Gabapentin for uremic pruritus in hemodialysis patients: a qualitative systematic review

Managing Pruritus in Advanced Chronic Disease

Even though pruritus affects a significant number of people with chronic disease, it is rarely adequately treated. Drug therapies often rely on antihistamines, which have not shown to be beneficial in systemic pruritus. Hydroxyzine is frequently used to treat pruritus associated with kidney failure. Since Canada's sole manufacturer of hydroxyzine is no longer making this product, this is an ideal time to review the mechanisms of itch in advanced organ failure and the specific therapies that give relief. Although there is literature describing itch in patients with cancer, this article is limited to pathogenesis and treatment of systemic itch secondary to chronic, noncancer diseases. We summarize recent systematic reviews, although the studies included in these reviews are often small, and mostly cohort studies.

Effect of Omega-3 Fatty Acid Supplementation in the Treatment of Uremic Pruritus among Dialytic Chronic Kidney Disease Patients: A Meta-analysis

Background and Objectives

Pruritus is a common and disabling symptom affecting as much as 50-90% of chronic kidney disease (CKD) patients undergoing dialysis. The pruritus experienced by these patients is often resistant to common anti-pruritic agents and has an overall negative impact on quality of life. With its antioxidant property and anti-inflammatory effects, omega-3 fatty acids have been used to alleviate pruritus. The objective of this study is to assess the effect of omega-3 fatty acid supplementation in reducing the severity of pruritus among dialytic CKD patients.

Methods

Various electronic databases were searched from inception to August 2022. Randomized controlled trials comparing the effect of omega-3 fatty acids versus placebo on the pruritus scores were included. The studies were independently assessed by three reviewers. Revman version 5.4 was used to analyze the data extracted from the studies while heterogeneity was evaluated using Chi2 and I2.

Results

A total of four studies with a population of 166 patients were included in the meta-analysis. The results show an overall beneficial effect of omega-3 fatty acids with a standardized mean difference of -1.40 (CI -1.74 to -1.05, Z=7.95, p value <0.00001). With a Chi2 of 2.91 (p=0.41) and I2 of 0%, there was no significant heterogeneity observed in the pooled analysis.

Conclusion

Overall, the results of the meta-analysis support the finding that omega-3 fatty acid supplementation may have a beneficial effect on reducing the severity of pruritus among CKD patients on dialysis.

Perception of Spanish nephrologists on an old unsolved problem: Pruritus associated with chronic kidney disease (CKD-aP)

INTRODUCTION

Pruritus associated with chronic kidney disease is defined as the sensation of itching, in people with chronic kidney disease, in a one area or all over the body that causes the need to scratch, after having ruled out other dermatological or systemic causes. It is an old and known problem whose prevalence has been able to decrease with the improvement of dialytic techniques but which still persists and is underdiagnosed.

OBJECTIVES

The objective of this study was to analyse the current perception of nephrologists about this problem that influences the quality of life of people with chronic kidney disease through a survey.

RESULTS

135 nephrologists, most of them engaged in haemodialysis, participated. 86% considered that pruritus associated with chronic kidney disease is still a problem today that affects the quality of life. Most nephrologists believe that the main pathophysiological cause is uremic toxins (60%) and only 16% believe that it is due to the dysregulation of the opioid system/endorphins-dynorphins. Only 16% comment that the prevalence of pruritus in their centre is greater than 20%. 40% believe that the diagnosis is made because it is manifested by the patient and only 27% because it is asked by the doctor. Moreover, it is not usual to use scales to measure it or the codification in the medical records. The main treatment used is antihistamines (96%), followed by moisturizers/anaesthetics (93%) and modification of the dialysis regimen (70%).

CONCLUSIONS

Pruritus associated with chronic kidney disease is still a current problem, it is underdiagnosed, not codified and with a lack of indicated, effective and safe treatments. Nephrologists do not know its real prevalence and the different pathophysiological mechanisms involved in its development. Many therapeutic options are used with very variable results, ignoring their efficacy and applicability at the present time. The new emerging kappa-opioid-receptor agonist agents offer us an opportunity to reevaluate this age-old problem and improve the quality of life for our patients with chronic kidney disease.

