Mirtazapine for pruritus

Novel therapies for nausea and vomiting in advanced illness and supportive cancer care

Nausea and vomiting are common experiences and are often dreaded more than pain. This review discusses blonanserin, mirtazapine, and isopropyl alcohol as antiemetics. Blonanserin, an atypical antipsychotic with a high affinity for dopamine D2 and D3 receptors and serotonin receptor 5-HT2A, has less of a risk of extrapyramidal adverse effects. Transdermal blonanserin, available in Korea, Japan, and China in a small number of trials, has improved nausea in patients not responding to standard antiemetics. Mirtazapine is a noradrenergic and specific serotonergic antidepressant that has been used for multiple symptoms besides depression. There is little evidence that mirtazapine improves anorexia or nausea in advanced cancer but is as effective as olanzapine in reducing chemotherapy-induced nausea and vomiting. Isopropyl alcohol aromatherapy has been successfully used in the emergency department for nausea and vomiting with an onset to benefit more rapidly than standard antiemetics. Isopropyl alcohol prep pads can be used for home-going antiemetic therapy and as a bridge to treating acute nausea until standard antiemetics take effect.

Pharmacological update of mirtazapine: a narrative literature review

Mirtazapine (MTZ) is an antidepressant drug with an exceptional pharmacological profile. It also has an excellent safety and tolerability profile. The present review provides a pharmacological update on MTZ and summarizes the research findings of MTZ's effects on different diseases. MTZ is hypothesized to have antidepressant effects because of the synergy between noradrenergic and serotonergic actions and is effective in treating major depressive disorder and depression associated with epilepsy, Alzheimer's disease, stroke, cardiovascular disease, and respiratory disease. In cancer patients, MTZ significantly reduced sadness, nausea, sleep disruption, and pain and improved quality of life. Also, it has promising effects on Parkinson's disease, schizophrenia, dysthymia, social anxiety disorder, alcohol dependency, posttraumatic stress disorder, panic disorder, pain syndromes, obsessive-compulsive disorder, and sleep disorders. Additionally, MTZ is potentially therapeutic in different situations associated with depression, such as liver, kidney, cardiovascular, respiratory, infertility, heavy metal-induced neurotoxicity, and pruritus. Potent antioxidative, anti-inflammatory, and anti-apoptotic bioactivities mediate these promising effects. These positive outcomes of the scientific investigations motivate more and more clinical trials for a golden exceptional antidepressant in different conditions.

Ocular surface itch and pain: key differences and similarities between the two sensations

PURPOSE OF REVIEW

To review the pathophysiology and treatment of ocular itch and pain, encompassing nociceptive and neuropathic categories.

RECENT FINDINGS

Ocular itch and pain are sensations that arise from activation of ocular surface polymodal nerves. Nociceptive itch, commonly comorbid with ocular pain complaints, is mainly driven by a histamine-mediated type 1 hypersensitivity reaction. Beyond topical therapy, novel drug delivery systems are being explored to improve ocular residence time of nonsteroidal anti-inflammatory drugs (NSAIDs) and antihistamines. Nociceptive ocular pain can be driven by a variety of factors. Treatment focuses on addressing the causative sources of pain. Neuropathic ocular itch and pain are driven by nerve damage and dysfunction and as such, topical and oral neuromodulation have been explored as treatments. Oral neuromodulators include alpha 2 delta ligands, tricyclic antidepressants (TCAs), and low dose naltrexone. Novel therapies are being evaluated for both modalities such as difelikefalin (κ-opioid receptor agonist) for neuropathic itch and libvatrep (transient receptor potential vanilloid 1 antagonist) for neuropathic pain.

SUMMARY

Both ocular itch and pain can be driven by nociceptive and/or neuropathic mechanisms. Identifying contributors to abnormal ocular sensations is vital for precise medical care. Novel therapeutics for these conditions aim to improve patient outcomes and quality of life.

Mirtazapine: A One-Stop Strategy for Treatment of Opioid Withdrawal Symptoms

Public health efforts to reduce the opioid overdose epidemic and treat opioid use disorder (OUD) have met with challenges associated with current non-standardized approaches to managing opioid withdrawal symptoms, such as itching, jitteriness, anxiety, depression, craving, vomiting, diarrhea, insomnia, and anorexia. These symptoms pose substantial obstacles to the safe initiation of medications for OUD, maintenance of long-term sobriety, and prevention of relapse. In clinical practice, multiple medications (polypharmacy) are prescribed to manage these withdrawal symptoms, including ondansetron and promethazine for vomiting and nausea, loperamide and Lomotil for diarrhea, hydroxyzine and doxepin for pruritus, benzodiazepines, the Z-drugs, and melatonin for insomnia, and benzos, tricyclic antidepressants (TCAs), and various serotonergic agents for anxiety. This polypharmacy is associated with an increased risk of adverse drug-drug interactions and adverse drug events, increased medical costs, and increased odds of medication non-adherence and relapse. We propose an alternative single medication, mirtazapine, a noradrenergic and specific serotonergic receptor antagonist, that can be used for myriad symptoms of opioid withdrawal. Case series, clinical studies, and clinical trials have shown mirtazapine to be effective for treating nausea and vomiting resulting from multiple etiologies, including hyperemesis gravidarum and chemotherapy-induced emesis. Other evidence supports the salutary effects of mirtazapine on itching and craving. Research findings support mirtazapine's beneficial effects on diarrhea and anxiety, a consequence of its modulating effects on serotonergic receptors mediating mood and gastrointestinal symptoms. There is also evidence supporting its efficacy as a potent and non-addictive sleep aid, which presents itself as a solution for insomnia associated with opioid withdrawal. The current review presents evidence from extant literature supporting mirtazapine as a one-drug strategy to treat the variety of symptoms of opioid withdrawal. This one-drug strategy has much potential to decrease polypharmacy, adverse drug events, relapse, and healthcare cost and increase the likelihood of prolonged sobriety and better quality of life for people living with OUD.

