The role of ondansetron in the management of cholestatic or uremic pruritus--a systematic review

Chronic kidney disease-associated pruritus: what is known and its application in children

Chronic kidney disease-associated pruritus (CKD-aP) or uremic pruritus (UP) is a frequent symptom in patients with kidney failure receiving kidney replacement therapy. Severe chronic kidney disease-associated pruritus correlates with poor outcome in patients on dialysis. It is multifactorial in etiology and has a significant impact on quality of life. There is, however, limited data for children. This review summarizes current epidemiology, clinical characteristics, pruritus scoring systems, and available therapeutic options for pruritus in patients with chronic kidney disease and those receiving dialysis. Optimal care requires proper awareness of the severity of symptoms, the impact on quality of life, and the possible long-term outcomes. Optimizing dialysis prescription and correcting electrolyte abnormalities are important treatment targets. A wide range of therapeutic options is also available although none are well-studied in children. An earlier recognition of this debilitating symptom in children and treatment is imperative. A higher resolution version of the Graphical abstract is available as Supplementary information.

Uremic Pruritus: From Diagnosis to Treatment

Uremic pruritus, or chronic kidney disease-associated pruritus, is common, bothersome, and sometimes debilitating in patients with chronic kidney disease or end-stage renal disease. Due to its variable clinical manifestations, the diagnosis of uremic pruritus requires exquisite evaluation. Excluding itch resulting from other dermatological causes as well as other systemic conditions is essential for a proper diagnosis. The pathophysiology of uremic pruritus remains uncertain. Hypotheses including toxin deposition, immune system dysregulation, peripheral neuropathy, and opioid imbalance are supposed. This review summarizes the way to accurately diagnose uremic pruritus and describes the latest treatment options.

Influence of ligand geometry on cholinesterase enzyme - A comparison of 1-isoindolinone based structural analog with Donepezil

Donepezil (DNPZ) is one of the few FDA-approved widely used medication in the clinical care of Alzheimer's disease (AD) patients. To investigate the effect of geometry and to find the significance of an enol form if any in DNPZ on acetylcholinesterase (AChE) inhibition, we changed the tetrahedral geometry of DNPZ to planar trigonal pyramidal geometry by replacing the α-carbon atom next to ketone functionality with a nitrogen atom. To mimic 1-indanone in DNPZ, we selected 1-isoindolinone framework to synthesize 25 new DNPZ derivatives and characterized using ¹H NMR, ¹³C NMR and ESI-MS spectroscopy methods. Drug likeliness profile for each compound was predicted using Molinspiration online software following Lipinski's rule. Commercially available assay kits were used to measure AChE and butyrylcholinesterase (BuChE) inhibitory effects. NIH/3T3 mouse embryonic fibroblast cell line was used to measure cytotoxic and proliferation effects using LDH and MTT assay, respectively. Compound #20 was selected for comparative computational docking, modelling and physicochemical studies. Our results show that DNPZ with tetrahedral geometry has 3-fold higher AChE inhibition as compared to compound #20 with planar trigonal pyramidal geometry. Our approach may be useful as a novel indirect method to study the significance of the enol form in DNPZ (or similar compounds), since constant interconversion between the keto and enol forms does not permit a direct determination of the effect of the enol form of DNPZ in vivo. Overall, we conclude that the tetrahedral is a better fit and any change in geometry significantly drives down the cholinesterase inhibitory effect of DNPZ.

Western and complementary alternative medicine treatment of uremic pruritus: A literature review

Uremic pruritus (UP), also called chronic kidney disease-associated pruritus (CKD-aP), is a bothersome symptom that causes sleep disturbance, anxiety, depression, and reduced quality of life. Pruritus often occurs in patients with end-stage renal disease. There is still no definite treatment for UP due to its unclear pathogenesis. We searched electronic databases (PubMed and Google Scholar) and gathered the latest clinical trials and pilot studies of Western and complementary alternative medicine (CAM) therapies for UP in English. These UP studies were separated into three main groups: systemic, topical, and others and CAM. Gabapentin, nalfurafine, acupuncture, and Chinese herbal bath therapy (CHBT) show antipruritic effects, with higher evidence grades in the meta-analysis. Emollients with additive compounds are more effective for reducing itch than emollients without additives. Supplements for deficient elements, such as zinc, omega-3, and omega-6, also show benefits for pruritus improvement. CAM therapies such as acupuncture, herbs, and herbal baths or creams all have good results for UP treatment. We summarize the treatments and suggest a treatment algorithm for UP according to severity. Some UP therapies are already supported by large-scale clinical evidence, and some new treatments can provide patients with new hope and treatment options. However, these new methods still need large population studies and further exploration.

