Chronic Kidney Disease-Associated Pruritus: A Review

CKD-Associated Pruritus is Associated with Greater Use of Antidepressants and Anti-pruritus Medications

INTRODUCTION

Chronic kidney disease-associated pruritus (CKD-aP) is a common, yet underdiagnosed condition among patients on hemodialysis. Considering the lack of established treatment pathways, we sought to evaluate the use of antidepressant, systemic antihistamines, or gabapentinoid medications among patients with CKD-aP in the year following pruritus assessment.

METHODS

We included 6209 patients on hemodialysis in the analysis. We retrospectively extracted clinical and patient-reported data from electronic health records. The intensity of CKD-aP was assessed by KDQOL-36 and 5-D Itch questionnaires. Prescription of antidepressant, antihistamine, and gabapentinoids was ascertained by the occurrence of a relevant active medical order in patients' medical records.

RESULTS

We observed a consistent and graded association between the severity of CKD-aP and the use of antidepressant, systemic antihistamines, and gabapentinoid medications. This association remained consistent and intensified over the duration of the year after pruritus screening. This trend was robust even after accounting for potential confounding factors.

CONCLUSIONS

Patterns of antipruritic medication use in a cohort of patients with CKD-aP was identified and the frequent use of off-label treatments in the absence of approved therapies was highlighted. These observations reflect clinical practices aimed at managing severe pruritus but do not imply a causal relationship between the medications and pruritus severity. Even though we cannot exclude the possibility that these drugs have been prescribed to treat medical conditions warranting their use, previous evidence suggested that doctors may also use such medications in an attempt to buffer CKD-aP. These findings underline the importance of further elucidating current treatment strategies adopted in clinical practice to address CKD-aP.

Identification and Management of CKD-Associated Pruritus: Current Insights

Chronic kidney disease-associated pruritus (CKD-aP) is a frequent and distressing problem for individuals with chronic kidney disease (CKD) and end-stage renal disease. It affects around 20% of those with CKD and 40% of those with end-stage renal disease. Despite its clear association with poorer psychosocial and medical outcomes, it is often underreported by patients and frequently remains unnoticed by healthcare providers. This is likely due to uncertainty regarding its diagnosis and treatment. Most commonly, CKD-aP could be screened with questionnaires like the KDQoL-36 and WI-NRS, chosen for their simplicity and ease of use. Prior treatment studies of CKD-aP were mostly limited by noncontrolled design and small sample size. First CKD-aP medication - difelikefalin a powerful, new therapeutic option was approved by Federal Drug Administration (FDA) in 2021 and European Medicines Agency (EMA) in 2022. Recent expert opinions, clinical trials and metanalysis identified difelikefalin and gabapentinoids as medications of choice in treatment of CKD-aP. All these findings improved current understanding and management of this condition.

Difelikefalin in the treatment of hemodialysis patients with pruritus: a systematic review and meta-analysis

Background and Objective

Uremic pruritus is a persistent condition that is difficult to cure in patients with end-stage renal disease who are having regular dialysis. It is highly prevalent, and current therapies have limited effectiveness and can cause significant adverse effects. Several trials have provided evidence that difelikefalin can be an effective treatment for uremic pruritus, with few side responses. However, it is important to note that the available evidence is limited. This study collected published randomized controlled trials for systematic review and Meta-analysis, to explore the efficacy and safety of difelikefalin treating uremic pruritus and to provide evidence-based medical evidence for clinical treatment.

Methods

A systematic literature search was conducted in PubMed, EMBASE, Web of Science, the Cochrane Library Data from building libraries to 6 January 2024. We extracted data from eligible studies to analyze the efficacy and safety of difelikefalin in the treatment of hemodialysis patients with pruritus.

Results

This study comprised 9 trials with 4,118 people. The meta-analysis demonstrated that difelikefalin is more effective than placebo in treating uremic pruritus. Specifically, difelikefalin resulted in a greater improvement in WI-NRS scores of at least 3 points from baseline (OR = 1.98) and at least 4 points from baseline (OR = 1.94). Additionally, difelikefalin led to a decrease in the total score of the 5-D itch scale (MD = 1.56), a decrease in the skindex-10 scale score (MD = 4.92), and a decrease in the WI-NRS scale score (MD = 0.91).

