Inhibition of leukotriene synthesis by azelastine

The Topical Novel Formulations of Interferon α-2в Effectively Inhibit HSV-1 Keratitis in the Rabbit Eye Model and HSV-2 Genital Herpes in Mice

Herpes simplex viruses type 1 (HSV-1) and type 2 (HSV-2) are widespread human pathogens that establish chronic latent infections leading to recurrent episodes. Current treatments are limited, necessitating the development of novel antiviral strategies. This study aimed to assess the antiviral efficacy of novel topical formulations containing interferon alpha-2b (IFN α-2b) against HSV-1 and HSV-2. The formulations, Oftalmoferon® forte (eye drops) and Interferon Vaginal Tablets, demonstrated potent antiviral effects against HSV-1 and HSV-2 in Vero cells, respectively, with concentration-dependent inhibition of viral replication. Subsequently, their efficacy was tested in animal models: HSV-1 keratitis in the rabbit eye model and HSV-2 genital herpes in mice. Oftalmoferon® forte effectively treated HSV-1 keratitis, reducing clinical symptoms and ulcerations compared to virus control. Interferon Vaginal Tablets showed promising results in controlling HSV-2 genital herpes in mice, improving survival rates, reducing clinical signs, weight loss and viral replication. The novel IFN α-2b formulations exhibited significant antiviral activity against HSV infections in cell culture and animal models. These findings suggest the potential of these formulations as alternative treatments for HSV infections, particularly in cases resistant to current therapies. Further studies are warranted to optimize treatment regimens and assess clinical efficacy in humans.

Early intervention with azelastine nasal spray may reduce viral load in SARS-CoV-2 infected patients

With the changing epidemiology of COVID-19 and its impact on our daily lives, there is still an unmet need of COVID-19 therapies treating early infections to prevent progression. The current study was a randomized, parallel, double-blind, placebo-controlled trial. Ninety SARS-CoV-2 positive patients were randomized into 3 groups receiving placebo, 0.02% or 0.1% azelastine nasal spray for 11 days, during which viral loads were assessed by quantitative PCR. Investigators assessed patients' status throughout the trial including safety follow-ups (days 16 and 60). Symptoms were documented in patient diaries. Initial viral loads were log₁₀ 6.85 ± 1.31 (mean ± SD) copies/mL (ORF 1a/b gene). After treatment, virus load was reduced in all groups (p < 0.0001) but was greater in the 0.1% group compared to placebo (p = 0.007). In a subset of patients (initial Ct < 25) viral load was strongly reduced on day 4 in the 0.1% group compared to placebo (p = 0.005). Negative PCR results appeared earlier and more frequently in the azelastine treated groups: being 18.52% and 21.43% in the 0.1% and 0.02% groups, respectively, compared to 0% for placebo on day 8. Comparable numbers of adverse events occurred in all treatment groups with no safety concerns. The shown effects of azelastine nasal spray may thus be suggestive of azelastine's potential as an antiviral treatment.Trial registration: The study was registered in the German Clinical Trial Register (DRKS-ID: DRKS00024520; Date of Registration in DRKS: 12/02/2021). EudraCT number: 2020-005544-34.

The Nose as a Route for Therapy: Part 1. Pharmacotherapy

This article reviews nasal structure and function in the light of intranasal pharmacotherapy. The nose provides an accessible, fast route for local treatment of nose and sinus diseases, with lower doses than are necessary systemically and few adverse effects. It can also be used for other medications as it has sufficient surface area protected from local damage by mucociliary clearance, absence of digestive enzymes, responsive blood flow, and provides a rapid route to the central nervous system.

Anti-allergic drug azelastine suppresses colon tumorigenesis by directly targeting ARF1 to inhibit IQGAP1-ERK-Drp1-mediated mitochondrial fission

This study aimed to screen novel anticancer strategies from FDA-approved non-cancer drugs and identify potential biomarkers and therapeutic targets for colorectal cancer (CRC).

Methods: A library consisting of 1056 FDA-approved drugs was screened for anticancer agents. WST-1, colony-formation, flow cytometry, and tumor xenograft assays were used to determine the anticancer effect of azelastine. Quantitative proteomics, confocal imaging, Western blotting and JC-1 assays were performed to examine the effects on mitochondrial pathways. The target protein of azelastine was analyzed and confirmed by DARTS, WST-1, Biacore and tumor xenograft assays. Immunohistochemistry, gain- and loss-of-function experiments, WST-1, colony-formation, immunoprecipitation, and tumor xenograft assays were used to examine the functional and clinical significance of ARF1 in colon tumorigenesis.

Results: Azelastine, a current anti-allergic drug, was found to exert a significant inhibitory effect on CRC cell proliferation in vitro and in vivo, but not on ARF1-deficient or ARF1-T48S mutant cells. ARF1 was identified as a direct target of azelastine. High ARF1 expression was associated with advanced stages and poor survival of CRC. ARF1 promoted colon tumorigenesis through its interaction with IQGAP1 and subsequent activation of ERK signaling and mitochondrial fission by enhancing the interaction of IQGAP1 with MEK and ERK. Mechanistically, azelastine bound to Thr-48 in ARF1 and repressed its activity, decreasing Drp1 phosphorylation. This, in turn, inhibited mitochondrial fission and suppressed colon tumorigenesis by blocking IQGAP1-ERK signaling.

