Effect of desloratadine versus placebo on nasal airflow and subjective measures of nasal obstruction in subjects with grass pollen-induced allergic rhinitis in an allergen-exposure unit

Selective Consecutive Determination of Desloratadine and Montelukast Sodium in Their Pure and Binary Dosage Form Based on Pencil Graphite Electrochemical Sensors

In this study, we present a new, green electrochemical method for potentiometric estimation of desloratadine and montelukast sodium in their pure and binary dosage form. For that, three pencil graphite sensors were fabricated; the first one was prepared to analyse desloratadine drug (DES) by coating the graphite bar with the coating membrane, which comprises the ion pair of desloratadine and ammonium reineckate reagent (RNK), the polymer poly vinyl chloride (PVC), and the plasticizers dibutyl phthalate (DBP). The second one, which was used to analyse montelukast (MON), was constructed by using the ion pair of cadmium chloride reagent (Cd.) with montelukast and the same earlier named polymer and plasticizer. As a trial to analyse both of the drugs by the same sensor consecutively, we have constructed a combined pencil graphite electrode, which contains the two earlier suggested ion pairs, that is, we can use this electrode to selectively analyse for each drug. The proposed electrodes were effectively used for analysis of DES and MON as a single dosage form and as combined pharmaceutical preparation, without any need for prior separation that was performed depending on the difference in the efficient pH range for each sensor. The proposed sensors exhibited a Nernstian equation slopes of -30.11, 27.70, (-29.16, 29.79) mv. decade^-1 in the linearity range 5.00 × 10^-5-1.00 × 10^-2 and 1.00 × 10^-5 - 1.00 × 10^-2 M, respectively. The sensors exhibit high sensitivity according to LOD values ((0.036-0.018) - (0.025-0.026) µM), respectively, and important selectivity toward the studied drugs in presence of interfering ions and excipients. The optimum circumstances were studied, and the method was validated by application of ICH rules. Finally, the method was compared with a documented method, and the required statistical values were calculated.

The use of nasal allergen vs allergen exposure chambers to evaluate allergen immunotherapy

INTRODUCTION

Allergen-specific immunotherapy (AIT) is the only disease-modifying treatment option for allergic rhinitis (AR) patients with persistent moderate-severe AR for whom traditional pharmacotherapies are ineffective. The nasal allergen challenge (NAC) and allergen exposure chamber (AEC) are two translational models of AR that can be used to investigate the properties, safety, and efficacy of AIT.

AREAS COVERED

Peer-reviewed, human-centered articles utilizing AEC or NAC models to investigate AIT between 2010 and 2020 were curated from PubMed, EMBASE, and OVID Medline databases. AECs have been used to evaluate traditional subcutaneous and sublingual administrations of AIT, including cross-protective effects and different dosing regimens. More recently, the effectiveness of novel AIT formulations has been evaluated. NACs are another model used to study AIT, including using novel intralymphatic routes of administration. It is an especially powerful and versatile tool to determine if basic science and animal model findings are clinically translatable.

EXPERT OPINION

The AEC and NAC models both produce clinically relevant and reproducible results. AECs are more effective for studying many participants but are limited because they require a specialized facility. As more AIT therapies and new formulations are developed over time, the versatility of the NAC will be especially useful.

Long-term omalizumab efficacy in allergic rhinitis

BACKGROUND

Omalizumab therapy was found to be safe and effective as an add-on therapy for patients with poorly controlled severe asthma. Although several studies over the last decade have demonstrated its efficacy in other Immunoglobulin E related diseases, its use in such conditions is off-label.

OBJECTIVE

This study aimed to assess the effectiveness of long-term therapy with Omalizumab in patients with persistent severe allergic rhinitis and inadequately controlled severe asthma.

METHODS

Patients with poorly controlled severe asthma and persistent allergic rhinitis were enrolled and treated with Omalizumab for 36 months with every four-week subcutaneous administration. The efficacy assessment included the severity of AR symptoms every six months using Visual Analogue Scale, Asthma Control Test, nasal endoscopy, spirometry, and biomarkers (blood eosinophils and neutrophils, fractional exhaled nitric oxide, total IgE).

RESULTS

Eleven patients aged between 26 and 70 years were enrolled, and 10 completed the study. A significant improvement of allergic rhinitis symptoms, Asthma Control Test, and lung function was observed. There was also a reduction in the status of the biomarkers at the end of the study.

CONCLUSION

Long-term therapy with Omalizumab was effective and safe in treating severe persistent allergic rhinitis and concomitant asthma.

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.

Copper (triazole-5-yl)methanamine complexes onto MCM-41: the synthesis of pyridine-containing pseudopeptides through the 6-endo-dig cyclization of 1,5-enynes

An efficient approach for the synthesis of immobilized copper (triazole-5-yl)methanamine complexes onto MCM-41 (Cu@TZMA@MCM-41), as a novel recyclable nanocatalyst, is described. This nanocatalyst was used for the synthesis of pyridine-containing pseudopeptides through a sequential Ugi/nucleophilic addition/1,5-enyne cyclization reaction and elicited good-to-excellent yields. The nanocatalyst was fully characterized by SEM, EDS, TEM, BET, ICP-OES, TGA, and XRD techniques. Furthermore, the catalyst was recovered by simple filtration and could be used for at least 5 cycles without significant loss of activity.

Anaphylaxis-a 2020 practice parameter update, systematic review, and Grading of Recommendations, Assessment, Development and Evaluation (GRADE) analysis

Anaphylaxis is an acute, potential life-threatening systemic allergic reaction that may have a wide range of clinical manifestations. Severe anaphylaxis and/or the need for repeated doses of epinephrine to treat anaphylaxis are risk factors for biphasic anaphylaxis. Antihistamines and/or glucocorticoids are not reliable interventions to prevent biphasic anaphylaxis, although evidence supports a role for antihistamine and/or glucocorticoid premedication in specific chemotherapy protocols and rush aeroallergen immunotherapy. Evidence is lacking to support the role of antihistamines and/or glucocorticoid routine premedication in patients receiving low- or iso-osmolar contrast material to prevent recurrent radiocontrast media anaphylaxis. Epinephrine is the first-line pharmacotherapy for uniphasic and/or biphasic anaphylaxis. After diagnosis and treatment of anaphylaxis, all patients should be kept under observation until symptoms have fully resolved. All patients with anaphylaxis should receive education on anaphylaxis and risk of recurrence, trigger avoidance, self-injectable epinephrine education, referral to an allergist, and be educated about thresholds for further care.

