The interaction of azelastine with human lung histamine H1, beta, and muscarinic receptor-binding sites

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.

Rhinitis 2020: A practice parameter update

This comprehensive practice parameter for allergic rhinitis (AR) and nonallergic rhinitis (NAR) provides updated guidance on diagnosis, assessment, selection of monotherapy and combination pharmacologic options, and allergen immunotherapy for AR. Newer information about local AR is reviewed. Cough is emphasized as a common symptom in both AR and NAR. Food allergy testing is not recommended in the routine evaluation of rhinitis. Intranasal corticosteroids (INCS) remain the preferred monotherapy for persistent AR, but additional studies support the additive benefit of combination treatment with INCS and intranasal antihistamines in both AR and NAR. Either intranasal antihistamines or INCS may be offered as first-line monotherapy for NAR. Montelukast should only be used for AR if there has been an inadequate response or intolerance to alternative therapies. Depot parenteral corticosteroids are not recommended for treatment of AR due to potential risks. While intranasal decongestants generally should be limited to short-term use to prevent rebound congestion, in limited circumstances, patients receiving regimens that include an INCS may be offered, in addition, an intranasal decongestant for up to 4 weeks. Neither acupuncture nor herbal products have adequate studies to support their use for AR. Oral decongestants should be avoided during the first trimester of pregnancy. Recommendations for use of subcutaneous and sublingual tablet allergen immunotherapy in AR are provided. Algorithms based on a combination of evidence and expert opinion are provided to guide in the selection of pharmacologic options for intermittent and persistent AR and NAR.

Onset of Action of Azelastine Nasal Spray Compared with Mometasone Nasal Spray and Placebo in Subjects with Seasonal Allergic Rhinitis Evaluated in an Environmental Exposure Chamber

Background

The objective of this study was to determine the onset of action of azelastine hydrochloride nasal spray compared with placebo and an intranasal steroid, mometasone furoate, in subjects with seasonal allergic rhinitis (SAR).

Methods

Subjects with a history of SAR and symptomatic while exposed to ragweed pollen in an environmental exposure chamber (EEC) were randomized to azelastine nasal spray (n = 150), mometasone nasal spray (n = 150), or placebo (n = 150) and recorded total nasal symptom scores (TNSS), consisting of sneezing, nasal pruritus, rhinorrhea, and congestion, during an 8-hour study period.

Results

Azelastine nasal spray showed a statistically significant improvement in the TNSS at 15 minutes compared with placebo. The effect was durable at each time point during the 8-hour study. Azelastine nasal spray also was significantly more effective than mometasone at each time point.

Conclusion

Azelastine nasal spray has a rapid (15 minute) onset of action. Azelastine nasal spray was superior to both placebo and mometasone nasal spray in reducing nasal symptoms of SAR occurring within 8 hours after an allergen challenge.

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.

A clinical pharmacokinetic study comparing two azelastine hydrochloride nasal formulations in a single-dose design

Azelastine hydrochloride is a potent second-generation antihistamine, available in Europe and the USA as a nasal spray formulation for the treatment of allergic rhinitis symptoms. GlaxoSmithKline (GSK) Consumer Healthcare has developed a new nasal formulation of azelastine hydrochloride. The present study was aimed at comparing the clinical pharmacokinetic profiles and assessing the bioequivalence of the new formulation of azelastine hydrochloride with a marketed reference nasal spray product. This was a randomized, two-way crossover, two-stage, single-dose pharmacokinetic study with 2 weeks washout between the two treatment periods. A dosage of 0.28 mg of the test and reference products was administered as a single dose to healthy volunteers according to the crossover design. Twenty-three subjects (15 subjects from stage 1 and 8 subjects from stage 2) were enrolled in the study. Adjusted mean values for AUC0-t were 1,526.8 h pg/mL for the test drug and 1,441.5 h pg/mL for the reference drug; for C max the values were 61.59 pg/mL for the test drug and 58.21 pg/mL for the reference drug. The 94.12 % CI of geometric mean ratios (test/reference) were 0.99-1.13 and 0.95-1.18 for AUC0-t and C max. This met the predefined criteria for bioequivalence between test and reference drugs. Secondary pharmacokinetic parameters for azelastine and for the metabolite desmethyl azelastine, AUC(0-∞) and t max, were numerically similar between the two study treatments. Both test and reference azelastine hydrochloride formulations were well tolerated at single dose. This study demonstrated the bioequivalence between the new azelastine hydrochloride nasal spray formulation and the marketed reference Allergodil(®) after single-dose administration.