Conclusions: This study provides the first evidence that azelastine may be novel therapeutics for CRC treatment. ARF1 promotes colon tumorigenesis, representing a promising biomarker and therapeutic target in CRC.

The complex pathophysiology of allergic rhinitis: scientific rationale for the development of an alternative treatment option

Allergic rhinitis (AR) poses a global health problem and can be challenging to treat. Many of the current symptomatic treatments for AR have been available for decades, yet there has been little improvement in patient quality of life or symptom burden over the years. In this review, we ask why this might be and explore the pathophysiological gaps that exist within the various AR treatment classes. We focus on the benefits and drawbacks of different treatment options and delivery routes for AR treatments and consider how, given what is known about AR pathophysiology and symptomatology, patients may be offered more effective treatment options for rapid, effective, and sustained AR control. In particular, we consider how a new AR preparation, MP-AzeFlu (Dymista^®, Meda, Sweden), comprising a formulation of an intranasal antihistamine (azelastine hydrochloride), an intranasal corticosteroid (fluticasone propionate), and excipients delivered in a single spray, may offer benefits over and above single and multiple AR therapy options. We review the evidence in support of this treatment across the spectrum of AR disease. The concept of AR control is also reviewed within the context of new European Union and Contre les Maladies Chroniques pour un VIeillissement Actif-Allergic Rhinitis and its Impact on Asthma initiatives.

Modulation of Allergic Inflammation in the Nasal Mucosa of Allergic Rhinitis Sufferers With Topical Pharmaceutical Agents

Allergic rhinitis (AR) is a chronic upper respiratory disease estimated to affect between 10 and 40% of the worldwide population. The mechanisms underlying AR are highly complex and involve multiple immune cells, mediators, and cytokines. As such, the development of a single drug to treat allergic inflammation and/or symptoms is confounded by the complexity of the disease pathophysiology. Complete avoidance of allergens that trigger AR symptoms is not possible and without a cure, the available therapeutic options are typically focused on achieving symptomatic relief. Topical therapies offer many advantages over oral therapies, such as delivering greater concentrations of drugs to the receptor sites at the source of the allergic inflammation and the reduced risk of systemic side effects. This review describes the complex pathophysiology of AR and identifies the mechanism(s) of action of topical treatments including antihistamines, steroids, anticholinergics, decongestants and chromones in relation to AR pathophysiology. Following the literature review a discussion on the future therapeutic strategies for AR treatment is provided.

Effect of nasal antihistamine on secretory IgA in nasal lavage of rats

The humoral IgA is an immunoglobulin which plays a defensive role for organisms on mucosal surfaces. Today, intranasal antihistamines are effectively used in the treatment of allergic rhinitis. In our study, the effect of azelastine hydrochloride-a nasal antihistaminic-on humoral IgA of the nasal mucosa has been reviewed empirically. Twenty-four female Sprague-Dawley rats were included in our study. The rats were divided into three groups randomly. Group 1(azelastine hydrochloride): rats in this group had nasal azelastine hydrochloride (0.05%) applied for 30 days at 10 µl/nostril dosage. Group 2 (saline): saline (0.09%) was applied to the rats in this group for 30 days at 10 µl/nostril dosage. Group 3 (control): no application was made throughout the study. The chemicals applied in Groups 1 and 2 were applied to both nostrils by mounting a flexible micropipette to the end of an insulin injector. At the beginning of the study, nasal lavage was performed to both nostrils of the rats in every group on the 15th and 30th day to aspirate irrigation solution (distilled water). The aspirated liquids were kept at - 80° temperature and reviewed together at the end of study. Within-group comparisons: in Group 1 (azelastine hydrochloride), the humoral IgA value on the 15th day was significantly higher than the basal value (p = 0.037). There is a significant difference between humoral IgA value on the 30th day and humoral IgA value on the 15th day (p = 0.045). In Group 2 (saline), no significant difference is available between basal, 15th day and 30th day humoral IgA values (p = 0.265). In Group 3 (control), no significant difference is available between basal, 15th day and 30th day humoral IgA values (p = 0.374). Between-group comparison: there is no significant difference in between-group humoral IgA basal values (p = 0.714). On days 15 and 30, Humoral IgA value of Group 1 was significantly higher than that of Groups 2 and 3 (p = 0.013, p = 0.024, respectively). According to the results we achieved in our study, nasal antihistaminic (azelastine hydrochloride) significantly increases the level of humoral IgA. Our study is the first one in the literature to reveal a relation between nasal antihistaminic and humoral IgA and there is a further need for clinical, randomized and prospective studies.

Effects of azelastine nasal spray on nasal and nasopharyngeal microflora

OBJECTIVE

Azelastine nasal spray is a topical antihistaminic drug for the symptomatic treatment of allergic rhinitis. This study aimed to investigate the effects of azelastine on nasal and nasopharyngeal microflora.

METHODS

Swab samples from 25 patients prescribed azelastine nasal spray monotherapy were collected just before treatment and after 1 month of treatment. After incubation of inoculates, the number of bacteria present in cultures was measured (in colony-forming units per millilitre).

RESULTS

Evaluation of the number of microflora revealed increased bacterial reproduction after treatment, but this difference was not statistically significant. The use of azelastine nasal spray decreased the reproduction of three potentially pathogenic bacteria; however, it did not affect the reproduction of other potentially pathogenic bacteria.

