The effect of azelastine on the early allergic response

Treatment of allergy: Overview of synthetic anti-allergy small molecules in medicinal chemistry

The prevalence of allergic diseases has been continuously increasing over the past few decades, affecting approximately 20-30% of the global population. Allergic reactions to infection of respiratory tract, digestive tract, and skin system involve multiple different targets. The main difficulty of anti-allergy research is how to develop drugs with good curative effect and less side effects by adopting new multi-targets and mechanisms according to the clinical characteristics of different allergic populations and different allergens. This review focuses on information concerning potential therapeutic targets as well as the synthetic anti-allergy small molecules with respect to their medicinal chemistry. The structure-activity relationship and the mechanism of compound-target interaction were highlighted with perspective to histamine-1/4 receptor antagonists, leukotriene biosynthesis, Th2 cytokines inhibitors, and calcium channel blockers. We hope that the study of chemical scaffold modification and optimization for different lead compounds summarized in this review not only lays the foundation for improvement of success rate and efficiency of virtual screening of antiallergic drugs, but also can provide valuable reference for the drug design of related promising research such as allergy, inflammation, and cancer.

Adverse Events Associated with Intranasal Sprays: An Analysis of the Food and Drug Administration Database and Literature Review

BACKGROUND

Intranasal sprays (INSs) are commonly used medications for the treatment of many rhinologic conditions. Despite their popularity, an analysis of a nationwide reporting database and comparison to the available literature has never been performed.

METHODS

The Food and Drug Administration Adverse Event Reporting System (FAERS) database was accessed to obtain adverse event (AE) records from 2014 to 2019 for varying INSs, including: 10 corticosteroids, 1 alpha adrenergic, and 3 antihistamines. The Proportional Reporting Ratios (PRR) and Reporting Odds Ratios (ROR) were calculated for dyspnea, anosmia, ageusia/dysgeusia, epistaxis, and headache. A PRR ≥ 2 or ROR ≥ 1 was considered significant.

RESULTS

Corticosteroids had 98 864 total reported AEs to the database, followed by antihistamines (7011) and alpha adrenergics (2071). In total, dyspnea was reported 5843 times, followed by headache (4230), epistaxis (1205), ageusia/dysgeusia (920), and anosmia (312). Overall, PRR and ROR values for dyspnea ranged from 0.51 to 4.25 and 0.51 to 4.49; for dysgeusia/ageusia from 0.56 to 6.09 and 0.56 to 6.12; and for epistaxis from 1.03 to 27.24 and 1.03 to 30.76, respectively. All medications which listed anosmia within the top AEs had PRR and ROR values exceeding 2 and 1, respectively. The PRR for headache exceeded 2 for 1 medication and the ROR exceeded 1 in 7 medications.

CONCLUSION

The AEs of dyspnea, anosmia, ageusia/dysgeusia, epistaxis, and headache are reported within the FAERS database for commonly prescribed INSs. When compared against the existing scientific literature, the clinical significance of this reporting tool from the FDA for these classes of medications remains unvalidated.

Structural and clinical impact of anti-allergy agents: An overview

Allergic disorders are markedly rising in industrialized countries. The identification of compounds that trigger the immunoglobulin E (IgE)-dependent allergic reaction remain the means to improve the quality of life by limiting patient's exposure to critical allergens. Information concerning the treatment and onset of allergic disorders including atopic dermatitis, allergic rhinitis, and bronchial asthma has been provided by the research over the past decade. Recent studies also indicated that allergic inflammation is associated closely with their exacerbation and progression and indeed is the basic pathophysiology of allergic diseases. As a result of immunological and molecular biological studies our understanding of the mechanism of allergic inflammation with regard to therapeutic agents has improved. While much effort has been paid to developing a new anti-allergic agent, the allergic disease has yet to be completely conquered. The more extensive research will allow the development of new therapeutics to combat allergic diseases. Currently, with respect to mechanism of action anti-allergy drugs are classified into five types including histamine H₁ antagonists, leukotriene antagonists, Th₂ cytokine inhibitors, thromboxane A₂ inhibitors and mediator-release inhibitors. The use of two or more anti-allergy agents together is not acknowledged at present, but this will be the subject of research in the future because with different mechanisms of action anti-allergy agents used at the same time will theoretically increase their effects. This review article focuses on anti-allergy agents highlighting their applications, clinical trials and recent advancement on drugs.

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.

MP29-02 reduces nasal hyperreactivity and nasal mediators in patients with house dust mite-allergic rhinitis

BACKGROUND

Nasal hyperreactivity (NHR) is an important clinical feature of allergic rhinitis (AR). The efficacy of MP29-02 (azelastine hydrochloride (AZE) and fluticasone propionate [FP]) nasal spray on local inflammatory mediators and NHR in AR is unknown. We tested if MP29-02 decreases inflammatory mediators and NHR in AR and if this effect is due to restoration of nasal epithelial barrier function.

METHODS

A 4-week double-blinded placebo-controlled trial with MP29-02 treatment was conducted in 28 patients with house dust mite (HDM) AR. The presence of NHR was evaluated by measuring reduction in nasal flow upon cold dry air exposure. The effects of AZE ± FP on barrier integrity and airway inflammation were studied in a murine model of HDM-induced NHR and on reduced activation of murine sensory neurons and human mast cells.