Next-generation Allergic Rhinitis and Its Impact on Asthma (ARIA) guidelines for allergic rhinitis based on Grading of Recommendations Assessment, Development and Evaluation (GRADE) and real-world evidence

The selection of pharmacotherapy for patients with allergic rhinitis aims to control the disease and depends on many factors. Grading of Recommendations Assessment, Development and Evaluation (GRADE) guidelines have considerably improved the treatment of allergic rhinitis. However, there is an increasing trend toward use of real-world evidence to inform clinical practice, especially because randomized controlled trials are often limited with regard to the applicability of results. The Contre les Maladies Chroniques pour un Vieillissement Actif (MACVIA) algorithm has proposed an allergic rhinitis treatment by a consensus group. This simple algorithm can be used to step up or step down allergic rhinitis treatment. Next-generation guidelines for the pharmacologic treatment of allergic rhinitis were developed by using existing GRADE-based guidelines for the disease, real-world evidence provided by mobile technology, and additive studies (allergen chamber studies) to refine the MACVIA algorithm.

Biological Effects of Thermal Water-Associated Hydrogen Sulfide on Human Airways and Associated Immune Cells: Implications for Respiratory Diseases

Natural mineral (thermal) waters have been used for centuries as treatment for various diseases. However, the scientific background of such therapeutic action is mostly empiric and based on knowledge acquired over time. Among the various types of natural mineral waters, sulfurous thermal waters (STWs) are the most common type in the center of Portugal. STWs are characterized by high pH, poor mineralization, and the presence of several ions and salts, such as bicarbonate, sodium, fluoride, silica, and carbonate. Furthermore, these waters are indicated as a good option for the treatment of various illnesses, namely respiratory diseases (e.g., allergic rhinitis, asthma, and chronic obstructive pulmonary disease). From the sulfide species present in these waters, hydrogen sulfide (H₂S) stands out due to its abundance. In healthy conditions, H₂S-related enzymes (e.g., cystathionine β-synthase and cystathionine γ-lyase) are expressed in human lungs, where they have mucolytic, antioxidant, anti-inflammatory, and antibacterial roles, thus contributing to airway epithelium homeostasis. These roles occur mainly through S-sulfhydration, a post-translational modification through which H₂S is able to change the activity of several targets, such as ion channels, second messengers, proteins, among others. However, in respiratory diseases the metabolism of H₂S is altered, which seems to contribute somehow to the respiratory deterioration. Moreover, H₂S has been regarded as a good biomarker of airway dysfunction and severity, and can be measured in serum, sputum, and exhaled air. Hence, in this review we will recapitulate the effects of STWs on lung epithelial-immune crosstalk through the action of its main component, H₂S.

Validation of Strasbourg environmental exposure chamber (EEC) ALYATEC® in mite allergic subjects with asthma

Objective: Environmental Exposure Chamber (EEC) should have standardized and controlled allergenic and non-allergenic exposures to perform reproducible clinical studies. The aim was to demonstrate that mite exposure in the Alyatec^® EEC could induce early (EAR) and/or late asthmatic reactions (LAR) in at least 60% of subjects allergic to mite.Methods: The EEC has a volume of 147-m³ with 20 seats. The nebulized particle number, airborne Der p1, endotoxins, and volatile organic compound (VOC) concentrations were measured. Twenty-four asthmatics allergic to mite were randomly exposed to 15, 25, and 46 ng/m³ Der p1. Specificity was assessed in not mite-sensitized asthmatics.Results: No significant endotoxin or VOC contamination was measured. The mean inter-assay CVs were 12.5% for the airborne particle number and 28.7% for airborne Der p1 concentrations. For the three Der p1 concentrations, at least 88% of the subjects developed EAR and/or LAR, and at least 46% developed a dual response. No reaction occurred with placebo or in the control group. No severe bronchial reaction occurred.Conclusions: The Alyatec^® EEC demonstrated a tight control of allergenic and non-allergenic exposures. The EEC was clinically validated, with airborne Der p1 levels close to levels found in natural settings.

A new strategy for the synthesis of pyridines from N-propargylic β-enaminothiones

A new robust method for the synthesis of 2,4,5-trisubstituted pyridines with high efficiency and broad functional group tolerance is described.

[Allergic rhinitis: the modern aspects of therapy]

The main objectives of the present article were to systematize the modern views of the causes and risk factors of allergic rhinitis, to clarify the manner of its development, to define the leading etiological mechanism underling the pathogenesis of this condition, to consider the methods used for the diagnostics and the treatment of this disease, and to sum up the clinical experience with the use of Levocetirizine (Allerwey) for the management of allergic rhinitis. Special attention is given to the achievement and the maintenance of control of the persistent or intermittent forms of allergic rhinitis and to approaches to its treatment based on the medications registered in the Russian Federation.

[Environmental exposure chambers (EEC): A novel tool for pathophysiological and pharmaceutical research]

Airborne allergic diseases (allergic asthma, rhinitis and conjunctivitis) have reached epidemic proportions and are a great burden for both society and individuals. Therefore we need to better understand the physiopathological mechanisms and to increase clinical research in these diseases. However, traditional outpatient studies are difficult and have number of limitations, in particular the variability of allergen exposure. Yet allergen provocation tests, especially bronchial challenges in asthma, are excellent tools to measure the efficiency of anti-allergic therapies. Environmental exposure chambers (EEC) allow the performance of controlled allergen provocation tests on a large scale with remarkable sensitivity, specificity and reproducibility. Moreover, they allow a precise collection of allergic symptoms, making them interesting tools for patho-physiological and clinical studies. During the last thirty years, they have assisted the study of anti-allergic therapies and provided data on their pharmacodynamic characteristics, particularly in allergic rhinitis. However, there are still no EEC tests centered on asthma. The EEC of Strasbourg (ALYATEC^®) was developed to fulfill two objectives: to allow standardized allergenic and non-allergenic exposures with better control of the parameters than in other EEC and to offer a place to study asthma and anti-asthmatic therapies safely.