[Quality of life of patients with mycosis fungoides and Sézary syndrome]

Mycosis fungoides as the most common type and Sézary syndrome as a leukemic variant belong to the rare group of cutaneous T‑cell lymphomas. Both diseases are considered incurable and show a chronic course. Since there is no curative treatment, maintaining quality of life and relief of symptoms should be important elements when treating patients with mycosis fungoides and Sézary syndrome. Pruritus, which is a common and burdensome symptom of cutaneous T‑cell lymphoma, may negatively impact quality of life. Pruritus and quality of life can be assessed with established measurement tools. Consistent recording enables physicians to recognize restrictions in physical and psychosocial aspects of quality of life early so that therapy can be adapted.

Challenging Dermatologic Considerations Associated with Immune Checkpoint Inhibitors

Immune checkpoint inhibitors have emerged as a new paradigm in oncologic care for many malignancies. However, nonspecific immune activation has led to "collateral damage" in the form of immune-related adverse events, with skin being a commonly affected organ. Cutaneous immune-related adverse events include a wide spectrum of clinical presentations and challenging considerations, often necessitating dermatology referral to support diagnosis and management, particularly for atypical presentations or more severe, cutaneous immune-related adverse events that may require specialized dermatologic evaluations including biopsy and histopathology. Close collaborations between oncologists and dermatologists may optimize clinical decision making in the following challenging management settings: non-steroidal therapies for corticosteroid-refractory, cutaneous immune-related adverse events, immune checkpoint inhibitor rechallenge, balancing cutaneous immune-related adverse events and treatments, and immune checkpoint inhibitors in patients with pre-existing autoimmune disease, skin conditions, and organ transplants. These complex clinical decisions that often lack rigorous data should be made in close collaboration with dermatologists to minimize unnecessary morbidity and mortality. This article provides a review of approaches to challenging dermatologic considerations associated with immune checkpoint inhibitor therapies.

When topical therapy of atopic dermatitis fails: a guide for the clinician

INTRODUCTION

While topical medications are the first line of treatment for mild-to-moderate atopic dermatitis, they are ineffective in individuals with diffuse disease and moderate-to-severe atopic itch. For these individuals, as well as those who do not respond to topical treatments, systemic medicines are typically essential and helpful.

AREAS COVERED

We conducted a review of the literature to identify established systemic therapies, novel biologic agents, and recent advances in the pathophysiology of atopic dermatitis. The review discusses these data, which show that the majority of atopic itch medications now in development target the type 2 immune axis and brain sensitization, two main etiologies of atopic itch. We emphasize the evidence, efficacy, and side effect profiles of currently available systemic medications for atopic itch, as well as future potential for tailored therapy.

EXPERT OPINION

We give our professional opinion on the current state of knowledge about atopic eczema pathogenesis and the innovative targets and therapies for atopic itch that include MRGPRX2, periostin, gabaergic medicines, and JAK/STAT inhibitors. Additionally, we discuss patient populations that stand to benefit the most from targeting these molecules or utilizing these drugs, as well as those who may face a disproportionate weight of adverse effects.

Use of Sertraline in Hemodialysis Patients

Depression and anxiety are the most common psychiatric disorders in end-stage renal disease (ESRD) patients treated with hemodialysis (HD) and may correlate with lower quality of life and increased mortality. Depression treatment in HD patients is still a challenge both for nephrologists and psychiatrists. The possible treatment of depressive disorders can be pharmacological and non-pharmacological. In our article, we focus on the use of sertraline, the medication which seems to be relatively safe and efficient in the abovementioned population, taking under consideration several limitations regarding the use of other selective serotonin reuptake inhibitors (SSRIs). In our paper, we discuss different aspects of sertraline use, taking into consideration possible benefits and side effects of drug administration like impact on QTc (corrected QT interval) prolongation, intradialytic hypotension (IDH), chronic kidney disease-associated pruritus (CKD-aP), bleeding, sexual functions, inflammation, or fracture risk. Before administering the medication, one should consider benefits and possible side effects, which are particularly significant in the treatment of ESRD patients; this could help to optimize clinical outcomes. Sertraline seems to be safe in the HD population when provided in proper doses. However, we still need more studies in this field since the ones performed so far were usually based on small samples and lacked placebo control.

Current Clinical Options for the Management of Itch in Atopic Dermatitis

Pruritus is the most burdensome and prevalent symptom in patients suffering from atopic dermatitis. Treating atopic itch has historically been a challenge due to multiple underlying mechanisms within its pathogenesis and an incomplete understanding of them. In recent years, our understanding of these mechanisms have increased tremendously and subsequently, new treatments have reached the market that target the pathophysiology of atopic itch from different angles. In addition, there are several promising new treatments currently in development and trials. In the current article, we discuss these currently available treatment options, their available evidence and efficacy, and highlight some of the more recent advancements in the field.