RESULTS

MP29-02 but not placebo reduced NHR (P < .0001 vs P = .21), levels of substance P (P = .026 vs P = .941), and β-hexosaminidase (P = .036 vs P = .632) in human nasal secretions. In wild-type C57BL6 mice, the reduction in β-hexosaminidase levels (P < .0001) by AZE + FP treatment upon HDM challenge was found in parallel with a decreased transmucosal passage (P = .0012) and completely reversed eosinophilic inflammation (P = .0013). In vitro, repeated applications of AZE + FP desensitized sensory neurons expressing the transient receptor potential channels TRPA1 and TRPV1. AZE + FP reduced MC degranulation to the same extent as AZE alone.

CONCLUSION

MP29-02 treatment reduces inflammatory mediators and NHR in AR. The effects of AZE + FP on MC degranulation, nasal epithelial barrier integrity, and TRP channels provide novel insights into the pathophysiology of allergic rhinitis.

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.

Allergic rhinitis: pharmacotherapy in pregnancy and old age

INTRODUCTION

Allergic rhinitis (AR) affects 20-30% of women in reproductive age and may worsen during pregnancy. About 10% of the elderly suffer from AR, and it could be under-diagnosed in these patients. Many drugs are currently available, however AR treatment during pregnancy and old age represents a challenging issue.

AREAS COVERED

A review of the literature on the topic has been performed. Expert commentary: In pregnancy, drug avoidance should be carefully balanced with the need for AR optimal control. Topical drugs are suggested as a first approach. The safety and tolerability profile of second-generation antihistamines is well supported. If allergen immunotherapy (AIT) is ongoing and well tolerated, there is no reason for stopping it. AIT initiation in pregnancy is not recommended. For elderly patients, no specific concerns have been highlighted regarding topical treatments, except from nasal decongestionants. Second generation antihistamines are generally well tolerated. Old age should not preclude AIT.

Choosing wisely: practical considerations on treatment efficacy and safety of asthma in the elderly

The prevalence of asthma in the most advanced ages is similar to that of younger ages. However, the concept that older individuals may suffer from allergic asthma has been largely denied in the past, and a common belief attributes to asthma the definition of "rare" disease. Indeed, asthma in the elderly is often underdiagnosed or diagnosed as COPD, thus leading to undertreatment of improper treatment. This is also due to the heterogeneity of clinical and functional presentations of geriatric asthma, including the partial loss of reversibility and the lower occurrence of the allergic component in this age range. The older asthmatic patients are also characterized the coexistence of comorbid conditions that, in conjunction with age-associated structural and functional changes of the lung, may contribute to complicate the management of asthma. The current review addresses the main issues related to the management of allergic asthma in the geriatric age. In particular, the paper aims at revising current pharmacological and non pharmacological treatments for allergic asthmatics of advanced ages, primarily focusing on their safety and efficacy, although most behaviors are an arbitrary extrapolation of what has been tested in young ages. In fact, age has always represented an exclusion criterion for eligibility to clinical trials. Experimental studies and real life observations specifically testing the efficacy and safety of therapeutic approaches in allergic asthma in the elderly are urgently needed.

A role for the intranasal formulation of azelastine hydrochloride/fluticasone propionate in the treatment of allergic rhinitis

Rhinitis is a very common disease and represents a health problem for both children and adults globally. Rhinitis can be allergic or occur without any IgE-mediated sensitization to aeroallergens. Common symptoms include nasal congestion, postnasal drainage, nasal itching, rhinorrhea and sneezing. The most effective drugs for the treatment of rhinitis are antihistamines and topical glucocorticoids. MP29-02 (Dymista(®)) is a novel intranasal formulation combining the second-generation antihistamine, azelastine hydrochloride, with fluticasone propionate in a single device that has recently been developed. Here, we review the efficacy and safety profile of this intranasal formulation in the treatment of allergic and nonallergic rhinitis.

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.

Efficacy and safety of azelastine 0.15% nasal spray administered once daily in patients with allergy to Texas mountain cedar pollen

BACKGROUND

A previous study with azelastine nasal spray in patients with seasonal allergic rhinitis (SAR) demonstrated that increasing the azelastine concentration from 0.1% to 0.15% allowed for once-daily dosing without increasing the incidence of adverse effects. This study evaluated the efficacy of azelastine 0.15% nasal spray administered once daily for treating symptoms of SAR.

METHODS

In this 14-day, randomized, double-blind, placebo-controlled study, patients with moderate-to-severe SAR were randomized to azelastine 0.15% (n = 251) or placebo (n = 255), both at a dosage of 2 sprays/nostril once daily. The primary efficacy variable was change from baseline in the 12-hour reflective Total Nasal Symptom Score (TNSS). Key secondary variables were change from baseline in 24-hour instantaneous TNSS, to establish the dosing interval, and change from baseline in the Total Ocular Symptom Score (TOSS).