Allergen exposure chambers: harmonizing current concepts and projecting the needs for the future - an EAACI Position Paper

BACKGROUND

Allergen exposure chambers (AECs) are clinical facilities allowing for controlled exposure of subjects to allergens in an enclosed environment. AECs have contributed towards characterizing the pathophysiology of respiratory allergic diseases and the pharmacological properties of new therapies. In addition, they are complementary to and offer some advantages over traditional multicentre field trials for evaluation of novel therapeutics. To date, AEC studies conducted have been monocentric and have followed protocols unique to each centre. Because there are technical differences among AECs, it may be necessary to define parameters to standardize the AECs so that studies may be extrapolated for driving basic immunological research and for marketing authorization purposes by regulatory authorities.

METHODS

For this task force initiative of the European Academy of Allergy and Clinical Immunology (EAACI), experts from academia and regulatory agencies met with chamber operators to list technical, clinical and regulatory unmet needs as well as the prerequisites for clinical validation.

RESULTS

The latter covered the validation process, standardization of challenges and outcomes, intra- and interchamber variability and reproducibility, in addition to comparability with field trials and specifics of paediatric trials and regulatory issues.

CONCLUSION

This EAACI Position Paper aims to harmonize current concepts in AECs and to project unmet needs with the intent to enhance progress towards use of these facilities in determining safety and efficacy of new therapeutics in the future.

The improved efficacy of a fixed-dose combination of fluticasone furoate and levocabastine relative to the individual components in the treatment of allergic rhinitis

BACKGROUND

Allergic rhinitis (AR) is a common chronic disease, which has significant detrimental effect on well-being and quality of life as well as substantial socio-economic impact. Combination pharmacotherapy is utilized by 40-50% of patients to treat their symptoms.

OBJECTIVE

To compare the effects of intranasal fluticasone furoate (FF)/levocabastine (LEVO) fixed-dose combination (FDC) with each component alone on allergen-induced nasal and ocular symptoms.

METHODS

A randomized, double-blind, placebo-controlled, three-way, incomplete block, cross-over, proof-of-concept study in 71 patients with AR, evaluated FF 100 μg, LEVO 200 μg and FDC (FF 100/LEVO 200 μg), once daily via intranasal spray for 8 days. On days 1 and 8, total nasal symptom score (TNSS) and total ocular symptom score (TOSS) were assessed every 15 min during a 4-h allergen exposure in the Vienna Challenge Chamber. The primary endpoint was Day 8 weighted mean TNSS.

RESULTS

After 8 days, FDC resulted in both statistically and clinically significant reductions in mean TNSS compared with FF and LEVO alone [adjusted mean differences (95% CI): FDC vs. FF: -2.26 (-2.90, -1.62); FDC vs. LEVO: -2.57 (-3.21, -1.93)]. All active treatments were significantly superior to placebo [adjusted mean difference (95% CI) from placebo: FDC: -4.1 (-4.86, -3.34); FF: -1.84 (-2.66, -1.03); LEVO: -1.53 (-2.34, -0.72)]. Onset of action was rapid following FDC and LEVO treatment with an approximate two unit reduction in mean TNSS from pre-dose levels by 30 min and 1 h. Mean TOSS was also reduced following all active treatments relative to placebo (range 0.6-0.8 unit reduction). All treatments were equally well tolerated.

CONCLUSIONS AND CLINICAL RELEVANCE

These results suggest that once daily FF/LEVO FDC could provide a clinical therapeutic advantage to existing standard monotherapies in the treatment of moderate-to-severe AR, and support progression to evaluation in larger phase III clinical studies.

Facile synthesis of heavily-substituted alkynylpyridines via a Sonogashira approach

A robust synthesis of highly-substituted alkynylpyridines via a Sonogashira approach is described, providing a library of functionalized pyridines for biological studies.

Controlled Allergen Challenge Facilities and Their Unique Contributions to Allergic Rhinitis Research

The aim of this study is to review advances in basic and clinical allergic rhinitis (AR) research over the past decade that have been conducted using controlled allergen challenge facility (CACF) models of allergen challenge. Databases, including PubMed, Medline, and Web of Science were searched for articles employing an ambient pollen exposure in a controlled facility to study AR, published between 2004 and the present date, using the terms as follows: CACF, Environmental Exposure Unit (EEU), Vienna Challenge Chamber (VCC), Fraunhofer Institute Environmental Challenge Chamber, Atlanta Allergen Exposure Unit, Biogenics Research Chamber, Allergen BioCube, Chiba and Osaka Environmental Challenge Chamber, exposure unit, challenge chamber, or environmental exposure chamber. Articles were then selected for relevance to the goals of the present review, including important contributions toward clinical and/or basic science allergy research. CACFs offer sensitive, specific, and reproducible methodology for allergen challenge. They have been employed since the 1980s and offer distinct advantages over traditional in-season multicentre trials when evaluating new treatments for AR. They have provided clinically applicable efficacy and pharmacologic information about important allergy medications, including antihistamines, decongestants, antileukotrienes, immunotherapies, and nasal steroids. CACF models have also contributed to basic science and novel/experimental therapy research. To date, no direct studies have been conducted comparing outcomes from one CACF to another. Over the past decade, CACF models have played an essential role in investigating the pathophysiology of AR and evaluating new therapies. The future opportunities for this model continue to expand.

Efficacy of Sublingual Immunotherapy with Dermatophagoides farinae Extract in Monosensitized and Polysensitized Patients with Allergic Rhinitis: Clinical Observation and Analysis

AIM

To investigate differences in the efficacy of sublingual immunotherapy with Dermatophagoides farinae drops in monosensitized and polysensitized allergic rhinitis patients.

