Analysis of questionnaire survey to determine worldwide trends in prescriptions of biologics for the treatment of unresponsive chronic urticaria

Background

Chronic spontaneous urticaria (CSU) is a common condition treated by allergist/immunologists, but the only FDA-approved biologic medication, omalizumab, may be underutilized globally.

Objective

This study was performed to determine the global prescription of omalizumab for treatment of CSU by allergists/immunologists.

Methods

Anonymous questionnaire surveys were distributed online to World Allergy Organization (WAO) members worldwide. Categorical data were analyzed for descriptive analysis using one-way frequency tabulation in SAS 9.4.

Results

There were 348 respondents (43 missing data); Average age 51 (range 28-90); M/F 48%/52%. 58% had > 15 years of clinical experience and 10% < 5; 42% worked in private clinics, 36% public hospitals, 24% academia, 18% private hospitals, and 4% in community practice. Eighty-two percent (82%) prescribed omalizumab for CSU patients and use of omalizumab was highest among young practitioners. The most significant barriers were cost (63%) and restricted formulary (24%). Drug safety (63%) and chances of adverse events (47%) were the most significant factors deciding treatment. Twenty-two percent (22%) reported 80-100% of CSU patients were complete responders to omalizumab; 34% preferred increasing frequency (q 2-weeks), and 18% preferred increasing dose (600 mg q 4-weeks) for partial or non-responders. UAS7, UCT, and CU-QoL were used to assess CSU by 55%, 29%, and 25% of respondents, respectively. Autoimmune thyroid disease (62%), thyroid abnormality (43%) and allergic rhinitis (35%) were the most frequent comorbidities reported.

Conclusions

Most clinicians favored omalizumab over other potential treatments due to safety. Although younger clinicians were more likely to prescribe omalizumab, cost and formulary access were major barriers. Only 22% of respondents reported 80% or greater of their patients had complete response to omalizumab, indicating the need for novel CSU therapies.

Variations of Thiol-Disulfide Homeostasis Parameters after Treatment with H1-Antihistamines in Patients with Chronic Spontaneous Urticaria

Background. The pathogenesis of chronic spontaneous urticaria involves metabolic, immunological, and psychological factors. The thiol–disulfide exchange reactions could be a mechanism to counteract oxidative stress in patients with chronic spontaneous urticaria. Objective: The assessment of thiol–disulfide homeostasis parameters (TDHPs) according to disease severity and the influence of H1-antihistamine therapy in patients with chronic spontaneous urticaria. Material and method. We have included 30 patients with chronic spontaneous urticaria in the study and we have determined the levels of native thiol, total thiol, disulfides as well as the disulfide/native thiol ratio, disulfide/total thiol ratio and the native thiol/total thiol ratio, before and after therapy with H1-antihistamines. Results. The results of the study showed altered levels of TDHPs and their normalization after treatment with H1-antihistamines in patients with chronic spontaneous urticaria. We determined a statistically significant increase in the serum levels of total thiol, native thiol, and native thiol/total thiol ratio and a significant reduction in the levels of disulfides, disulfide/native thiol ratio and disulfide/total thiol ratio after treatment with H1-antihistamines. The normalization of the serum levels of TDHPs has been associated with the relief of symptoms and reduction or resolution of pruritus and urticarial plaques. Conclusion. These results suggest the involvement of thiol–disulfide homeostasis in the defense against the harmful effects of reactive oxygen species in patients with chronic spontaneous urticaria and the potential role of TDHPs in monitoring H1-antihistamine therapy. To the best of our knowledge, this is the first study investigating TDHPs in patients with chronic spontaneous urticaria before and after treatment.

Management of allergic rhinitis with leukotriene receptor antagonists versus selective H1-antihistamines: a meta-analysis of current evidence

BACKGROUND

Inconsistencies remain regarding the effectiveness and safety of leukotriene receptor antagonists (LTRAs) and selective H1-antihistamines (SAHs) for allergic rhinitis (AR). A meta-analysis of randomized controlled trials (RCTs) was conducted to compare the medications.

METHODS

Relevant head-to-head comparative RCTs were retrieved by searching the PubMed, Embase, and Cochrane's Library databases from inception to April 20, 2020. A random-effects model was applied to pool the results. Subgroup analyses were performed for seasonal and perennial AR.