A case of severe paraneoplastic itch resistant to antihistamines and responding to serotonin reuptake inhibitors

This article covers an interesting topic. Paraneoplastic pruritus is rare but can be severe. It can sometimes be resistant to usual treatments. In our case, it was resistant to antihistamines but was relieved by inhibitors of serotonin scrapping.

Differential onset time of mirtazapine on pruritus and depression in a patient receiving hemodialysis

A 63-year-old male receiving hemodialysis for renal insufficiency developed severe and widespread pruritus, which was unresponsive to antihistamines and severe depression with insomnia, agitation, and anxiety. The oral administration of 7.5 mg mirtazapine daily alleviated his severe pruritus after 4 days and severe depression after 14 days. Mirtazapine has potential as a therapeutic option for patients receiving hemodialysis with depressive disorder and severe pruritus unresponsive to antihistamines.

Development of mirtazapine loaded solid lipid nanoparticles for topical delivery: Optimization, characterization and cytotoxicity evaluation

Mirtazapine, an antidepressant drug has been proved to exert antipruritic effect upon oral administration in numerous clinical trial studies. The objective of the current study was to develop mirtazapine loaded solid lipid nanoparticles (SLNs) and evaluate its potential as a topical drug delivery system for management of pruritus. Mirtazapine loaded SLNs were successfully developed and optimized applying Box-Behnken design. The optimized mirtazapine loaded SLNs were characterized for physicochemical parameters and morphology. The in vitro cytotoxicity and cellular uptake studies of optimized SLNs were performed in human epithelial A-431 cell line. Further, the optimized mirtazapine loaded SLNs dispersion was incorporated into gel and characterized for rheology and texture analysis. The particle size and PDI of optimized mirtazapine loaded was found to be 180.3 nm and 0.209 respectively. The cytotoxicity studies revealed the safety of mirtazapine loaded SLNs on topical administration. The developed gel showed pseudoplastic flow behavior and good textural profile. The in vitro drug release studies showed that the developed mirtazapine loaded SLNs dispersion and its gel followed Korsmeyer-Peppas model (R² = 0.905) and Higuchi model (R² = 0.928) respectively. The ex vivo drug permeation studies showed higher values for mean cumulative amount of drug released (548.25 ± 29.29 μg/cm²), permeation flux (45.10 ± 0.78 μg/cm²/h) and skin retention (11.33 ± 0.85%) of SLNs gel in comparison to pure drug gel. The stability studies indicate the stability of SLNs gel for three months at refrigerated and ambient temperatures. Therefore, abovementioned findings suggest that mirtazapine loaded SLNs could be a potential system for topical management of pruritus.

Update on Pharmacotherapy in Psychodermatological Disorders

Psychodermatological (PD) conditions encountered in dermatologic practice include primary psychiatric conditions such as delusions of parasitosis or secondary psychiatric conditions such as anxiety and depression due to dermatologic disease. The psychotropics include antipsychotic agents, anti-anxiety agents, antidepressants, and miscellaneous drugs such as anti convulsants. Anti psychotics are further divided into first-generation and second-generation drugs. Currently, second-generation drugs e.g., risperidone are preferred over first-generation drugs e.g., pimozide in delusional infestation owing to the side effect profile of the latter. Anti-anxiety agents include benzodiazepines used in acute anxiety and buspirone in chronic anxiety disorders. They are frequently prescribed along with antidepressants. Although dependence and necessity of tapering is a problem with benzodiazepines, delayed onset of action is a feature of buspirone. The commonly used antidepressants in dermatology include selective serotonin reuptake inhibitors (citalopram, escitalopram, fluoxetine, fluvoxamine, paroxetine, and sertraline), selective serotonin norepinephrine reuptake inhibitors (venlafaxine, desvenlefaxine, and duloxetine), norepinephrine dopamine reuptake inhibitors (bupropion), tricyclic antidepressants (doxepin, amitriptyline, imipramine, and clomipramine), and tetracyclic antidepressants (mirtazapine). Miscellaneous drugs include anticonvulsants such as gabapentin and pregabalin, naltrexone, and N-acetyl cysteine. The principles of PD treatment are first establish the psychiatric diagnosis, followed by initiating drug treatment. The choice of drugs is dependent on multiple factors such as side-effect profile, drug interactions, and co-morbid conditions. Usually, drugs are started at a low dose and gradually increased. A literature search was done in Pubmed, Google Scholar, and Medline databases, and articles on treatment were analyzed.

Serotonin and noradrenaline modulate chronic itch processing in mice

The roles of serotonin and noradrenaline in the modulation of chronic pruriceptive processing currently remain unclear. To clarify the contribution of serotonin and noradrenaline to chronic itch, the effects of the administration of antidepressants or noradrenaline reuptake inhibitors were evaluated in the present study. A pretreatment with milnacipran, a serotonin and noradrenaline reuptake inhibitor, and mirtazapine, a noradrenergic and specific serotonergic antidepressant, attenuated the induction of spontaneous scratching behavior in mice with chronic itch. The administration of a serotonin reuptake inhibitor, such as fluvoxamine and paroxetine, but not escitalopram, or a noradrenaline reuptake inhibitor, such as atomoxetine and nisoxetine, ameliorated the induction of spontaneous scratching behavior in mice with chronic itch. Furthermore, this attenuation was reversed by the administration of yohimbine, a selective α₂-adrenoceptor antagonist, or methysergide, a non-selective serotonin receptor antagonist. These results suggest that elevated serotonin and noradrenaline levels are involved in the attenuation of scratching behavior induced by chronic itch, and serotonin receptors and an α₂-adrenoceptor play a crucial role in chronic pruriceptive processing.