Synthesis and pharmacological investigation of azaphthalazinone human histamine H(1) receptor antagonists

5-Aza, 6-aza, 7-aza and 8-aza-phthalazinone, and 5,8-diazaphthalazinone templates were synthesised by stereoselective routes starting from the appropriate pyridine/pyrazine dicarboxylic acids by activation with CDI, reaction with 4-chlorophenyl acetate ester enolate to give a β-ketoester, which was hydrolysed, and decarboxylated. The resulting ketone was condensed with hydrazine to form the azaphthalazinone core. The azaphthalazinone cores were alkylated with N-Boc-D-prolinol at N-2 by Mitsunobu reaction, de-protected, and then alkylated at the pyrrolidine nitrogen to provide the target H(1) receptor antagonists. All four mono-azaphthalazinone series had higher affinity (pK(i)) for the human H(1) receptor than azelastine, but were not as potent as the parent non-aza phthalazinone. The 5,8-diazaphthalazinone was equipotent with azelastine. The least potent series were the 7-azaphthalazinones, whereas the 5-azaphthalazinones were the most lipophilic. The more hydrophilic series were the 8-aza series. Replacement of the N-methyl substituent on the pyrrolidine with the n-butyl group caused an increase in potency (pA(2)) and a corresponding increase in lipophilicity. Introduction of a β-ether oxygen in the n-butyl analogues (2-methoxyethyl group) decreased the H(1) pA(2) slightly, and increased the selectivity against hERG. The duration of action in vitro was longer in the 6-azaphthalazinone series. The more potent and selective 6-azaphthalazinone core was used to append an H(3) receptor antagonist fragment, and to convert the series into the long acting single-ligand, dual H(1) H(3) receptor antagonist 44. The pharmacological profile of 44 was very similar to our intranasal clinical candidate 1.

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.

Azelastine hydrochloride, a dual-acting anti-inflammatory ophthalmic solution, for treatment of allergic conjunctivitis

Over 50% of patients who seek treatment for allergies present with ocular symptoms. Our current ability to control ocular allergic symptoms is greater than ever before. Newer dual-acting topical eyedrops attack multiple facets of the allergic cascade. Azelastine has antihistaminic effects providing immediate relief, mast cell stabilization providing early-phase intervention, and inhibition of expression and activation of anti-inflammatory mediators which characterize the late phase of the immune reaction. The ophthalmic eyedrop formulation is approved for treatment of allergic conjunctivitis in adults and children aged over 3 years. In clinical trials comparing azelastine with other dual-acting eyedrops, such as levocabastine and olopatadine, azelastine was reported to be slightly less efficacious and to sting briefly upon administration. Even so, many patients experienced the full benefit of symptom relief, and preferred azelastine. As a broad-spectrum drug, azelastine offers many desirable properties for management of ocular allergies. Because it can often produce maximal effect with just twice-daily dosing, azelastine is a particularly good choice for the allergic population in whom minimizing exposure to topical products and preservatives is a key concern.

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.

Azelastine and olopatadine in the treatment of allergic rhinitis

OBJECTIVE

To review the literature supporting current recommendations for nasal antihistamines as first-line therapy for allergic rhinitis.