RESULTS

Fourteen RCTs comprising 4458 patients were included. LTRAs were inferior to SAHs in terms of the daytime nasal symptoms score (mean difference [MD]: 0.05, 95% confidence interval [CI] 0.02 to 0.08, p = 0.003, I² = 89%) and daytime eye symptoms score (MD: 0.05, 95% CI 0.01 to 0.08, p = 0.009, I² = 89%), but were superior in terms of the nighttime symptoms score (MD: - 0.04, 95% CI - 0.06 to - 0.02, p < 0.001, I² = 85%). The effects of the two treatments on the composite symptom score (MD: 0.02, 95% CI - 0.02 to 0.05, p = 0.30, I² = 91%) and rhinoconjunctivitis quality-of-life questionnaire (RQLQ) (MD: 0.01, 95% CI - 0.05 to 0.07, p = 0.71, I² = 99%) were similar. Incidences of adverse events were comparable (odds ratio [OR]: 0.97, 95% CI 0.75 to 1.25, p = 0.98, I² = 0%). These results were mainly obtained from studies on seasonal AR. No significant publication bias was detected.

CONCLUSIONS

Although both treatments are safe and effective in improving the quality of life (QoL) in AR patients, LTRAs are more effective in improving nighttime symptoms but less effective in improving daytime nasal symptoms compared to SAHs.

Improvement of patient outcomes following therapeutic optimization of chronic urticaria: two-year data from France as part of the international real-life AWARE study

BACKGROUND

It is important to assess the burden of chronic urticaria (CU) with real-life studies. The AWARE study was performed in 36 countries over two years in CU patients resistant to H1-antihistamines.

OBJECTIVES

To correlate patient-reported outcomes and available therapeutic options in CU patients.

MATERIALS & METHODS

The AWARE study was a prospective, non-interventional, international study that included adult patients who have had H1-antihistamine-resistant CU for at least two months. The primary endpoints were the evolution of disease activity (UAS7), urticaria control (UCT), dermatological quality of life (DLQI) and treatment satisfaction (visual analogic scale) during a two-year follow-up. The data from French centres are reported.

RESULTS

Ninety-two patients were included (mean age: 47.8 years; women: 70.7%; mean disease duration: 6.5 years; angioedema: 34.1%). The percentage of patients with CU treatment increased from 56.5% at inclusion to 86.0% after two years (for patients with non-sedative H1-antihistamines from 52.2% to 74.4%, and omalizumab from 2.2% to 25.6%). During the follow-up, the percentage of patients with UAS7 score <6 increased from 12.5% to 60.9%, and patients with well-controlled CU (UCT score >12) increased from 11.1% to 62.2%. The negative impact on quality of life (DLQI >10) decreased from 34.1% to 10.5%. The mean score of patient satisfaction for treatment increased from 4.6 to 7.6.

CONCLUSION

The management of CU patients resistant to H1-antihistamines was not optimal at inclusion with uncontrolled disease, impaired quality of life and insufficient treatment. After a two-year follow-up, disease symptoms and quality of life improved, but the therapeutic management could be further optimized.

Chronic urticaria in children under 15 years of age: Clinical experience beyond the clinical trials

BACKGROUND/OBJECTIVES

The aim of the study was to describe the clinical characteristics, management, and outcome of a series of children with chronic urticaria (CU).

METHODS

We retrospectively studied children aged <15 years diagnosed with CU in a tertiary teaching hospital in Palma de Mallorca, Spain, between January 2014 and March 2019. CU was defined as persistence of symptoms of wheals, with or without angioedema, for >6 weeks.

RESULTS

Twenty-nine patients (17 girls, mean age 8 years) were included. Family history of atopy was found in 31% of the cases. In 41.3% of patients, episodes of CU were associated with angioedema. Physical triggers were found in 34.5% of the cases. Most episodes of CU were successfully managed with the recommended (60.7%) or double the recommended dose (17.2%) of H1-antihistamines. Quadruple the recommended dose of H1 antihistamines was used in six patients, five of whom were finally treated with off-label omalizumab. Treatment with anti-leukotrienes was needed in one patient. Associated thyroiditis was diagnosed in one patient, which was controlled with levothyroxine.

CONCLUSIONS

Pediatric CU showed features similar to CU in adulthood, including a greater predominance in females and frequent association with personal or family history of atopy. Adult guidelines for the treatment of CU are currently extrapolated to the pediatric population. Specific tools for the assessment of disease activity and impairment of quality of life in pediatric CU are needed for use in prospective studies aimed to define treatment strategies for children with CU.