Evaluation of Efficacy of Mirtazapine on Pruritus and Serum Histamine and Serotonin Levels in Patients Undergoing Hemodialysis: A Before-After Pilot Clinical Trial

Background

Although chronic kidney disease-associated pruritus (CKD-aP) remains a frequent and frustrating symptom in patients with advanced kidney diseases, its optimal treatments are not well defined. Based on its mechanism of action, as a histamine-1 (H1), 5-(hydroxytryptamine) HT2, and 5HT3-receptor blocker, mirtazapine may be effective in the treatment of CKD-aP. Hence, this study aimed to investigate the efficacy of mirtazapine for the treatment of pruritus in patients undergoing hemodialysis (HD).

Methods

A before-after clinical trial was conducted from September 2018 until March 2019, on 30 HD-patients that had been referred to the HD ward of a tertiary hospital, in Hamadan, Iran. After the 2-week washout period, mirtazapine was administered with a dosage of 15 mg/day for an additional 2 weeks. At baseline and at each dialysis session, the effects of the mirtazapine on the pruritus severity based on the visual analogue scale (VAS) and degree of sleep interference resulting from the pruritus were asked and recorded. Additionally, at the baseline and the end of 2 weeks of treatment, the serum histamine and serotonin levels, as the main chemical pruritogens evoking pruritus symptoms, were also determined.

Results

Twenty-seven patients completed the entire course of the study. Based on the general linear model analysis, a progressive decline in the mean VAS score was observed over time during the study. The mean VAS score decreased from 8.48 ± 1.01 at baseline to 1.04 ±0.79 at the end of treatment (P-value<0.001). Similarly, the mean sleep interference scores were also significantly improved throughout treatment (decreased from 8.07±1.43 to 2.81± 0.74; P-value<0.001). Further, at the end of the treatment, a noticeable decrement in the serum histamine level was also seen (P-value = 0.006). The drug was acceptably well-tolerated and a majority of the patients were satisfied with this treatment.

Conclusion

This pilot study suggests that mirtazapine may be an effective treatment option for the management of CKD-aP. However, further studies would be needed to confirm these results.

Epidermolysis Bullosa Pruriginosa successfully treated with concomitant topical and systemic agents

Epidermolysis bullosa pruriginosa, a genetic mechanobullous disease, manifests at birth or late in life and is characterised by intense pruritus, resulting in lichenified or nodular prurigo-like lesions and scarring most prominent on the shins. Treatment is unsatisfactory. We report a patient treated with success using a combination of topical and systemic agents.

Current and emerging systemic treatments targeting the neural system for chronic pruritus

INTRODUCTION

Pruritus is a debilitating symptom that significantly affects the quality of life of patients who suffer from it. Many current and emerging systemic treatments targeting the neural system have been successful in treating itch of various underlying etiologies.

AREAS COVERED

A complete search of the PUBMED and Google Scholar databases was completed and literature pertinent to current and emerging systemic anti-pruritic drugs which target the neural system was compiled. The purpose of this review is to give the reader with an overview of the current and emerging systemic therapeutic options which target the neural system for chronic pruritus. The authors then provide the reader with their expert perspectives on the future of these therapies.

EXPERT OPINION

Exciting new anti-pruritic therapies targeting the neural system which show promise include NK-1 inhibitors, opioid receptor modulators, and drugs targeting specific itch receptors such as Mrgpr, Na_v1.7, and PAR2, as well as selective GABA modulators. Future studies should be conducted in order to fully understand these exciting therapeutic options.

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.

Pruritic Manifestation of Peripheral T Cell Lymphoma Effectively Managed with Mirtazapine: A Case Report

Chronic pruritus associated with underlying malignancy can greatly hinder a patient's quality of life. The severity is variable and patients frequently fail traditional first line therapies. We report a patient with diffuse, chronic pruritus secondary to peripheral T Cell Lymphoma (PTCL) who had same day response to mirtazapine after a litany of other agents were unsuccessful.

Safety considerations when using drugs to treat pruritus

Introduction: Treatment for chronic pruritus ranges from use of topical formulations to newer biologic agents. Targeting treatment to the underlying etiology is key in reducing the burden of disease while avoiding systemic or adverse effects.Areas covered: This review details the effective medical treatments used in various etiologies of chronic itch with a focus on the potential adverse effects and safety data available for each.Expert opinion: New drug developments in the areas of neural signaling and immune targeting show great promise for the future of chronic itch treatment. These new therapies broaden the available treatment options but also pose new considerations for safety and adverse effects.

Interventions for chronic pruritus of unknown origin

BACKGROUND

Pruritus is a sensation that leads to the desire to scratch; its origin is unknown in 8% to 15% of affected patients. The prevalence of chronic pruritus of unknown origin (CPUO) in individuals with generalised pruritus ranges from 3.6% to 44.5%, with highest prevalence among the elderly. When the origin of pruritus is known, its management may be straightforward if an effective treatment for the causal disease is available. Treatment of CPUO is particularly difficult due to its unknown pathophysiology.

OBJECTIVES

To assess the effects of interventions for CPUO in adults and children.

SEARCH METHODS

We searched the following up to July 2019: Cochrane Skin Group Specialised Register, CENTRAL, MEDLINE, Embase, and trials registries. We checked the reference lists of included studies for additional references to relevant trials.