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.

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.

Effect of mirtazapine on pruritus in patients on hemodialysis: a cross-over pilot study

BACKGROUND

Uremic pruritus (UP) is a highly prevalent and disturbing problem in patients with advanced chronic kidney disease (CKD); however, treatment of UP is largely unsatisfactory. The present study was designed to investigate the effectiveness of mirtazapine, an atypical antidepressant agent with potent antagonistic activity against serotonin (5HT2, 5HT3) and histamine (H1) receptors, in the treatment of pruritus in hemodialysis (HD) patients.

METHODS

An 8-week long, prospective, open-label, and cross-over randomized clinical trial study was conducted on 77 HD patients with chronic pruritus. After a 2-week washout period, eligible patients were randomly assigned either to the mirtazapine (15 mg per day) or gabapentin (100 per day) for 2 weeks. Following 2 weeks washout period, subjects crossed over to the other treatment arm for 2 more weeks. The severity of pruritus was measured seven times during each treatment period using the visual analogue scale (VAS). Furthermore, at the end of the study, patients also were blindly asked which treatment (first or last in the sequential course of the study) they preferred.

RESULTS

Sixty-one patients completed two treatment periods of the study. Although, compared to baseline, both gabapentin and mirtazapine treatment resulting in significant improvement in VAS scores, decreasing in pruritus severity was significantly greater in the mirtazapine treatment period compared with the gabapentin treatment period (P < 0.001). Furthermore, although side effects such as drowsiness and dry mouth more reported in the mirtazapine treatment period, overall higher percentage of the study patients preferred mirtazapine over gabapentin for the treatment of their pruritus symptoms.

CONCLUSIONS

Although preliminary, our study provides evidence that mirtazapine can be an effective therapy for UP in patients who are on maintenance HD. However, further studies would be necessary to confirm effectiveness as well as the safety of mirtazapine in the long-term management of chronic pruritus.

Development and Validation of a Uremic Pruritus Treatment Algorithm and Patient Information Toolkit in Patients With Chronic Kidney Disease and End Stage Kidney Disease

CONTEXT

Uremic pruritus (UP) affects up to half of all patients with kidney disease and has been independently associated with poor patient outcomes. UP is a challenging symptom for clinicians to manage as there are no validated guidelines for its treatment.

OBJECTIVES

The study aimed to develop and validate an algorithm and patient information toolkit for the treatment of UP in patients with kidney disease.

METHODS

The study involved a literature search and development of an initial draft algorithm, followed by content and face validation of this algorithm. Validation entailed three rounds of interviews with six nephrology clinicians per round. Participants assessed the relevance of each component of the algorithm and then rated a series of statements on a scale of 1-5 to assess face validity of the algorithm. After each round, the content validity index (CVI) of each algorithm component was calculated, and the algorithm was revised by the study team in response to findings. This process was followed by a second study that developed and validated a patient information pamphlet and video.

RESULTS

Algorithm validation participants were affiliated with three institutions and included seven physicians, four registered nurses, three nurse practitioners, three pharmacists, and a dietician. The average CVI of the algorithm components across all three rounds was 0.89, with 0.80 commonly cited as the lower acceptable limit for content validation. More than 78% of participants rated each face validity statement as "Agree" or "Strongly Agree". For the patient information tools, five clinicians and 15 patients were included in validation. The average CVI was 1.00 for both tools, and the average face validity was 92%.

CONCLUSION

A treatment algorithm and patient information toolkit for managing UP in patients with kidney disease were developed and validated through expert review. Further research will be conducted on implementation of the treatment algorithm and evaluating patient-reported outcomes.

