Treatment of pain in patients with renal insufficiency: The World Health Organization three-step ladder adapted

How to manage the dose of drugs in cancer patients with acute kidney injury, practical recommendations

Acute kidney injury (AKI) and chronic kidney disease (CKD) are common in cancer patients. AKI is a brutal and reversible condition which makes it hard to manage from a pharmacological perspective when patients are receiving anticancer regimens and other supportive care drugs, such as anticoagulants, analgesics and other drugs. In contrast to CKD, which is a slow progressive disease, there is no clear guidance on how to manage and/or modify the dosage of drugs during AKI. Indeed, the slow progression of CKD allows physicians to monitor the renal function by using the glomerular filtration rate. Consequently, publications have explored the management of drugs in cancer patients with CKD, which is currently not the same for AKI. There are no recommendations or suggestions on how to manage drug doses in case of AKI in cancer patients. This commentary explores the different options to manage drugs (anticancer drugs, anticoagulants, and other supportive care drugs) during AKI in cancer patients.

Therapeutics in rheumatology and the kidney

The field of rheumatology has advanced significantly in recent years to provide rheumatologists with an extensive array of medications to combat rheumatic joint conditions. In contrast to an older era, when NSAIDs and other nephrotoxic agents were the mainstay of treatment, modern DMARDs vary considerably in their nephrotoxic potential and their use is not always precluded in populations with pre-existing chronic kidney disease (CKD). This review will explore in detail the safety and efficacy profiles of medications used to treat rheumatologic disease, specifically in the setting of CKD. Specifically, we discuss both traditional agents used, i.e. NSAIDs, CSs and conventional synthetic DMARDs, as well as novel biologic DMARDs and targeted synthetic DMARDs. Anti-gout prescribing in CKD is also reviewed. We aim to provide practical guidance to rheumatologists, nephrologists and general physicians when prescribing these medications in the setting of CKD.

Choosing the right chronic medication for hemodialysis patients. A short ABC for the dialysis nephrologist

BACKGROUND

Adapting drug treatments for patients on hemodialysis with multiple chronic pathologies is a complex affair. When prescribing a medication, the risk-benefit analysis usually focuses primarily on the indication of the drug class prescribed. However, the pharmacokinetics of the chosen drug should also be taken into account. The purpose of our review was to identify the drugs to be favored in each therapeutic class, according to their safety and pharmacokinetic profiles, for the most common chronic diseases in patients on chronic hemodialysis.

METHODS

We conducted a narrative review of the literature using Medline and Web of Science databases, targeting studies on the most commonly-prescribed drugs for non-communicable diseases in patients on chronic hemodialysis.

RESULTS

The search identified 1224 articles, 95 of which were further analyzed. The main classes of drugs included concern the cardiovascular system (anti-hypertensives, anti-arrhythmics, anti-thrombotics, hypocholesterolemics), the endocrine and metabolic pathways (anti-diabetics, gastric anti-secretory, anticoagulant, thyroid hormones, anti-gout) and psychiatric and neurological disorders (antidepressants, anxiolytics, antipsychotics and anti-epileptics).

CONCLUSION

We report on the most often prescribed drugs for chronic pathologies in patients on chronic hemodialysis. Most of them require adaptation, and in some cases one better alternative stands out among the drug class. More pharmacokinetic data are needed to define the pharmacokinetics in the various dialysis techniques.

Population-Based Analysis of Nonsteroidal Anti-inflammatory Drug Prescription in Subjects With Chronic Kidney Disease

Background

Pain is a prevalent symptom experienced by patients with chronic kidney disease (CKD) and appropriate management of pain is an important element of comprehensive care. Nonsteroidal anti-inflammatory drugs (NSAID) are known to be nephrotoxic in persons with CKD.

Objective

This study examined the pattern of NSAID prescribing practices in a population based-cohort of patients with CKD.

Design

Retrospective cohort study using linked population-based health care data.

Setting

Entire province of Alberta, Canada.

Participants

All adults in Alberta with eGFR defined CKD G3 or greater between 2009 and 2017 were included.