SELECTION CRITERIA

We sought to include randomised controlled trials and quasi-randomised controlled trials that assessed interventions for CPUO, as defined in category VI ('Other pruritus of undetermined origin, or chronic pruritus of unknown origin') of the International Forum for the Study of Itch (IFSI) classification, in children and adults. Eligible interventions were non-pharmacological or topical or systemic pharmacological interventions, and eligible comparators were another active treatment, placebo, sham procedures, or no treatment or equivalent (e.g. waiting list).

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. Our primary outcomes were 'Patient- or parent-reported pruritus intensity' and 'Adverse events'. Our secondary outcomes were 'Health-related quality of life', 'Sleep disturbances', 'Depression', and 'Patient satisfaction'. We used GRADE to assess the certainty of evidence.

MAIN RESULTS

We found there was an absence of evidence for the main interventions of interest: emollient creams, cooling lotions, topical corticosteroids, topical antidepressants, systemic antihistamines, systemic antidepressants, systemic anticonvulsants, and phototherapy. We included one study with 257 randomised (253 analysed) participants, aged 18 to 65 years; 60.6% were female. This study investigated the safety and efficacy of three different doses of oral serlopitant (5 mg, 1 mg, and 0.25 mg, once daily for six weeks) compared to placebo for severe chronic pruritus; 25 US centres participated (clinical research centres and universities). All outcomes were measured at the end of treatment (six weeks from baseline), except adverse events, which were monitored throughout. A pharmaceutical company funded this study. Fifty-five per cent of participants suffered from CPUO, and approximately 45% presented a dermatological diagnosis (atopic dermatitis/eczema 37.3%, psoriasis 6.7%, acne 3.6%, among other diagnoses). We unsuccessfully attempted to retrieve outcome data from study authors for the subgroup of participants with CPUO. Participants had pruritus for six weeks or longer. Total study duration was 10 weeks. Participants who received serlopitant 5 mg may have a greater rate of relief of patient-reported pruritus intensity as measured by the visual analogue scale (VAS; a reduction in VAS score indicates improvement) compared to placebo (126 participants, risk ratio (RR) 2.06, 95% confidence interval (CI) 1.27 to 3.35; low-certainty evidence). We are uncertain of the effects of serlopitant 5 mg compared to placebo on the following outcomes due to very low-certainty evidence: adverse events (127 participants; RR 1.48, 95% CI 0.87 to 2.50); health-related quality of life (as measured by the Dermatology Life Quality Index (DLQI); a higher score indicates greater impairment; 127 participants; mean difference (MD) -4.20, 95% CI -11.68 to 3.28); and sleep disturbances (people with insomnia measured by the Pittsburgh Sleep Symptom Questionnaire-Insomnia (PSSQ-I), a dichotomous measure; 128 participants; RR 0.49, 95% CI 0.24 to 1.01). Participants who received serlopitant 1 mg may have a greater rate of relief of patient-reported pruritus intensity as measured by VAS compared to placebo; however, the 95% CI indicates that there may also be little to no difference between groups (126 participants; RR 1.50, 95% CI 0.89 to 2.54; low-certainty evidence). We are uncertain of the effects of serlopitant 1 mg compared to placebo on the following outcomes due to very low-certainty evidence: adverse events (128 participants; RR 1.45, 95% CI 0.86 to 2.47); health-related quality of life (DLQI; 128 participants; MD -6.90, 95% CI -14.38 to 0.58); and sleep disturbances (PSSQ-I; 128 participants; RR 0.38, 95% CI 0.17 to 0.84). Participants who received serlopitant 0.25 mg may have a greater rate of relief of patient-reported pruritus intensity as measured by VAS compared to placebo; however, the 95% CI indicates that there may also be little to no difference between groups (127 participants; RR 1.66, 95% CI 1.00 to 2.77; low-certainty evidence). We are uncertain of the effects of serlopitant 0.25 mg compared to placebo on the following outcomes due to very low-certainty evidence: adverse events (127 participants; RR 1.29, 95% CI 0.75 to 2.24); health-related quality of life (DLQI; 127 participants; MD -5.70, 95% CI -13.18 to 1.78); and sleep disturbances (PSSQ-I; 127 participants; RR 0.60, 95% CI 0.31 to 1.17). The most commonly reported adverse events were somnolence, diarrhoea, headache, and nasopharyngitis, among others. Our included study did not measure depression or patient satisfaction. We downgraded the certainty of evidence for all outcomes due to indirectness (only 55% of study participants had CPUO) and imprecision. We downgraded outcomes other than patient-reported pruritus intensity a further level due to concerns regarding risk of bias in selection of the reported result and some concerns with risk of bias due to missing outcome data (sleep disturbances only). We deemed risk of bias to be generally low.

AUTHORS' CONCLUSIONS

We found lack of evidence to address our review question: for most of our interventions of interest, we found no eligible studies. The neurokinin 1 receptor (NK1R) antagonist serlopitant was the only intervention that we could assess. One study provided low-certainty evidence suggesting that serlopitant may reduce pruritus intensity when compared with placebo. We are uncertain of the effects of serlopitant on other outcomes, as certainty of the evidence is very low. More studies with larger sample sizes, focused on patients with CPUO, are needed. Healthcare professionals, patients, and other stakeholders may have to rely on indirect evidence related to other forms of chronic pruritus when deciding between the main interventions currently used for this condition.