Conclusion

Difelikefalin demonstrates significant efficacy in alleviating pruritus in individuals suffering from uremia. Althogh it has adverse events, they are mild.

Chronic Kidney Disease-Associated Pruritus Burden: A Patient Survey Study

Rationale & Objective

Chronic kidney disease-associated pruritus (CKD-aP) is a common, underrecognized condition in patients with chronic kidney disease (CKD), especially those receiving hemodialysis (HD). The present study analyzed the clinical treatment journey and overall burden of pruritus among patients with CKD-aP.

Study Design

Cross-sectional, patient-reported online survey.

Setting & Participants

Data from adult patients undergoing HD (December 2021-May 2022) in the United States.

Exposure

Patients participated in an online survey and responded to questions on validated patient-reported outcome instruments related to CKD-aP.

Outcomes

Self-reported measures analyzed at the end of this survey include itch characteristics; symptom management; health care provider (HCP) engagement; and effect on HD, quality of life (QoL), sleep, and work productivity.

Analytical Approach

Bivariate analysis assessed the association of itch severity with CKD-specific QoL.

Results

Overall, 354 patients with CKD-aP were included in analyses, of which 49% and 30% had moderate and severe itch, respectively (22% were mild). Around 68% reported symptoms to HCPs, most commonly a nephrologist or primary care provider, and 55% received a treatment recommendation. The most common treatments were topical lotions/moisturizers (75%) and corticosteroids (48%); use of oral prescriptions was low (20%), with limited satisfaction with treatments. Overall, 23% of patients reported shortening and 17% reported missing HD sessions because of itch. In bivariate analysis, patients with more severe CKD-aP reported significantly worse disease and function scores (kidney disease score, cognitive function, quality of social interaction, sleep [all, P < 0.001], and sexual function [P < 0.05]), suggesting a direct effect of CKD-aP on QoL.

Limitations

Possible recall bias, especially for questions with longer recall periods.

Conclusions

CKD-aP is often inadequately treated and disruptive of dialysis treatment, even among patients who report itch to HCPs. Worse itch severity is associated with poorer QoL, sleep quality, and functional/work impairment.

Effectiveness of topical gabapentin cream in treating pruritus in dialysis patients: A randomized controlled trial

INTRODUCTION

Gabapentin is an antiepileptic drug that alleviates neuropathic pain. Its oral use reduces the intensity of pruritus in patients receiving chronic dialysis therapy. However, it could lead to toxicity because of the patients' renal deficiency. In this study, we assessed the use of gabapentin topical in treating pruritus in dialysis patients.

METHODS

This randomized, triple-blinded trial was performed on 80 patients divided into two groups randomly (40 in each group). In intervention group, 92.5% of the patients were on hemodialysis. Patients in intervention and control groups were provided with 5% gabapentin and placebo topical creams every 2 weeks for a month. Both Visual Analog Scale and 12-item Pruritus Severity Score questionnaire were used to evaluate itching intensity and score before treatment, a month, and 2 months after starting treatment in both groups. In addition, the effect of itching on quality of life was investigated with the same questionnaire.

FINDINGS

Eighty patients (40 in each group) participated in our study. No complication was found in our intervention group. Itching score significantly decreased after a month and 2 months of follow-up in intervention group (p < 0.001).

DISCUSSION

Our results showed that 5% gabapentin topical cream can be effective in reducing itching in different areas of the body. None of our patients reported complications.

Information and consensus document for the diagnostic and therapeutic management of pruritus associated with chronic kidney disease in patients on haemodialysis in Spain

Chronic kidney disease-associated pruritus (CKD-aP) is one of the most common and disabling comorbidities in patients with advanced CKD. In addition, it is associated with an increased risk of mortality, poorer quality of life, sleep disorders, mental health disorders, and increased use of health care resources. The clinical presentation of CKD-aP is very heterogeneous, making it difficult to diagnose and treat. Currently, there are no national guidelines on the management of CKD-aP. The aim of this document is to provide national consensus recommendations for the diagnostic and therapeutic management of CKD-aP. The document was prepared in three phases: a diagnostic and therapeutic management algorithm was proposed by a small group of nephrology specialists; the proposal was validated by a larger group of nephrologists; and a second validation by a multidisciplinary group that also included dermatology specialists. The diagnostic and therapeutic management algorithm attempts to cover the current need of a lack of specific guidelines for the adequate management of CKD-aP. At the same time, it introduces the use of difelikefalin, the first and only drug specifically approved for CKD-aP, with a good safety and efficacy profile.