Association of H1-antihistamines with torsade de pointes: a pharmacovigilance study of the food and drug administration adverse event reporting system

Background: This study aimed to measure the association of various H1-antihistamines (H1A) with Torsade de Pointes (TdP), and present a comprehensive overview of H1A-induced TdP cases reported to the Food and Drug Administration Adverse Event Reporting System (FAERS). Methods: All H1A-induced TdP cases (n = 406) were retrieved from the FAERS database using the preferred term 'Torsade de Pointes' of MedDRA version-22 from 1990 to 2019. Four data-mining algorithms were used for disproportionality analysis: Reporting Odds Ratio (ROR); Proportional Reporting Ratio (PRR), Empirical Bayes Geometric Mean (EBGM), and Information Content (IC). H1A with >3 TdP cases were included. Results: A total of 12 signals (Astemizole, cetirizine, chlorpheniramine, clemastine, desloratadine, diphenhydramine, hydroxyzine, loratadine, meclizine, promethazine, terfenadine, and trimeprazine) were identified including six new signals (cetirizine, chlorpheniramine, clemastine, desloratadine, loratadine, and meclizine). The number of risk factors (p = 0.031) and concomitant QT-prolonging drugs (p = <0.001) were significantly lower among new signals vs old signals. Moreover, new signals were strongly associated with QT-prolongation, cardiac reactions, and electrolyte abnormalities as compared with old signals. Conclusions: Our study found the increased torsadogenic potential of new signals compared with previously known old signals, hence necessitating clinical studies to determine the actual torsadogenic potential of newly identified signals.

Safety of Ramucirumab Regimen Without H1-antihistamine Premedication in Patients With Solid Cancers

BACKGROUND/AIM

To prevent infusion-related reactions (IRRs), H1-antihistamines (H1AT) are recommended as a premedication for monoclonal antibodies, such as Ramucirumab (RAM), even though there are H1AT-related side effects, such as drowsiness and dizziness. Here, we investigated the safety of H1AT-free RAM regimens in patients with solid cancer.

PATIENTS AND METHODS

We retrospectively reviewed the patients with solid cancer receiving RAM without H1AT at Osaka Medical College Hospital between 2015 and 2019.

RESULTS

Among the 123 registered patients, 58 were identified as eligible. The total number of RAM infusions was 291, and the median number of RAM administration was 4 cycles (range=1-23 cycles). IRRs were not observed in any patient.

CONCLUSION

Although our data are preliminary and limited, H1AT-free RAM regimens may be a treatment option for cancer patients having a significant risk of developing H1AT-related side effects. Further studies are needed to confirm the safety of H1AT-free RAM regimens.

Elucidation of Inverse Agonist Activity of Bilastine

H₁-antihistamines antagonize histamine and prevent it from binding to the histamine H₁ receptor (H1R). Some of them also act as inverse agonists, which are more potent than pure antagonists because they suppress the constitutive H1R activity. Bilastine is a non-sedative antihistamine which is one of the most satisfy the requirements for oral antihistamines. However, there is no information to show the inverse agonist activity of bilastine including inositol phosphates accumulation, and its inverse agonist activity is yet to be elucidated. Here we evaluated whether bilastine has inverse agonist activity or not. Intracellular calcium concentration was measured using Fluo-8. Inositol phosphates accumulation was assayed using [³H]myo-inositol. The H1R mRNA level was measured using real-time RT-PCR. At rest, Ca²⁺ oscillation was observed, indicating that H1R has intrinsic activity. Bilastine attenuated this fluorescence oscillation. Bilastine suppressed the increase in IPs formation in a dose-dependent manner and it was about 80% of the control level at the dose of 3 μM. Bilastine also suppressed histamine-induced increase in IPs formation to the control level. Furthermore, bilastine suppressed basal H1R gene expression in a dose-dependent manner. Data suggest that bilastine is an inverse agonist. Preseasonal prophylactic administration with bilastine could down-regulate basal H1R gene expression in the nasal mucosa and ameliorate the nasal symptoms during the peak pollen period.

The burden of chronic urticaria: French baseline data from the international real-life AWARE study

BACKGROUND

The AWARE study is an ongoing international study of patients with chronic urticaria refractory to H1-antihistamines. The aim of this study is to evaluate the burden of disease and the use of healthcare resources in real-life conditions.

OBJECTIVES

To analyse the baseline data of French patients included in the AWARE study.