Measurements

CKD was defined using at least 2 outpatient serum creatinine (SCr) greater than 90 days apart; the date of second SCr measurement was used as index date. We determined the incidence of hyperkalemia using the peak serum potassium. Prescription drug information was obtained from the Pharmaceutical Information Network (PIN) database.

Methods

All patients were followed from the index date until March 31, 2019, with a minimum follow-up of 2 years. Prescription drug information and the follow-up laboratory testing of serum creatinine and serum potassium were obtained. Patients with kidney failure defined as eGFR < 15 mL/min per 1.73 m², receiving chronic dialysis, or prior kidney transplant at baseline were excluded.

Results

A total of 170 574 adults (mean age 76.3; 44% male) with CKD were identified and followed for a median of 7 years; 27% were dispensed at least 1 NSAID prescription. While there was a trend toward fewer prescriptions in patients with more advanced CKD (P < .001), 16% of those with CKD G4 were prescribed an NSAID. Primary care providers provided 79% of the prescriptions. Among NSAID users, 21% had a follow-up serum creatinine (SCr) within 30 days of the index prescription.

Limitations

Data collected were from clinical and administrative databases not created for research purposes. The study cohort is limited to subjects who sought medical care and had a serum creatinine measurement obtained. Measurement of NSAID use is limited to those who were dispensed a prescription, over-the-counter NSAIDs use is not captured.

Conclusions

Despite guidelines advocating cautious use of NSAIDs in patients with CKD, this study indicates that there is a discrepancy from best practice recommendations. Effective strategies to better support and educate prescribers, as well as patients, may help reduce inappropriate prescribing and adverse events.

Drug-Dosing Adjustment in Dogs and Cats with Chronic Kidney Disease

Chronic kidney disease is a common kidney disorder in adult and aged dogs and cats; the management of associated complications and comorbidities generally requires a life-long medical treatment to ensure a good quality of life of affected patients. However, indications and the literature on drug dosing in dogs and cats with chronic kidney disease are often lacking. The aim of this review is to revise the current literature on drug dosing in canine and feline patients with renal impairment, with a special focus on the most commonly used medications to manage chronic kidney disease and possible comorbidities.

Tapentadol Versus Tramadol: A Narrative and Comparative Review of Their Pharmacological, Efficacy and Safety Profiles in Adult Patients

We conducted a narrative review of the literature to compare the pharmacological, efficacy and safety profiles of tapentadol and tramadol, and to assess the clinical interest of tapentadol in adult patients. Tapentadol and tramadol share a mixed mechanism of action, including both mu-agonist and monoaminergic properties. Tapentadol is approximately two to three times more potent than tramadol and two to three times less potent than morphine. It has no identified analgesically active metabolite and is not significantly metabolised by cytochrome P450 enzymes, thus overcoming some limitations of tramadol, including the potential for pharmacokinetic drug-drug interactions and interindividual variability due to genetic polymorphisms of cytochrome P450 enzymes. The toxicity profiles of tramadol and tapentadol are similar; however tapentadol is likely to result in less exposure to serotoninergic adverse effects (nausea, vomiting, hypoglycaemia) but cause more opioid adverse effects (constipation, respiratory depression, abuse) than tramadol. The safety of tapentadol in real-world conditions remains poorly documented, particularly in at-risk patient subgroups and also in the ability to assess the risk associated with its residual serotonergic activity (serotonin syndrome, seizures). Because of an earlier market introduction, more real-world safety data are available for tramadol, including data from at-risk patient subgroups. The level of evidence on the efficacy of both tramadol and tapentadol for the treatment of chronic pain is globally low. The trials published to date show overall that tapentadol does not provide a clinically significant analgesic improvement compared to existing treatments, for which the safety profile is much better known. In conclusion, tapentadol is not a first-line opioid but represents an additional analgesic in the therapeutic choices, which some patients may benefit from after careful examination of their clinical situation, co-morbidities and co-medications.

