is used to treat cancer pain, is commonly administered with paclitaxel in advanced tumors. However, the effect of fentanyl on the hepatotoxicity of paclitaxel and its potential mechanism of action is not well studied. The purpose of this study was to investigate the effect of fentanyl on the hepatotoxicity of paclitaxel and its potential mechanisms of action. Pharmacokinetic parameters of paclitaxel were tested using reversed phase high-performance liquid chromatography (RP-HPLC). Aspartate transaminase (AST), alanine aminotransferase (ALT), and mouse liver histopathology were examined. Moreover, the cytotoxicity of anti-carcinogens was examined using 1-(4, 5-dimethylthiazol-2-yl)-3,5-diphenylformazan (MTT), and the intracellular accumulation of doxorubicin and rhodamine 123 was detected by flow cytometry. Furthermore, the expression of ABCB1 and the activity of ABCB1 ATPase and CYP3A4 were also examined. In this study, the co-administration of fentanyl and paclitaxel prolonged the half-life (t_1/2) of paclitaxel from 1.455 hours to 2.344 hours and decreased the clearance (CL) from 10.997 ml/h to 7.014 ml/h in mice. Fentanyl significantly increased the levels of ALT in mice to 88.2 U/L, which is more than 2-fold higher than the level detected in the control group, and it increased the histological damage in mouse livers. Furthermore, fentanyl enhanced the cytotoxicity of anti-carcinogens that are ABCB1 substrates and increased the accumulation of doxorubicin and rhodamine 123. Additionally, fentanyl stimulated ABCB1 ATPase activity and inhibited CYP3A4 activity in the liver microsomes of mice. Our study indicates that the obvious hepatotoxicity during this co-administration was due to the inhibition of CYP3A4 activity and ABCB1 transport activity. These findings suggested that the accumulation-induced hepatotoxicity of paclitaxel when it is combined with fentanyl should be avoided.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

The Risk of Opioid Intoxications or Related Events and the Effect of Alcohol-Related Disorders: A Retrospective Cohort Study in German Patients Treated with High-Potency Opioid Analgesics

INTRODUCTION

Intoxications involving prescription opioids are a major public health problem in many countries. When taken with opioids, alcohol can enhance the effects of opioids, particularly in the central nervous system. However, data quantifying the impact of alcohol involvement in opioid-related intoxications are limited.

METHODS

Using claims data from the German Pharmacoepidemiological Research Database (GePaRD), we conducted a retrospective cohort study based on users of high-potency opioid (HPO) analgesics during the years 2005-2009. HPO use was classified as extended-release, immediate-release or both. We calculated incidence rates (IRs) for opioid intoxications or related events as well as adjusted IR ratios (aIRR) comparing HPO-treated patients with alcohol-related disorders (ARDs) to those without ARDs overall and within each HPO category.

RESULTS

During the study period, 308,268 HPO users were identified with an overall IR of 340.4 per 100,000 person-years [95 % confidence interval (CI) 325.5-355.7]. The risk was highest when patients received concomitant treatment with extended- and immediate-release HPOs (IR 1093.8; 95 % CI 904.6-1310.9). ARDs increased the risk during HPO use by a factor of 1.7 and the highest aIRR was seen when comparing patients simultaneously exposed to extended- and immediate-release HPOs with ARDs to those without ARD also after excluding patients with potential improper/non-medical HPO use.

CONCLUSIONS

Physicians should be aware of these elevated risks in HPO patients with ARDs. Active patient education by healthcare providers regarding the risk of opioid intoxications or related events due to alcohol in conjunction with HPOs is warranted.

Before you call renal: Acute kidney injury for hospitalists

Acute kidney injury is a clinical problem of growing incidence in hospitalized patients. It increases the risk of poor outcomes, length of stay and the cost of hospitalization. Successful management of acute kidney injury requires early recognition and diagnosis through detailed medical history, careful physical exam, judicious use of laboratory and radiologic tests and timely renal consultation. Subsequent management is tailored to the likely mechanism of injury with emphasis on limiting both further injury and systemic consequences. A common sense approach to acute kidney injury is essential for hospitalists aiming to limit further injury, prevent acute complications and lessen the risk of chronic morbidity.

Prevalence of Renal Impairment in Palliative Care Inpatients: A Retrospective Analysis

BACKGROUND AND OBJECTIVE

Multiple drugs used in palliative care, including most opioids or their active metabolites may accumulate in patients with abnormal renal function, leading to serious adverse effects. The incidence and severity of renal impairment in palliative care inpatients has not been evaluated. The aim of the study was to investigate the incidence and severity of renal impairment in palliative care inpatients.

METHODS

A retrospective analysis of medical records of patients admitted to the palliative care ward was performed. Estimated glomerular filtration rate (eGFR) was derived using the Cockcroft-Gault (C-G) and abbreviated Modification of Diet in Renal Disease (aMDRD) equations.