CONCLUSION

The use of azelastine nasal spray for one month did not have a statistically significant effect on the numbers of nasal and nasopharyngeal microflora; it is therefore safe from a microbiological viewpoint.

Diverse ways of perturbing the human arachidonic acid metabolic network to control inflammation

Inflammation and other common disorders including diabetes, cardiovascular disease, and cancer are often the result of several molecular abnormalities and are not likely to be resolved by a traditional single-target drug discovery approach. Though inflammation is a normal bodily reaction, uncontrolled and misdirected inflammation can cause inflammatory diseases such as rheumatoid arthritis and asthma. Nonsteroidal anti-inflammatory drugs including aspirin, ibuprofen, naproxen, or celecoxib are commonly used to relieve aches and pains, but often these drugs have undesirable and sometimes even fatal side effects. To facilitate safer and more effective anti-inflammatory drug discovery, a balanced treatment strategy should be developed at the biological network level. In this Account, we focus on our recent progress in modeling the inflammation-related arachidonic acid (AA) metabolic network and subsequent multiple drug design. We first constructed a mathematical model of inflammation based on experimental data and then applied the model to simulate the effects of commonly used anti-inflammatory drugs. Our results indicated that the model correctly reproduced the established bleeding and cardiovascular side effects. Multitarget optimal intervention (MTOI), a Monte Carlo simulated annealing based computational scheme, was then developed to identify key targets and optimal solutions for controlling inflammation. A number of optimal multitarget strategies were discovered that were both effective and safe and had minimal associated side effects. Experimental studies were performed to evaluate these multitarget control solutions further using different combinations of inhibitors to perturb the network. Consequently, simultaneous control of cyclooxygenase-1 and -2 and leukotriene A4 hydrolase, as well as 5-lipoxygenase and prostaglandin E2 synthase were found to be among the best solutions. A single compound that can bind multiple targets presents advantages including low risk of drug-drug interactions and robustness regarding concentration fluctuations. Thus, we developed strategies for multiple-target drug design and successfully discovered several series of multiple-target inhibitors. Optimal solutions for a disease network often involve mild but simultaneous interventions of multiple targets, which is in accord with the philosophy of traditional Chinese medicine (TCM). To this end, our AA network model can aptly explain TCM anti-inflammatory herbs and formulas at the molecular level. We also aimed to identify activators for several enzymes that appeared to have increased activity based on MTOI outcomes. Strategies were then developed to predict potential allosteric sites and to discover enzyme activators based on our hypothesis that combined treatment with the projected activators and inhibitors could balance different AA network pathways, control inflammation, and reduce associated adverse effects. Our work demonstrates that the integration of network modeling and drug discovery can provide novel solutions for disease control, which also calls for new developments in drug design concepts and methodologies. With the rapid accumulation of quantitative data and knowledge of the molecular networks of disease, we can expect an increase in the development and use of quantitative disease models to facilitate efficient and safe drug discovery.

Transient receptor potentials (TRPs) and anaphylaxis

The transient receptor potential (TRP) superfamily consists of 28 members in mammals (27 in human) that act as polymodal sensors and ion channels. They regulate cellular calcium influx, generate depolarization thereby triggering voltage dependent cellular processes, and in turn they are critical in inducing the metabolic activities of cells. It is increasingly apparent that many of the inflammatory mediators released in allergic reactions involve at least two of these ion channels, the 'Vanilloid' TRPV1 and the 'Ankyrin" TRPA1. This review mainly focuses on TRPV1 and TRPA1 and the role they have in the allergic response and how these receptors may be influenced in exercise-induced anaphylaxis. The threshold to react to an allergen for mast cells and lymphocytes can be reduced by activating the melastatin channel TRPM4. This channel is briefly discussed in the context of allergy.

Effectiveness of twice daily azelastine nasal spray in patients with seasonal allergic rhinitis

Azelastine nasal spray (Allergodil^®, Lastin^®, Afluon^®; Meda AB, Stockholm, Sweden) is a fast-acting, efficacious and well-tolerated H1-receptor antagonist for the treatment of rhinitis. In addition it also has mast-cell stabilizing and anti-inflammatory properties, reducing the concentration of leukotrienes, kinins and platelet activating factor in vitro and in vivo, as well as inflammatory cell migration in rhinitis patients. Well-controlled studies in patients with seasonal allergic rhinitis (SAR), perennial rhinitis (PR) or vasomotor rhinitis (VMR) confirm that azelastine nasal spray has a rapid onset of action, and improves nasal symptoms associated with rhinitis such as nasal congestion and post-nasal drip. Azelastine nasal spray is effective at the lower dose of 1 spray as well at a dose of 2 sprays per nostril twice daily, but with an improved tolerability profile compared to the 2-spray per nostril twice daily regimen. Compared with intranasal corticosteroids, azelastine nasal spray has a faster onset of action and a better safety profile, showing at least comparable efficacy with fluticasone propionate (Flonase^®; GSK, USA), and a superior efficacy to mometasone furoate (Nasonex^®; Schering Plough, USA). In combination with fluticasone propionate, azelastine nasal spray exhibits greater efficacy than either agent used alone, and this combination may provide benefit for patients with difficult to treat seasonal allergic rhinitis. In addition, azelastine nasal spray can be used on an as-needed basis without compromising clinical efficacy. Compared with oral antihistamines, azelastine nasal spray also demonstrates superior efficacy and a more rapid onset of action, and is effective even in patients who did not respond to previous oral antihistamine therapy. Unlike most oral antihistamines, azelastine nasal spray is effective in alleviating nasal congestion, a particularly bothersome symptom for rhinitis sufferers. Azelastine nasal spray is well tolerated in both adults and children with allergic rhinitis. Bitter taste which seems to be associated with incorrect dosing technique is the most common side effect reported by patients, but this problem can be minimized by correct dosing technique.