MATERIALS & METHODS

AWARE is a prospective, non-interventional, international study that includes adult patients who have had chronic urticaria, refractory to at least one H1-antihistamine, for at least two months.

RESULTS

Ninety-four patients (mean age: 47.9 years; 71.3% women) with chronic urticaria (50.0% spontaneous only, 9.6% inducible only, and 40.4% both) were included in French centres. The median duration from diagnosis was three years and angioedema was present in 31.5% of patients for the past six months. In 63.8% of cases, the patients received at least one treatment for urticaria (H1-antihistamine for 66.0%). Chronic urticaria was poorly controlled (UCT score <12) in 88.9% of patients and quality of life was severely impaired (mean DLQI score: 8.6). The use of healthcare resources was significant with frequent visits to general practitioners (80.8% of patients; mean: 8.1 visits). However, more than half of patients had not previously consulted a dermatologist.

CONCLUSION

These baseline data of French patients in the AWARE study show that patients suffering from chronic urticaria, refractory to H1-antihistamines for a median of three years, are insufficiently treated and that their quality of life is impaired. Despite the significant use of healthcare resources, access to specialised consultations remains insufficient.

CSACI position statement: Newer generation H1-antihistamines are safer than first-generation H1-antihistamines and should be the first-line antihistamines for the treatment of allergic rhinitis and urticaria

Oral H₁-antihistamines (AHs) are the most commonly used therapy to treat allergic rhinitis and chronic urticaria. Older, first-generation AHs (e.g. diphenhydramine, hydroxyzine) have significant and common side effects including sedation, impairment with decreased cognitive function, poor sleep quality, dry mouth, dizziness, and orthostatic hypotension. These drugs have also been found to result in death from accidents, intentional or unintentional overdoses, and sudden cardiac death. The unfavourable risk–benefit profile of first-generation AHs led to the development of newer, less-sedating second- and third-generation AHs, which first became available in Canada in the 1980s. High-quality trials have proven that newer generation AHs are superior in safety compared to older first-generation AHs. On average, they have improved potency and efficacy. Second- and third-generation AHs are the recommended first-line treatment for mild allergic rhinitis and acute and chronic urticaria. Despite this evidence, older first-generation AHs continue to be over-utilized because of their over-the-counter (OTC) status and long history of use. The Canadian Society of Allergy Clinical Immunology (CSACI) recommends that newer generation AHs should be preferred over first-generation AHs for the treatment of allergic rhino-conjunctivitis and urticaria. To promote this recommendation, education of health professionals and the public is necessary. Further, given the dangers of older first-generation AHs, we believe they should be used only as a last resort with eventual consideration given to having them only available behind the counter in pharmacies.

Expert opinion: defining response to omalizumab in patients with chronic spontaneous urticaria

Omalizumab (a recombinant, humanized anti-immunoglobulin-E antibody) has been shown in three pivotal Phase III trials (ASTERIA I, II and GLACIAL) and real-world studies to be effective and well-tolerated for the treatment of chronic spontaneous urticaria (CSU), and is the only licensed third-line treatment for CSU. However, the definition of response to omalizumab treatment often differs between clinical trials, real-world studies, and daily practice of individual physicians globally. As such, a consensus definition of "complete", "partial" and "non-response" to omalizumab is required in order to harmonize treatment management and compare data. Here, it is proposed that a disease measurement tool, for example, the 7-Day Urticaria Activity Score (UAS7) or Urticaria Control Test (UCT) is required for defining response. The addition of quality of life measurements is helpful to gain insight into a patient's disease burden and its changes during treatment. A potential omalizumab treatment approach based on speed and pattern of response at 1-3 and 3-6 months is suggested. In cases where there is no response during the first 1-3 months, physicians should consider reassessing the original CSU diagnosis. Moreover, in patients showing partial response at 12 weeks, treatment with omalizumab should be continued in order to maximize the possibility of achieving symptom control. If patients have a UAS7>6 and/or UCT<12, then continued treatment is advised, dependent on physician judgement and patient expectations. In treatment responders, omalizumab treatment can be resumed at a later stage after discontinuation with the same degree of symptom control.

Allergy, Histamine and Antihistamines

This chapter concentrates on the role in allergic disease of histamine acting on H₁-receptors. It is clear that allergy has its roots in the primary parasite rejection response in which mast cell-derived histamine creates an immediate hostile environment and eosinophils are recruited for killing. This pattern is seen in allergic rhinitis where the early events of mucus production and nasal itching are primarily histamine mediated whereas nasal blockage is secondary to eosinophil infiltration and activation. In asthma, the role of histamine is less clear. Urticaria is characterized by mast cell driven pruritic wheal and flare-type skin reactions that usually persist for less than 24 h. Although the events leading to mast cell degranulation have been unclear for many years, it is now becoming evident that urticaria has an autoimmune basis. Finally, the properties of first- and second-generation H₁-antihistamines and their role in allergic is discussed.