Lettuce as an Effective Remedy in Uremic Pruritus: Review of the Literature Supplemented by an In Silico Study

Uremic pruritus is a frequent and prominent symptom in patients with advanced or end-stage renal disease. Lack of an effective treatment for kidney disease-associated pruritus often leads to many problems for these patients and makes it difficult to choose an appropriate treatment. The purpose of this evidence-based hypothesis is to share the scientific reasons and related mechanisms in order to claim that lettuce could be useful in the treatment of uremic pruritus. This hypothesis is based on studies related to lettuce and its anti-inflammatory, antioxidant, antidiabetic, sedative, hypnotic, nephroprotective, potassium balancing, and blood purification properties. As a result, we suggest that lettuce could be a good choice for improving and reducing uremic pruritus due to its certain characteristics. Although proof of this hypothesis requires further clinical trial studies, this hypothesis can nevertheless lead to formulating an appropriate therapy for uremic-induced pruritus. By conducting a molecular docking study, we investigated the interactions between nineteen natural bioactive components of lettuce (Lactuca sativa L.) and human kappa opioid receptors. The in silico docking studies revealed that most of the ligands showed better antipruritic efficacy than gabapentin. Gamma-tocopherol, delta-tocopherol, and campesterol demonstrated the highest binding affinities toward the target protein.

Chronic Kidney Disease-Associated Pruritus: A Review

BACKGROUND

Chronic kidney disease-associated pruritus (CKD-aP), also known as uraemic pruritus, is a disabling symptom for patients and a challenging condition for clinicians. Despite being common amongst end-stage kidney disease (ESKD) patients, it remains underestimated and underdiagnosed. The exact pathogenesis remains largely elusive, which hampers the synthesis of a definite treatment approach.

SUMMARY

Chronic pruritus (lasting 6 weeks or more in duration) is a common and potentially disabling symptom in patients with advanced CKD. A unified hypothesis of pathogenesis has not yet been concluded. Studies have shown changes in the immunochemical milieu of the skin in patients with CKD-aP with several inciting stimuli identified. However, other unrecognized factors are likely to be involved. This article will review the current observations and understanding of the postulated pathogenesis of CKD-aP, as well as the evidence for current management strategies. Key Messages: CKD-aP is a common and troubling symptom amongst ESKD patients that is associated with decreased quality of life and poor prognosis. Its exact pathogenesis, at the time of writing, is not well-understood. A stepwise approach is recommended for management. Systematic reviews show the largest body of evidence was found for the effectiveness of gabapentin. Comparison is needed between newly emerging pharmacological agents such as kappa-opioid receptor agonists and more established agents, such as the gabapentinoids. Finally, renal transplantation should be considered in severe and refractory cases who are suitable transplant candidates as it has shown an excellent outcome in most cases.

Chronic Kidney Disease-Associated Pruritus

Pruritus is a distressing condition associated with end-stage renal disease (ESRD), advanced chronic kidney disease (CKD), as well as maintenance dialysis and adversely affects the quality of life (QOL) of these patients. It has been reported to range from 20% to as high as 90%. The mechanism of CKD-associated pruritus (CKD-aP) has not been clearly identified, and many theories have been proposed to explain it. Many risk factors have been found to be associated with CKD-aP. The pruritus in CKD presents with diverse clinical features, and there are no set features to diagnose it.The patients with CKD-aP are mainly treated by nephrologists, primary care doctors, and dermatologists. Many treatments have been tried but nothing has been effective. The search of literature included peer-reviewed articles, including clinical trials and scientific reviews. Literature was identified through March 2021, and references of respective articles and only articles published in the English language were included.

Interventions for itch in people with advanced chronic kidney disease

BACKGROUND

Itch in patients with chronic kidney disease (CKD) is common, often very distressing and associated with depression, reduced quality of life, and increased death. The most common first-line treatment has been the use of antihistamines despite the lack of substantial evidence for its use for uraemic itch. Few recommendations and guidelines exist for treatment.

OBJECTIVES

We aimed to determine: 1) the benefits and harms (both absolute and relative) of all topical and systemic interventions for the treatment of uraemic itch, either alone or in combination, when compared with placebo or standard care; and, 2) the dose strength or frequency, stage of kidney disease or method of dialysis used (where applicable) in cases where the effects of these interventions vary depending on co-interventions.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to 17 December 2019 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

Randomised controlled trials (RCTs) in adults with CKD stages 4 or 5 comparing treatments (pharmacological, topical, exposure, dialysis modality) for CKD associated itch to either placebo or other established treatments.