Review of the pharmacology, clinical efficacy, and safety of azelastine hydrochloride

Rhinitis is one of the most common diseases in the general population. Although it is not a life-threatening condition, rhinitis can cause significant discomfort and, therefore, negatively impact quality of life. Several treatment options are available; however, optimal relief of symptoms is difficult to achieve for most patients. Azelastine hydrochloride (Astelin) nasal spray is the only prescription intranasal antihistamine available in the USA, and is approved for treating symptoms of both seasonal allergic rhinitis and nonallergic vasomotor rhinitis. Oral formulations of azelastine are available outside the USA for use in seasonal and perennial allergic rhinitis, asthma and urticaria. Azelastine hydrochloride has demonstrated a favorable safety profile during approximately 20 years of clinical use.

The effects of the nasal antihistamines olopatadine and azelastine in nasal allergen provocation

BACKGROUND

Olopatadine, an antihistamine used in allergic conjunctivitis, is under development as a nasal preparation for the treatment of allergic rhinitis.

OBJECTIVES

To evaluate the efficacy of olopatadine in suppressing symptoms and biomarkers of the immediate reaction induced by nasal allergen provocation and to compare olopatadine with azelastine in the same model.

METHODS

The study was approved by the Johns Hopkins University institutional review board, and all subjects gave written consent. We studied 20 asymptomatic subjects with seasonal allergic rhinitis. The study had 2 randomized, double-blind, placebo-controlled, crossover phases that evaluated 2 concentrations of olopatadine, 0.1% and 0.2%. In a third exploratory phase, olopatadine, 0.1%, was compared with topical azelastine, 0.1%, in a patient-masked design. Efficacy variables were the allergen-induced sneezes, other clinical symptoms, and the levels of histamine, tryptase, albumin, lysozyme, and cysteinyl-leukotrienes (third study only) in nasal lavage fluids.

RESULTS

Both concentrations of olopatadine produced significant inhibition of all nasal symptoms, compared with placebo. Olopatadine, 0.1%, inhibited lysozyme levels, but olopatadine, 0.2%, inhibited histamine, albumin, and lysozyme. The effects of olopatadine, 0.1%, were comparable to those of azelastine, 0.1%.

CONCLUSIONS

Olopatadine, at 0.1% and 0.2% concentrations, was effective in suppressing allergen-induced nasal symptoms. At 0.2%, olopatadine provided evidence suggestive of inhibition of mast cell degranulation.

Azelastine hydrochloride: a review of pharmacology, pharmacokinetics, clinical efficacy and tolerability

INTRODUCTION

Azelastine hydrochloride (Astelin) nasal spray 0.1% solution is a second-generation intranasal antihistamine available in the US for treatment of both seasonal allergic rhinitis (SAR) and nonallergic vasomotor rhinitis (VMR).

SCOPE

Searches of journal articles including the title word 'azelastine' from 1979 through the present were conducted by the product manufacturer primarily through Medline and EMBASE but also included, at various times, Dialog, Biosis, Toxline, and Diogenes (an adverse-event database). One limitation of the present review is that it could not exclude the possibility of publication bias, whereby findings from smaller studies and/or trials with negative findings may not have been published.

FINDINGS

Azelastine is a phthalazinone derivative with H(1)-receptor binding approximately tenfold greater than chlorpheniramine on a milligram-per-milligram basis. Azelastine has demonstrated a wide range of pharmacologic effects on chemical mediators of inflammation including leukotrienes, kinins, and platelet activating factor in vitro and in vivo. The molecule also has been shown to downregulate intercellular adhesion molecule-1 expression and to reduce inflammatory cell migration in patients with rhinitis. Well-controlled studies in SAR and VMR demonstrated that azelastine nasal spray improves nasal symptoms of rhinitis, including congestion and postnasal drip, and has a rapid onset of action that appears likely due to topical activity. Azelastine nasal spray has demonstrated greater efficacy when used in combination with fluticasone propionate nasal spray when compared to either agent alone, and this combination may provide benefit for patients with moderate-to-severe rhinitis. Bitter taste is the most common side effect associated with azelastine nasal spray and this problem can be mitigated by the dosing technique recommended by the manufacturer in the product labeling. The incidence of somnolence also may be reduced with the recommended administration technique.

CONCLUSIONS

Azelastine is an effective, rapid-acting, and well-tolerated second-generation antihistamine that improves nasal symptoms associated with SAR and VMR. Clinical studies demonstrated that azelastine nasal spray can improve symptoms of SAR in patients who remained symptomatic after treatment with oral antihistamines and that azelastine nasal spray in combination with fluticasone nasal spray provided significantly (p < 0.05) greater relief than either agent alone in patients with SAR.