Prevalence, patient burden and physicians' perception of pruritus in haemodialysis patients

BACKGROUND

Chronic kidney disease-associated pruritus (CKD-aP) is an underrated symptom in patients with impaired kidney function. The present study assessed the prevalence, impact on quality of life (QoL) and risk factors for CKD-aP in a contemporary national cohort of patients on haemodialysis. In addition, we evaluated attending physicians' awareness and approach to therapy.

METHODS

Validated patient's and physician's questionnaires on pruritus severity and QoL were used in combination with information obtained by the Austrian Dialysis and Transplant Registry.

RESULTS

The prevalence of mild, moderate and severe pruritus in 962 observed patients was 34.4%, 11.4% and 4.3%. Physicians' estimated prevalence values were 25.0 (95% CI 16.8-33.2), 14.4 (11.3-17.6) and 6.3% (4.9-8.3), respectively. The estimated national prevalence estimate extrapolated from the observed patients was 45.0% (95% CI 39.5-51.2) for any, 13.9% (95% CI 10.6-17.2) for moderate and 4.2% (95% CI 2.1-6.2) for severe CKD-aP. CKD-aP severity was significantly associated with impaired QoL. Risk factors for moderate-severe pruritus were higher C-reactive protein [odds ratio (OR) 1.61 (95% CI 1.07-2.43)] and parathyroid hormone (PTH) values [OR 1.50 (95% CI 1.00-2.27)]. Therapy for CKD-aP included changes in the dialysis regimen, topical treatments, antihistamines, gabapentin and pregabalin and phototherapy in a majority of centres.

CONCLUSIONS

While the overall prevalence of CKD-aP in our study is similar to that in previously published literature, the prevalence of moderate-severe pruritus is lower. CKD-aP was associated with reduced QoL and elevated markers of inflammation and PTH. The high awareness of CKD-aP in Austrian nephrologists may explain the lower prevalence of more severe pruritus.

Does Indoxyl Sulfate Have a Role in Uremic Pruritus? A Laboratory and Interventional Study

BACKGROUND

Pruritus is a common complaint in patients with end-stage renal disease. Indoxyl sulfate (IS) is a tryptophan end metabolite extremely renal excreted. Activated charcoal can interfere with IS intestinal absorption.

OBJECTIVES

To evaluate the serum level of IS and the effect of activated charcoal on uremic pruritus.

MATERIALS AND METHODS

In all, 135 participants were divided into 2 main groups. In total, 45 normal and healthy individuals as a control group and 90 patients on regular hemodialysis; 45 of these patients had uremic pruritus and the other 45 were not complaining of uremic pruritus. Serum IS was measured. Activated charcoal was used by patients with uremic pruritus. The severity of pruritus and Dermatology Life Quality Index (DLQI) were assessed.

RESULTS

The serum IS was significantly elevated in uremic patients than in control subjects (P < .001) and significantly elevated in uremic patients without pruritus (P < .001). Furthermore, there were positive significant correlations between the serum IS and both severity of pruritus (P < .001) and DLQI (P < .001). After activated charcoal usage, there was a significant decrease in IS level with the improvement of pruritus and quality of life of patients.

CONCLUSIONS

IS may play a role in uremic pruritus. Activated charcoal could be considered a treatment for uremic pruritus.