Successful liver transplantation for drug-induced vanishing bile duct syndrome

Drug-induced cholestasis has a wide range of clinical presentations, and in a small number of patients, it can progress to severe ductopenia. A 63-year-old woman was referred to our department with progressive cholestasis and hyperbilirubinaemia following a course of flucloxacillin. Despite the comprehensive laboratory, imaging and genetic investigations, no other cause for the cholestasis was demonstrated. Sequential liver biopsies confirmed the development of vanishing bile duct syndrome. She developed significant cachexia and pruritus that did not respond to medical therapy, and hence she was listed for liver transplantation. She underwent liver transplantation 6 months after the initial drug-induced injury. She has remained well with good graft function at 1-year follow-up. The case highlights an extreme form of drug-induced ductopenia and underscores the need for meticulous hepatology input and consideration of liver transplantation in some patients.

Treatment of Uremic Pruritus: A Systematic Review

BACKGROUND

Uremic pruritus is a common and burdensome symptom afflicting patients with advanced chronic kidney disease (CKD) and has been declared a priority for CKD research by patients. The optimal treatments for uremic pruritus are not well defined.

STUDY DESIGN

Systematic review.

SETTING & POPULATION

Adult patients with advanced CKD (stage ≥ 3) or receiving any form of dialysis.

SELECTION CRITERIA FOR STUDIES

PubMed, CINAHL, Embase, International Pharmaceutical Abstracts, Scopus, Cochrane Library, and ClinicalTrials.gov from their inception to March 6, 2017, were systematically searched for randomized controlled trials (RCTs) of uremic pruritus treatments in patients with advanced CKD (stage ≥ 3) or receiving any form of dialysis. 2 reviewers extracted data independently. Risk of bias was assessed using the Cochrane Collaboration risk-of-bias tool.

INTERVENTION

Any intervention for the treatment of uremic pruritus was included.

OUTCOMES

A quantitative change in pruritus intensity on a visual analogue, verbal rating, or numerical rating scale.

RESULTS

44 RCTs examining 39 different treatments were included in the review. These treatments included gabapentin, pregabalin, mast cell stabilizers, phototherapy, hemodialysis modifications, and multiple other systemic and topical treatments. The largest body of evidence was found for the effectiveness of gabapentin. Due to the limited number of trials for the other treatments included, we are unable to comment on their efficacy. Risk of bias in most studies was high.

LIMITATIONS

Heterogeneity in design, treatments, and outcome measures rendered comparisons difficult and precluded meta-analysis.

CONCLUSIONS

Despite the acknowledged importance of uremic pruritus to patients, with the exception of gabapentin, the current evidence for treatments is weak. Large, simple, rigorous, multiarm RCTs of promising therapies are urgently needed.

Psychotropics in different causes of itch: systematic review with controlled studies

Among the wide range of symptoms neglected or resistant to conventional treatments in clinical practice, itch is emerging gradually as a theme to be studied. Itch complaints and the negative effects in the quality of life are observed in several medical fields. Although the partially obscure pathophysiology, some researchers decided to check and test the use of psychotropic drugs in resistant itch to conventional topical treatments and antihistamines. The objective of this study was to evaluate scientific evidence in psychotropic use in the treatment of itch of various causes. This is a systematic review of scientific literature. The following databases were used: PubMed, Web of Science, Scopus and Scielo. Randomized controlled trials that should focus on treatment with psychotropic drugs of pruritus of various causes were the inclusion criteria. All articles were analyzed by the authors, and the consensus was reached in cases of disagreement. Fifteen articles were included after analysis and selection in databases, with the majority of clinical trials focusing on psychopharmacological treatment of itch on account of chronic kidney disease. Clinical trials with psychotropic drugs mostly indicated significant improvement in the itching. In most trials of chronic kidney disease as basal disease for itch, greater effectiveness was observed with the use of psychotropic drugs compared with placebo or other antipruritic. However, the small amount of controlled trials conducted precludes the generalization that psychiatric drugs are effective for itch of various causes.

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.