Characterization of human sulfotransferases catalyzing the formation of p-cresol sulfate and identification of mefenamic acid as a potent metabolism inhibitor and potential therapeutic agent for detoxification

p-Cresol sulfate, the primary metabolite of p-cresol, is a uremic toxin that has been associated with toxicities and mortalities. The study objectives were to i) characterize the contributions of human sulfotransferases (SULT) catalyzing p-cresol sulfate formation using multiple recombinant SULT enzymes (including the polymorphic variant SULT1A1*2), pooled human liver cytosols, and pooled human kidney cytosols; and ii) determine the potencies and mechanisms of therapeutic inhibitors capable of attenuating the production of p-cresol sulfate. Human recombinant SULT1A1 was the primary enzyme responsible for the formation of p-cresol sulfate (K_m = 0.19 ± 0.02 μM [with atypical kinetic behavior at lower substrate concentrations; see text discussion], V_max = 789.5 ± 101.7 nmol/mg/min, K_si = 2458.0 ± 332.8 μM, mean ± standard deviation, n = 3), while SULT1A3, SULT1B1, SULT1E1, and SULT2A1 contributed negligible or minor roles at toxic p-cresol concentrations. Moreover, human recombinant SULT1A1*2 exhibited reduced enzyme activities (K_m = 81.5 ± 31.4 μM, V_max = 230.6 ± 17.7 nmol/mg/min, K_si = 986.0 ± 434.4 μM) compared to the wild type. The sulfonation of p-cresol was characterized by Michaelis-Menten kinetics in liver cytosols (K_m = 14.8 ± 3.4 μM, V_max = 1.5 ± 0.2 nmol/mg/min) and substrate inhibition in kidney cytosols (K_m = 0.29 ± 0.02 μM, V_max = 0.19 ± 0.05 nmol/mg/min, K_si = 911.7 ± 278.4 μM). Of the 14 investigated therapeutic inhibitors, mefenamic acid (K_i = 2.4 ± 0.1 nM [liver], K_i = 1.2 ± 0.3 nM [kidney]) was the most potent in reducing the formation of p-cresol sulfate, exhibiting noncompetitive inhibition in human liver cytosols and recombinant SULT1A1, and mixed inhibition in human kidney cytosols. Our novel findings indicated that SULT1A1 contributed an important role in p-cresol sulfonation (hence it can be considered a probe reaction) in liver and kidneys, and mefenamic acid may be utilized as a potential therapeutic agent to attenuate the generation of p-cresol sulfate as an approach to detoxification.

Pain Management Evaluation in Maintenance Hemodialysis Patients

CONTEXT

Pain is a common complaint in maintenance hemodialysis (MHD) patients, and it is often inadequately assessed and inappropriately treated.

OBJECTIVES

The study goal was to preliminarily evaluate pain management in MHD patients.

METHODS

The study was a cross-sectional study conducted in 2013-2015. A sample of 277 MHD patients who reported pain within the last 24 hours from five hospital hemodialysis units in Israel were interviewed and evaluated. Study tools included the Brief Pain Inventory, the Pain Management Index (PMI), demographic and clinical characteristics. Pharmacy computerized data were reviewed to identify the type of analgesics used.

RESULTS

Mean pain level was 7.2 ± 2.2 (median: 8). Pain level was mild in 17 (6.1%), moderate in 120 (43.3%) and severe in 140 (50.5%) of patients. Only 185 participants (66.8%) were treated with analgesics during the year prior to the interview. Of these, 99 (53.5%) received opioids. Using the PMI to preliminarily assess the appropriateness of the treatment, 214 (77.3%) of patients with pain in the last 24 hours were undertreated, and 52 patients (18.8%) were appropriately treated. In a multivariable analysis, factors associated with inappropriate treatment were severe pain intensity and a higher Functional Independent Measure (FIM). A lower FIM was associated with opioid use in a multivariable analysis.

CONCLUSIONS

According to the PMI, most dialysis patients were found to be inappropriately treated. About one third received opioids, but even among them, inappropriate treatment was common. Pain management in MHD patients needs to be improved.