DATA COLLECTION AND ANALYSIS

Two authors independently abstracted study data and assessed study quality. Data were analysed using a random effects meta-analysis design estimating the relative effects of treatment versus placebo. Estimates of the relative effects between treatments are included where possible. For continuous measures of severity of itch up to three months, mean difference (MD) or standardised mean difference (SMD) were used. When reported, adverse effects were tabulated. The certainty of the evidence was estimated using GRADE.

MAIN RESULTS

Ninety-two RCTs, randomising 4466 participants were included. Fifty-eight studies (3285 participants) provided sufficient data to be meta-analysed. Of these, 30 compared an intervention to a placebo or control. The 10 cm Visual Analogue Scale (VAS) was the dominant instrument utilized for itch reporting and the Duo score was used in a minority of studies. GABA analogues including, gabapentin and pregabalin, reduce itch in patients with CKD (5 studies, 297 participants: 4.95 cm reduction, 95% CI 5.46 to 4.44 lower in VAS compared to placebo; high certainty evidence). Kappa opioid agonists, including nalfurafine also reduced itch in this population (6 studies, 661 participants: 1.05 cm reduction, 95% CI 1.40 to 0.71 lower in VAS compared to placebo; high certainty evidence). Ondansetron had little or no effect on itch scores (3 studies, 183 participants: 0.38 cm reduction, 95% CI 1.04 lower to 0.29 higher in VAS compared to placebo; high certainty evidence). Reduction in the severity of itch was reported with oral montelukast, turmeric, zinc sulfate and topical capsaicin. For all other interventions, the certainty of the evidence was low to moderate, and the interventions had uncertain effects on uraemic pruritus. Six studies have disclosed significant financial support from their respective manufacturers, six were affected by lack of blinding, and 11 studies have 15 participants or less. Older, smaller RCTs often failed to follow intention-to-treat protocols with unexplained dropouts after randomisation. Adverse effects were generally poorly and inconsistently reported across all RCTs. No severe adverse events were reported for any intervention.

AUTHORS' CONCLUSIONS

The RCTs of this meta-analysis contain a large array of interventions with a diverse set of comparators. For many interventions, trials are sparse. This served to make informative meta-analysis challenging. Of all treatments for uraemic pruritus, gabapentinoids (gabapentin and pregabalin) were the most studied and show the greatest reduction in itch scores. Further RCTs, even of the scale of the largest trials included in this review, are unlikely to significantly change this finding. Kappa-opioid agonists (mainly nalfurafine) also may reduce itch, but indirect comparison suggests a much more modest effect in comparison to GABA analogues. Evidence for oral montelukast, turmeric, zinc sulfate, and topical capsaicin also showed an itch score reduction. However, these reductions were reported in small studies, and warrant further investigation. Ondansetron did not reduce itch. It is somewhat unlikely that a further study of ondansetron will change this result.

Comparison of gabapentin and doxepin in the management of uremic pruritus: A randomized crossover clinical trial

Gabapentin and doxepin are well-known treatments of uremic pruritus in hemodialysis patients but no head-to-head studies were conducted to date. The aim of this trial is to compare the efficacy and the tolerability of gabapentin and doxepin in the treatment of uremic pruritus in hemodialysis patients. A single-blind crossover randomized trial was conducted that included hemodialysis patients with uremic pruritus. Patients were randomized to receive 10 mg doxepin daily or 100 mg gabapentin for 4 weeks and the two groups were treated conversely for another 4 weeks after a 4-week washout period. Eighty-five patients were screened for eligibility. Thirty-one met the inclusion criteria and four were excluded. Sixteen patients agreed and signed the consent and two withdrew from the study. VAS scores at baseline were 6.71 and 6.14, and dropped to 0.57 and 2.35 at week 4 in the gabapentin and doxepin groups, respectively. Mean scores of the 5-Domain Itch Scale (5-D) at baseline were 14.71 and 14.64, and dropped to 5.78 and 7.57 at week 4 in the gabapentin and doxepin groups, respectively. Mean scores of the Dermatology Life Quality Index (DLQI) at baseline were 9.6429 and 8.7857, and dropped to 0.71 and 3.35 at week 4 in the gabapentin and doxepin groups, respectively. Reductions in Visual Analog Scale (VAS), 5-D and DLQI were statistically significant (P < .05). No serious side effects were recorded. Limitations of this study include single-blind design, small number of included cases and lack of placebo control. Gabapentin was more effective than doxepin in decreasing uremic pruritus severity and improving quality of life of these patients.