Itching as the onset of pain (part 1)

PAIN is a psychophysiological reaction of an organism that occurs with severe irritation of the sensitive nerve endings embedded in organs and tissues. And also pain is the body’s protective reaction. It is signaling about a discomfort and triggers an appropriate response by the body to eliminate the cause of the pain. Pain is one of the earliest symptoms of some diseases [84]. ITCHING – an unpleasant sensation of irritation, heartburn and tingling in any area of the skin caused by various factors (exposure to chemicals, bacteria, parasites). This feeling is often manifested by the urgent need to rub or scratch some areas of the skin (or mucous membrane) [85]. When considering the pathogenesis of these concepts, a sufficiently large resemblance to the realization of mechanisms of origin, or a certain identity thereof is revealed. The question naturally arises whether itching is an early manifestation of pain, especially in those groups of diseases that are not characterized by pain. Pathology of the hematopoietic system is not accompanied by a symptom such as pain. But for conditions such as iron overload, iron deficiency or polycythemia, itching is a clear symptom. The unknown etiology of chronic itching of the skin is indicative of histological examination of the skin in order to exclude skin lymphoma. One of the least understood mechanisms of itching is itching associated with malignant solid tumors. What pain that itching is a subjective sensation that can have an acute or chronic course, a clear intensity and a very significant impact on quality of life, especially in the case of comorbidity. In addition, the question arises whether itching is an early manifestation of pain, especially in those groups of diseases that are not characterized by pain. How can a doctor manage itching effectively to prevent complications? To these and other questions, we have attempted to systematize the manifestations of itching in pathologies of organs and systems that are not traditionally accompanied by pain.

Mirtazapine for the Treatment of Chronic Pruritus

Background: Chronic pruritus is a debilitating condition associated with a wide range of dermatologic, systemic and psychogenic etiologies. In patients with chronic pruritus that is refractory to conventional therapy, symptoms can significantly decrease quality of life by contributing to anxiety, sleep disturbances, and in many cases depression. Recent studies have demonstrated the effectiveness of mirtazapine in relieving chronic itch that is refractory to standard first-line therapies. Methods: We searched PubMed for English-language articles containing the words (“pruritus” or “itch”) AND “antidepressant” and then conducted a systematic review of the current literature to summarize the efficacy of mirtazapine in treating chronic itch. Results: All studies reported a reduction in itch intensity following the administration of mirtazapine. Conclusion: Collectively, these studies suggest the potential for mirtazapine to relieve chronic itch attributed to dermatological causes and malignancies. As, such mirtazapine may be an option for patients with chronic pruritus that is refractory to typical first-line treatments.

Defining the role of mirtazapine in the treatment of refractory pruritus

BACKGROUND/OBJECTIVE

Mirtazapine has traditionally been used for the treatment of major depressive disorder, with an added benefit in patients who have comorbid insomnia or anxiety. Recent studies describe its usefulness in treating refractory pruritus of various causes as well. Our goal is to better define the use of mirtazapine in the treatment of refractory pruritus.

METHOD

Through a thorough literature review of PubMed, we identified all reports of the use of mirtazapine for pruritus.

RESULTS

Upon examination of 8 supporting articles, we found mirtazapine has quality evidence for the treatment of intra-thecal morphine-induced pruritus. Mirtazapine may also be effective in treating pruritus related to various other conditions, including psoriasis, atopic dermatitis, cutaneous malignancies (primary or metastatic), hematologic malignancies (lymphomas and leukemias), liver failure, renal failure, cholestasis, as well as pruritus of unknown origin.

CONCLUSIONS

Mirtazapine plays a role in treatment for intra-thecel morphine-induced pruritis yet high-quality trials are needed to confirm its efficacy in other dermatologic conditions.

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.

Itching at night: A review on reducing nocturnal pruritus in children

The most common causes of chronic nocturnal itching in children are atopic dermatitis and psoriasis, with lichen simplex chronicus and prurigo nodularis contributing to lesser degrees. Despite the prevalence of nocturnal itching, its pathophysiology remains poorly understood. The most troubling consequence of itching at night is poor quality of sleep. Poor sleep quality in children with nocturnal itching has been linked to adverse neurocognitive, behavioral, and physiologic outcomes, including poor performance in school, attention deficit hyperactivity disorder, short stature, hypertension, obesity, and impaired immune function. There is no consensus on the best management of nocturnal itching in children. We conducted a review of the literature evaluating the efficacy of various treatment options for children with chronic nocturnal pruritus. Our review found three recently conducted randomized controlled trials and one case report demonstrating the efficacy of topical corticosteroids, oral melatonin, and clonidine in reducing nocturnal itching or improving sleep quality in children with nocturnal pruritus. Future research is needed to elucidate the pathophysiology of nocturnal itching to best develop targeted, effective treatment strategies.