Top Ten Tips Palliative Care Clinicians Should Know About Delivering Specialty-Aligned Palliative Care

Specialty-aligned palliative care (SAPC) refers to interprofessional palliative care (PC) that is delivered to a specific population of patients in close partnership with other primary or specialty clinicians. As evolving PC models address physical, psychosocial, and spiritual suffering across illnesses and settings, PC clinicians must acquire advanced knowledge of disease-specific symptoms, common treatments, and complications that impact prognosis and outcomes. The tips provided in this article draw on the experience and knowledge of interprofessional PC and other specialist clinicians from diverse institutions across the United States who have developed and studied SAPC services across different disease groups. Recommendations include focusing on approaching specialty team partnerships with humility, curiosity, and diplomacy; focusing on patient populations where PC needs are great; clarifying how work and responsibilities will be divided between PC and other clinicians to the extent possible; using consults as opportunities for bidirectional learning; and adapting workflows and schedules to meet specialty team needs while managing expectations and setting limits as appropriate. Furthermore, to provide effective SAPC, PC clinicians must learn about the specific symptoms, prognoses, and common treatments of the patients they are serving. They must also build trusting relationships and maintain open communication with patients and referring clinicians to ensure integrated and aligned PC delivery.

Chronic Kidney Disease-Associated Pruritus and Quality of Life: Learning from Our Patients

Chronic kidney disease-associated pruritus is itching directly related to kidney disease that cannot be explained by any other condition. Despite technological advances in the different aspects of dialysis sessions and the best treatment for chronic kidney disease patients, it is still a common problem in our patients. The many complex physiological mechanisms involved, the different hypotheses made over the years on the aetiology of the condition, and the great clinical variability may partially explain the limited knowledge about this problem and the difficulties in treating it. The presence of all these factors leads to the persistence of unpleasant symptoms, which must affect the disease burden and quality of life of kidney patients. Through the presentation of an illustrative clinical case, the aim of this review article is to highlight the need for adequate diagnosis and an improved approach to all aspects of chronic kidney disease-associated pruritus, in view of the heavy burden of the disease and the huge impact on the patient's quality of life.

Incidence and Risk Factors for Pruritus in Patients with Nondialysis CKD

BACKGROUND

Pruritus is a common symptom experienced by patients with nondialysis CKD, but risk factors for incident pruritus in this patient population have not been evaluated.

METHODS

We identified 1951 participants with CKD in the Chronic Renal Insufficiency Cohort Study without pruritus at the baseline assessment. Pruritus was assessed by the Kidney Disease Quality of Life-36 (KDQOL-36) instrument, and moderate-to-severe pruritus was defined as a response of 3 or higher on a Likert scale of 1-5. We used time-updated multivariable joint models to evaluate the association of patient clinical characteristics, eGFR, and laboratory parameters with incident pruritus.

RESULTS

Over a median follow-up of 6 years, 660 (34%) participants developed incident moderate-to-severe pruritus, with a higher incidence rate observed among participants with more advanced CKD. In multivariable models, the hazard ratio (95% confidence interval [CI]) for pruritus associated with a 10 ml/min per 1.73 m 2 lower eGFR was 1.16 (95% CI, 1.10 to 1.23). Older age (≥65 years), higher body mass index, diabetes, current smoking, opioid use, depressive symptoms, and serum parathyroid hormone were also associated with a higher risk of incident pruritus, whereas low serum calcium (<9 mg/dl) was associated with a lower risk (all P <0.05). Serum phosphate was not associated with incident pruritus in the primary analysis.

CONCLUSIONS

A substantial proportion of patients with nondialysis CKD develop moderate-to-severe pruritus. Although lower eGFR is associated with the risk of pruritus, other comorbidities, particularly depressive symptoms, were potential risk factors.

PODCAST

This article contains a podcast at https://www.asn-online.org/media/podcast/CJASN/2023_02_08_CJN09480822.mp3.

Geriatric Medicine Principles in Conservative Kidney Management: Frailty, Functional Assessments, and Selective Deprescribing

Conservative kidney management is a nondialytic treatment option for advanced chronic kidney disease that involves interventions to delay kidney function loss, medications to treat symptoms, and psychosocial support for patients and their loved ones. Several geriatric medicine principles are applicable to patients who are considering or receiving conservative kidney management, including the integration of physical, psychological, and social factors into medical care and medical decisions; careful review of medication lists with selective deprescribing; and screening for geriatric syndromes such as frailty and functional impairment. In this review, we discuss how functional and frailty assessments as well as selective deprescribing can be useful for patients considering or receiving conservative kidney management.