Complementary and alternative medicine therapies for uremic pruritus - A systematic review of randomized controlled trials

INTRODUCTION

Uremic pruritus (UP) is one of the most bothersome symptoms among chronic kidney disease (CKD) patients. The pathophysiology of UP remains elusive, resulting in limited treatment options. The inability of standard medical treatments to provide effective relief has piqued interest in complementary and alternative medicine (CAM).

METHODOLOGY

A systematic review of randomized controlled trials (RCTs) summarizing the efficacy and safety profile of CAM used for UP in CKD patients was performed. CAM interventions were classified using categories proposed by the National Center for Complementary and Integrative Health. The efficacy of each CAM was determined from changes in UP severity and all reported adverse effects were extracted.

RESULTS

Of 5242 articles screened, 34 RCTs were included, with 15 (44.1 %) studies having a sample size greater than 50. The studies considered 21 treatments including omega-3 fatty acid supplementation (n=5), acupuncture (n=5), topical capsaicin (n=4) and acupressure (n=3). Acupuncture, acupressure and topical capsaicin were shown to be effective in improving uremic pruritus. Interventions which include oral omega-3 fatty acid and zinc supplementation demonstrated mixed efficacy. Other therapies such as evening primrose oil, turmeric, vitamin B3, vitamin D and thermal therapy were not effective for treatment of UP. Common adverse effects reported with topical capsaicin included mild burning sensations (50.0-88.2 %) or erythema (6.7-22.7%) while that of acupuncture included soreness (7.5 %), bleeding (6.0-7.5%) and hematoma (1.9 %).

CONCLUSIONS

Acupuncture, acupressure and topical capsaicin have the largest body of evidence for efficacy in the treatment of UP. Larger and higher quality RCTs are required to examine the efficacy and safety of promising CAM.

Comparison of Safety and Efficacy of Pregabalin versus Gabapentin for the treatment of Uremic Pruritus in Patients with Chronic Kidney Disease on Maintenance Haemodialysis

Background:

Uremic pruritus (UP) affects many patients suffering from chronic kidney disease (CKD) and has a negative impact on the quality of life. The severity of UP ranges from sporadic discomfort to complete restlessness during both day and night time. It has become increasingly evident that central transmission and sensitization processes similar to those observed in chronic pain are important mechanisms of pruritus.

Methodology:

This was a randomized single-blind prospective-interventional study carried out for 6 weeks. Male and female patients aged between 20 and 85 years with end-stage renal disease undergoing maintenance hemodialysis and who had substantial pruritus defined as persistent were included in our study. Informed consent was obtained from each patient before enrolling in the study. Patients were randomly divided into two groups (Group A and B), with Group A receiving pregabalin 25 mg and Group B receiving gabapentin 100 mg. The efficacy and safety of drugs were assessed after 6 weeks using visual analog scale and 5D itch scale.

Results:

We used gabapentin 100 mg or pregabalin 25 mg for 42 consecutive patients with CKD on maintenance hemodialysis with a mean age of patients in Group A (pregabalin 25 mg) 55.29 ± 14.58 and B (gabapentin 100 mg) 58.10 ± 11.09. Both gabapentin and pregabalin produced a significant difference in itching intensity with P < 0.001; however, there was no statistically significant difference between the effectiveness of two drugs in reducing itch. While receiving gabapentin, 11 of 21 patients (52.38%) reported fatigue, dizziness, somnolescence, which was statistically significant (P ≤ 0.001) and 4 of these patients discontinued use of the drug due to excessive somnolence, all after the first dose. A statistically significant difference was found in each domain of 5D-Pruritus scale after gabapentin and pregabalin therapy.

Comparison of gabapentin and hydroxyzine in the treatment of pruritus in patients on dialysis

BACKGROUND

Pruritus is one of the most common problems in patients with chronic renal failure. Of all patients with end-stage renal disease (ESRD), 60-80% report pruritus during their life.

AIM

To compare the effect of gabapentin (GBP) and hydroxyzine (HYDZ) in treating pruritus in patients on dialysis.