RESULTS

The mean improvement (3.57) and percentage improvement (19.3%) in 12-hour reflective TNSS was significant (p < 0.012) with azelastine 0.15% compared to placebo (2.14 and 11.4%, respectively). The mean improvement in 24-hour instantaneous TNSS was also significant (p < 0.001) for azelastine 0.15% compared to placebo, indicating efficacy with once-daily dosing. The overall improvement and percentage improvement in TOSS was significant (p ≤ 0.012) with azelastine 0.15% (2.21 and 16.7%, respectively) compared to placebo (1.28 and 6.0%, respectively). The overall score for the Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ) was significantly (p < 0.001) improved from baseline in the azelastine group compared with the placebo group. Nasal discomfort (3.6%) and bitter taste (2.4%) were the most common adverse events. There were no reports of somnolence with azelastine.

CONCLUSION

Azelastine 0.15% was effective and well tolerated with once-daily dosing. Azelastine 0.15% nasal spray significantly improved a complex of eye symptoms compared to placebo.

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.

Review of azelastine nasal spray in the treatment of allergic and non-allergic rhinitis

Azelastine is a potent H(1)-antihistamine, which is available as a topical nasal spray and indicated for both seasonal allergic and non-allergic vasomotor rhinitis. In addition to its antihistaminic effects, it has also been shown to have a number of other potentially important attributes, including effects on cytokines, adhesion molecules and inflammatory cells. Azelastine nasal spray has been shown to benefit patients who have not responded adequately to loratadine and fexofenadine, and is significantly more efficacious than cetirizine and levocabastine in patients with seasonal allergic rhinitis. Given its unique pharmacologic properties and clinical profile, azelastine maintains an important role in the treatment of chronic rhinitis.

Impact of azelastine nasal spray on symptoms and quality of life compared with cetirizine oral tablets in patients with seasonal allergic rhinitis

BACKGROUND

In fall 2004, the first Azelastine Cetirizine Trial demonstrated statistically significant improvements in the total nasal symptom score (TNSS) and Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ) scores with the use of azelastine nasal spray vs oral cetirizine in patients with seasonal allergic rhinitis (SAR).

OBJECTIVE

To compare the effects of azelastine nasal spray vs cetirizine on the TNSS and RQLQ scores in patients with SAR.

METHODS

This 2-week, double-blind, multicenter trial randomized 360 patients with moderate-to-severe SAR to azelastine, 2 sprays per nostril twice daily, or cetirizine, 10-mg tablets once daily. The primary efficacy variable was the 12-hour reflective TNSS (rhinorrhea, sneezing, itchy nose, and nasal congestion). Secondary efficacy variables were individual symptom scores and the RQLQ score.

RESULTS

Azelastine nasal spray and cetirizine significantly improved the TNSS and individual symptoms compared with baseline (P < .001). The TNSS improved by a mean of 4.6 (23.9%) with azelastine nasal spray compared with 3.9 (19.6%) with cetirizine. Significant differences favoring azelastine nasal spray were seen for the individual symptoms of sneezing and nasal congestion. Improvements in the RQLQ overall (P = .002) and individual domain (P < or = .02) scores were greater with azelastine nasal spray. Both treatments were well tolerated.

CONCLUSIONS

Azelastine nasal spray and cetirizine effectively treated nasal symptoms in patients with SAR. Improvements in the TNSS and individual symptoms favored azelastine over cetirizine, with significant differences for nasal congestion and sneezing. Azelastine nasal spray significantly improved the RQLQ overall and domain scores compared with cetirizine.

Effectiveness of azelastine nasal spray compared with oral cetirizine in patients with seasonal allergic rhinitis

BACKGROUND

Azelastine nasal spray and oral cetirizine are selective histamine H(1)-receptor antagonists that are approved in the United States for the treatment of seasonal allergic rhinitis (SAR).

OBJECTIVE

The objective of the present study was to compare the efficacy and tolerability of azelastine nasal spray administered at the recommended dosage of 2 sprays per nostril twice daily with those of cetirizine in the treatment of moderate to severe SAR.

METHODS

This multicenter, randomized, double-blind, parallel-group, 2-week comparative study was conducted during the 2004 fall allergy season in patients with moderate to severe SAR. After a 1-week placebo lead-in period, patients were randomized to receive azelastine nasal spray 2 sprays per nostril twice daily plus placebo tablets or cetirizine 10-mg tablets once daily plus a placebo saline nasal spray for the 2-week double-blind treatment period. The primary efficacy variables were (1) change from baseline to day 14 in the 12-hour reflective total nasal symptom score (TNSS), which combines scores for rhinorrhea, sneezing, itchy nose, and nasal congestion, and (2) onset of action, based on the instantaneous TNSS over 4 hours after the first dose of study drug. During the double-blind treatment period, patients recorded their symptom scores on diary cards twice daily (morning and evening). Patients aged > or =18 years also completed the Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ) at baseline and on day 14.

RESULTS

Three hundred seven patients were randomized to treatment, and 299 completed 2 weeks of study treatment. The age of the population ranged from 12 to 74 years (mean, 35 years), 62.9% were female, and 69.6% were white. Over 2 weeks of treatment, both groups had significant improvements in the TNSS compared with baseline (P < 0.001). The overall change in TNSS was significantly greater with azelastine nasal spray compared with cetirizine (29.3% vs 23.0% improvement, respectively; P = 0.015). In terms of onset of action, azelastine nasal spray significantly improved the instantaneous TNSS compared with cetirizine at 60 and 240 minutes after the initial dose (both, P = 0.040). Scores on each domain of the RQLQ were significantly improved in both groups compared with baseline (P < 0.001); the overall RQLQ score was significantly improved with azelastine nasal spray compared with cetirizine (P = 0.049). Both treatments were well tolerated.