RESULTS

Serum creatinine levels (SCr) were determined in 332 subjects aged 66.4±11.80 years (194 women; mean body mass index [BMI] 22.7±5.21 kg/m(2)). Mean SCr was 107.7±112.31 μmol/L. Elevated SCr (>115 μmol/L) was found in 20.2% of patients. Mean eGFR calculated with C-G and aMDRD equations was 66.6±38.52 mL/min and 78.7±43.55 mL/min/1.73 m(2), respectively. Between 35.2% and 51.8% of patients had eGFR <60 mL/min/1.73 m(2) (depending on the equation used). More than 10% of patients had eGFR <30 mL/min/1.73 m(2). In patients with normal SCr, between 18.9% and 39.2% had eGFR <60 mL/min/1.73 m(2).

CONCLUSION

Renal impairment is common in palliative care inpatients, including considerable number of subjects with moderately to severely reduced kidney function.

[Update on oncological pain in the elderly]

Pain is a prevalent symptom in cancer geriatric patients, appearing in up to 90% of patients with terminal cancer. This requires a multidimensional approach, as there is a high percentage of inappropriate assessments and treatments. Unrecognized or poorly treated pain in the geriatric population, especially in cancer patients, leads to the development of disabling symptoms such as depression, anxiety, isolation, sleep disturbances, and appetite, and very especially, loss of functional capacity and quality of life. In this review an analysis is made on the most relevant studies on the diagnosis and management of cancer pain in the geriatric population.

Good clinical practice guide for opioids in pain management: the three Ts - titration (trial), tweaking (tailoring), transition (tapering)

BACKGROUND AND OBJECTIVES

Achieving good clinical practice in the use of opioids as part of a comprehensive pain management regimen can face significant challenges. Despite guidelines from governmental and pain society/organization sources, there are still significant hurdles. A review of some basic tenets of opioid analgesia based on current published knowledge and experiences about this important healthcare imperative is warranted.

CONTENT

Consistent with guidelines, the literature supports using the lowest total opioid dose that provides adequate pain control with the fewest adverse effects. Titration (or trial) during opioid initiation is a way of starting low and going slow (and assessing the appropriateness of a specific opioid and formulation). Recognizing that multiple factors contribute to an individual's personal experience of pain, the physical, psychological, social, cultural, spiritual, pharmacogenomic, and behavioral factors of the individual patient should be taken into account (tweaking, or tailoring). Finally, for those patients for whom transition (tapering) from opioid is desired, doing so too rapidly can have negative consequences and minimization of problems during this step can be achieved by proper tapering.

CONCLUSION

We conclude that a simultaneously aggressive, yet conservative, approach is advocated in the literature in which opioid therapy is divided into three key steps (the 3 T's): titration (or trial), tweaking (or tailoring), and transition (or tapering). Establishment of the 3 T's along with the application of other appropriate good medical practice and clinical experience/judgment, including non-pharmacologic approaches, can assist healthcare providers in the effort to achieve optimal management of pain.

Narrative reviews

Although qualitative researches (QR) are invaluable in understanding complex healthcare situations, the quantitative systematic reviews could not treat them. To improve quality of healthcare services, results of QR should be considered in healthcare decision-making processes. Several methods and theories for synthesizing evidences of QR have been developed. In order to activate the narrative reviews and mixed methods reviews in Korean healthcare academies, I arranged the related nomenclatures and suggested some issues to conduct them.

Preclinical toxicity evaluation of AAV for pain: evidence from human AAV studies and from the pharmacology of analgesic drugs

Gene therapy with adeno-associated virus (AAV) has advanced in the last few years from promising results in animal models to >100 clinical trials (reported or under way). While vector availability was a substantial hurdle a decade ago, innovative new production methods now routinely match the scale of AAV doses required for clinical testing. These advances may become relevant to translational research in the chronic pain field. AAV for pain targeting the peripheral nervous system was proven to be efficacious in rodent models several years ago, but has not yet been tested in humans. The present review addresses the steps needed for translation of AAV for pain from the bench to the bedside focusing on pre-clinical toxicology. We break the potential toxicities into three conceptual categories of risk: First, risks related to the delivery procedure used to administer the vector. Second, risks related to AAV biology, i.e., effects of the vector itself that may occur independently of the transgene. Third, risks related to the effects of the therapeutic transgene. To identify potential toxicities, we consulted the existing evidence from AAV gene therapy for other nervous system disorders (animal toxicology and human studies) and from the clinical pharmacology of conventional analgesic drugs. Thereby, we identified required preclinical studies and charted a hypothetical path towards a future phase I/II clinical trial in the oncology-palliative care setting.

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.

Neuropathic cancer pain: What we are dealing with? How to manage it?