DATA SOURCES

Published articles in the peer-reviewed medical literature.

STUDY SELECTION

Clinical trials focusing on the efficacy, safety, and recommended uses of the currently approved nasal antihistamines in the United States: azelastine nasal spray, 0.1%, and olopatadine nasal spray, 0.6%.

RESULTS

Azelastine nasal spray, 0.1%, and olopatadine nasal spray, 0.6%, have rapid onsets of action, are well tolerated, and have clinical efficacy for treating allergic rhinitis that is equal or superior to oral second-generation antihistamines. Both also have a clinically significant effect on nasal congestion. Azelastine is also approved for nonallergic rhinitis. Although older data suggest that intranasal steroids have greater clinical efficacy than nasal antihistamines, more recent comparisons in patients with mild to moderate disease have shown equal or noninferior efficacy. In addition, in contrast to oral antihistamines or leukotriene antagonists, the combination of a nasal antihistamine and intranasal steroid may provide additive benefits for treating patients with more severe disease.

CONCLUSION

The data support current recommendations for nasal antihistamines as first-line therapy for allergic rhinitis. Future studies should address possible as needed use, the use of premixed antihistamine-steroid combinations, and the treatment of mixed rhinitis.

Double-Blind, Placebo-Controlled Trial of Reformulated Azelastine Nasal Spray in Patients with Seasonal Allergic Rhinitis

Background

Azelastine nasal spray is a topical antihistamine with a distinctive taste that may be objectionable to some patients. The primary objectives of this clinical trial were (1) to determine if a reformulated azelastine nasal spray (Astepro) with sucralose as a taste-masking agent provides comparable efficacy to the original formulation (Astelin) and (2) to evaluate dose–response relationships between groups.

Methods

Eight hundred thirty-five patients with seasonal allergic rhinitis were randomized to six treatment groups: (1) original azelastine nasal spray, 1 spray/nostril b.i.d.; (2) reformulated azelastine, 1 spray/nostril b.i.d.; (3) placebo, 1 spray/nostril b.i.d.; (4) original azelastine nasal spray, 2 sprays/nostril b.i.d., (5) reformulated, 2 sprays/nostril b.i.d.; and (6) placebo, 2 sprays/nostril b.i.d. The primary efficacy variable was the change from baseline to day 14 in total nasal symptom score (TNSS) consisting of runny nose, sneezing, itchy nose, and nasal congestion.

Results

Original azelastine nasal spray and the reformulated spray produced comparable improvements in the TNSS at both dosages. There was a dose-related difference in TNSS comparing the 1- and 2-spray dosages. The percentage changes from baseline in the TNSS in the 2-sprays/nostril dosage groups were 27.9% (p < 0.001) with the reformulated nasal spray, 23.5% (p < 0.01) with the original formulation, and 15.4% with placebo. The incidence of bitter taste was 7% with the reformulated spray and 8% with the original at the 2-sprays/nostril dosage.

Conclusion

The results of this study showed efficacy both with original azelastine nasal spray and with the reformulated nasal spray and a clear dose–response difference between the 1- and 2-spray dosages.

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.

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.

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.

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.

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.

Second-generation antihistamines: a comparative review

Second-generation histamine H1 receptor antagonists (antihistamines) have been developed to reduce or eliminate the sedation and anticholinergic adverse effects that occur with older H1 receptor antagonists. This article evaluates second-generation antihistamines, including acrivastine, astemizole, azelastine, cetirizine, ebastine, fexofenadine, ketotifen, loratadine, mizolastine and terfenadine, for significant features that affect choice. In addition to their primary mechanism of antagonising histamine at the H1 receptor, these agents may act on other mediators of the allergic reaction. However, the clinical significance of activity beyond that mediated by histamine H1 receptor antagonism has yet to be demonstrated. Most of the agents reviewed are metabolised by the liver to active metabolites that play a significant role in their effect. Conditions that result in accumulation of astemizole, ebastine and terfenadine may prolong the QT interval and result in torsade de pointes. The remaining agents reviewed do not appear to have this risk. For allergic rhinitis, all agents are effective and the choice should be based on other factors. For urticaria, cetirizine and mizolastine demonstrate superior suppression of wheal and flare at the dosages recommended by the manufacturer. For atopic dermatitis, as adjunctive therapy to reduce pruritus, cetirizine, ketotifen and loratadine demonstrate efficacy. Although current evidence does not suggest a primary role for these agents in the management of asthma, it does support their use for asthmatic patients when there is coexisting allergic rhinitis, dermatitis or urticaria.