METHODS

In a double-blind, randomized, crossover clinical trial, 32 patients on dialysis who reported pruritus were assigned randomly to receive either GBP or HYDZ for 6 weeks; the first group received GBP 100 mg/day orally and the second group received HYDZ 25 mg/day orally for 6 weeks. After this 6-week period (Period 1) there was a washout period of 2 weeks then patients were crossed over to the other drug (the first group receiving HYDZ and second group receiving GBP) and followed up for a further 6 weeks (Period 2). A visual analogue scale was used to measure pruritus intensity in the groups before and after the first and second period.

RESULTS

In Period 1, pruritus severity decreased from 7.1 ± 1.46 at baseline to 2.17 ± 1.82 at 6 weeks in the GBP group (P = 0.001) and from 6.83 ± 2.11 to 2.86 ± 1.67 in the HYDZ group (P = 0.001). In Period 2, pruritus severity decreased from 5.1 ± 1.61 at baseline to 1.56 ± 0.82 at 6 weeks in the GBP group (P < 0.01) and from 5.23 ± 2.11 to 2.1 ± 1.87 in the HYDZ group (P = 0.001).

CONCLUSION

Results showed that both HYDZ and GBP significantly improved and controlled pruritus in patients on dialysis, with no significant difference observed between the two drugs.

The Effect of Ostrich Oil as a Complementary Medicine on the Severity of Pruritus and Quality of Life in Hemodialysis Patients

INTRODUCTION

Pruritus is one of the most common problems in a uremic syndrome that reduces the quality of life due to the constant unpleasant feeling. The purpose of this study was to investigate the effect of ostrich oil massage on the severity of pruritus and quality of life in hemodialysis patients.

METHODS

In this study, 68 hemodialysis patients with pruritus were selected based on the available sampling method. The intervention group used 1 mL ostrich oil on the pruritus area for 10 min each night for 1 month. The control group received a placebo massage. Pruritus severity questionnaire-based itch severity scale and quality of life questionnaire were completed, respectively, at the end of each week and at the end of the period. Statistical analysis was done using SPSS software version 23 and applying on independent t test, paired t test, and analysis of covariance.

RESULTS

During the first and second weeks after the treatment, there was no statistical difference between the mean scores of pruritus severity in both groups (p > 0.05); however, in the third and fourth weeks after the treatment, the mean severity level of pruritus in the ostrich oil group was lower than in the placebo group, and these differences were statistically significant between the two groups (p < 0.05). There was no significant difference in quality of life between two groups of ostrich and placebo.

CONCLUSION

The use of ostrich oil was effective in reducing pruritus in hemodialysis patients. This method can be proposed as a complementary method for relieving pruritus in hemodialysis patients.

CKD-Associated Pruritus: New Insights Into Diagnosis, Pathogenesis, and Management

Chronic kidney disease–associated pruritus (CKD-aP) is a common, troubling and in some cases debilitating problem for patients with CKD and end-stage renal disease. Despite a prevalence rate of approximately 20% in CKD and 40% in end-stage renal disease, and a clear association with poorer psychosocial and medical outcomes, this condition is often underreported by patients and overlooked by health care providers. This is likely due, in part, to uncertainty regarding its pathogenesis and treatment. Most commonly, CKD-aP is attributed to toxin build-up, peripheral neuropathy, immune system dysregulation, or opioid dysregulation. Prior treatment studies of CKD-aP have targeted these potential etiologies but have been limited by noncontrolled design, small sample size, and non-uniform definitions of CKD-aP. Recently, several large, randomized controlled trials targeting opioid dysregulation have yielded promising results. These trials have spurred new hope for understanding and treating this condition.

Prescribing in renal supportive care

Renal supportive care incorporates the principles of palliative care into the management of patients with advanced kidney disease. Its focus is on improving the quality of life for patients with a high burden of symptoms Common problems include pain, restless legs syndrome and uraemic pruritus. Symptom management must involve patient participation, education and non-pharmacological strategies to address both physical and psychosocial problems, and to prioritise patient-centred goals The patients are medically complex and polypharmacy is common. When prescribing, it is important to consider the altered pharmacokinetics, potential drug interactions and the clearance of drugs by dialysis

A transcriptomics-based analysis of the toxicity mechanisms of gabapentin to zebrafish embryos at realistic environmental concentrations