Etiopathogenesis of chronic kidney disease-associated pruritus: putting the pieces of the puzzle together

Defined as the unpleasant sensation that causes the desire to scratch, pruritus is the most common skin symptom associated with uremia and appears in almost half of patients with advanced chronic kidney disease (CKD). Beyond its direct impact on quality of life, CKD-associated pruritus (CKD-aP) is an independent predictor of mortality that also has a synergistic effect with other quality of life-related symptoms, such as insomnia, depression, and anxiety. Although different mechanisms have been proposed to explain the origin of Pa-ERC, its etiopathogenesis is still not fully understood. Since new therapeutic targets have been identified and several clinical trials have recently shown promising results, our current understanding of the interrelationships has expanded significantly and the pathophysiological mechanisms underlying CKD-aP are now considered to be multifactorial. The potential triggers of pruritus in patients with CKD are discussed in this review, including hypotheses about skin xerosis, accumulation of uremic toxins, dysregulation of the immune system and systemic inflammation, uremic neuropathy, and imbalances in the endogenous opioid system. Other non-uremic causes of pruritus are also discussed, with the aim of guiding the physicians to apply an adequate aetiopathogenic approach to CKD-aP in their day-to-day clinical practice.

Treatment of Severe Atopic Dermatitis with Dupilumab in Three Patients with Renal Diseases

BACKGROUND

Atopic dermatitis (AD) is a chronic relapsing inflammatory skin disease that can affect patients' quality of life. Dupilumab is the first biologic agent approved for the treatment of patients with inadequately controlled moderate-to-severe AD and its mechanism of action is based on the inhibition of the interleukin (IL)-4 and IL-13 signaling. There are only a few data on the safety of dupilumab in AD patients with comorbidities, including kidney disorders.

MATERIALS AND METHODS

Descriptive retrospective series of three patients with chronic kidney diseases (Alport syndrome, IgA nephropathy, and hypertensive nephrosclerosis, respectively) receiving dupilumab for their concomitant severe AD.

RESULTS

Treatment with a standard dosage of dupilumab caused a relevant improvement of AD in all patients without any adverse events or worsening of renal function. In a patient with severe renal failure, the drug was effective and well tolerated without the need for any dose adjustments, also after the initiation of peritoneal dialytic treatment.

CONCLUSION

Our case series suggests the use of dupilumab as an effective and safe treatment for AD patients suffering from renal diseases, although additional studies are required to confirm such preliminary findings.

Epidemiology of peritoneal dialysis outcomes

Peritoneal dialysis (PD) is an important home-based treatment for kidney failure and accounts for 11% of all dialysis and 9% of all kidney replacement therapy globally. Although PD is available in 81% of countries, this provision ranges from 96% in high-income countries to 32% in low-income countries. Compared with haemodialysis, PD has numerous potential advantages, including a simpler technique, greater feasibility of use in remote communities, generally lower cost, lesser need for trained staff, fewer management challenges during natural disasters, possibly better survival in the first few years, greater ability to travel, fewer dietary restrictions, better preservation of residual kidney function, greater treatment satisfaction, better quality of life, better outcomes following subsequent kidney transplantation, delayed need for vascular access (especially in small children), reduced need for erythropoiesis-stimulating agents, and lower risk of blood-borne virus infections and of SARS-CoV-2 infection. PD outcomes have been improving over time but with great variability, driven by individual and system-level inequities and by centre effects; this variation is exacerbated by a lack of standardized outcome definitions. Potential strategies for outcome improvement include enhanced standardization, monitoring and reporting of PD outcomes, and the implementation of continuous quality improvement programmes and of PD-specific interventions, such as incremental PD, the use of biocompatible PD solutions and remote PD monitoring.

The use of peritoneal dialysis (PD) can be advantageous compared with haemodialysis treatment, although several barriers limit its broad implementation. This review examines the epidemiology of peritoneal dialysis (PD) outcomes, including clinical, patient-reported and surrogate PD outcomes.