Treatment of chronic spontaneous urticaria with an inadequate response to H1-antihistamines: an expert opinion

Chronic spontaneous urticaria (CSU) is characterized by the sudden, continuous or intermittent appearance of pruritic wheals (hives), angioedema, or both for six weeks or more, with no known specific trigger. The international EAACI/GA²LEN/EDF/WAO urticaria guideline advises standard-dose, second-generation H1-antihistamines as first-line therapy. However, H1-antihistamine treatment leads to absence of symptoms in fewer than 50% of patients. Updosing of second-generation H1-antihistamines (up to fourfold) as recommended by the EAACI/GA²LEN/EDF/WAO urticaria guideline as second-line therapy, can improve response, but many patients remain symptomatic. Definitions of response are often subjective and a consensus is needed regarding appropriate treatment targets. There is also an unmet need for biomarkers to assess CSU severity and activity and to predict treatment response. The EAACI/GA²LEN/EDF/WAO urticaria guideline recommends add-on omalizumab, ciclosporin A (CsA), or montelukast third-line treatment in patients with an inadequate response to high-dose H1-antihistamines. Omalizumab is currently the only licensed systemic biologic for use in CSU. Both omalizumab and CsA are effective third-line CSU treatments; montelukast appears to have lower efficacy in this setting. Omalizumab carries a label warning for anaphylaxis, although no cases of anaphylaxis were reported in the phase III trials of omalizumab in CSU and it is generally well tolerated in patients with CSU. Omalizumab arguably has a better safety profile than CsA.

Second generation H1 - antihistamines interaction with food and alcohol-A systematic review

Histamine is a mediator of many physiological processes. It plays an important role in modulating allergy reactions and immune system responses. H1 receptor is a therapeutic target for drugs applied in allergic diseases such as allergic rhinoconjunctivitis, urticarial, or atopic dermatitis. H1-antihistamines display different chemical structures, pharmacokinetics and a potential for drug-drug and drug-food interactions. Drug-food interactions are known to reduce therapeutic effects of the medicine, as well as to induce a potent adverse drug reactions. Considering it all, a systematic review was conducted to investigate the importance of drug-food interaction for H1-antihistamine drugs. As non-sedating second generation H1-antihistamines remain to be drugs of choice in treating allergic conditions, the review has been focused on this particular class of medicines. The aim of this paper is to examine the evidence of food-drug and food-alcohol interactions for second generation H1-antihistamine drugs. A systematic literature queries were performed in the following databases: Medline (via PubMed), Cochrane Library, Embase and Web of Science (all from their inception date till October 2016). The queries covered nine specific names of second generation anthistamine drugs, namely bilastine, cetirizine, desloratadine, ebastine, fexofenadine, levocetirizine, loratadine, mizolastine, and rupatadine, in combinations with such terms as "food", "juice", "grapefruit", "fruits", "alcohol", "pharmacokinetics", and "meal". Additional publications were found by checking all the reference lists. Where none data on drug-food interaction could be found within the investigated databases, a specific drug prescribing information was used. 2326 publications were identified with the database queries. Articles were subjected to analysis by reviewing their title, abstract and full text; duplicated papers were removed. Having collected a complete set of data, a critical review was undertaken. For selected H1-antihistamines food, fruit juices or alcohol consumption may significantly impact the efficacy and safety of the therapy. This issue shall be well understood to educate patients properly, as it provides the major therapeutic element in allergic diseases.

The efficacy and safety of H1-antihistamine versus Montelukast for allergic rhinitis: A systematic review and meta-analysis

PURPOSE

In order to verify the differences of effectiveness and safety between SAHs and Montelukast, and to find out potential uncared-for problems, we performed a systematic review and Meta-analysis to proceed a qualitative describe and quantitative assessment.

METHODS

We searched the databases of Pubmed, the Cochrane Library, Nature and Science as well as Wanfang data and CNKI from 2000 to March 2016, using key words "Montelukast SAH" or "H1-antihistamine Montelukast", or "Loratadine Montelukast", or "Desloratadine Montelukast", or "Levocetirizine Montelukast", or "Cetirizen Montelukast", or "Fexofenadine Montelukast". And also we included studies through relevant citations in related literature. Meta-analysis and bias of risk were performed. We analyzed Heterogeneity and publish bias as well.