METHODS

The patients enrolled in the study were treated for more than one year by sublingual immunotherapy (SLIT) using Dermatophagoides farinae drops and were divided into a monosensitized group (n = 20) and a polysensitized group (n = 30). Total nasal symptom scores of patients before and after SLIT were analyzed to evaluate the curative effect. The phylogenetic tree of dust mite allergens as well as other allergens that were tested by skin prick test was constructed to help the analysis.

RESULTS

There was no significant difference in the efficacy of SLIT between dust mite monosensitized and polysensitized patients.

CONCLUSIONS

Both dust mite monosensitized and polysensitized patients could be cured by SLIT using Dermatophagoides farinae drops. This study provides a reference for the selection of allergens to be used in immunotherapy for polysensitized AR patients.

Environmental exposure chambers in allergen immunotherapy trials: Current status and clinical validation needs

As required by the European Medicines Agency and the US Food and Drug Administration for pivotal trials involving allergen immunotherapy (AIT) products, clinical efficacy assessment is currently based on double-blind, placebo-controlled field studies with natural allergen exposure during the allergen season. However, this study design is associated with several drawbacks, such as the high variability of allergen exposure in different trial sites or seasons and the presence of confounding environmental factors. On the contrary, environmental exposure chambers (EECs) aim to operate with a stable and reproducible allergen exposure under highly standardized environmental conditions. Technical validation parameters for different EECs worldwide have been published by several groups. However, full clinical validation of EEC study outcomes is required for their classification as an appropriate alternative to natural allergen exposure for AIT product efficacy assessment. Some clinical validation parameters have already been addressed for EEC units. The reliability of provoked symptoms in repeated EEC sessions is high, but the predictive power of EEC settings for the clinical response on natural exposure and the impact of seasonal priming on test results still have to be validated systematically, as does the inter-EEC variability. Thus the authors recommend a continued in-depth validation of EECs to exploit the potential of this technology for future AIT product development.

Safety evaluation of desloratadine in allergic rhinitis

INTRODUCTION

Desloratadine is a biologically active metabolite of second-generation antihistamine loratadine. It is also indicated for the treatment of allergic diseases, including allergic rhinitis.

AREAS COVERED

A Medline search was conducted to identify preclinical and clinical studies of desloratadine. This was supplemented with additional articles obtained from online sources. The focus of this review is on the safety profile of desloratadine.

EXPERT OPINION

The review of these data indicates that the safety profile of desloratadine is similar to other second-generation antihistamines. Desloratadine is highly selective for histamine H₁-receptors, does not cross the blood-brain barrier (BBB), and has minimal adverse events (very low sedation rate), with a better safety and tolerability than first-generation antihistamines. Desloratadine is safe and well tolerated without having central nervous system (CNS) or cardiovascular effects and with low drug interaction.

Treatment of allergic rhinitis with desloratadine: results of a multinational observational study in the middle East gulf region

Background

Allergic rhinitis (AR) affects up to 36% of the population in the Middle East Gulf States. The second-generation nonsedating antihistamine desloratadine has demonstrated safety and efficacy in the treatment of AR; however, few studies have evaluated this agent in Arab and Asian populations in the Middle East.

Methods

This open-label study enrolled subjects ≥ 12 years with moderate-to-severe AR; they received desloratadine 5 mg QD for 2 weeks. Endpoints included change in mean individual nasal and ocular symptom scores, total symptom score (TSS), and peak nasal inspiratory flow (PNIF) and percentage improvement in global response to therapy.

Results

There were 602 subjects from 5 Middle East countries enrolled. After 2 weeks, desloratadine significantly (P < 0.0001) reduced mean scores for individual nasal and total ocular symptom scores and TSS. PNIF measures of nasal congestion were significantly (P < 0.0001) improved after treatment. Most subjects obtained complete (38.1%) or marked (47.2%) relief of AR symptoms. Treatment failure was reported in 2.2% of subjects. No adverse events were reported, and no subjects discontinued treatment.

Conclusion

Most subjects reported significant symptom relief with desloratadine 5 mg/d for 2 weeks. Desloratadine is effective in the treatment of AR in Arab and Asian subjects in the Middle East Gulf region.

Predicting and establishing the clinical efficacy of a histamine h(1)-receptor antagonist : desloratadine, the model paradigm

Antihistamines are well established as a mainstay for treating allergic diseases, including seasonal and perennial allergic rhinitis as well as other conditions, such as chronic idiopathic urticaria. The development of new antihistamines is a multistage process that includes in vitro and in vivo assessments of the antihistaminic, anti-inflammatory and antiallergic properties of new therapies. Results of these assessments are critical for predicting and establishing the clinical efficacy of an antihistamine. The focus of this article is to review the investigational methods used to assess the efficacy, safety and tolerability of newer histamine H(1)-receptor antagonists. Desloratadine, a new-generation H(1)-receptor antagonist, was chosen to illustrate the use of this model paradigm. Data obtained from two large observational studies are presented, confirming results obtained from clinical trials that the in vitro inhibition of release of inflammatory mediators such as histamine, prostaglandins, leukotrienes and the reduction of secretion of cytokines such as IL-4 and IL-13 at physiological concentrations is reflected in increased efficacy, particularly upon nasal obstruction. A recent discovery that des- loratadine inhibits nuclear factor-kappaB may be the underlying explanation for much of this extra anti-inflammatory activity.

Intranasal steroids in the treatment of allergy-induced rhinorrhea

While nasal congestion has been identified as one of the most bothersome and prevalent symptoms of allergic rhinitis, it is underappreciated that many patients find rhinorrhea also to be bothersome. Rhinorrhea as a symptom of allergic rhinitis virtually never occurs alone; about 97% of patients with allergic rhinitis suffer from at least two symptoms, a finding that underscores the advantage of treating a broad range of symptoms with a single medication. Along with sneezing and nasal obstruction, rhinorrhea is a classic acute symptom of allergic rhinitis; it appears as a late-phase symptom as well. In this review, the characterization and epidemiology of rhinorrhea, the pathophysiology of rhinorrhea in allergic rhinitis, the roles played by mediators in early- and late-phase rhinorrhea, the prevalence and impact of this symptom, and the efficacy and safety of available treatment options are all discussed in context of relevant literature. A review of the clinical studies assessing the efficacy of intranasal corticosteroids (INS) for rhinorrhea is presented. Many clinical studies and several meta-analyses conclusively demonstrate that, in addition to being safe and well-tolerated, INS are more effective than other agents (including oral and intranasal antihistamines) across the spectrum of AR symptoms, including rhinorrhea and nasal congestion.