Effects of in vitro mast cell degranulation on human lung beta-receptor binding parameters

BACKGROUND

Numerous studies have demonstrated that subjects with allergic asthma have beta-adrenergic hyporesponsiveness, predisposing these individuals toward bronchospasm, mucous production, and mast cell degranulation. Since sympathetic innervation of the human respiratory tract is sparse, reduced beta-responsiveness probably results from alterations at or beyond the receptor level.

OBJECTIVE

We therefore examined whether anaphylaxis of human lung tissue acutely modulated the human lung beta-receptor system in ways that might lead to decreased beta-adrenergic responsiveness.

METHODS

Fresh thoracotomy peripheral lung samples from 26 patients were incubated with (anaphylaxis) or without (control) anti-IgE (1:100) for up to 90 minutes and histamine release was documented. Lung fragments were quick frozen at various times after anti-IgE for analyses of beta-receptor binding parameters. Antagonist Kd (dissociation constant) and receptor concentration values were determined using (-)[125I]pindolol and agonist IC50 values were determined using isoproterenol.

RESULTS

In comparison with time O, neither anaphylaxis nor control samples had differences in receptor binding parameters with time. There were also no differences between anaphylaxis and control lung samples at any time point, and ratios of log control binding parameter/log anaphylaxis binding parameter ranged from 0.96 to 1.01.

CONCLUSIONS

Anaphylaxis of lung does not lead to acute changes in antagonist or agonist affinity for beta-receptors or changes in receptor concentration. Under the conditions studied, lung mast cell degranulation does not acutely alter the human lung beta-receptor system in ways that might account for the beta-adrenergic hyporesponsiveness found in allergic asthma.

Azelastine protects against CA1 traumatic neuronal injury in the hippocampal slice

Activation of NMDA receptors appears to play a important role in traumatic neuronal injury. Additionally, N-methyl-D-aspartate (NMDA) excitotoxicity may involve leukotriene production. Therefore, we investigated whether azelastine, an anti-allergic agent inhibiting the synthesis and release of leukotrienes, could protect against CA1 traumatic neuronal injury in the hippocampal slice. Fluid percussion trauma produced evidence of severe neuronal injury with CA1 antidromic population spike amplitude recovering after 95 min to only a mean 16 +/- 1 % S.E. of initial amplitude. With 15 microM azelastine treatment given after trauma for 35 min this recovery improved to 112 +/- 17%. The azelastine EC50 for this protection was 10 microM. Significant protection was also seen with azelastine application begun 15 min after trauma. Azelastine also protected the ability to induce long-term potentiation after trauma. The specific leukotriene inhibitors, MK-571 and MK-886, similarly provided significant neuroprotection. These findings suggest that CA1 traumatic neuronal injury may be mediated by leukotriene production.