Safe Use of Opioids in Chronic Kidney Disease and Hemodialysis Patients: Tips and Tricks for Non-Pain Specialists

In patients suffering from moderate-to-severe chronic kidney disease (CKD) or end-stage renal disease (ESRD), subjected to hemodialysis (HD), pain is very common, but often underestimated. Opioids are still the mainstay of severe chronic pain management; however, their prescription in CKD and HD patients is still significantly low and pain is often under-treated. Altered pharmacokinetics and the lack of clinical trials on the use of opioids in patients with renal impairment increase physicians' concerns in this specific population. This narrative review focused on the correct and safe use of opioids in patients with CKD and HD. Morphine and codeine are not recommended, because the accumulation of their metabolites may cause neurotoxic symptoms. Oxycodone and hydromorphone can be safely used, but adequate dosage adjustments are required in CKD. In dialyzed patients, these opioids should be considered as second-line agents and patients should be carefully monitored. According to different studies, buprenorphine and fentanyl could be considered first-line opioids in the management of pain in CKD; however, fentanyl is not appropriate in patients undergoing HD. Tapentadol does not need dosage adjustment in mild-to-moderate renal impairment conditions; however, no data are available on its use in ESRD. Opioid-related side effects may be exacerbated by common comorbidities in CKD patients. Opioid-induced constipation can be managed with peripherally-acting-μ-opioid-receptor-antagonists (PAMORA). Unlike the other PAMORA, naldemedine does not require any dose adjustment in CKD and HD patients. Accurate pain diagnosis, opioid titration and tailoring are mandatory to minimize the risks and to improve the outcome of the analgesic therapy.

The Role of Community Pharmacists in the Detection of Clinically Relevant Drug-Related Problems in Chronic Kidney Disease Patients

Community pharmacists (CPs) have traditionally had limited access to patients’ estimated glomerular filtration rate (eGFR) during the medication-dispensing process. The increasing access to shared electronic health records is making eGFR available, but the skills needed to detect and manage clinically relevant drug-related problems (DRPs) are poorly documented. The primary objective of this study was to investigate the role of CPs in the medication-dispensation process for elderly patients with renal impairment. A total of 70 CPs participated in this 6 month study. Community pharmacists asked all patients ≥65 years to bring their laboratory test values for the next medication-dispensing process. Drug-related problem detection rates were compared between CPs (prospective period) and expert pharmacists (retrospectively). The clinical relevance of each DRP was assessed by nephrologists and general practitioners using an appropriate tool. Community pharmacists recruited n = 442 patients with eGFR < 60 mL/min/1.73 m² and detected n = 99 DRPs, whereas expert pharmacists detected n = 184 DRPs. The most frequently detected DRPs were dosage problems and contraindications. According to assessment by clinicians, CPs and expert pharmacists identified 54.0% and 84.7% of clinically relevant DRPs, respectively. This study suggests a positive impact of the systematic availability of eGFR to CPs on the detection of several DRPs with clinical relevance.

Indian Society for Study of Pain, Cancer Pain Special Interest Group Guidelines on Pharmacological Management of Cancer Pain (Part III)

The Indian Society for Study of Pain (ISSP), Cancer Pain Special Interest Group, guidelines on pharmacological management of cancer pain in adults provide a structured, step-wise approach which will help to improve the management of cancer pain and to provide patients with a minimally acceptable quality of life. The guidelines have been developed based on the available literature and evidence, to suit the needs, patient population, and situations in India. A questionnaire based on the key elements of each sub draft addressing certain inconclusive areas where evidence was lacking, was made available on the ISSP website and circulated by E-mail to all the ISSP and Indian Association of Palliative Care members. Antidepressants and/or anticonvulsants should be used to treat neuropathic cancer pain and the dose should be titrated according to the clinical response and side effects. External beam radiotherapy should be offered to all patients with painful metastatic bone pain. There is evidence on the use of ketamine in cancer neuropathic pain, but with no beneficial effect, thus it is not recommended.

Nonsteroidal anti-inflammatory drug use and risk of acute kidney injury and hyperkalemia in older adults: a population-based study

BACKGROUND

Clinical guidelines caution against nonsteroidal anti-inflammatory drug (NSAID) use in older adults. The study objective was to quantify the 30-day risk of acute kidney injury (AKI) and hyperkalemia in older adults after NSAID initiation and to develop a model to predict these outcomes.