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.

Remodelling of nasal mucosa in mild and severe persistent allergic rhinitis with special reference to the distribution of collagen, proteoglycans, and lymphatic vessels

BACKGROUND

Small leucine-rich repeat proteoglycans (decorin, biglycan, and lumican), collagen, and lymphangiogenesis are involved in tissue remodelling of various organs with inflammatory diseases.

OBJECTIVE

We determined the expression level and the distribution pattern of small leucine-rich repeat proteoglycans (decorin, biglycan, and lumican), collagen and lymphatic vessels in healthy, mild, and severe persistent allergic nasal mucosa.

METHODS

The distribution pattern of collagen, proteoglycans, and lymphatic vessels in healthy, mild, and severe persistent allergic nasal mucosa was evaluated by the van Gieson staining, immunohistochemistry, RT-PCR, and Western blotting. Quantitative analyses of collagen deposition were calculated as the median of the total percentage area in the tissue specimen. For the evaluation of proteoglycans, the percentage area stained and median optical density were measured for each image. Lymphatic vessels were identified by D2-40 antibody and calculated using the lymphatic vessel density and endothelial length density in tissue specimens. The expression of MMP 2 and 9, TIMP1 and 2 was evaluated with RT-PCR and Western blotting.

RESULTS

In mild and severe persistent allergic nasal mucosa, compared with healthy nasal mucosa, collagen showed more intense staining in the superficial and submucosal layer. In healthy and allergic nasal mucosa, decorin was lightly stained without significant differences in the percentage area and optical density of staining. However, lumican and biglycan showed strong immunoreactivity in mild and severe persistent allergic nasal mucosa, which was verified by Western blotting. The number and endothelial length density of lymphatic vessels were increased in mild and severe persistent allergic nasal mucosa compared with healthy nasal mucosa. The expression of MMP 9 was increased in severe persistent allergic rhinitis.

CONCLUSION AND CLINICAL RELEVANCE

These results suggest that the altered distribution pattern of collagen, proteoglycans, and lymphatic vessels could potentially modulate the remodelling of nasal mucosa in mild and severe persistent allergic nasal mucosa.

The patient with allergies

Allergic disease affects a sizeable percentage of the general population, has a significant impact on patient quality of life, and exerts a significant financial burden on society. Atopic symptoms from inhalant allergens are among the most frequent complaints in outpatient medical visits. Key history and physical examination findings help to distinguish allergic rhinitis from other forms of chronic rhinosinusitis. Diagnostic testing may not be necessary unless immunotherapy is contemplated.

Histamine in allergic rhinitis

Histamine plays a major role in allergic rhinitis. In susceptible individuals, allergen induces nasal mast cell degranulation and the release of histamine into the nasal mucosa. Histamine has been detected after controlled challenges with allergen and, when administered into the nasal cavity, elicits signs and symptoms similar to those elicited by allergen. All four histamine receptors have been demonstrated in the nasal mucosa. The role of the four histamine receptors in the pathophysiology of allergic rhinitis are discussed.

Desloratadine for the treatment of cypress pollen-induced allergic rhinitis

BACKGROUND

Few studies have been conducted to assess treatment options for patients with sensitivities to cypress pollens, important triggers of allergic rhinitis (AR) in the Mediterranean region.

OBJECTIVE

To evaluate the effect of desloratadine, a second-generation antihistamine, on AR symptoms caused by cypress pollens native to France.

METHODS

Adults (N=233) with symptomatic cypress pollen allergies were randomized to receive desloratadine, 5 mg, or placebo daily for 15 days during 2 consecutive cypress pollen seasons. The primary end point was the percentage change from baseline in morning total nasal symptom scores on day 14; secondary assessments included total symptom score, peak nasal inspiratory flow, the Rhinoconjunctivitis Quality of Life Questionnaire, and global response to therapy.

RESULTS

On day 14, the desloratadine group had a significantly greater percentage decrease in total nasal symptom score vs the placebo group (-40% vs. -30%; P < .04). Similarly, on day 14, there was a 47% and 37% respective decrease in total symptom score (P = .01). Mean peak nasal inspiratory flow scores showed numeric, albeit not statistically significant, improvements from baseline through day 14 with desloratadine. A significantly greater improvement in Rhinoconjunctivitis Quality of Life Questionnaire scores occurred with desloratadine vs placebo on day 14 (-1.4 vs. -0.9; P = .004). The mean global response to therapy was better with desloratadine vs placebo (3.4 vs. 3.9; P = .004). The adverse event rate was similar in both groups.

CONCLUSION

Desloratadine is efficacious and safe for the treatment of AR induced by cypress pollens; it also improved disease-related quality of life.

Desloratadine relieves nasal congestion and improves quality-of-life in persistent allergic rhinitis

BACKGROUND

Symptoms of allergic rhinitis (AR), particularly nasal congestion, can impair quality-of-life (QoL). However, only a modest correlation exists between these symptoms and Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ) scores, suggesting that both be evaluated for a complete assessment of health.

METHODS

Subjects with a > or =2-year history of moderate-to-severe AR to dust mite or cat dander were randomized to desloratadine 5 mg/day (n = 293) or placebo/day (n = 291) for 28 days. Primary endpoint was change from baseline in a.m./p.m. nasal congestion score. Secondary outcomes included change from baseline in total nasal symptom score, individual symptom scores and RQLQ scores (completed on days 1, 7, and 28).

RESULTS

The Allergic Rhinitis and its Impact on Asthma criteria for persistent allergic rhinitis (PER) were fulfilled by 99% of subjects in the placebo arm. Between-treatment difference in a.m./p.m. nasal congestion score, observed from day 8 onward, significantly favored desloratadine (P = 0.0003). Desloratadine significantly improved a.m./p.m. nasal congestion and RQLQ scores after 1 week and at treatment end (P < 0.05). Improvements in 5 of 7 RQLQ domain scores exceeded the minimal important difference. On days 7 and 28, desloratadine was also significantly superior to placebo in mean change from baseline in a.m./p.m. total nasal symptom score and rhinorrhea score (both P < or = 0.01). Symptomatic benefit was primarily driven by improvement in nasal congestion and rhinorrhea.