Influence of epithelial removal on the antihistaminic activity of azelastine in the guinea-pig airway smooth muscles

The influence of epithelial removal on the antihistaminic activity of azelastine in the guinea-pig isolated cervical trachea and main bronchus was examined. In both preparations with an intact epithelium, histamine produced a concentration-dependent contraction, but its potency (pD2) and contractility (Emax) were significantly higher in the main bronchus than in the cervical trachea. Epithelial removal from these preparations significantly increased the pD2 values in both tracheal and bronchial preparation, while the Emax value was significantly increased only in the cervical trachea. When these preparations were pretreated with azelastine (20 or 200 nM), concentration-response curves for histamine shifted downward, but were not influenced by the presence of an intact epithelium. Neither concentration of azelastine significantly modified the contractile responsiveness of tracheal and bronchial preparations to carbachol or neurokinin A. These results indicate that azelastine selectively antagonizes the histamine-induced contraction of the guinea-pig airway smooth muscles with or without an intact epithelium.

Protection from hypoxic and N-methyl-D-aspartate injury with azelastine, a leukotriene inhibitor

The 5-lipoxygenase metabolites, leukotrienes, increase in concentration during cerebral ischemia. Azelastine is a new anti-allergic agent which inhibits leukotriene C4 synthesis and release. We examined the neuroprotective properties of azelastine using the hippocampal slice. Azelastine 15 microM significantly protected CA1 evoked responses from hypoxic injury, with CA1 population spike amplitude recovering to a mean 76 +/- 13% in azelastine treated slices, compared to 4 +/- 3% recovery in paired unmedicated slices. The EC50 for this azelastine hypoxic protection was 9.8 microM. Azelastine additionally protected against injury induced by N-methyl-D-aspartate (NMDA), but not non-NMDA glutamate receptor agonists. No hypoxic protection was afforded by diphenhydramine 50 microM, suggesting that azelastine protection did not occur through histamine H1 receptor blockade. The finding of protection with azelastine against hypoxic and NMDA-induced injury suggests that leukotriene production is a common pathway in these forms of neuronal injury, and that leukotriene inhibition may be a useful neuroprotective strategy.

Acute effects of in vitro mast cell degranulation on human lung muscarinic receptors

Allergic asthmatic patients have baseline airway cholinergic hyperresponsiveness that rapidly increases after antigen inhalation and mediator release. We therefore examined whether anaphylaxis of human lung tissue (exposure to mast cell mediators) acutely modulated the human lung muscarinic receptor system in ways that might account for these increased in vivo cholinergic airway responses. Fresh thoracotomy peripheral lung samples from 24 patients were incubated with (anaphylaxis) or without (control) anti-IgE (1:100) for up to 90 min. The average percentage of histamine released ranged from 20 to 30% in anaphylaxis and 3 to 5% in control samples, with > 80% of total histamine released by 15 to 30 min. Lung fragments were quick frozen at various times after anti-IgE for analyses of muscarinic receptor binding parameters. Antagonist Kd (dissociation constant) and receptor concentration values were determined using [3H]quinuclidinyl benzilate, and agonist IC50 values were determined using carbachol. In comparison with time 0, neither anaphylaxis nor control samples had differences in receptor binding parameters with time. There were also no differences between anaphylaxis and control lung samples at any time point, and ratios of log control binding parameter/log anaphylaxis binding parameter ranged from 0.96 to 1.04. Thus, anaphylaxis of lung does not lead to acute changes in antagonist or agonist affinity for muscarinic receptors or changes in receptor concentration. Therefore, under the conditions studied, lung mast cell degranulation does not appear to acutely alter the human lung muscarinic receptor system in ways that might account for the increased in vivo lung cholinergic hyperresponsiveness found in allergic asthmatic patients.

Inhibitory effects of azelastine on nasal allergic responses in sensitized guinea pigs

The in vivo effects of the antiallergic drug azelastine were investigated in sensitized guinea pigs. Topical administration of antigen into the nasal cavity produced an increase in nasal vascular permeability together with an increase in both the histamine and leukotriene C4 (LTC4) concentrations of nasal lavage fluid. Pre-treatment with azelastine significantly inhibited both the LTC4 release and the increase in nasal vascular permeability. These results suggest that azelastine inhibits the release of antigen-induced leukotrienes and increases nasal vascular permeability in vivo.