METHODS

We conducted a population-based retrospective cohort study in Ontario, Canada from 2007 to 2015 of patients ≥66 years. We matched 46 107 new NSAID users with 46 107 nonusers with similar baseline health. The primary outcome was 30-day risk of AKI and secondary outcomes were hyperkalemia and all-cause mortality.

RESULTS

NSAID use versus nonuse was associated with a higher 30-day risk of AKI {380 [0.82%] versus 272 [0.59%]; odds ratio (OR) 1.41 [95% confidence interval (CI) 1.20-1.65]} and hyperkalemia [184 (0.40%) versus 123 (0.27%); OR 1.50 (95% CI 1.20-1.89); risk difference 0.23% (95% CI 0.13-0.34)]. There was no association between NSAID use and all-cause mortality. A prediction model incorporated six predictors of AKI or hyperkalemia: older age, male gender, lower baseline estimated glomerular filtration rate, higher baseline serum potassium, angiotensin-converting enzyme inhibitor or angiotensin receptor blocker use or diuretic use. This model had moderate discrimination [C-statistic 0.72 (95% CI 0.70-0.74)] and good calibration.

CONCLUSIONS

In older adults, new NSAID use compared with nonuse was associated with a higher 30-day risk of AKI and hyperkalemia but not all-cause mortality. Prescription NSAID use among many older adults may be safe, but providers should use caution and assess individual risk.

Opioid Analgesics and Adverse Outcomes among Hemodialysis Patients

BACKGROUND AND OBJECTIVES

Patients on hemodialysis frequently experience pain and may be particularly vulnerable to opioid-related complications. However, data evaluating the risks of opioid use in patients on hemodialysis are limited.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Using the US Renal Data System, we conducted a cohort study evaluating the association between opioid use (modeled as a time-varying exposure and expressed in standardized oral morphine equivalents) and time to first emergency room visit or hospitalization for altered mental status, fall, and fracture among 140,899 Medicare-covered adults receiving hemodialysis in 2011. We evaluated risk according to average daily total opioid dose (>60 mg, ≤60 mg, and per 60-mg dose increment) and specific agents (per 60-mg dose increment).

RESULTS

The median age was 61 years old, 52% were men, and 50% were white. Sixty-four percent received opioids, and 17% had an episode of altered mental status (15,658 events), fall (7646 events), or fracture (4151 events) in 2011. Opioid use was associated with risk for all outcomes in a dose-dependent manner: altered mental status (lower dose: hazard ratio, 1.28; 95% confidence interval, 1.23 to 1.34; higher dose: hazard ratio, 1.67; 95% confidence interval, 1.56 to 1.78; hazard ratio, 1.29 per 60 mg; 95% confidence interval, 1.26 to 1.33), fall (lower dose: hazard ratio, 1.28; 95% confidence interval, 1.21 to 1.36; higher dose: hazard ratio, 1.45; 95% confidence interval, 1.31 to 1.61; hazard ratio, 1.04 per 60 mg; 95% confidence interval, 1.03 to 1.05), and fracture (lower dose: hazard ratio, 1.44; 95% confidence interval, 1.33 to 1.56; higher dose: hazard ratio, 1.65; 95% confidence interval, 1.44 to 1.89; hazard ratio, 1.04 per 60 mg; 95% confidence interval, 1.04 to 1.05). All agents were associated with a significantly higher hazard of altered mental status, and several agents were associated with a significantly higher hazard of fall and fracture.

CONCLUSIONS

Opioids were associated with adverse outcomes in patients on hemodialysis, and this risk was present even at lower dosing and for agents that guidelines have recommended for use.

Nephrotoxicity of methadone: a systematic review

Background

Methadone is commonly administered for chronic pain relief and treatment of opioid dependence. Concurrent with its increased consumption, toxicities and fatalities have increased. One of the adverse effects of opioid analgesics, including methadone, is that of nephrotoxicity. Opioids can have an effect on renal function through several different mechanisms.