CONCLUSIONS

Desloratadine 5 mg/day significantly improved symptoms associated with PER, including nasal congestion, and provided significant improvement in QoL after 1 week of treatment.

A review of the efficacy of desloratadine, fexofenadine, and levocetirizine in the treatment of nasal congestion in patients with allergic rhinitis

BACKGROUND

Nasal congestion is the most troublesome symptom of allergic rhinitis (AR). First-generation and older second-generation antihistamines, while effective against nasal itching, sneezing, and rhinorrhea, have limited efficacy in relieving nasal congestion.

OBJECTIVE

This review included nasal challenge studies and clinical trials that reported the effects on nasal congestion of the newer second-generation antihistamines desloratadine, fexofenadine, and levocetirizine.

METHODS

MEDLINE and EMBASE were searched for nasal challenge studies and clinical trials published in English between January 1, 1991, and January 31, 2009, using the following terms, alone or in combination: antihistamines, second-generation antihistamines, allergic rhinitis, intermittent allergic rhinitis, perennial allergic rhinitis, persistent allergic rhinitis, seasonal allergic rhinitis, nasal challenge, nasal blockage, and nasal congestion. Studies that were not active or placebo controlled, that did not evaluate change in nasal congestion scores, or that focused on treatments other than desloratadine, fexofenadine, and levocetirizine for nasal congestion associated with AR were excluded.

RESULTS

Twenty-six clinical trials met the criteria for inclusion in the review. In 11 placebo-controlled trials that included objective assessment of nasal congestion, desloratadine, fexofenadine, and levocetirizine were associated with reductions in the severity of nasal congestion through maintenance of nasal airflow. The mean AUC for nasal airflow over 6 hours was significantly greater with desloratadine compared with placebo in 3 studies (P < 0.05); placebo-controlled trials of fexofenadine and levocetirizine had similar results. In 25 placebo- and active-controlled trials that reported subject-rated symptom scores, the 3 newer antihistamines were efficacious in the treatment of nasal congestion associated with AR. In 10 trials that reported objective and/or subjective measures, desloratadine was associated with significant improvements in nasal congestion compared with placebo (P < or = 0.05), beginning as early as the first 2 hours after allergen challenge. Fexofenadine was associated with significantly lower nasal congestion scores compared with placebo in 4 studies (P <- 0.05); nasal congestion scores were significantly reduced with levocetirizine in 3 placebo-controlled trials (P < or = 0.005).

CONCLUSIONS

In the studies reviewed, desloratadine, fexofenadine, and levocetirizine were effective in relieving the nasal congestion associated with AR compared with placebo. This effect began as early as day 2 and was consistent and progressive throughout treatment. Desloratadine, fexofenadine, and levocetirizine are appropriate options for the treatment of nasal congestion in patients with AR.

Complexities of diagnosis and treatment of allergic respiratory disease in the elderly

Atopic diseases such as rhinitis and asthma are relatively common in children and young adults. However, many patients aged >65 years are also affected by these disorders. Indeed, the literature suggests that between 3-12% and 4-13% of individuals in this age range have allergic rhinitis and asthma, respectively. However, these numbers are most likely underestimates because atopic diseases are frequently not considered in older patients. The diagnosis of both allergic rhinitis and asthma in older patients is more difficult than in younger patients because of a wide differential diagnosis of other diseases that can produce similar symptoms and must be excluded. Furthermore, treatment of these disorders is complicated by the potential for drug interactions, concern about the adverse effects of medications, in particular corticosteroids, and the lack of drug trials specifically targeting treatment of older patients with allergic rhinitis and asthma.

Levocetirizine modulates lymphocyte activation in patients with allergic rhinitis

Levocetirizine, a second generation non-sedating antihistamine that blocks the H(1) histamine receptor, may exhibit immunoregulatory properties that augment its primary pharmacological mechanism. To investigate this possibility, 13 Kuwaiti seasonal allergic rhinitis (SAR) patients were treated with levocetirizine for four weeks in comparison with a 7-member placebo-treated control group, followed by clinical evaluation and flow cytometric analysis of peripheral venous blood for inflammatory cell and lymphocyte subpopulation profiles. Relative to the controls, levocetirizine-treated patients exhibited an expected reduction in early phase allergic symptoms, including sneezing (P<0.001), nasal itching (P<0.01), nasal congestion, and running nose (P<0.001); reduced percentages of eosinophils (P<0.05); and three subpopulations of activated T lymphocytes: CD4+CD29+, CD4+CD212+, and CD4+CD54+ (P<0.05). Levocetirizine treatment also correlated with a significant increase in the percentage of CD4+CD25+ T cells (P<0.001). The ability of levocetirizine to reduce percentage representation of cell phenotypes known to contribute to inflammatory tissue damage (eosinophils, CD4+CD29+, CD4+CD212+, and CD4+CD54+) and expand percentages of CD4+CD25+, which may include protective immunoregulatory (Treg) cells, indicates that the drug has pharmacological potential beyond the immediate effects of H(1) histamine-receptor inhibition. Although the present data does not define a therapeutic mechanism, the results reported here establish important trends that may be used to guide future mechanistic examination of immunoregulatory capacity of H(1) inhibitors.

Fluticasone furoate versus placebo in symptoms of grass-pollen allergic rhinitis induced by exposure in the Vienna Challenge Chamber

OBJECTIVE

The Vienna Challenge Chamber (VCC) offers a controlled and controllable paradigm in which to reproducibly evaluate the efficacy of anti-allergic treatment. The aim of this study was to assess the efficacy of the novel intranasal corticosteroid fluticasone furoate (FF) in the VCC.