CONCLUSION

In this 2-week study in patients with moderate to severe SAR, azelastine nasal spray was well tolerated and produced significantly greater improvements in TNSS and total RQLQ score compared with cetirizine.

Allergic rhinitis in children : diagnosis and management strategies

The incidence of allergic rhinitis has been increasing for the last few decades, in keeping with the rising incidence of atopy worldwide. Allergic rhinitis has a prevalence of up to 40% in children, although it frequently goes unrecognized and untreated. This can have enormous negative consequences, particularly in children, since it is associated with numerous complications and comorbidities that have a significant health impact on quality of life. In fact, allergic rhinitis is considered to be a risk factor for asthma. There are numerous signs of allergic rhinitis, particularly in children, that can alert an observant clinician to its presence. Children with severe allergic rhinitis often have facial manifestations of itching and obstructed breathing, including a gaping mouth, chapped lips, evidence of sleep deprivation, a long face, dental malloclusions, and the allergic shiner, allergic salute, or allergic crease. The medical history is extremely important as it can reveal information regarding a family history of atopy and the progression of atopy in the child. It is also important to identify the specific triggers of allergic rhinitis, because one of the keys to successful management is the avoidance of triggers. A tripartite treatment strategy that embraces environmental control, immunotherapy, and pharmacologic treatment is the most comprehensive approach. Immunotherapy has come to be viewed as potentially prophylactic, capable of altering the course of allergic rhinitis. The most recent guidelines for the management of allergic rhinitis issued by the WHO recommend a tiered approach that integrates diagnosis and treatment, in which allergic rhinitis is subclassified both by frequency, as either intermittent or persistent, and by severity, as either mild or moderate to severe. Oral or topical antihistamines and intranasal corticosteroids are the mainstay of pharmacologic therapy for allergic rhinitis, depending upon its severity, and several agents have been approved for use in children aged 5 years old and younger.

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.

H1-receptors: localization and role in airway physiology and in immune functions

Histamine H(1)-receptors are involved in the pathologic processes of allergy. Clinical trials of H(1)-receptor antagonists have demonstrated the efficacy of these agents in reducing the sneezing, pruritus, and rhinorrhea associated with allergic rhinitis. In the lung, H(1)-receptors mediate the bronchoconstrictive effects of histamine and increase vascular permeability, which lead to plasma exudation. H(1)-receptors are present on T cells, B cells, monocytes, and lymphocytes, and stimulation of these receptors induces pro-inflammatory effects. It has been suggested that a signal from the H(1)-receptor contributes to the antigen receptor-mediated signaling pathways that induce proliferative responses and lead to the production of cytokines and antibodies by T cells and B cells, respectively. It would appear, therefore, that the H(1)-receptor has a wider role in inflammatory processes than simply mediating the actions of histamine.

Histamine skin test reactivity following single and multiple doses of azelastine nasal spray in patients with seasonal allergic rhinitis

OBJECTIVE

To determine whether azelastine nasal spray suppresses the dermal response to epicutaneous histamine in allergic patients and the duration of suppression after azelastine use is discontinued.

METHODS

Seventy-eight patients with seasonal allergic rhinitis were entered into this randomized, double-blind, parallel-group, placebo-controlled study. Patients received either azelastine nasal spray (2 sprays per nostril twice daily) or placebo nasal spray for 14 days. Skin tests were performed 5 hours after the first dose of study drugs to determine the effect of a single dose of azelastine nasal spray on the wheal-and-flare response to histamine. At the end of the 14-day treatment period, skin tests were performed 5 hours after the last dose of study drugs and at 24-hour intervals thereafter, until each patient's wheal-and-flare response to histamine (1.0 and 5.0 mg/mL) returned to within 20% of baseline values.

RESULTS

A single dose of azelastine nasal spray did not significantly alter the wheal-and-flare response to histamine. The wheal response was within 20% of the baseline value in 82% and 88% (1.0 and 5.0 mg/mL of histamine, respectively) of the patients 5 hours after discontinuing 14 days of treatment with azelastine nasal spray. Wheal responses were within 20% of baseline values 48 hours after treatment was discontinued, whereas flare responses returned to within 20% of baseline within 48 hours in 92% of the patients.

CONCLUSIONS

Azelastine nasal spray should be discontinued for at least 48 hours before beginning allergy skin test procedures.

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.

Overview of allergic rhinitis

BACKGROUND

Allergic rhinitis is the most common chronic condition seen in the outpatient practice of medicine. Its incidence is rising in parallel with other IgE-mediated diseases, affecting 10 to 30% of adults and up to 40% of children. Half the patients with allergic rhinitis experience symptoms up to 4 months per year, whereas 20% are symptomatic more than 9 months of the year. This disease is often associated with asthma, sinusitis, and otitis media.