RESULT

Montelukast seems more effective in nighttime symptoms compare with SAHs (P=0.008, MD=-0.04, 95%CI: -0.08, -0.01). No significant difference was found between Montelukast and SAHs in CSS (P=0.10, MD=0.03, 95%CI: -0.01, 0.07). Montelukast and SAHs combined therapy was more effective than Montelukast DNSS (P=0.0006, MD=0.15, 95%CI: 0.07, 0.24) but not in CSS (P=0.04, MD=0.08, 95%CI: 0.00, 0.15; Bonferroni correction α=0.017).

CONCLUSION

Montelukast has a significant influence in improving patients' nasal symptoms quality of live but is not as effective as SAHs, and may have a slight advantage over SAHs in relieving nighttime symptoms significantly. Combined therapy is more effective in improving patients' day time symptom than Montelukast. Probably, patients might have a lower asthenia incidence rate when using Montelukas.

Emerging drugs for the treatment of perennial allergic rhinitis

INTRODUCTION

Allergic rhinitis is a worldwide health problem, currently affecting up to 40% of the general population, and characterized by the following symptoms in a variable degree of severity and duration: nasal congestion/obstruction, rhinorrhea, itchy nose and/or eyes, and/or sneezing. General symptoms like fatigue, reduced quality of sleep, impaired concentration and reduced productivity, if left untreated, may significantly affect quality of life. In addition, of being associated to various comorbidities, allergic rhinitis is also an independent risk factor for the development and worsening of asthma. Perennial allergic rhinitis is caused by allergens present around the year.

AREAS COVERED

Allergic Rhinitis and its Impact on Asthma (ARIA) guidelines currently recommend a stepwise therapeutic approach that combines patient education with specific allergen avoidance, symptomatic pharmacotherapy and allergen immunotherapy. The available treatment strategies provide suboptimal symptom relief in patients with moderate-to-severe disease who continue to experience symptoms while treated, even on multiple therapies.

EXPERT OPINION

New insights into current therapy have been provided with the development of new symptomatic drugs with improved pharmacokinetics and safety. However, the ultimate research goal is beyond symptomatic treatment, and is mainly directed at modifying the immune response to allergens and prevent the progression of allergic rhinitis towards asthma. In this direction, promising advances are expected in the fields of allergen immunotherapy and biological drugs, such as omalizumab. Finally, significant research efforts are also focused on the growing number of new specific molecular targets involved in the Th2 pathway inflammation of allergic diseases.

Computational Analysis of Structure-Based Interactions for Novel H₁-Antihistamines

As a chronic disorder, insomnia affects approximately 10% of the population at some time during their lives, and its treatment is often challenging. Since the antagonists of the H₁ receptor, a protein prevalent in human central nervous system, have been proven as effective therapeutic agents for treating insomnia, the H₁ receptor is quite possibly a promising target for developing potent anti-insomnia drugs. For the purpose of understanding the structural actors affecting the antagonism potency, presently a theoretical research of molecular interactions between 129 molecules and the H₁ receptor is performed through three-dimensional quantitative structure-activity relationship (3D-QSAR) techniques. The ligand-based comparative molecular similarity indices analysis (CoMSIA) model (Q² = 0.525, R²ncv = 0.891, R²pred = 0.807) has good quality for predicting the bioactivities of new chemicals. The cross-validated result suggests that the developed models have excellent internal and external predictability and consistency. The obtained contour maps were appraised for affinity trends for the investigated compounds, which provides significantly useful information in the rational drug design of novel anti-insomnia agents. Molecular docking was also performed to investigate the mode of interaction between the ligand and the active site of the receptor. Furthermore, as a supplementary tool to study the docking conformation of the antagonists in the H₁ receptor binding pocket, molecular dynamics simulation was also applied, providing insights into the changes in the structure. All of the models and the derived information would, we hope, be of help for developing novel potent histamine H₁ receptor antagonists, as well as exploring the H₁-antihistamines interaction mechanism.

H1-antihistamines for primary mast cell activation syndromes: a systematic review

BACKGROUND

Primary mast cell activation syndromes (MCAS) are a group of disorders presenting with symptoms of mast cell mediator release.