METHODS

The single-centre, randomised, double-blind, placebo-controlled, two-period crossover study was conducted in 59 adult males with grass pollen allergic rhinitis (AR). Patients received either Fluticasone furoate 200 mcg once-daily, or placebo intranasally for 8 days. AR symptoms were induced during 4-hour allergen challenges with grass pollen in the VCC at the end of each 8-day treatment period. A first challenge was conducted at 1-5 hours post-dose, followed by a second challenge at 22-26 hours post-dose. The primary endpoint was total nasal symptom score (TNSS; sum of itch, sneeze, rhinorrhoea, obstruction symptoms assessed on a categorical scale of 0-3) weighted mean over 2-5 hours post-dose. Secondary endpoints included: TNSS weighted mean over 23-26 hours post-dose and global symptom score, eye symptom score, nasal secretions and nasal airflow weighted means over 2-5 and 23-26 hours post-dose.

RESULTS

Fluticasone furoate showed consistent attenuation of AR symptoms in both the early and late challenges. Compared with placebo, weighted mean of TNSS was reduced on average by 4.14 point-scores at 2-5 hours post-dose and 3.63 point scores at 23-26 hours post-dose. These positive effects were also seen across all secondary endpoints.

CONCLUSION

An 8-day treatment course of intranasal FF 200 mcg given once-daily statistically significantly reduced symptoms of AR including associated eye symptoms. Statistical significance was declared where the relevant two-sided 95% confidence interval did not contain zero. This positive effect was sustained over 24 hours suggesting that fluticasone furoate could be efficacious as a once daily steroid.

Effectiveness of desloratadine 5 mg once daily in patients with symptoms of seasonal allergic rhinitis: results of a Canadian multicenter, open-label trial

BACKGROUND

Seasonal allergic rhinitis (SAR) is an inflammatory response to seasonal allergens. Desloratadine, a once-daily selective histamine H(1)-receptor antagonist, has been reported to be efficacious in relieving symptoms of SAR in controlled clinical trials. However, to assess the actual effectiveness of a drug, it is important to examine information about its use in routine clinical practice.

OBJECTIVE

The Partners in Allergy Control and Therapy (PACT) study examined the effectiveness of desloratadine in patients with SAR symptoms receiving treatment in a community setting of primary care physicians in Canada.

METHODS

Patients with symptoms of SAR received desloratadine 5 mg once daily for 7 days during the spring-summer allergy season (April-July 2002). Patients rated their SAR symptoms along with their physicians by completing a questionnaire at baseline and day 7. Nasal, ocular, respiratory, and overall symptoms were rated on a scale of 0 (no symptoms evident) to 3 (severe/interfere with activities of daily living and/or sleeping). Physicians were asked to keep a record of adverse events reported by patients. The Wilcoxon signed-rank test was used to evaluate symptom severity scores. A 2-way (time x treatment), repeated measures, mixed analysis of variance (ANOVA) model was constructed to assess differences in variables over time.

RESULTS

A total of 6829 patients participated in the study. Patients reported nasal stuffiness/congestion as their most severe symptom. Just over half (50.1%) of patients were receiving another medication for SAR at study entry; 29.7% were receiving an intranasal corticosteroid. After 7 days of treatment with desloratadine, individual symptom scores and overall symptom scores were significantly reduced compared with baseline (all scores, P<0.001). An improvement in nasal/stuffiness/ congestion was reported by 88.0% of patients. The ANOVA detected a statistically significant incremental benefit with desloratadine and an intranasal corticosteroid compared with desloratadine monotherapy (P<0.001). No severe adverse events were reported.

CONCLUSION

Desloratadine 5 mg once daily was associated with significant improvement in symptoms of SAR, and appeared to provide additional benefit in relieving moderate to severe nasal stuffiness/congestion in 6786 patients receiving 7-day treatment in an actual practice setting of primary care physicians in Canada.

The effect of regular versus on-demand desloratadine treatment in children with allergic rhinitis

OBJECTIVE

Desloratadine is a potent antihistamine. Whether regular or on-demand use of desloratadine influences its therapeutic efficacy in allergic rhinitis is unknown. The aim of the study was to compare the clinical efficacy and the anti-inflammatory activity of regularly administered desloratadine to its on-demand use in children with allergic rhinitis due to pollen allergy.

METHODS

Thirty-seven patients with allergic rhinitis with or without mild intermittent asthma were enrolled in a prospective parallel group study. Patients were treated with desloratadine regularly or on-demand during pollen season. Rescue medications and symptom scores were recorded on a diary card. Nasal flow rate and inflammatory markers were recorded, and methacholine (Mch) challenge test was administered before and within the pollen season.

RESULTS

Though symptoms were lower in the evening than in the morning (p<0.001), there was no difference between the two groups. There was no difference between the groups with respect to medication score except that the salbutamol use was lower in the regular treatment group during the fourth week (p=0.032) in the pollen season. Nasal flow rate and inflammatory markers failed to show any difference between the groups. A significant reduction in PC20 values (provocative concentration of Mch causing a 20% fall in FEV(1)) was observed in regular (p=0.016) and on-demand (p=0.005) treatment groups compared to the pre-season measurements. The number of children with a PC20 below 8 mg/ml increased significantly in the on-demand group.

CONCLUSION

Our study demonstrates that on-demand use of desloratadine during the pollen season is clinically as effective as regular treatment. However, regular treatment may provide better control of lower airway symptoms and airway reactivity.

Preliminary study on Japanese cedar pollinosis in an artificial exposure chamber (OHIO Chamber)

BACKGROUND

A pollen exposure chamber (OHIO Chamber) was built in central Tokyo, Japan, in order to study seasonal allergic rhinitis (SAR). Since satisfactory outcomes were obtained from the controlled pollen exposure at the chamber, we conducted preliminary studies in volunteers with SAR.

METHODS

Ten volunteers with SAR sensitive to Japanese cedar (JC) pollen were enrolled in this study. In order to investigate the intranasal and intraocular pollen number, volunteers were initially exposed to a low concentration of JC (2500 grains/m3) for at most 1 hour in this chamber. Before and after the exposure, nasal cavities and eyes were washed with 100ml and 25 ml of saline, respectively. Nasal and eye washing solutions were collected and the number of JC pollen was counted. After 3 hours the volunteers were subsequently exposed to a moderate concentration of JC (4500 grains/m3) for 2 hours. Subjective nasal and ocular symptoms were recorded and the amount of nasal secretion was measured during the allergen exposure periods.