Methods

We searched common bibliographical databases for the terms methadone, toxicity, poisoning, kidney, renal, and nephrotoxicity and summarize our findings in this review.

Results

Methadone can have both direct and indirect effects on the kidney. These effects include rhabdomyolysis (leading to acute kidney injury), volumetric changes, renal lipidosis and amyloidosis, kidney growth during pregnancy, and kidney transplant rejection.

Conclusion

Improved understanding of the effects of methadone on kidney function can promote safer and more confident use of the drug.

Renal dosing in high-risk populations

In patients with diminished kidney function, the pharmacokinetics of many medications are altered. Alterations in absorption, distribution, and metabolism are observed in addition to altered elimination through the kidney. Classes of intravenous medications in which dose modifications are frequently required for patients with diminished kidney function include antibiotics, some anticoagulants, and chemotherapy agents. Failure to follow renal dose adjustment recommendations can lead to an increased risk of toxicity. Equations frequently used to estimate kidney function for the purpose of making renal dose adjustments include the Cockcroft-Gault, Modification of Diet in Renal Disease (MDRD), and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations.

Safety issues of current analgesics: an update

Pain represents a complex experience which can be approached by various medicines. Non-opioid and opioid analgesics are the most common drugs used to manage different types of pain. The increased attention nowadays to pain management entailed concomitantly more frequent adverse drug reactions (ADRs) related to analgesic use. Drug-drug interactions can be sometimes responsible for the adverse effects. However, a significant proportion of analgesic ADRs are preventable, which would avoid patient suffering. In order to draw the attention to analgesics risks and to minimize the negative consequences related to their use, the present review comprises a synthesis of the most important safety issues described in the scientific literature. It highlights the potential risks of the most frequently used analgesic medicines: non-opioid (paracetamol, metamizole, non-steroidal anti-inflammatory drugs) and opioid analgesics. Even if there is a wide experience in their use, they continue to capture attention with safety concerns and with potential risks recently revealed. Acknowledging potential safety problems represents the first step for health professionals in assuring a safe and efficient analgesic treatment with minimum risks to patients. Taking into consideration all medical and environmental factors and carefully monitoring the patients are also essential in preventing and early detecting analgesic ADRs.

Pain in chronic kidney disease: a scoping review

There is increasing international attention in efforts to integrate palliative care principles, including pain and symptom management, into the care of patients with advanced chronic kidney disease (CKD). The purpose of this scoping review was to determine the extent, range, and nature of research activity around pain in CKD with the goal of (i) identifying gaps in current research knowledge; (ii) guiding future research; and (iii) creating a rich database of literature to serve as a foundation of more detailed reviews in areas where the data are sufficient. This review will specifically address the epidemiology of pain in CKD, analgesic use, pharmacokinetic data of analgesics, and the management of pain in CKD. It will also capture the aspects that pertain to specific pain syndromes in CKD such as peripheral neuropathy, carpal tunnel syndrome, joint pain, and autosomal dominant polycystic kidney disease.

Management of acute and post-operative pain in chronic kidney disease

Chronic kidney disease is common and patients with many co-morbid conditions frequently have to undergo surgical procedures and, therefore, require effective pain management. The pharmacokinetics of various analgesic agents are not well studied in patients with chronic kidney disease and the risk of accumulation of the main drug or their metabolites, resulting in serious adverse events, is a common scenario on medical and surgical wards. It is common for these patients to be cared for by 'non-nephrologists' who often prescribe the standard dose of the commonly used analgesics, without taking into consideration the patient's kidney function. It is important to recognize the problems and complications associated with the use of standard doses of analgesics, and highlight the importance of adjusting analgesic dosage based on kidney function to avoid complications while still providing adequate pain relief.

Management of acute and post-operative pain in chronic kidney disease

Chronic kidney disease is common and patients with many co-morbid conditions frequently have to undergo surgical procedures and, therefore, require effective pain management. The pharmacokinetics of various analgesic agents are not well studied in patients with chronic kidney disease and the risk of accumulation of the main drug or their metabolites, resulting in serious adverse events, is a common scenario on medical and surgical wards. It is common for these patients to be cared for by 'non-nephrologists' who often prescribe the standard dose of the commonly used analgesics, without taking into consideration the patient's kidney function. It is important to recognize the problems and complications associated with the use of standard doses of analgesics, and highlight the importance of adjusting analgesic dosage based on kidney function to avoid complications while still providing adequate pain relief.