Inhibition of IgE-mediated phosphorylation of FcεRIγ protein by antiallergic drugs in rat basophilic leukemia (RBL-2H3) cells: A novel action of antiallergic drugs

We examined the effect of antiallergic drugs, azelastine and epinastine, on the expression of FcepsilonRIalpha, beta, and gamma chains and phosphorylation of the gamma chains in rat basophilic leukemia (RBL-2H3) cells. The cells were cultured for 24 h with IgE treatment in the presence of azelastine or epinastine at the concentration of 10(-5) M. The FcepsilonRIalpha mRNA expression was determined by northern blot analysis. The protein level of FcepsilonRI expressed on the plasma membrane was examined following IgE treatment by immunoprecipitation with anti-IgE light chain, followed by western blot analysis with anti-gamma chain of FcR. Azelastine and epinastine had no effect on the FcepsilonRIalpha, beta and gamma mRNA levels. Although the amount of gamma chain assembled into IgE-bound FcepsilonRI was not changed by treatment with azelastine nor epinastine, phosphorylation levels of gamma chains of IgE-bound FcepsilonRI were inhibited by azelastine. The inhibitory effect of azelastine on the IgE-mediated expression of FcepsilonRIgamma protein is not due to their inhibition of mRNA and protein expression, but due to abrogating phosphorylation of the gamma chains, which is important for initiation of FcepsilonRI signaling cascade elicited by IgE interaction.

Antiallergic drugs, azelastine hydrochloride and epinastine hydrochloride, inhibit ongoing IgE secretion of rat IgE-producing hybridoma FE-3 cells

We asked whether or not antiallergic drugs, azelastine hydrochloride and epinastine hydrochloride, inhibit IgE secretion from IgE-producing hybridoma FE-3 cells. FE-3 cells were cultured in the presence of azelastine or epinastine for 24 h, washed in phosphate-buffered saline , and then recultured in the medium in the absence of the antiallergic drugs. IgE levels in the cultured medium as well as those in the cytoplasm of FE-3 cells were measured by enzyme-linked immunosorbent assay. mRNA levels of Cepsilon, activation-induced cytidine deaminase (AID), XBP-1, and Bip were estimated by northern blot or reverse transcriptase polymerase chain reaction analysis. The activities of nuclear factor-kappa B (NF-kappaB) were analyzed by electrophoretic mobility shift assay (EMSA). Phosphorylation of I kappa B alpha (IkappaBalpha) was analyzed by immunoprecipitation followed by western blot analysis. IgE levels in the cultured medium and in the microsome fraction were lower on the treatment with 10(-5) M azelastine or epinastine than those on the treatment with vehicle. Cepsilon and AID mRNA levels were lower on the treatment with 10(-5) M azelastine than those on the treatment with vehicle, but were not decreased on the treatment with 10(-5) M epinastine. XBP-1 and Bip mRNA levels were not altered following treatment of the antiallergic drugs. Azelastine at 10(-5) M, but not epinastine, reduced DNA binding activity of NF-kappaB and also diminished IkappaBalpha phosphorylation, leading to sustaining IkappaBalpha protein levels. These findings suggest that azelastine exerts its inhibitory effect on the IgE secretion from FE-3 cells through the inhibition of Cepsilon mRNA expression, and that the inhibitory effect of epinastine is, at least in part, due to suppression of IgE synthesis at the post-transcriptional level.

Anthrax lethal toxin induces ketotifen-sensitive intradermal vascular leakage in certain inbred mice

Bacillus anthracis lethal toxin (LT) is a bipartite toxin composed of protective antigen (PA) and lethal factor (LF). Injection of LT produces clinical signs characteristic of anthrax infection, including pleural edema and vascular collapse in various animal models. We utilized the classic Miles leakage assay to quantify vascular leakage in mice. LT injected intradermally induced leakage as early as 15 to 25 min in some inbred mouse strains, but not in others, whereas PA or LF individually did not induce leakage. A third component of anthrax toxin, edema factor, did not induce leakage alone or with PA. Leakage was quantified in eight mouse strains, and no correlation was found between sensitivity to intradermal leakage and sensitivity to the lethality of systemically administered LT. The leakage could be inhibited by ketotifen, an inhibitor of mast cell degranulation, but not by azelastine, a histamine receptor 1 antagonist, or by ketanserin, a serotonin 5-HT2A receptor antagonist. LT was cytotoxic to MC/9 mast cells (in vitro) by 7 h after toxin treatment but did not induce histamine release from these cells. Mast cell-deficient mice exhibited the leakage event and had no increased resistance to systemic LT. Human umbilical vein endothelial cells were resistant to LT over 12 h, with only 20% of cells succumbing by 24 h, suggesting that endothelial cell killing is not the cause of the rapid LT-mediated leakage event. We describe here a ketotifen-sensitive vascular leakage event induced by LT which is the most rapid in vivo or in vitro LT-mediated effect reported to date.