S2k Guidelines for the diagnosis and treatment of chronic pruritus - update - short version

Associated with a host of different diseases, pruritus is a cardinal symptom that poses an interdisciplinary diagnostic and therapeutic challenge. Over time, that symptom may progress independently of the initial cause, thus losing its function as a warning sign and turning into a clinically relevant disease of its own. In Germany, approximately 13.5 % of the general population are affected by chronic pruritus, with an incidence of 7 %. All forms of chronic pruritus require targeted treatment consisting of (a) diagnosis and management of the underlying disease, (b) dermatological treatment of primary or secondary (for example, dry skin, scratch lesions) symptoms, (c) symptomatic antipruritic treatment, and (d) psychological/psychotherapeutic treatment in case of an underlying or associated psychological or psychosomatic condition. Medical care of patients with chronic pruritus should therefore include an interdisciplinary approach, in particular with respect to diagnosis and therapy of the underlying disease as well as in terms of the management of treatment and adverse events. The objective of the present interdisciplinary guidelines is to define and standardize diagnostic and therapeutic procedures in patients with chronic pruritus. This is a short version of the current S2 guidelines on chronic pruritus. The long version may be found at www.awmf.org.

Itch and psyche: psychiatric aspects of pruritus

Itch, also referred to as pruritus, is an unpleasant cutaneous sensation provoking the desire to scratch. It is often an uncomfortable, subjective sensation responsible for decreased quality of life in a variety of psychodermatological conditions. Comorbid psychiatric conditions, including depression and anxiety, are frequently associated with itch and scratch cycle. The reciprocal and intricate relationship between the psyche and itch has been widely studied. The neurobiology of itch involves the complexity of specific mediators, itch-related neuronal pathways, and central processing of itch. The connection between itch and the psyche can be grouped under three headings: pruritic diseases with psychosocial sequelae, pruritic diseases aggravated by psychosocial factors, and psychiatric disorders causing pruritus. Itch and pain modulation go together in most circumstances and involve various substances including histamine, interleukins, protease-activated receptors, transient receptor potential receptors, opioids, and cannabinoids. The close interaction between keratinocytes and nerve endings modulating pain and itch also play a major role. Management of itch associated with its psychosomatic components is directed at an underlying cause and adopting a holistic approach to address not only dermatologic and somatosensory aspects, but also the cognitive, emotional, and psychosocial components. An integrated multidisciplinary team consisting of a dermatologist, psychiatrist, psychologist, and social worker is vital in addressing the multifaceted aspects of pruritus.

Management of Itch in Atopic Dermatitis

Atopic dermatitis (AD) is the most common itchy dermatosis that affects millions of children and adults worldwide. Chronic itch in this condition has significant impact on measures of quality of life, such as sleep. Treating itch in AD has been challenging for decades, but new drugs have emerged in the last year with significant anti-pruritic effect. The optimal treatment regimen for atopic itch addresses barrier dysfunction, inflammation, neural hypersensitivity, and the itch-scratch cycle. Topical moisturizers remain the foundation of treatment and should be used by all patients with AD-associated pruritus. Step-wise therapy, from topical anti-inflammatory creams to systemic monoclonal antibodies and immunosuppressants, is recommended. There are multiple adjuvant therapies that can be used, especially to target itch in the setting of minimal skin inflammation. Finally, patient education, sleep management, and stress relief are important components to optimize outcomes. This review assesses the latest advances and treatment recommendations for pruritus in AD. Finally, suggested therapeutic ladders and emerging treatments are discussed.

Pruritus: Progress toward Pathogenesis and Treatment

Pruritus, the most common cutaneous symptom, is widely seen in many skin complaints. It is an uncomfortable feeling on the skin and sometimes impairs patients' quality of life. At present, the specific mechanism of pruritus still remains unclear. Antihistamines, which are usually used to relieve pruritus, ineffectively work in some patients with itching. Recent evidence has suggested that, apart from histamine, many mediators and signaling pathways are involved in the pathogenesis of pruritus. Various therapeutic options for itching correspondingly have been developed. In this review, we summarize the updated pathogenesis and therapeutic strategies for pruritus.

Antidepressants as antipruritic agents: A review

Pruritus is a concomitant symptom of various underlying disorders viz. dermatological, systemic and psychiatric disorders that provoke the person to scratch the skin. Many natural as well as, antipruritic therapies are usually practiced in the treatment of pruritus including general preventive measures, topical therapies such as cooling agents, antihistamines, anesthetics, capsaicin, corticosteroids, immunomodulators and; systemic therapies including administration of antihistamines, opioid antagonists/agonists, antiepileptic drugs/neuroleptics (e.g., gabapentin and pregabalin), antidepressants (e.g., doxepin, amitriptyline, paroxetine, fluvoxamine, sertraline, escitalopram and mirtazapine) (Patel and Yosipovitch, 2010; Reich et al., 2011; Martín and Padilla, 2015; Eskeland et al., 2016). Topical therapies are the mainstay of treatment of delicate and localized pruritus while other systemic drug therapies are used to treat stern and generalized pruritus. The reported antipruritic activity of some antidepressant drugs has intrigued this review to focus on the types of pruritus, pruritus mechanism, the antipruritic mechanism of antidepressants and to comprehend the role of antidepressants in the management of pruritus.

The vicious cycle of itch and anxiety

Chronic itch is associated with increased stress, anxiety, and other mood disorders. In turn, stress and anxiety exacerbate itch, leading to a vicious cycle that affects patient behavior (scratching) and worsens disease prognosis and quality of life. This cycle persists across chronic itch conditions of different etiologies and even to some extent in healthy individuals, suggesting that the final common pathway for itch processing (the central nervous system) plays a major role in the relationship between itch and anxiety. Pharmacological and nonpharmacological treatments that reduce anxiety have shown promising anti-itch effects. Further research is needed to establish specific central mechanisms of the itch-anxiety cycle and provide new targets for treatment.