Pharmacological interventions for pruritus in adult palliative care patients

BACKGROUND

This is an update of the original Cochrane review published in 2013 (Issue 6). Pruritus occurs in patients with disparate underlying diseases and is caused by different pathologic mechanisms. In palliative care patients, pruritus is not the most prevalent but is one of the most puzzling symptoms. It can cause considerable discomfort and affects patients' quality of life.

OBJECTIVES

To assess the effects of different pharmacological treatments for preventing or treating pruritus in adult palliative care patients.

SEARCH METHODS

For this update, we searched CENTRAL (the Cochrane Library), and MEDLINE (OVID) up to 9 June 2016 and Embase (OVID) up to 7 June 2016. In addition, we searched trial registries and checked the reference lists of all relevant studies, key textbooks, reviews and websites, and we contacted investigators and specialists in pruritus and palliative care regarding unpublished data.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) assessing the effects of different pharmacological treatments, compared with a placebo, no treatment, or an alternative treatment, for preventing or treating pruritus in palliative care patients.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed the identified titles and abstracts, performed data extraction and assessed the risk of bias and methodological quality. We summarised the results descriptively and quantitatively (meta-analyses) according to the different pharmacological interventions and the diseases associated with pruritus. We assessed the evidence using GRADE (Grading of Recommendations Assessment, Development and Evaluation) and created 10 'Summary of findings' tables.

MAIN RESULTS

In total, we included 50 studies and 1916 participants in the review. We added 10 studies with 627 participants for this update. Altogether, we included 39 different treatments for pruritus in four different patient groups.The overall risk of bias profile was heterogeneous and ranged from high to low risk. However, 48 studies (96%) had a high risk of bias due to low sample size (i.e. fewer than 50 participants per treatment arm). Using GRADE criteria, we downgraded our judgement on the quality of evidence to moderate in seven and to low in three comparisons for our primary outcome (pruritus), mainly due to imprecision and risk of bias.In palliative care participants with pruritus of different nature, the treatment with the drug paroxetine, a selective serotonin reuptake inhibitor, reduced pruritus by 0.78 points (numerical analogue scale from 0 to 10; 95% confidence interval (CI) -1.19 to -0.37; one RCT, N = 48, quality of evidence: moderate) compared to placebo.For participants suffering from uraemic pruritus (UP), gabapentin was more effective than placebo (visual analogue scale (VAS): 0 to 10), mean difference (MD) -5.91, 95% CI -6.87 to -4.96; two RCTs, N = 118, quality of evidence: moderate). The κ-opioid receptor agonist nalfurafine showed amelioration of UP (VAS 0 to 10, MD -0.95, 95% CI -1.32 to -0.58; three RCTs, N = 422, quality of evidence: moderate) and only few adverse events. Moreover, cromolyn sodium relieved UP participants from pruritus by 2.94 points on the VAS (0 to 10) (95% CI -4.04 to -1.83; two RCTs, N = 100, quality of evidence: moderate) compared to placebo.In participants with cholestatic pruritus (CP), data favoured rifampin (VAS: 0 to 100, MD -24.64, 95% CI -31.08 to -18.21; two RCTs, N = 42, quality of evidence: low) and flumecinol (RR > 1 favours treatment group; RR 1.89, 95% CI 1.05 to 3.39; two RCTs, N = 69, quality of evidence: low) and showed a low incidence of adverse events in comparison with placebo. The opioid antagonist naltrexone reduced pruritus for participants with CP (VAS: 0 to 10, MD -2.26, 95% CI -3.19 to -1.33; two RCTs, N = 52, quality of evidence: moderate) compared to placebo. However, effects in participants with UP were inconclusive (percentage difference -12.30%, 95% CI -25.82% to 1.22%, one RCT, N = 32). Furthermore, large doses of opioid antagonists (e.g. naltrexone) could be inappropriate in palliative care patients because of the risk of reducing analgesia.For participants with HIV-associated pruritus, it is uncertain whether drug treatment with hydroxyzine hydrochloride, pentoxifylline, triamcinolone or indomethacin reduces pruritus because the evidence was of very low quality (e.g. small sample size, lack of blinding).