OBJECTIVES

To assess the effectiveness and safety of orally administered H1 -antihistamines in the treatment of primary MCAS compared with placebo and other pharmacologic treatments.

METHODS

We systematically searched five databases and three trial repositories and contacted an international panel of experts to identify published and unpublished trials.

RESULTS

A total of 36 potentially relevant studies were identified. Of these, five crossover trials, enrolling a total of 71 patients (63 adults), met the eligibility criteria. All five of these studies were judged to be at moderate or high risk of bias. Two studies compared an H1 -antihistamine with placebo, two compared two different H1 -antihistamines, and one study compared H1 - and H2 -antihistamines with oral cromolyn sodium. Four of the five randomized controlled trials were historic (reported from 1983-1993), small (enrolling 8-15 patients), and used agents and/or dosing regimens that are now less commonly used in clinical practice (i.e. azelastine, chlorpheniramine, hydroxyzine, and ketotifen). The fifth trial, which enrolled 33 adults with cutaneous and systemic mastocytosis found 4 weeks of treatment with the second-generation H1 -antihistamine rupatadine, compared with placebo, resulted in significant improvements in quality of life, symptom control (itching, wheals and flares, flushing, tachycardia, and headache, but not gastrointestinal symptoms), and reduction in itching and whealing after standardized skin provocation to elicit Darier's sign.

CONCLUSIONS

There is an urgent need for large, well-designed, double-blind, placebo-controlled randomized trials investigating the effectiveness, cost-effectiveness, and safety of second-generation H1 -antihistamines in treatment of primary MCAS.

H1-antihistamines exacerbate high-fat diet-induced hepatic steatosis in wild-type but not in apolipoprotein E knockout mice

We examined the effects of two over-the-counter H1-antihistamines on the progression of fatty liver disease in male C57Bl/6 wild-type and apolipoprotein E (ApoE)-/- mice. Mice were fed a high-fat diet (HFD) for 3 mo, together with administration of either cetirizine (4 mg/kg body wt) or fexofenadine (40 mg/kg body wt) in drinking water. Antihistamine treatments increased body weight gain, gonadal fat deposition, liver weight, and hepatic steatosis in wild-type mice but not in ApoE-/- mice. Lobular inflammation, acute inflammation, and necrosis were not affected by H1-antihistamines in either genotype. Serum biomarkers of liver injury tended to increase in antihistamine-treated wild-type mice. Serum level of glucose was increased by fexofenadine, whereas lipase was increased by cetirizine. H1-antihistamines reduced the mRNA expression of ApoE and carbohydrate response element-binding protein in wild-type mice, without altering the mRNA expression of sterol regulatory element-binding protein 1c, fatty acid synthase, or ApoB100, in either genotype. Fexofenadine increased both triglycerides and cholesterol ester, whereas cetirizine increased only cholesterol ester in liver, with a concomitant decrease in serum triglycerides by both antihistamines in wild-type mice. Antihistamines increased hepatic levels of conjugated bile acids in wild-type mice, with the effect being significant in fexofenadine-treated animals. The increase was associated with changes in the expression of organic anion transport polypeptide 1b2 and bile salt export pump. These results suggest that H1-antihistamines increase the progression of fatty liver disease in wild-type mice, and there seems to be an association between the severity of disease, presence of ApoE, and increase in hepatic bile acid levels.

International consensus on (ICON) anaphylaxis

ICON: Anaphylaxis provides a unique perspective on the principal evidence-based anaphylaxis guidelines developed and published independently from 2010 through 2014 by four allergy/immunology organizations. These guidelines concur with regard to the clinical features that indicate a likely diagnosis of anaphylaxis -- a life-threatening generalized or systemic allergic or hypersensitivity reaction. They also concur about prompt initial treatment with intramuscular injection of epinephrine (adrenaline) in the mid-outer thigh, positioning the patient supine (semi-reclining if dyspneic or vomiting), calling for help, and when indicated, providing supplemental oxygen, intravenous fluid resuscitation and cardiopulmonary resuscitation, along with concomitant monitoring of vital signs and oxygenation. Additionally, they concur that H1-antihistamines, H2-antihistamines, and glucocorticoids are not initial medications of choice. For self-management of patients at risk of anaphylaxis in community settings, they recommend carrying epinephrine auto-injectors and personalized emergency action plans, as well as follow-up with a physician (ideally an allergy/immunology specialist) to help prevent anaphylaxis recurrences. ICON: Anaphylaxis describes unmet needs in anaphylaxis, noting that although epinephrine in 1 mg/mL ampules is available worldwide, other essentials, including supplemental oxygen, intravenous fluid resuscitation, and epinephrine auto-injectors are not universally available. ICON: Anaphylaxis proposes a comprehensive international research agenda that calls for additional prospective studies of anaphylaxis epidemiology, patient risk factors and co-factors, triggers, clinical criteria for diagnosis, randomized controlled trials of therapeutic interventions, and measures to prevent anaphylaxis recurrences. It also calls for facilitation of global collaborations in anaphylaxis research. IN ADDITION TO CONFIRMING THE ALIGNMENT OF MAJOR ANAPHYLAXIS GUIDELINES, ICON: Anaphylaxis adds value by including summary tables and citing 130 key references. It is published as an information resource about anaphylaxis for worldwide use by healthcare professionals, academics, policy-makers, patients, caregivers, and the public.