OBJECTIVE

To review the literature concerning the evaluation and treatment of allergic rhinitis.

DATA SOURCES

Epidemiologic, pathophysiologic, and clinical studies published in peer-reviewed journals concerning the topic of allergic rhinitis.

RESULTS

Diagnosis of allergic rhinitis is based on patient history, signs and symptoms, physical examination, and appropriate testing procedures. Management includes aggressive environmental control measures to reduce exposure to implicated allergens, immunotherapy that can change the potential clinical course of allergic rhinitis by preventing the initiation and progression of airway inflammation, and pharmacotherapeutic management, including antihistamines and topical nasal corticosteroids.

CONCLUSIONS

Early recognition and management of allergic rhinitis, which include allergen avoidance, immunotherapy, and pharmacologic treatment, can prevent serious complications and significantly improve the patient's quality of life.

Rapid anti-inflammatory action of azelastine eyedrops for ongoing allergic reactions

BACKGROUND

Some second-generation antihistamines have anti-inflammatory activities, but the clinical relevance of this property is still unclear.

OBJECTIVE

The aim of our study was to investigate the effects of azelastine when administered during the early-phase reaction.

METHODS

This investigation was designed as a randomized, placebo-controlled, double-blind, parallel-group study. Clinical and inflammatory events were evaluated after a single dose of azelastine eyedrops or placebo was administered 30 minutes after an allergen-specific conjunctival challenge. Twenty outpatients with allergic rhinoconjunctivitis attributable to Parietaria judaica were enrolled in the study outside the pollen season. Patients were evaluated at baseline, after allergen challenge (at 30 minutes), and after administration of azelastine (at 30 minutes and at 6 hours). The following variables were evaluated: hyperemia, lacrimation, itching, eyelid swelling, number of inflammatory cells (neutrophils, eosinophils, monocytes, and lymphocytes), and intercellular adhesion molecule-1 expression on conjunctival epithelial cells.

RESULTS

Azelastine, in comparison to placebo, significantly reduced symptom scores, number of inflammatory cells, and intercellular adhesion molecule-1 expression during the early- and late-phase reaction.

CONCLUSIONS

The ability of azelastine to reduce symptoms and inflammation during an ongoing allergic reaction can be considered concrete and convincing proof of a clinically relevant anti-inflammatory activity.

Effects of fexofenadine on the early response to nasal allergen challenge

BACKGROUND

Previous studies using nasal allergen challenge models have shown that terfenadine, an H1 antihistamine, inhibits histamine release during the early response to allergen provocation. Fexofenadine, the active metabolite of terfenadine, has strong H1-antihistaminic activity and no cardiac effects. Clinical studies have documented the efficacy of fexofenadine in the treatment of allergic rhinitis.

OBJECTIVE

To determine whether fexofenadine, like terfenadine, inhibits histamine and tryptase release during the early allergic response.

METHODS

Randomized, double blind, placebo-controlled, two-way crossover study in 20 subjects with seasonal allergic rhinitis, out of their allergy season (median age 27.5 years, 13 males and 7 females). Subjects were medicated with either placebo or fexofenadine 180 mg orally daily for 1 week followed by nasal challenge with allergen. After each challenge, sneezes and nasal symptoms were recorded, and a nasal lavage was obtained for the assay of albumin, an indicator of vascular permeability, and histamine and tryptase, indicators of mast cell degranulation.

RESULTS

When patients were on placebo, allergen challenges led to significant increases in all measured parameters compared with the sham challenges with diluent. Treatment with fexofenadine resulted in inhibition of allergen-induced symptoms and increased vascular permeability, but not the release of histamine and tryptase.

CONCLUSION

Fexofenadine is an effective H1 antihistamine, but in contrast to its parent compound, terfenadine, it does not affect the release of the mast cell mediators histamine and tryptase.

Topical immunopharmacology of ocular allergies

PURPOSE OF REVIEW

To review the histamine-1 receptor antagonists, mast cell blockers and natural agents with such actions that can be used for the topical treatment of ocular allergies.

RECENT FINDINGS

Increasing evidence indicates that some histamine-1 receptor antagonists have additional actions to inhibit secretion of inflammatory mediators, especially cytokines, from ocular mast cells and other cell types. Emerging information suggests that such actions may be through regulation of intracellular calcium ion levels of NF-kappaB activation.

SUMMARY

A number of available drugs and natural non-prescription agents may have anti-histaminic and anti-inflammatory actions.