Inflammatory and Noninflammatory Itch: Implications in Pathophysiology-Directed Treatments

Itch is the main chief complaint in patients visiting dermatologic clinics and has the ability to deeply impair life quality. Itch results from activation of cutaneous nerve endings by noxious stimuli such as inflammatory mediators, neurotransmitters and neuropeptides, causing itch signal transduction from peripheral skin, through the spinal cord and thalamus, to the brain cortex. Primarily noninflammatory diseases, such as uremic pruritus, cause itch through certain pruritogens in the skin. In inflammatory skin diseases, atopic dermatitis (AD) is the prototypic disease causing intensive itch by aberrant skin inflammation and epidermal barrier disruption. Recent understanding of disease susceptibility, severity markers, and mechanisms have helped to develop targeted therapy for itch in AD, including monoclonal antibodies against IL-4, IL-13, thymic stromal lymphopoietin (TSLP), IgE and IL-31. Promising effects have been observed in some of them. In this review, we summarized targeted therapies for inflammatory itch in AD and for managing abnormal itch transductions in other common itching skin diseases.

Adjunctive Management of Itch in Atopic Dermatitis

Itch, or pruritus, is a hallmark feature of atopic dermatitis (AD). The impact of AD-related pruritus can range from mildly distressing or distracting to completely disabling. Traditionally, management of itch in AD patients has focused on restoring the altered skin barrier with topical emollients and/or reducing inflammation. A growing emphasis has been placed on directly targeting the neural transmission pathways that mediate itch signaling. Off-label use of neuromodulatory agents has helped reduce this aggravating symptom in atopic patients. This article reviews the current literature on the use of neuromodulatory agents and nonpharmacologic alternative therapies used to treat AD-related pruritus.

Diagnosis and Management of Chronic Pruritus: An Expert Consensus Review

The aim of this study is to formulate the best clinical practice in the diagnosis and management of chronic pruritus (CP). We searched PubMed, EMBASE, Scopus, Web of Science, and the WHO's regional databases, for studies on "Diagnosis and management of chronic pruritus" from January 1, 2014, to July 31, 2015. We included programmatic reports and hand-searched references of published reviews and articles. Two independent reviewers screened articles and extracted data. We screened 87 of 95 studies that contained qualitative data. Avoid: Dry climate, heat, alcohol compress, ice packs, frequent bathing and washing, intake of very hot and spicy food, intake of alcohol, contact with irritant substances, excitement, strain and stress, and allergens. Using: Mild nonalkaline soaps, moisturizers, bathing oils, lukewarm water while bathing, soft cotton clothing and night creams/lotions, relaxation therapy, autogenic training, psychosocial education, educating patients to cope with itching and scratching, and educational programs. Especially use of moisturizers is considered important. In addition, symptomatic treatment options include systemic H1 antihistamines and topical corticosteroids. Symptomatic therapy directed toward the cause (hepatic, renal, atopic, polycythemia, etc.). If refractory or cause is unknown, consider capsaicin, calcineurin inhibitors for localized pruritus and naltrexone, pregabalin, ultraviolet therapy, Cyclosporine for generalized itching. CP is quite frequent finding associated with skin and systemic diseases in the overall population. It is known to significantly affect quality life score of an individual and also adds burden on the health-care cost. A specific recommendation for treatment of CP is difficult as a result of varied and diverse possibility of underlying diseases associated with CP.

Current and Emerging Therapies for Itch Management in Psoriasis

Pruritus is a common and significant symptom among patients with psoriasis. Pruritus is often present beyond the borders of psoriatic plaques, and frequently affects the scalp and genital regions. Psoriatic itch may be severe and can profoundly affect quality of life and sleep, even in the context of mild-to-moderate disease. These features often make the treatment of psoriatic pruritus challenging. However, there are a variety of effective topical and systemic treatment modalities available to address this symptom. While there remains a need for treatments that specifically target psoriatic itch, newly licensed therapies including secukinumab, ixekizumab and apremilast have been shown to rapidly and effectively mediate itch reduction.

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.

Chronic Pruritus in the Absence of Skin Disease: Pathophysiology, Diagnosis and Treatment

Chronic pruritus arises not only from dermatoses, but also, in up to half of cases, from extracutaneous origins. A multitude of systemic, neurological, psychiatric, and somatoform conditions are associated with pruritus in the absence of skin disease. Moreover, pruritus is a frequently observed side effect of many drugs. It is therefore difficult for physicians to make a correct diagnosis. Chronic pruritus patients frequently present to the dermatologist with skin lesions secondary to a long-lasting scratching behavior, such as lichenification and prurigo nodularis. A structured clinical history and physical examination are essential in order to evaluate the pruritus, along with systematic, medical history-adapted laboratory and radiological tests carried out according to the differential diagnosis. For therapeutic reasons, a symptomatic therapy should be promptly initiated parallel to the diagnostic procedures. Once the underlying factor(s) leading to the pruritus are identified, a targeted therapy should be implemented. Importantly, the treatment of accompanying disorders such as sleep disturbances or mental symptoms should be taken into consideration. Even after successful treatment of the underlying cause, pruritus may persist, likely due to chronicity processes including peripheral and central sensitization or impaired inhibition at spinal level. A vast arsenal of topical and systemic agents targeting these pathophysiological mechanisms has been used to deter further chronicity. The therapeutic options currently available are, however, still insufficient for many patients. Thus, future studies aiming to unveil the complex mechanisms underlying chronic pruritus and develop new therapeutic agents are urgently needed.