AUTHORS' CONCLUSIONS

Different interventions tended to be effective for CP and UP. However, therapies for patients with malignancies are still lacking. Due to the small sample sizes in most meta-analyses and the heterogeneous methodological quality of the included trials, the results should be interpreted cautiously in terms of generalisability.

Peripheral and spinal 5-HT receptors participate in cholestatic itch and antinociception induced by bile duct ligation in rats

Although 5-HT has been implicated in cholestatic itch and antinociception, two common phenomena in patients with cholestatic disease, the roles of 5-HT receptor subtypes are unclear. Herein, we investigated the roles of 5-HT receptors in itch and antinociception associated with cholestasis, which was induced by common bile duct ligation (BDL) in rats. 5-HT-induced enhanced scratching and antinociception to mechanical and heat stimuli were demonstrated in BDL rats. 5-HT level in the skin and spinal cord was significantly increased in BDL rats. Quantitative RT-PCR analysis showed 5-HT_1B, 5-HT_1D, 5-HT_2A, 5-HT_3A, 5-HT_5B, 5-HT₆, and 5-HT₇ were up-regulated in peripheral nervous system and 5-HT_1A, 5-HT_1F, 5-HT_2B, and 5-HT_3A were down-regulated in the spinal cord of BDL rats. Intradermal 5-HT₂, 5-HT₃, and 5-HT₇ receptor agonists induced scratching in BDL rats, whereas 5-HT₃ agonist did not induce scratching in sham rats. 5-HT_1A, 5-HT₂, 5-HT₃, and 5-HT₇ agonists or antagonists suppressed itch in BDL rats. 5-HT_1A agonist attenuated, but 5-HT_1A antagonist enhanced antinociception in BDL rats. 5-HT₂ and 5-HT₃ agonists or antagonists attenuated antinociception in BDL rats. Our data suggested peripheral and central 5-HT system dynamically participated in itch and antinociception under cholestasis condition and targeting 5-HT receptors may be an effective treatment for cholestatic itch.

Neuraxial opioid-induced itch and its pharmacological antagonism

Given its profound analgesic nature, neuraxial opioids are frequently used for pain management. Unfortunately, the high incident rate of itch/pruritus after spinal administration of opioid analgesics reported in postoperative and obstetric patients greatly diminishes patient satisfaction and thus the value of the analgesics. Many endeavors to solve the mystery behind neuraxial opioid-induced itch had not been successful, as the pharmacological antagonism other than the blockade of mu opioid receptors remains elusive. Nevertheless, as the characteristics of all opioid receptor subtypes have become more understood, more studies have shed light on the potential effective treatments. This review discusses the mechanisms underlying neuraxial opioid-induced itch and compares pharmacological evidence in nonhuman primates with clinical findings across diverse drugs. Both nonhuman primate and human studies corroborate that mixed mu/kappa opioid partial agonists seem to be the most effective drugs in ameliorating neuraxial opioid-induced itch while retaining neuraxial opioid-induced analgesia.

Pruritus ani: diagnosis and treatment

Pruritus ani is a common condition with multiple causes. Primary causes are thought to be fecal soiling or food irritants. Secondary causes include malignancy, infections including sexually transmitted diseases, benign anorectal diseases, systemic diseases, and inflammatory conditions. A broad differential diagnosis must be considered. A reassessment of the diagnosis is required if symptoms or findings are not responsive to therapy. The pathophysiology of itching, an overview of primary and secondary causes, and various treatment options are reviewed.

Ondansetron to treat pruritus due to cholestatic jaundice

Intractable itching is a symptom of cholestatic liver disease of various causes that is bothersome and difficult to manage. Although treatment of the primary cause of cholestasis is paramount in resolving the issue, given the debilitating consequences of pruritus, symptomatic treatment is frequently necessary. Although many medications including cholestyramine, rifampin, opioid antagonists (i.e., naloxone, naltrexone), phenobarbital, and antihistamines have been used to treat cholestatic-induced pruritus, none has resulted in uniform success. We report anecdotal success with the use of ondansetron to treat pruritus associated with cholestasis following prolonged intensive care unit course of a 16-year-old. The theories accounting for pruritus with cholestasis are presented, treatment options are reviewed, and the role of ondansetron in the treatment of pruritus is discussed.