Cancer pain is a serious health problem, and imposes a great burden on the lives of patients and their families. Pain can be associated with delay in treatment, denial of treatment, or failure of treatment. If the pain is not treated properly it may impair the quality of life. Neuropathic cancer pain (NCP) is one of the most complex phenomena among cancer pain syndromes. NCP may result from direct damage to nerves due to acute diagnostic/therapeutic interventions. Chronic NCP is the result of treatment complications or malignancy itself. Although the reason for pain is different in NCP and noncancer neuropathic pain, the pathophysiologic mechanisms are similar. Data regarding neuropathic pain are primarily obtained from neuropathic pain studies. Evidence pertaining to NCP is limited. NCP due to chemotherapeutic toxicity is a major problem for physicians. In the past two decades, there have been efforts to standardize NCP treatment in order to provide better medical service. Opioids are the mainstay of cancer pain treatment; however, a new group of therapeutics called coanalgesic drugs has been introduced to pain treatment. These coanalgesics include gabapentinoids (gabapentin, pregabalin), antidepressants (tricyclic antidepressants, duloxetine, and venlafaxine), corticosteroids, bisphosphonates, N-methyl-D-aspartate antagonists, and cannabinoids. Pain can be encountered throughout every step of cancer treatment, and thus all practicing oncologists must be capable of assessing pain, know the possible underlying pathophysiology, and manage it appropriately. The purpose of this review is to discuss neuropathic pain and NCP in detail, the relevance of this topic, clinical features, possible pathology, and treatments of NCP.

Drug therapy optimization at the end of life

Older people reaching end-of-life status are particularly at risk of adverse effects of drug therapy. Polypharmacy, declining organ function, co-morbidity, malnutrition, cachexia and changes in body composition all sum up to increase the risk of many drug-related problems in individuals who receive end-of-life care. End of life is defined by a limited lifespan or advanced disability. Optimal prescribing for end-of-life patients with multimorbidity, especially in those dying from non-cancer conditions, remains mostly unexplored, despite the increasing recognition that the management goals for patients with chronic diseases should be redefined in the setting of reduced life expectancy. Most drugs used for symptom palliation in end-of-life care of older patients are used without solid evidence of their benefits and risks in this particularly frail population. Appropriate dosing or optimal administration routes are in most cases unknown. Avoiding or discontinuing drugs that aim to prolong life or prevent disability is usually common sense in end-of-life care, particularly when the time needed to obtain the expected benefits from the drug is longer than the life expectancy of a particular individual. However, discontinuation of drugs is not standard practice, and prescriptions are usually not adapted to changes in the course of advanced diseases. Careful consideration of remaining life expectancy, time until benefit, goals of care and treatment targets for each drug seems to be a sensible framework for decision making. In this article, some key issues on drug therapy at the end of life are discussed, including principles of decision making about drug treatments, specific aspects of drug therapy in some common geriatric conditions (heart failure and dementia), treatment of acute concurrent problems such as infections, evidence to guide the choice and use of drugs to treat symptoms in palliative care, and avoidance of some long-term therapies in end-of-life care. Solid evidence is lacking to guide optimal pharmacotherapy in most end-of-life settings, especially in non-cancer diseases and very old patients. Some open questions for research are suggested.

Analgesics in patients with hepatic impairment: pharmacology and clinical implications

The physiological changes that accompany hepatic impairment alter drug disposition. Porto-systemic shunting might decrease the first-pass metabolism of a drug and lead to increased oral bioavailability of highly extracted drugs. Distribution can also be altered as a result of impaired production of drug-binding proteins or changes in body composition. Furthermore, the activity and capacity of hepatic drug metabolizing enzymes might be affected to various degrees in patients with chronic liver disease. These changes would result in increased concentrations and reduced plasma clearance of drugs, which is often difficult to predict. The pharmacology of analgesics is also altered in liver disease. Pain management in hepatically impaired patients is challenging owing to a lack of evidence-based guidelines for the use of analgesics in this population. Complications such as bleeding due to antiplatelet activity, gastrointestinal irritation, and renal failure are more likely to occur with nonsteroidal anti-inflammatory drugs in patients with severe hepatic impairment. Thus, this analgesic class should be avoided in this population. The pharmacokinetic parameters of paracetamol (acetaminophen) are altered in patients with severe liver disease, but the short-term use of this drug at reduced doses (2 grams daily) appears to be safe in patients with non-alcoholic liver disease. The disposition of a large number of opioid drugs is affected in the presence of hepatic impairment. Certain opioids such as codeine or tramadol, for instance, rely on hepatic biotransformation to active metabolites. A possible reduction of their analgesic effect would be the expected pharmacodynamic consequence of hepatic impairment. Some opioids, such as pethidine (meperidine), have toxic metabolites. The slower elimination of these metabolites can result in an increased risk of toxicity in patients with liver disease, and these drugs should be avoided in this population. The drug clearance of a number of opioids, such as morphine, oxycodone, tramadol and alfentanil, might be decreased in moderate or severe hepatic impairment. For the highly excreted morphine, hydromorphone and oxycodone, an important increase in bioavailability occurs after oral administration in patients with hepatic impairment. Lower doses and/or longer administration intervals should be used when these opioids are administered to patients with liver disease to avoid the risk of accumulation and the potential increase of adverse effects. Finally, the pharmacokinetics of phenylpiperidine opioids such as fentanyl, sufentanil and remifentanil appear to be unaffected in hepatic disease. All opioid drugs can precipitate or aggravate hepatic encephalopathy in patients with severe liver disease, thus requiring cautious use and careful monitoring.