Ocular allergy guidelines: a practical treatment algorithm

The treatment of ocular allergy requires a better understanding of the spectrum of clinical disorders involving various components of the immune system, and of interactions at the conjunctival surface. The immune response focuses primarily on the different levels of activity of Th2 lymphocytes and various other immune cells associated with allergic disorders, including mast cells, eosinophils, fibroblasts, and epithelial and endothelial cells. Ocular allergic disorders include seasonal allergic conjunctivitis (SAC), perennial allergic conjunctivitis (PAC), vernal keratoconjunctivitis (VKC), giant papillary conjunctivitis (GPC) and atopic keratoconjunctivitis (AKC), which, through immunopathological and molecular immunological techniques, can all be better appreciated as being part of a larger spectrum of an atopic disease state. In SAC, pathological changes, such as increased mast-cell activation, the presence of migratory inflammatory cells, and early signs of cellular activation at the molecular level, are minimal. In PAC, these changes are more pronounced in line with the increased duration of allergenic stimulation. In more chronic forms of allergic conjunctivitis, such as VKC in children and AKC in adults, the following changes are evident: a persistent state of mast cell, eosinophil and lymphocyte activation; noted switching from connective-tissue to mucosal-type mast cells; increased involvement of corneal pathology; and follicular development and fibrosis. The treatment of acute and more chronic forms of allergic conjunctivitis has focused in the past on symptomatic relief of symptoms, but with a better understanding of the mechanisms involved we can now provide interventional therapeutic strategies and symptomatic relief. Our advances in the basic understanding of these conditions are providing the foundation for guidelines that improve the ocular health of patients with ocular allergies.

Azelastine is more potent than olopatadine n inhibiting interleukin-6 and tryptase release from human umbilical cord blood-derived cultured mast cells

BACKGROUND

Mast cells are involved in early- and late-phase reactions by releasing vasoactive molecules, proteases, and cytokines. Certain histamine-1 receptor antagonists and other antiallergic drugs seem to inhibit the release of mediators from rat and human mast cells.

OBJECTIVE

Azelastine and olopatadine are antiallergic agents present in the ophthalmic solutions azelastine hydrochloride (Optivar, Asta Medica/Muro Pharmaceuticals, Tewksbury, MA), and olopatadine hydrochloride (Patanol, Alcon Laboratories, Fort Worth, TX), respectively. We investigated the effect of these drugs on interleukin-6 (IL-6), tryptase, and histamine release from cultured human mast cells (CHMCs).

METHODS

CHMCs were grown from human umbilical cord blood-derived CD34+ cells in the presence of stem cell factor and IL-6 for 14 to 16 weeks. Sensitized CHMCs were pretreated with various concentrations of azelastine or olopatadine for 5 minutes. CHMCs were then challenged with anti-immunoglobulin E, and the released mediators were quantitated.

RESULTS

The greatest inhibition of mediator release was seen with 24 microM azelastine; this level of inhibition was matched with the use of 133 microM olopatadine. At this concentration, these drugs inhibited IL-6 release by 83% and 74%, tryptase release by 55% and 79%, and histamine release by 41% and 45%, respectively. Activated CHMCs were characterized by numerous filopodia that were inhibited by both drugs as shown by electron microscopy.

CONCLUSIONS

These results indicate that azelastine and olopatadine can inhibit CHMCs activation and release of IL-6, tryptase, and histamine. On an equimolar basis, azelastine was a more potent inhibitor than olopatadine.

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.

Allergic rhinitis in children

Epidemiologic and pathophysiologic evidence indicates that allergic rhinitis, whether seasonal or perennial, is one piece of a larger atopic clinical picture that often occurs concomitantly with asthma. Allergic rhinitis usually develops during childhood and has a prevalence of up to 40% in the pediatric population. Careful attention to food allergies and the presence of household allergens during infancy and early childhood may limit potential sensitizations. Many antihistamines and topical corticosteroids now are available for the treatment of allergic rhinitis in children, which is all the more important because optimal management may improve quality of life and curtail the development of serious sequelae.

A comparison of the anti-inflammatory properties of intranasal corticosteroids and antihistamines in allergic rhinitis

Allergic rhinitis manifests itself clinically due to the local release of mediators from activated cells within the nasal mucosa. Treatment strategies aim either to reduce the effects of these mediators on the sensory neural and vascular end organs, or to reduce the tissue accumulation of the activated cells that generate them. Corticosteroids intervene at a number of steps in the inflammatory pathway, and, by reducing the release of cytokines and chemokines, inhibit cell recruitment and activation. These effects are evident both in vivo and in vitro. While antihistamines also have some anti-inflammatory effects in vitro, these require higher concentrations than with corticosteroids and are not consistently reproduced in vivo. In addition, although antihistamines and corticosteroids might appear to have complementary mechanisms of action, clinical trials suggest that their co-administration does not confer any additional long-term benefits compared with that achieved with corticosteroids alone. Topical corticosteroids are therefore the preferred anti-inflammatory therapy for persistent allergic rhinitis.

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.

Beyond the histamine receptor: effect of antihistamines on mast cells

Many antihistamines exhibit inhibition of mediator release from mast cells and basophils, in in vitro studies in addition to H1 antagonism. The underlying mechanism is unclear but is unrelated to H1-receptor antagonism. Clinical studies of antihistamins in antigen challenge and seasonal allergy demonstrate reduction of mast cell mediators in nasal lavage. It is not known what mechanism(s) underly these observations, although the concentrations required in in vitro studies suggests that a direct effect on mast cells is unlikely. Furthermore, the therapeutic contribution of this effect is difficult to assess because of concomitant clinically significant H1 antagonism. This and other potential anti-allergic effects may enhance the therapeutic benefit of antihistamines and long-term studies are underway to explore this possibility.

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.