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

BACKGROUND

Opioid use in patients with renal impairment can lead to increased adverse effects. Opioids differ in their effect in renal impairment in both efficacy and tolerability. This systematic literature review forms the basis of guidelines for opioid use in renal impairment and cancer pain as part of the European Palliative Care Research Collaborative's opioid guidelines project.

OBJECTIVE

The objective of this study was to identify and assess the quality of evidence for the safe and effective use of opioids for the relief of cancer pain in patients with renal impairment and to produce guidelines.

SEARCH STRATEGY

The Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, MedLine, EMBASE and CINAHL were systematically searched in addition to hand searching of relevant journals.

SELECTION CRITERIA

Studies were included if they reported a clinical outcome relevant to the use of selected opioids in cancer-related pain and renal impairment. The selected opioids were morphine, diamorphine, codeine, dextropropoxyphene, dihydrocodeine, oxycodone, hydromorphone, buprenorphine, tramadol, alfentanil, fentanyl, sufentanil, remifentanil, pethidine and methadone. No direct comparator was required for inclusion. Studies assessing the long-term efficacy of opioids during dialysis were excluded.

DATA COLLECTION AND ANALYSIS

This is a narrative systematic review and no meta-analysis was performed. The Grading of RECOMMENDATIONS Assessment, Development and Evaluation (GRADE) approach was used to assess the quality of the studies and to formulate guidelines.

MAIN RESULTS

Fifteen original articles were identified. Eight prospective and seven retrospective clinical studies were identified but no randomized controlled trials. No results were found for diamorphine, codeine, dihydrocodeine, buprenorphine, tramadol, dextropropoxyphene, methadone or remifentanil.

CONCLUSIONS

All of the studies identified have a significant risk of bias inherent in the study methodology and there is additional significant risk of publication bias. Overall evidence is of very low quality. The direct clinical evidence in cancer-related pain and renal impairment is insufficient to allow formulation of guidelines but is suggestive of significant differences in risk between opioids.

RECOMMENDATIONS

RECOMMENDATIONS regarding opioid use in renal impairment and cancer pain are made on the basis of pharmacokinetic data, extrapolation from non-cancer pain studies and from clinical experience. The risk of opioid use in renal impairment is stratified according to the activity of opioid metabolites, potential for accumulation and reports of successful or harmful use. Fentanyl, alfentanil and methadone are identified, with caveats, as the least likely to cause harm when used appropriately. Morphine may be associated with toxicity in patients with renal impairment. Unwanted side effects with morphine may be satisfactorily dealt with by either increasing the dosing interval or reducing the 24 hour dose or by switching to an alternative opioid.

Opioid and benzodiazepine use in end-stage renal disease: a systematic review

BACKGROUND AND OBJECTIVES

Chronic pain and psychiatric disorders are common in dialysis patients, but the extent to which opioids and benzodiazepines are used is unclear. We conducted a systematic review to determine the: (1) prevalence of opioid and benzodiazepine use among dialysis patients; (2) reasons for use; (3) effectiveness of symptom control; and (4) incidence of adverse events.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Two authors reviewed all relevant citations in MEDLINE/EMBASE/CINAHL/BIOSIS Previews/Cochrane and hand-searched bibliographies. Studies after 1990 reporting prevalence estimates for opioid and/or benzodiazepine use in ≥50 dialysis patients were included.

RESULTS

We identified 15 studies from 12 countries over 1995 to 2006. Sample size ranged from 75 to 12,782. Prevalence of opioid and benzodiazepine use was variable, ranging from 5 to 36% (95% CI, 4.1 to 45.5%; n=10) and 8 to 26% (95% CI, 7.1 to 27.3%; n=9), respectively. Prevalence was positively correlated with years on dialysis. Five studies reported on the same cohorts but gave different prevalence estimates. One study verified medication use through patient interviews. Reasons for use were reported in one study. Effectiveness of pain control varied from 17 to 38%, and 72 to 84% of patients with significant pain had no analgesia (n=2). No study rigorously examined for adverse events.