Gabapentin (GPT) has become an emerging contaminant in aquatic environments due to its wide application in medical treatment all over the world. In this study, embryos of zebrafish were exposed to gabapentin at realistically environmental concentrations, 0.1 μg/L and 10 μg/L, so as to evaluate the ecotoxicity of this emergent contaminant. The transcriptomics profiling of deep sequencing was employed to illustrate the mechanisms. The zebrafish (Danio rerio) embryo were exposed to GPT from 12 hpf to 96 hpf resulting in 136 and 750 genes differentially expressed, respectively. The results of gene ontology (GO) analysis and the Kyoto encyclopedia of genes and genomes (KEGG) pathway analysis illustrated that a large amount of differentially expressed genes (DEGs) were involved in the antioxidant system, the immune system and the nervous system. RT-qPCR was applied to validate the results of RNA-seq, which provided direct evidence that the selected genes involved in those systems mentioned above were all down-regulated. Acetylcholinesterase (AChE), lysozyme (LZM) and the content of C-reactive protein (CRP) were decreased at the end of exposure, which is consistent with the transcriptomics results. The overall results of this study demonstrate that GPT simultaneously affects various vital functionalities of zebrafish at early developmental stage, even at environmentally relevant concentrations.

Can we use psychoactive drugs to treat pruritus?

Pruritus is a frequent complaint both in dermatology and general medicine. This burdensome symptom has a complex and multifactorial pathogenesis, with the key involvement of central nervous system in its development. Psychoactive drugs (psychopharmaceuticals) encompass several therapeutic groups utilized mainly in psychiatry. However, these drugs are occasionally used in dermatological practice and may contribute to alleviation of pruritus in a variety of cutaneous and extracutaneous disorders. This review article summarizes the role of H1-antihistamines, antidepressants, antipsychotics and antiepileptics in managing pruritus.

The Itch-Scratch Cycle: A Review of the Mechanisms

BACKGROUND

Despite being one of the most common presenting dermatological symptoms, itching continues to perplex health care professionals because it is notoriously difficult to control.

OBJECTIVE

This review gathers evidence to answer the 2-part question, "Why do we itch and scratch?" by exploring the history of itchy disease, the neurobiology of itch, and the 4 different clinical origins of itch: pruritogenic, neurological, neuropathic, and psychological.

RESULTS

The automated scratching reflex and its biological and psychological reasons for existence are complicated and poorly understood. Currently, there are a myriad of treatments available for individuals suffering from this condition; however, many remain symptomatic.

CONCLUSIONS

The itch-scratch cycle is a complex pain-like sensation with a reflex-like response. In the future, continued exploration into the mechanisms behind itch and scratch may open the doors for new therapeutic interventions.

Assessing and Treating Chronic Pain in Patients with End-Stage Renal Disease

Pain is one of the most common symptoms among patients with end-stage renal disease (ESRD), and is often under recognized and not adequately managed in hemodialysis (HD) patients. Barriers to adequate pain management include poor awareness of the problem, insufficient medical education, fears of possible drug-related side effects, and common misconceptions about the inevitability of pain in elderly and HD patients. Caregivers working in HD should be aware of the possible consequences of inadequate pain assessment and management. Common pain syndromes in HD patients include musculoskeletal diseases and metabolic neuropathies, associated with typical intradialytic pain. Evaluating the etiology, nature, and intensity of pain is crucial for choosing the correct analgesic. A mechanism-based approach to pain management may result in a better outcome. Pharmacokinetic considerations on clearance alterations and possible toxicity in patients with ESRD should drive the right analgesic prescription. Comorbidities and polymedications may increase the risk of drug-drug interactions, therefore drug metabolism should be taken into account when selecting analgesic drugs. Automedication is common among HD patients but should be avoided to reduce the risk of hazardous drug administration. Further research is warranted to define the efficacy and safety of analgesic drugs and techniques in the context of patients with ESRD as generalizing information from studies conducted in the general population could be inappropriate and potentially dangerous. A multidisciplinary approach is recommended for the management of complex pain syndromes in frail patients, such as those suffering from ESRD.