Histamine and tryptase in nasal lavage fluid after allergen challenge: effect of 1 week of pretreatment with intranasal azelastine or systemic cetirizine

BACKGROUND

Antihistamines (H1-receptor antagonists) act by competitive antagonism of histamine at H1-receptors. In addition, high concentrations of some antihistamines inhibit allergen-induced histamine release from mast cells in vitro.

OBJECTIVE

The purpose of this study was to determine the effect of intranasal azelastine or systemic cetirizine (both potent antihistamines) on the allergen-induced release of mast-cell mediators from the human nasal mucosa in vivo.

METHODS

Patients allergic to birch pollen (n = 11) and control subjects not allergic to birch pollen (n = 5) were included in a randomized, double-blind, placebo-controlled, 3-way crossover study outside the pollen season. Each subject was treated with azelastine nasal spray 0.14 mg per nostril twice daily, cetirizine tablets 10 mg every day, or placebo for 1 week using a double-dummy design. At the end of each treatment period, nasal allergen challenges were performed, and the number of sneezes were counted. In addition, nasal lavage fluid was collected, and the levels of mast-cell mediators (histamine and tryptase) were measured.

RESULTS

The allergen challenge of patients allergic to pollen produced sneezing and a significant increase in the levels of histamine and tryptase. The challenge of subjects not allergic to pollen produced no such response. Azelastine and cetirizine significantly reduced allergen-induced sneezing and the associated increase in histamine and tryptase levels. No significant differences were found between the azelastine and cetirizine treatments.

CONCLUSION

Pretreatment with azelastine or cetirizine inhibits the allergen-induced release of mast-cell mediators from the human nasal mucosa. Our results are consistent with the hypothesis that both antihistamines reduce mediator release from nasal mucosa mast cells in vivo. However, further studies are necessary to test this hypothesis.

Pros and cons of the use of antihistamines in managing allergic rhinitis

Histamine H1 -receptor antagonists are generally considered first-line therapy for the management of allergic rhinitis. Other than histamine antagonism, several of the second-generation antihistamines have also shown inhibitory effects on chemical mediators of inflammation such as leukotrienes, prostaglandins, and kinins. This article reviews the pharmacology, clinical use, and side effect profiles of the commonly used H1 -receptor antagonists.

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.

Mediators of inflammation and the inflammatory process

A complex interplay of inflammatory cells and chemical mediators is responsible for allergic inflammation. It is now understood that the allergic reaction consists of an early-phase response involving mast cell degranulation with the release of histamine and a late-phase response characterized by the migration of inflammatory cells. This review provides a summary of the early- and late-phase events associated with allergic inflammation and an overview of the principal chemical mediators involved in the inflammatory process.

Diagnosis and management of rhinitis

This article reviews the differential diagnoses for rhinitis, medications available for the treatment of rhinitis, and special circumstances (such as pregnancy or medication side-effects) that may influence a clinician's decision. Considering the economic impact of rhinitis, the cost of prescription medications, and quality-of-life issues that are affected by rhinitis, physicians dealing with managed care organizations should make their diagnosis and treatment decisions carefully.

The Medical Management of Rhinosinusitis

The management of rhinosinusitis depends on a number of variables related to the duration and severity of symptoms in the individual patient. Furthermore acute rhinosinusitis is managed differently than chronic rhinosinusitis. Because a variety of conservative and pharmacologic interventions are available, the physician can find it difficult to develop a cohesive and logical approach to treatment. An understanding of the pathophysiology, microbiology, and natural history of rhinosinusitis is necessary to formulate the best treatment plan for the individual patient.

Inhibition of leukotriene synthesis by azelastine

BACKGROUND

Azelastine, oxatomide, and ketotifen are used for patients with allergic diseases. These drugs inhibit the release of chemical mediators including the leukotrienes; however, the mechanism involved is unclear.

OBJECTIVE

To clarify the mechanism of inhibition, we investigated the effects of three drugs on the function of phospholipase A2, 5-lipoxygenase, leukotriene C4 synthase, and leukotriene A4 hydrolase, which are all catabolic enzymes involved in synthesizing leukotriene C4 and leukotriene B4 in rat basophilic leukemia (RBL)-1 cells.

METHODS AND RESULTS

The production of leukotriene C4 and leukotriene B4 was measured by high performance liquid chromatography (HPLC). All three drugs inhibited the production of leukotriene C4 and leukotriene B4 when cells were stimulated with A23187. All three drugs also inhibited the A23187-stimulated release of 3H-arachidonic acid from membrane phospholipids. Azelastine inhibited the production of leukotriene C4, but not leukotriene B4, when either arachidonic acid or leukotriene A4 free acid was used as the substrate in our cell free system. Oxatomide and ketotifen did not inhibit the synthesis of either leukotriene C4 or leukotriene B4 in the same cell free study.

CONCLUSION

Results indicated that oxatomide and ketotifen inhibit the production of leukotriene C4 and leukotriene B4 by inhibiting phospholipase A2 activity, whereas, azelastine inhibits the leukotriene C4 production by inhibiting phospholipase A2 and leukotriene C4 synthase.

Safety and efficacy of azelastine nasal spray (Astelin NS) for seasonal allergic rhinitis: a 4-week comparative multicenter trial

BACKGROUND

Azelastine is a chemically novel investigational antiallergy drug with the ability to antagonize the effects of chemical mediators of the early- phase and late phase allergic responses suggesting its usefulness in the treatment of upper and lower airway diseases.