[Accidental levomethadone intoxication in a palliative patient]

Levomethadone is a strong opioid which is used rarely in the treatment of special pain syndromes in Germany. A main field for the usage of Levomethadone, which has be applied as a oral fluid, is the opioid replacement therapy of heroin-addicts. Due to the long plasma half life and its high inter-individual variability, the application implies a risk of cumulation leading to an overdosage. It is not recommended to use a fixed equianalgesic formula for the dosage conversion from other opioids. The conversion starts with a low start dose, an individual titration follows. In this case-report, the difficulty of cumulation, inaccurate drug dispensary and the characteristic of dosage calculation of levomethadone is discussed.

The ethics of end-of-life care for patients with ESRD

Patients with ESRD have extensive and unique palliative care needs, often for years before death. The vast majority of patients, however, dies in acute care facilities without accessing palliative care services. High mortality rates along with a substantial burden of physical, psychosocial, and spiritual symptoms and an increasing prevalence of decisions to withhold and stop dialysis all highlight the importance of integrating palliative care into the comprehensive management of ESRD patients. The focus of renal care would then extend to controlling symptoms, communicating prognosis, establishing goals of care, and determining end-of-life care preferences. Regretfully, training in palliative care for nephrology trainees is inadequate. This article will provide a conceptual framework for renal palliative care and describe opportunities for enhancing palliative care for ESRD patients, including improved chronic pain management and advance care planning and a new model for delivering high-quality palliative care that includes appropriate consultation with specialist palliative care.

The challenge of international consensus: defining an opioid essential prescription package

PURPOSE OF REVIEW

To describe a new strategy that aimed to facilitate opioid prescription for better pain management.

RECENT FINDINGS

The International Association of Hospice and Palliative Care recently develop a single prescription package (drugs and dosing) with one opioid, one laxative, and one antiemetic for the initiation of opioid treatment in cancer pain and other life-threatening conditions, with the intention to facilitate opioid use, improve patient compliance, and reduce adverse effects.

SUMMARY

The opioid essential prescription package was an international project designed to ensure that opioids are better tolerated by reducing the adverse effects of opioids, which could lead to more sustained improvements in pain management.

Cancer Pain Management and Bone Metastases: An Update for the Clinician

Breast cancer patients with bone metastases often suffer from cancer pain. In general, cancer pain treatment is far from being optimal for many patients. To date, morphine remains the gold standard as first-line therapy, but other pure μ agonists such as hydromorphone, fentanyl, or oxycodone can be considered. Transdermal opioids are an important option if the oral route is impossible. Due to its complex pharmacology, methadone should be restricted to patients with difficult pain syndromes. The availability of a fixed combination of oxycodone and naloxone is a promising development for the reduction of opioid induced constipation. Especially bone metastases often result in breakthrough pain episodes. Thus, the provision of an on-demand opioid (e.g., immediate-release morphine or rapid-onset fentanyl) in addition to the baseline (regular) opioid therapy (e.g., sustained-release morphine tablets) is mandatory. Recently, rapid onset fentanyls (buccal or nasal) have been strongly recommended for breakthrough cancer pain due to their fast onset and their shorter duration of action. If available, metamizole is an alternative non-steroid-anti-inflammatory-drug. The indication for bisphosphonates should always be checked early in the disease. In advanced cancer stages, glucocorticoids are an important treatment option. If bone metastases lead to neuropathic pain, coanalgetics (e.g., pregabalin) should be initiated. In localized bone pain, radiotherapy is the gold standard for pain reduction in addition to pharmacologic pain management. In diffuse bone pain radionuclids (such as samarium) can be beneficial. Invasive measures (e.g., neuroaxial blockage) are rarely necessary but are an important option if patients with cancer pain syndromes are refractory to pharmacologic management and radiotherapy as described above. Clinical guidelines agree that cancer pain management in incurable cancer is best provided as part of a multiprofessional palliative care approach and all other domains of suffering (psychosocial, spiritual, and existential) need to be carefully addressed («total pain»).

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.