Gabapentin and Pregabalin Use and Association with Adverse Outcomes among Hemodialysis Patients

Background Gabapentin and pregabalin are used to manage neuropathic pain, pruritus, and restless legs syndrome in patients on hemodialysis. These patients may be especially predisposed to complications related to these agents, which are renally cleared, but data regarding the risk thereof are lacking.Methods From the US Renal Data System, we identified 140,899 Medicare-covered adults receiving hemodialysis with Part D coverage in 2011. Using Cox regression models in which we adjusted for demographics, comorbidities, duration of exposure, number of medications, and use of potentially confounding concomitant medications, we investigated the association between gabapentin and pregabalin, modeled as separate time-varying exposures, and time to first emergency room visit or hospitalization for altered mental status, fall, and fracture. We evaluated risk according to daily dose categories: gabapentin (>0-100, >100-200, >200-300, and >300 mg) and pregabalin (>0-100 and >100 mg).Results In 2011, 19% and 4% of patients received gabapentin and pregabalin, respectively. Sixty-eight percent of gabapentin or pregabalin users had a diagnosis of neuropathic pain, pruritus, or restless legs syndrome. Gabapentin was associated with 50%, 55%, and 38% higher hazards of altered mental status, fall, and fracture, respectively, in the highest dose category, but even lower dosing was associated with a higher hazard of altered mental status (31%-41%) and fall (26%-30%). Pregabalin was associated with up to 51% and 68% higher hazards of altered mental status and fall, respectively.Conclusions Gabapentin and pregabalin should be used judiciously in patients on hemodialysis, and research to identify the most optimal dosing is warranted.

International Comparisons of Prevalence, Awareness, and Treatment of Pruritus in People on Hemodialysis

BACKGROUND AND OBJECTIVES

Uremic pruritus in patients on hemodialysis is associated with depression, lower quality of life, and mortality. We studied the prevalence, awareness, and treatment of pruritus to assess how well this important condition is currently managed internationally.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Data from 35,452 patients on hemodialysis in up to 17 countries from the Dialysis Outcomes and Practice Patterns Study were analyzed to describe pruritus prevalence from 1996 to 2015. Data from 6256 patients and 268 medical directors in 17 countries in 2012-2015 were analyzed to describe predictors, effects, medical directors' awareness, and treatment of pruritus.

RESULTS

Patients very much or extremely bothered by itching declined from 28% in 1996 to 18% in 2015. In 2012-2015, among patients nearly always or always bothered by itching, pruritus had a major effect on work and social life; 18% used no treatment for pruritus, and 17% did not report itching to health care staff. In total, 69% of medical directors underestimated the prevalence of pruritus in their unit. Managing high serum phosphorus and low Kt/V was ranked as the most important intervention, but no relationship was found between these factors and pruritus; 57% of medical directors used oral antihistamines for first-line chronic treatment of pruritus. Gabapentin was used by 45% as first-, second-, or third-line treatment. Nalfurafine was only used in Japan.

CONCLUSIONS

The prevalence of pruritus in people on hemodialysis is decreasing but remains underestimated. Large numbers of patients on hemodialysis with severe pruritus do not receive treatment. There is wide variation in the use of unlicensed medications for the treatment of pruritus. These data provide a benchmark for initiatives to improve the management of uremic pruritus.

MULTIMEDIA

This article contains multimedia at https://vimeo.com/49458473This article contains multimedia at vimeo.com/49455976.

Chronic kidney disease-associated pruritus: impact on quality of life and current management challenges

Chronic kidney disease-associated pruritus (CKD-aP) is a distressing, often overlooked condition in patients with CKD and end-stage renal disease. It affects ~40% of patients with end-stage renal disease and has been associated with poor quality of life, poor sleep, depression, and mortality. Prevalence estimates vary based on the instruments used to diagnose CKD-aP, and standardized diagnostic instruments are sorely needed. Treatment studies have often yielded conflicting results. This is likely related to studies that are limited by small sample size, flawed designs, and nonstandardized diagnostic instruments. Several large well-designed treatment trials have recently been completed and may soon influence CKD-aP management.

Sleep Disorders, Restless Legs Syndrome, and Uremic Pruritus: Diagnosis and Treatment of Common Symptoms in Dialysis Patients

Maintenance dialysis patients experience a high burden of physical and emotional symptoms that directly affect their quality of life and health care utilization. In this review, we specifically highlight common troublesome symptoms affecting dialysis patients: insomnia, restless legs syndrome, and uremic pruritus. Epidemiology, pathophysiology, and evidence-based current treatment are reviewed with the goal of providing a guide for diagnosis and treatment. Finally, we identify multiple additional areas of further study needed to improve symptom management in dialysis patients.