Peritoneal dialysis (PD) has distinct advantages compared with haemodialysis, including the convenience of home treatment, improved quality of life, technical simplicity, lesser need for trained staff, greater cost-effectiveness in most countries, improved equity of access to dialysis in resource-limited settings, and improved survival, particularly in the first few years of initiating therapy.

Important barriers can hamper PD utilization in low-income settings, including the high costs of PD fluids (owing to the inability to manufacture them locally and the exorbitant costs of their import), limited workforce availability and a practice culture that limits optimal PD use, often leading to suboptimal outcomes.

PD outcomes are highly variable around the world owing in part to the use of variable outcome definitions, a heterogeneous practice culture, the lack of standardized monitoring and reporting of quality indicators, and kidney failure care gaps (including health care workforce shortages, inadequate health care financing, suboptimal governance and a lack of good health care information systems).

Key outcomes include not only clinical outcomes (typically defined as medical outcomes based on clinician assessment or diagnosis) — for example, PD-related infections, technique survival, mechanical complications, hospitalizations and PD-related mortality — but also patient-reported outcomes. These outcomes are directly reported by patients and focus on how they function or feel, typically in relation to quality of life or symptoms; patient-reported outcomes are used less frequently than clinical outcomes in day-to-day routine care.

Difelikefalin in the Treatment of Chronic Kidney Disease-Associated Pruritus: A Systematic Review

Chronic kidney disease-associated pruritus (CKD-aP) is a chronic condition that significantly reduces the quality of life of patients with end-stage renal disease. The etiology is not fully understood, but imbalance in the activity of the opioid pathways, including downregulation of the kappa-opioid receptor, may contribute to itching sensation. Difelikefalin is a selective, peripherally acting kappa-opioid receptor (KOR) agonist. Recently, difelikefalin has been approved as a first drug for the treatment of pruritus associated with chronic kidney disease (CKD) in adult hemodialysis patients. A systematic review of currently available clinical trials was performed to assess the efficacy and safety of difelikefalin in patients with uremic pruritus. A literature review was conducted in May 2022 based on the PRISMA 2020 guidelines. The analyzed clinical trials showed that difelikefalin was effective in reducing pruritus in patients as assessed by the Worst Itching Intensity Numerical Rating Scale. Improvement in quality of life assessed on the basis of the Skindex score and the 5-D itch scale was also noticed. The most commonly reported side effects were mild and included nausea, vomiting, dizziness, and diarrhea. Due to its proven efficacy and good safety profile, difelikefalin is a promising drug for the treatment of pruritus in patients with chronic kidney disease.

Cannabinoids for Symptom Management in Patients with Kidney Failure

People with kidney failure can experience a range of symptoms that lead to suffering and poor quality of life. Available therapies are limited, and evidence for new treatment options is sparse, often resulting in incomplete relief of symptoms. There is growing interest in the potential for cannabinoids, including cannabidiol and tetrahydrocannabinol, to treat symptoms across a wide range of chronic diseases. As legal prohibitions are withdrawn or minimized in many jurisdictions, patients are increasingly able to access these agents. Cannabinoid receptors, CB1 and CB2, are widely expressed in the body, including within the nervous and immune systems, and exogenous cannabinoids can have anxiolytic, anti-emetic, analgesic and anti-inflammatory effects. Considering their known physiological actions and successful studies in other patient populations, cannabinoids may be viewed as potential therapies for a variety of common symptoms affecting those with kidney failure, including pruritus, nausea, insomnia, chronic neuropathic pain, anorexia, and restless legs syndrome. In this review, we summarize the pharmacology and pharmacokinetics of cannabinoids, along with what is known about the use of cannabinoids for symptom relief in those with kidney disease, and the evidence available concerning their role in management of common symptoms. Presently, while these agents show varying efficacy with a reasonable safety profile in other patient populations, evidence-based prescribing of cannabinoids for people with symptomatic kidney failure is not possible. Given the symptom burden experienced by individuals with kidney failure, there is an urgent need to understand the tolerability and safety of these agents in this population, which must ultimately be followed by robust, randomized controlled trials to determine if they are effective for symptom relief.