RESULTS

During the initial exposure, all volunteers except one stayed in the chamber for 1 hour without any nasal or ocular symptoms. The number of pollen in the nose and eyes was 249.2 +/- 120.9 and 13.6 +/- 13.6 grains, respectively. During the subsequent 2-hour exposure to JC pollen, nasal and ocular symptoms developed gradually in a time dependent manner in all the volunteers except one.

CONCLUSIONS

This is the first clinical study using Japanese cedar pollen under well-controlled conditions in the OHIO chamber in which the induction of allergic symptoms was observed. The OHIO chamber will be useful for studying allergic rhinitis in Japan.

Efficacy of desloratadine in the treatment of allergic rhinitis: a meta-analysis of randomized, double-blind, controlled trials

The objective of the study is to assess the efficacy of the nonsedating antihistamine, desloratadine, in the treatment of allergic rhinitis (AR). A search of MEDLINE, EMBASE, LILACS, and CINAHL databases was undertaken from January, 1966 to May, 2006. Double-blind, randomized, controlled studies of desloratadine in the treatment of AR in adult patients were carried out. The measured outcomes included the total symptoms score, the total nasal symptoms score, nasal airflow, and inflammatory markers (nasal eosinophils, nasal interleukin-4). The analysis included the calculation of standardized mean difference (SMD). A total of 57 studies were analyzed, and 13 randomized, double-blind, controlled trials were included in the meta-analysis. The trials included 3108 subjects who had completed studies involving desloratadine. There was significant heterogeneity among the study results, because of differing study methodologies. Desloratadine was associated with significant reductions in total symptoms scores (SMD -1.63; 95% CI -2.75 to -0.51; P = 0.004) and total nasal symptoms score (SMD -0.66; 95% CI -0.91 to -0.42; P < 0.001), when compared with placebo. Analysis of objective data on nasal blockage demonstrated a significant improvement in nasal airflow with desloratadine, when compared with placebo (SMD 0.32; 95% CI 0.10 to 0.55; P = 0.005). A benefit favoring desloratadine over placebo in terms of nasal eosinophil levels was also noted in the analysis. This meta-analysis confirms the reduction of AR symptoms and improvement in nasal airflow seen in individual studies of desloratadine. Objective improvements in nasal airflow, total symptoms, and total nasal symptoms seen with desloratadine are supported by Ia evidence.

The safety and efficacy of desloratadine for the management of allergic disease

Allergic disease is an increasing problem worldwide. Allergic rhinitis, an inflammatory response to an allergen, affects an estimated 20-40 million people in the US, while chronic idiopathic urticaria is a dermatoallergic condition that affects 0.1-3% of people in the US and Europe. The primary goals of treatment for allergic rhinitis are to reduce symptoms, which include sneezing, rhinorrhoea and nasal congestion, improve quality of life and prevent the sequelae associated with this disease, while the goal for chronic idiopathic urticaria is the rapid and prolonged control of symptoms. Quantitatively, histamine is the most abundant mediator present during an allergic episode - thus, antihistamines (historically called histamine H(1) receptor antagonists, now called H(1) receptor inverse agonists) are a first-line defense against allergic rhinitis and chronic idiopathic urticaria. Although first-generation antihistamines can cause sedation and cognitive impairment, second-generation antihistamines are relatively non-sedating and free of such adverse events owing to their comparative inability to penetrate the blood-brain barrier. Desloratadine is one such second-generation antihistamine and is indicated for the treatment of allergic diseases, including allergic rhinitis and chronic idiopathic urticaria. It has proven efficacy against the symptoms associated with seasonal and perennial allergic rhinitis, including nasal congestion, and chronic idiopathic urticaria. As a result, it has been shown to improve patients' quality of life. The safety and efficacy profiles of desloratadine are well established, and published postmarketing analyses have assessed >54 000 patients. Although earlier second-generation antihistamines have been associated with cardiovascular adverse effects, desloratadine has been shown to be safe and well tolerated at nine times the recommended dose. In addition, it has been shown to not interact with concomitantly administered drugs and food. Overall, current data indicate that desloratadine is a safe and effective treatment for allergic diseases.

Pharmacologic and anti-IgE treatment of allergic rhinitis ARIA update (in collaboration with GA2LEN)

The pharmacologic treatment of allergic rhinitis proposed by ARIA is an evidence-based and step-wise approach based on the classification of the symptoms. The ARIA workshop, held in December 1999, published a report in 2001 and new information has subsequently been published. The initial ARIA document lacked some important information on several issues. This document updates the ARIA sections on the pharmacologic and anti-IgE treatments of allergic rhinitis. Literature published between January 2000 and December 2004 has been included. Only a few studies assessing nasal and non-nasal symptoms are presented as these will be discussed in a separate document.

Pathophysiology of nasal obstruction and meta-analysis of early and late effects of levocetirizine

Nasal obstruction, also referred to as congestion, blockage or stuffiness, is a crucial symptom in allergic rhinitis (AR) and may affect sleep as well as quality of life. Early- and late-phase-allergic reactions both contribute to nasal obstruction, although it primarily represents a major symptom in the chronic allergic reaction. A complex network of inflammatory and neurogenic phenomena relates to chronic nasal obstruction, including the subepithelial accumulation of inflammatory cells, particularly mast cells and eosinophils, and the release of neuropeptides. Nasal obstruction is a difficult-to-treat symptom. Vasoconstrictors (decongestants) and intranasal corticosteroids, due to their anti-inflammatory properties, have mainly been used for relieving the nasal passages from the congested mucosa. However, there is accumulating evidence recently that the latest-generation potent antihistamines have decongestant properties in AR. This paper aims to review the pathophysiologic background of nasal obstruction and the evidence for an antihistamine, levocetirizine, in relieving nasal congestion. A meta-analysis on the early and late effects of levocetirizine on nasal obstruction under artificial and natural allergen exposure conditions is presented, demonstrating convincingly that levocetirizine shows a consistent effect on nasal obstruction as early as over the first 2 h and sustained over 6 weeks.