Allergic rhinitis: impact of the disease and considerations for management

AR is a common condition affecting individuals of all ages. Those afflicted with AR often suffer from associated inflammatory conditions of the mucosa,such as AC, rhinosinusitis, asthma, otitis media with effusion, and other atopic conditions, such as eczema and food allergies. Lack of treatment or treatment with suboptimal therapy may result in reduced quality of life and compromise productivity at work or school. Although environmental controls may prove difficult to implement, and not all controls appear adequately to mitigate symptoms of AR, they continue to represent a foundation for treatment. Many different classes of medications are now available, and they have been shown to be effective and safe in a large number of well-designed, double-blind, placebo-controlled clinical trials. Some of the over-the-counter medi-cations have been associated with increased sedation, potentially leading to accidents and fatalities at work or while operating complex machinery, such as automobiles. Only immunotherapy with increasing doses of individually targeted allergens results in sustained changes in the immune system. Although anti-IgE is probably only the first successful immunomodulator commercially available to treat AR, monoclonal antibodies will remain too costly, at least in the near future, to find their way into routine AR treatment.

Drug therapy for ocular allergy

The spectrum of ocular allergy ranges from mild, non-sight threatening disease, such as hay fever, to disorders such as atopic keratoconjunctivitis (AKC) which cause permanent ocular surface changes and reduced vision. The ideal treatment is with topical preparations. Launched topical preparations include anti-histamines and mast cell (MC) stabilisers, which are safe, but only moderately potent, steroids, which are very potent, but carry very serious side-effects, and cyclosporin A, which is not widely available and difficult to tolerate. There are a number of anti-histamines, MC stabilisers (and combinations thereof) and steroids in development which are of potential interest. Other possibilities for therapeutic intervention include inhibition of tryptase, cyclooxygenase (COX), leukotrienes (LTs), bradykinins (BKs), platelet activating factor (PAF) and immunoglobulin E (IgE). Therapies based on cytokine antagonism and agonism, T-cell inhibition and adhesion molecule antagonism might be expected to provide safe, but potent new modes of treatment. The increasing interest in research into the pathogenesis of ocular allergic inflammation may lead to more relevant approaches, such as eosinophil inhibition. Success will be highly dependent on the ability to produce suitable topical ophthalmic preparations.

Efficacy of azelastine nasal spray in seasonal allergic rhinitis patients who remain symptomatic after treatment with fexofenadine

BACKGROUND

Currently available oral second-generation antihistamines do not provide adequate symptom relief for many allergy patients.

OBJECTIVE

To determine the ability of azelastine nasal spray to improve rhinitis symptoms in patients with seasonal allergic rhinitis who remained symptomatic after treatment with fexofenadine.

METHODS

This was a multicenter, randomized, double-blind, placebo-controlled, 2-week study in patients with moderate-to-severe seasonal allergic rhinitis. The study began with a 1-week, open-label lead-in period, during which patients received fexofenadine, 60 mg twice daily. Patients who improved less than 25% to 33% with fexofenadine were randomized to treatment with (1) azelastine nasal spray, 2 sprays per nostril twice daily; (2) azelastine nasal spray, 2 sprays per nostril twice daily, plus fexofenadine, 60 mg twice daily; or (3) placebo (saline) nasal spray and placebo capsules twice daily. The primary efficacy variable was the change from baseline to day 14 in the total nasal symptom score (TNSS), consisting of runny nose, sneezing, itchy nose, and nasal congestion symptom scores.

RESULTS

A total of 334 patients who remained symptomatic after treatment with fexofenadine were included in the efficacy analysis. After 2 weeks of treatment, azelastine nasal spray (P = .007) and azelastine nasal spray plus fexofenadine (P = .003) significantly improved the TNSS compared with placebo. Azelastine nasal spray monotherapy was as effective as the combination of azelastine nasal spray plus fexofenadine as measured by the TNSS and individual symptoms of the TNSS.

CONCLUSIONS

Azelastine nasal spray is effective monotherapy for patients who remain symptomatic after treatment with fexofenadine and should be considered in the initial management of patients with seasonal allergic rhinitis.

Efficacy of azelastine nasal spray in patients with an unsatisfactory response to loratadine

OBJECTIVE

To evaluate the effectiveness and safety of azelastine nasal spray, desloratadine, and the combination of azelastine nasal spray plus loratadine compared with placebo in patients with seasonal allergic rhinitis who had an unsatisfactory response to loratadine.

METHODS

This was a 2-week, multicenter, placebo-controlled, randomized, double-blind study in patients with moderate-to-severe symptoms of seasonal allergic rhinitis. Following a 1-week, open-label lead-in period, during which the patients received loratadine 10 mg daily, those patients who met the symptom qualification criteria (<25% to 33% improvement taking loratadine) were randomized to treatment with azelastine nasal spray 2 sprays per nostril, twice daily, azelastine nasal spray 2 sprays per nostril, twice daily, plus loratadine 10 mg daily, desloratadine 5 mg daily plus placebo (saline) nasal spray, or placebo (saline) nasal spray/placebo capsules. The primary efficacy variable was the change from baseline to day 14 in the total nasal symptom score, consisting of runny nose, sneezing, itchy nose, and nasal congestion symptom scores recorded twice daily (AM and PM) in patient diary cards.

RESULTS

A total of 428 patients with an unsatisfactory response to loratadine completed the double-blind treatment period. After 2 weeks of treatment, azelastine nasal spray (P < 0.001), azelastine nasal spray plus loratadine (P < 0.001), and desloratadine (P = 0.039) significantly improved the total nasal symptom score compared with placebo.