OBJECTIVE

The objective of this 4-week, double- bind, multicenter trial was to evaluate the efficacy of azelastine nasal spray in subjects with seasonal allergic rhinitis.

METHODS

Two hundred sixty-four subjects 12 years of age and older were randomized to receive either azelastine, 2 sprays/nostril qd; azelastine, 2 sprays/nostril bid; oral chlorpheniramine maleate, 12 mg bid; or placebo. The primary efficacy parameters were the changes in major and total symptom severity scores.

RESULTS

Overall, across all 4 weeks of treatment, the mean percent improvements in the total and major symptom complex severity scores in both azelastine treatment groups were greater than those for the placebo group. For the azelastine 2 sprays bid group, the overall results were significant at P = .05 for the major symptom complex score and at .05 < P = .10 for the total symptom complex score versus placebo. For both azelastine treatment groups, improvements in all of the individual rhinitis symptoms were superior to those for the placebo group and, in general were clinically and statistically significant. Azelastine nasal spray was well tolerated; adverse experiences were generally application site reactions, mild to moderate, and not limiting to continued treatment.

CONCLUSIONS

Azelastine nasal spray demonstrated broad clinical antirhinitis activity that for the 2 sprays/nostril bid dosage regimen was consistently clinically and statistically significant.

Effect of intranasal azelastine and beclomethasone dipropionate on nasal symptoms, nasal cytology, and bronchial responsiveness to methacholine in allergic rhinitis in response to grass pollens

BACKGROUND

We compared the effect of nasal azelastine (0.56 mg/day), nasal beclomethasone dipropionate (BDP, 200 micrograms/day) and matched placebo on seasonal symptoms, nasal cytology, and the increase in bronchial responsiveness occurring during pollen season in a group of subjects with history of allergic rhinitis to grass pollens only.

METHODS

The study was completed by nine subjects in the azelastine group, 13 subjects in the BDP group, and 13 subjects in the placebo group. Treatments were randomly administered for 6 weeks. Each subject recorded daily nasal, eye and chest symptoms and additional treatment requirement for the entire pollen season. Each subject performed nasal lavage 4 weeks into the pollen season. Bronchial responsiveness to methacholine was measured before and 4 weeks into the pollen season. Response was expressed as provocative dose causing a 20% fall in forced expiratory volume in 1 second in micromoles.

RESULTS

Azelastine-treated subjects had significantly fewer nasal symptoms during week 4 (p < 0.05), and BDP-treated subjects had fewer nasal symptoms during week 4 (p < 0.05) and week 5 (p < 0.05) compared with subjects given placebo. Both treatments significantly reduced the need for additional medications. BDP, but not azelastine, treatment significantly reduced the percent of eosinophils recovered in nasal lavage (p < 0.05). Neither azelastine nor BDP protected against the increase in bronchial responsiveness to methacholine occurring during the pollen season.

CONCLUSION

We demonstrated that both azelastine and BDP are effective treatments for nasal symptoms of seasonal allergic rhinitis after 4 weeks of therapy. However, we were not able to demonstrate an antiinflammatory activity of nasally administered azelastine. Nasal therapy with azelastine and BDP did not block the increase in bronchial responsiveness to methacholine caused by seasonal allergen exposure.

Azelastine--a novel in vivo inhibitor of leukotriene biosynthesis: a possible mechanism of action: a mini review

Leukotrienes have been proposed as important chemical mediators of allergic inflammation, and there is evidence that azelastine (Astelin) can affect leukotriene-mediated allergic responses. One of the enzymes required for the synthesis of leukotrienes from arachidonic acid is 5-lipoxygenase (5-LO). Azelastine, which is preferentially taken up by the lung and alveolar macrophages, inhibits leukotriene generation in the airways. This property of azelastine may contribute to its therapeutic efficacy in the long-term treatment and management of rhinitis and asthma. Azelastine does not directly inhibit 5-LO in disrupted murine peritoneal cells and rat basophilic leukemia cells (IC50 > 100 microM), but does have moderate 5-LO inhibitory activity in intact murine peritoneal cells (IC50 = 10 microM, 5 min) and in chopped guinea pig liver (IC50 = 14 microM, 2 hr). The generation and release of leukotrienes in human neutrophils and eosinophils is also inhibited by azelastine (IC50 = 0.9-1.1 microM). Furthermore, azelastine is a potent and specific inhibitor of allergen-induced generation of leukotrienes in the nose of the guinea pig (ID50 < 100 micrograms/kg, im, 20 min) as well as in patients with rhinitis (2 mg, po, 4 hr; ID50 < 30 micrograms/kg). Azelastine also inhibits allergen-induced, leukotriene-mediated, pyrilamine-resistant bronchoconstriction (oral ID50 = 60 micrograms/kg, 2 hr and 120 micrograms/kg, 24 hr). This profile suggests that azelastine may be a novel inhibitor of Ca(2+)-dependent translocation of 5-lipoxygenase from cytosol to the nuclear envelope or a FLAP inhibitor rather than a direct 5-LO inhibitor.