CONCLUSIONS

The prevalence of opioid and benzodiazepine use in dialysis patients is highly variable between centers. Further information is needed regarding the appropriateness of these prescriptions, adequacy of symptom control, and incidence of adverse effects in this population.

An analysis of renal dysfunction in 1511 patients with fractured neck of femur: the implications for peri-operative analgesia

SUMMARY

Following two deaths from respiratory failure secondary to opioid toxicity in patients admitted for surgical repair of fractured neck of femur, we retrospectively studied the serum urea and electrolyte concentrations of 1511 consecutive patients requiring surgery for proximal femoral fracture, and calculated their glomerular filtration rate. Five hundred and forty-five (36.1%) patients had renal dysfunction on admission (glomerular filtration rate < 60 ml x min(-1).1.73 m(-2)); 435 (28.8%) had grade 3 chronic kidney disease (moderate; glomerular filtration rate 30-59 ml x min(-1).1.73 m(-2)), 82 (5.4%) had grade 4 disease (severe; glomerular filtration rate 15-29 ml x min(-1).1.73 m(-2)) and 28 (1.9%) had grade 5 (renal failure; glomerular filtration rate < 15 ml min(-1).1.73 m(-2)). The 30-day mortality for patients with renal dysfunction (62/536; 11.6%) was significantly greater (p = 0.004) than for patients with normal renal function (68/958; 7.1%), although median (IQR [range]) postoperative lengths of stay were similar 15 (10-22 [1-125]) vs 14 (9-22 [1-120]) days respectively; p = 0.06). Renal impairment is common in patients admitted for fixation of fractured neck of femur, who are consequently at risk of opioid toxicity.

Pain management in patients with chronic kidney disease

Pain has been reported to be a common problem in the general population and end-stage renal disease (ESRD) patients. Although similar data for pre-ESRD patients are lacking, we recently reported that the prevalence of pain is also very high (>70%) among pre-ESRD patients at a Los Angeles County tertiary referral centre. The high prevalence of pain in the CKD population is particularly concerning because pain has been shown to be associated with poor quality of life. Of greater concern, poor quality of life, at least in dialysis patients, has been shown to be associated with poor survival. We herein discuss the pathophysiology of common pain conditions, review a commonly accepted approach to the management of pain in the general population, and discuss analgesic-induced renal complications and therapeutic issues specific for patients with reduced renal function.

The prevalence and management of current daily pain among older home care clients

The aim of this cross-sectional study was to examine the prevalence and correlates of pharmacotherapy for current daily pain in older home care clients, focusing on analgesic type and potential contraindications to treatment. The sample included 2779 clients aged 65+years receiving services from Community Care Access Centres in Ontario during 1999-2001. Clients were assessed with the Resident Assessment Instrument-Home Care (RAI-HC). Prescription and over-the-counter (OTC) medications listed on the RAI-HC were used to categorize analgesic treatment into two groups (relative to no analgesic use): use of non-opioids (acetaminophen or non-steroidal anti-inflammatory drugs only); and, use of opioids alone or in combination with non-opioids. Associations between client characteristics and analgesic treatment among those in current daily pain were examined using multivariable multinomial logistic regression. Approximately 48% (n=1,329) of clients had daily pain and one-fifth (21.6%) of this group received no analgesic. In multivariable analyses, clients aged 75+years and those with congestive heart failure, diabetes, other disease-related contraindications, cognitive impairment and/or requiring an interpreter were significantly less likely to receive an opioid alone or in combination with a non-opioid. Clients with congestive heart failure and without a diagnosis of arthritis were significantly less likely to receive a non-opioid alone. A diagnosis of arthritis or cancer and use of nine or more medications were significantly associated with opioid use. The findings provide evidence of both rational prescribing practices and potential treatment bias in the pharmacotherapeutic management of daily pain in older home care clients.