CONCLUSIONS

Azelastine nasal spray is an effective treatment for patients with seasonal allergic rhinitis who do not respond to loratadine and is an alternative to switching to another oral antihistamine or to using multiple antihistamines.

Effects of intranasal azelastine on the response to nasal allergen challenge

OBJECTIVES/HYPOTHESIS

Azelastine, a second-generation H1-receptor antagonist, is available for topical administration. The aim of the study was to evaluate the effects of topical intranasal azelastine on the early-phase and the late-phase allergic responses and on nasal hyper-responsiveness to methacholine.

STUDY DESIGN

Double-blind, placebo-controlled, two-way crossover study in 20 subjects with seasonal allergic rhinitis, out of their allergy season.

METHODS

Subjects were randomly assigned to receive either placebo or two puffs of azelastine twice a day (548 microg/d) for 2 weeks followed by nasal challenge with allergen. Twenty-four hours later, while still receiving treatment, subjects underwent a nasal lavage and a nasal challenge with methacholine. End points included symptom scores, levels of mediators and number of eosinophils in nasal lavages, and the weight of secretions after methacholine challenge.

RESULTS

Compared with placebo, treatment with intranasal azelastine resulted in significant reductions in allergen-induced sneezing, rhinorrhea, itching, nasal congestion, and levels of albumin during the early-phase response (P <.05). Azelastine had no effect on levels of histamine or tryptase during the early-phase response. There was a significant eosinophil influx 24 hours after challenge, which was not inhibited by azelastine. Treatment with azelastine had no effect on the levels of albumin, interleukin-4, interleukin-5, intercellular adhesion molecule-1, tumor necrosis factor-alpha, and eosinophil cationic protein during the late-phase response. However, azelastine did show a significant inhibitory effect on the methacholine response 24 hours after nasal allergen challenge (P <.05).

CONCLUSIONS

The effects of intranasal azelastine are similar to those of oral second-generation antihistamines.

New insights into the second generation antihistamines

Second generation antihistamines are recognised as being highly effective treatments for allergy-based disease and are among the most frequently prescribed and safest drugs in the world. However, consideration of the therapeutic index or the benefit/risk ratio of the H1 receptor antagonists is of paramount importance when prescribing this class of compounds as they are used to treat non-life threatening conditions. There are many second generation antihistamines available and at first examination these appear to be comparable in terms of safety and efficacy. However, the newer antihistamines in fact represent a heterogeneous group of compounds, having markedly differing chemical structures, adverse effects, half-life, tissue distribution and metabolism, spectrum of antihistaminic properties, and varying degrees of anti-inflammatory effects. With regard to the latter, there is growing awareness that some of these compounds might represent useful adjunct medications in asthma therapy. In terms of safety issues, the current second generation grouping includes compounds with proven cardiotoxic effects and others with the potential for adverse drug interactions. Moreover, some of the second generation H1 antagonists have given cause for concern regarding their potential to cause a degree of somnolence in some individuals. It can be argued, therefore, that the present second generation grouping is too large and indistinct since this was based primarily on the concept of separating the first generation sedating compounds from nonsedating H1 antagonists. Although it is too early to talk about a third generation grouping of antihistamines, future membership of such a classification could be based on a low volume of distribution coupled with a lack of sedating effects, drug interactions and cardiotoxicity.

Efficacy of azelastine nasal spray in the treatment of vasomotor (perennial nonallergic) rhinitis

BACKGROUND

Azelastine hydrochloride is an antihistamine with anti-inflammatory properties that is available in the United States in a nasal spray formulation for the treatment of seasonal allergic rhinitis. Vasomotor (perennial nonallergic) rhinitis (VMR) is a noninfectious, chronic rhinitis usually not associated with inflammatory cell infiltration.

OBJECTIVE

Two multicenter, randomized, double-blind, placebo-controlled, parallel-group clinical trials were conducted to determine whether patients with symptoms of VMR (rhinorrhea, sneezing, postnasal drip, and nasal congestion) could be effectively treated with azelastine nasal spray.

METHODS

All of the patients who participated in the trials had a diagnosis of VMR, symptoms for at least 1 year, negative skin tests for a mixed panel of seasonal and perennial allergens, and a nasal cytology examination negative for eosinophils. After a 1-week, single-blind, placebo lead-in period, patients who met the symptom severity qualification criteria were randomized to receive either azelastine nasal spray (two sprays per nostril twice daily, 1.1 mg/day) or placebo nasal spray for 21 days. Patients recorded the severity of their VMR symptoms on diary cards each morning and evening of the trial using a four-point symptom rating scale (0 = none to 3 = severe). The primary efficacy variable was the overall reduction from baseline in the total vasomotor rhinitis symptom score (TVRSS) over the 21-day, double-blind treatment period.

RESULTS

In both studies, azelastine nasal spray significantly (study 1, P = .002; study 2, P = .005) reduced the TVRSS from baseline when compared with placebo. Significant improvement was observed within the first week and improvement in all symptoms favored treatment with azelastine nasal spray. No serious or unexpected adverse events were reported in either study. Bitter taste (19% vs 2%) was the only adverse experience that occurred with a statistically significantly greater incidence in the azelastine group than in the placebo group.

CONCLUSIONS

This is the first demonstration of the efficacy of an antihistamine in the therapy of VMR in two double-blind, placebo-controlled clinical trials.