Pharmacology of antihistamines

H1-antihistamines, the mainstay of treatment for urticaria, were developed from anticholinergic drugs more than 70 years ago. They act as inverse agonists rather than antagonists of histamine H1-receptors which are members of the G-protein family. The older first generation H1-antihistamines penetrate readily into the brain to cause sedation, drowsiness, fatigue and impaired concentration and memory causing detrimental effects on learning and examination performance in children and on impairment of the ability of adults to work and drive. Their use should be discouraged. The newer second-generation H1-antihistamines are safer, cause less sedation and are more efficacious. Three drugs widely used for symptomatic relief in urticaria, desloratadine, levocetirizine and fexofenadine are highlighted in this review. Of these levocetirizine and fexofenadine are the most potent in humans in vivo. However, levocetirizine may cause somnolence in susceptible individuals, whereas fexofenadine has a relatively short duration of action and may be required to be given twice daily for all round daily protection. Although desloratadine is less potent, it has the advantages of rarely causing somnolence and having a long duration of action.

A direct comparison of efficacy between desloratadine and rupatadine in seasonal allergic rhinoconjunctivitis: a randomized, double-blind, placebo-controlled study

Background

H1-antihistamines are recommended as the first-line symptomatic treatment of allergic rhinitis. The objective of this study was to evaluate the effects of rupatadine (RUP) versus desloratadine (DES) in subjects with seasonal allergic rhinitis (SAR).

Method

To assess the efficacy and safety of RUP in SAR in comparison with placebo (PL) and DES. A randomized, double-blind, multicenter, international, and PL-controlled study was carried out. The main selection criteria included SAR patients over 12 years old with a positive prick test to a relevant seasonal allergen for the geographic area. Symptomatic patients at screening with a nasal symptom sum score of ≥6 points (nasal discharge, nasal obstruction, sneezing, and nasal pruritus), a non-nasal score of ≥3 points (ocular pruritus, ocular redness, and tearing eyes), and a rhinorrhea score of ≥2 points with laboratory test results and electrocardiography within acceptable limits were included in the study. Change from baseline in the total symptom-score (T7SS) over the 4-week treatment period (reflective evaluation) was considered the primary efficacy variable. Secondary efficacy measures included total nasal symptom score (T4NSS) and conjunctival symptom score (T3NNSS), both of which are reflective and instantaneous evaluations. Furthermore questions related to quality of life (eg, sleep disturbances or impairment of daily activities) have also been evaluated. Safety was assessed according to adverse events reported, as well as laboratory and electrocardiography controls.

Results

A total of 379 patients were randomized, of which 356 were included and allocated to PL (n = 122), RUP (n = 117), or DES (n = 117). Mean change of T7SS over the 4-week treatment period was significantly reduced in the RUP (–46.1%, P = 0.03) and DES (–48.9%, P = 0.01) groups, compared with PL. Similarly, RUP and DES were comparable and significantly superior to PL for all secondary endpoints, including nasal and conjunctival symptoms and patients’ and investigator’s overall clinical opinions. Symptom score evaluation (both reflective and instantaneous evaluations) throughout the treatment period showed a progressive and maintained significant improvement with both treatments at day 7 (P = 0.01), day 14 (P = 0.007), and day 21 (P = 0.01) in comparison with PL. Adverse events were scarce and were similar in both treatment groups. Electrocardiography (QTc) and lab test results did not show any relevant findings

Conclusion

RUP is a very good choice for SAR due to its contribution to the improvement of nasal (including obstruction) and non-nasal symptoms to a similar degree as DES.