Effect of topical nasal azelastine on the symptoms of rhinitis, sleep, and daytime somnolence in perennial allergic rhinitis

BACKGROUND

Recent data suggested that daytime somnolence in patients with allergic rhinitis was secondary to disrupted sleep caused by nasal congestion. Medications, which decreased congestion, would be expected to improve sleep and daytime somnolence. Previously, we demonstrated that nasal steroids improved all three symptoms. The effect of topical nasal antihistamines on these symptoms has yet to be studied.

OBJECTIVE

The objective of this 8-week, double-blind, placebo-controlled study was to determine whether topical nasal azelastine was effective at decreasing congestion, daytime somnolence, and improving sleep.

METHODS

We recruited 24 subjects with perennial allergic rhinitis and randomized them in a double-blinded, crossover fashion, to receive placebo or azelastine two sprays BID, using Balaam's design. Questionnaires, daily diary, and Epworth Sleepiness Scale were used as tools. The last 2 weeks of each 4-week treatment period were summarized, scored, and compared by PROC MIXED in SAS.

RESULTS

The analysis of the Rhinitis Severity Score showed significant improvement only of rhinorrhea in the azelastine group (P = .03). The symptom severity of nasal congestion and daytime somnolence was not significantly different between placebo and azelastine. Subjects considered azelastine effective at improving their sleep (P = .04), but daytime somnolence (P = .06) and congestion (P = .09) were not statistically improved.

CONCLUSION

Azelastine is effective in reducing rhinorrhea and improving sleep quality. We were unable to demonstrate that azelastine can significantly reduce the severity of congestion or daytime somnolence.

Double-blind trials of azelastine nasal spray monotherapy versus combination therapy with loratadine tablets and beclomethasone nasal spray in patients with seasonal allergic rhinitis. Rhinitis Study Groups

BACKGROUND

Azelastine hydrochloride is an H1-receptor antagonist with antiinflammatory properties that is available in the US as Astelin Nasal Spray for the treatment of seasonal allergic rhinitis. The symptoms of seasonal allergic rhinitis can initially be treated with monotherapy using either an antihistamine or an intranasal corticosteroid. Patients whose symptoms do not respond adequately are often prescribed a combination of both an antihistamine and an intranasal corticosteroid.

OBJECTIVE

Three multicenter, randomized, double-blind studies were conducted to determine whether patients with moderate-to-severe symptoms of seasonal allergic rhinitis who had responded inadequately to monotherapy with either an oral antihistamine or an intranasal corticosteroid, and who were candidates for combination therapy with both an oral antihistamine and an intranasal corticosteroid, could be effectively treated with azelastine nasal spray monotherapy.

METHODS

Following a 1- to 2-week washout period, patients were randomized to 7 days of double-blind treatment with either azelastine nasal spray (2 sprays per nostril bid, 1.1 mg/day) monotherapy or combination therapy with oral loratadine (Claritin, one 10-mg tablet/day) plus intranasal beclomethasone dipropionate monohydrate (Beconase AQ, 2 sprays per nostril bid, 336 microg/day). Efficacy was determined at the end of the study by both a physician assessment of the need for additional anti-rhinitis medication and a patient global evaluation of therapeutic effectiveness. The three studies were conducted at 71 investigational sites during the 1998 spring allergy season. Three separate studies were conducted to verify the reproducibility of the new study design.

RESULTS

In all three studies a total of 1,070 patients were randomized to double-blind treatment. There were no statistically significant differences in the percentage of patients treated with azelastine nasal spray versus patients treated with a combination of loratadine tablets and beclomethasone nasal spray who did not require additional anti-rhinitis medication (32% to 45% and 39% to 46%, respectively). The patient global evaluation indicated that 77% to 84% of the patients treated with azelastine nasal spray had symptomatic improvement and 85% to 90% of the patients treated with loratadine tablets and beclomethasone nasal spray had symptomatic improvement. The most commonly reported adverse experience with azelastine nasal spray was a transient aftertaste (8%), while the most commonly reported adverse experience with loratadine tablets and beclomethasone nasal spray in combination was headache (6%).

CONCLUSIONS

Based on the percentage of patients not requiring additional antirhinitis medication and the patient assessment of efficacy, azelastine nasal spray monotherapy was as effective as the combination of oral loratadine plus intranasal beclomethasone in treating moderate-to-severe symptoms of seasonal allergic rhinitis.

Management of allergic rhinitis with a combination antihistamine/anti-inflammatory agent

Azelastine nasal spray is a topical antihistamine treatment for the symptoms of seasonal allergic rhinitis. Besides histamine antagonism, azelastine affects other chemical mediators of the inflammatory response including leukotrienes and kinins. This article reviews and discusses the antihistaminic and anti-inflammatory properties of azelastine and the results of pharmacokinetic studies and controlled clinical trials.

Pharmacological inhibition of leukotriene actions

Leukotrienes represent a group of lipid mediators that play a very important role in a wide variety of pathological conditions. The presence of leukotrienes in inflammatory sites has been extensively documented, and accordingly research efforts have been directed towards the development of drugs that interfere with the formation or effects of leukotrienes. Although clinical application of such drugs has been disappointing in the past, recent discoveries of more potent and selective drugs seem to be promising. This review attempts to highlight some of these exciting developments.