A direct comparison of the efficacy of antihistamines in SAR and PAR: randomised, placebo-controlled studies with levocetirizine and loratadine using an environmental exposure unit - the Vienna Challenge Chamber (VCC)

Clinical validation of grass pollen exposure chamber in patients with allergic rhinitis triggered by timothy grass

BACKGROUND

The fluctuation in concentrations of airborne allergens frequently presents a challenge to assessing the efficacy of allergen immunotherapy (AIT) in 'field' studies. Allergen exposure chambers (AECs) are specialized medical installations developed to expose individuals to allergens at defined and consistent concentrations under a controlled environment. The aim of the study was to validate the provocation test with timothy grass pollen as well as to assess its safety in the AEC in patients with allergic rhinitis.

METHODS

In the ALLEC® AEC, varying concentrations of timothy grass pollen were dispersed. Allergic symptoms were measured by total nasal symptom score (TNSS), acoustic rhinometry, peak nasal inspiratory flow (PNIF) and nasal discharge volume. Lung function, assessed through peak expiratory flow rate (PEFR) and forced expiratory volume in the first second (FEV1), was used to evaluate safety.

RESULTS

The consistency of the test was proved by the stability of environmental conditions, including temperature, humidity and CO2 levels, as well as constant concentrations of grass pollen at predetermined levels ranging from 1000 to 10,000 particles per cubic meter (p/m3). Allergic individuals developed symptoms at concentrations of 3000 p/m3 and above, across all measured endpoints. Lung function was not affected throughout all the challenges. The reproducibility of symptoms was confirmed throughout the tests. The concentration of 8000 p/m3 together with a challenge duration of 120 min was found to be optimal.

CONCLUSION

The study demonstrates that the ALLEC® grass pollen exposure chamber provides a reliable and safe method for inducing repeatable symptoms in patients with allergic rhinitis. This approach can be effectively applied for allergy diagnostics and clinical endpoint determination during AIT.

Pharmacotherapy and immunotherapy of allergic rhinitis induced by house dust mite, grass, and birch pollen allergens: a meta-analysis of randomized clinical trials

BACKGROUND

The aim of this study was to assess the efficacy and safety of oral antihistamines (AHs), intranasal antihistamines (INAH) intranasal glucocorticosteroids (INCS), subcutaneous immunotherapy (SCIT), and sublingual immunotherapy (SLIT) in the management of allergic rhinitis (AR). The authors focused on the division into selected AR's triggers: house dust mites (HDMs), grass pollen, and birch pollen.

METHODS

For each drug and allergen class, a meta-analysis of the efficacy and adverse events (AEs) was performed. The obtained results were presented as a therapeutic index (TIX-Score).

RESULTS

Twenty-seven randomized clinical trials (RCTs) were included. The best total efficacy was observed for: HDMs for INCS and grass pollen for combination of INCS with INAH in a single device and for INAH. Considering the data that was obtained for birch pollen, SLIT showed statistically significant total efficacy. Summation scores for efficacy and AEs showed highest TIX-Score for combination of INCS and INAH in a single device in grass pollen.

CONCLUSIONS

Treatment methods selected for this review may serve as an effective and safe treatment in reducing perennial and seasonal AR's symptoms. However, due to high heterogeneity probably associated with potential confounders existence in control in some cases, results should be interpreted with caution.

Pharmacoeconomic Assessment of Antiallergic Drugs by Comparing Serum Immunoglobulin E Level as a Diagnostic and Monitoring Indicator of Allergic Rhinitis in Rural Population of India

Allergic rhinitis (AR) is a chronic inflammatory disease induced by IgE mediated reaction and identified clinically by presence of nasal discharge, sneezing, itching and nasal congestion. Aim of this study was to determine Serum IgE level which is an important indicator of AR. To analyse the diagnostic significance of serum IgE level and their pharmacoeconomic status in the management of AR with commonly used antihistaminic. Estimation of serum IgE can serve as a simple and reliable investigative tool in the diagnostic and management of AR. Fifty two adult patient with history of allergic rhinitis were randomly divided into four study groups and administered either Cetirizine, Levocetirizine, Loratidine or Fexofenadine respectively for one week. Blood samples were analysed to determine serum IgE level and the results were subjected to statistical analysis. The mean value and standard deviation were obtained and tabulated using paired t test. A total 52 patient were divided into four group, 13 in each group of age between 18 and 65 years (mean age 33.73 ± 10.23 years); 48.08% females and 51.92% male were randomized. Mean compliance with treatment was 100% for all study groups. The mean serum IgE level was significantly reduced in Levocetirizine as compared to Cetirizine, Loratidine and Fexofenadine groups. Levocetirizine controls the symptoms of AR better as compared to Cetirizine, Loratidine and Fexofenadine and is a better choice due to its cost effectiveness, tolerability and safety profile.

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.

Utility of Environmental Exposure Unit Challenge Protocols for the Study of Allergic Rhinitis Therapies

PURPOSE OF REVIEW

This paper explores how the Environmental Exposure Unit (EEU) experimental model can be used to further our understanding of pharmacotherapies and immunotherapies for the treatment of allergic rhinitis (AR).

RECENT FINDINGS

EEUs are used increasingly for the study of combination therapies, immunotherapies, and novel AR treatments. A combined antihistamine/corticosteroid nasal spray formulation was seen to have a faster onset of action relative to the therapies individually in the Environmental Exposure Chamber. House dust mite sublingual immunotherapy tablets are both safe and efficacious as evaluated by the Vienna Challenge Chamber. The Kingston EEU found that a novel peptide-based immunotherapy approach to be effective in reducing grass pollen-induced AR. Lastly, nasal filters were determined to reduce seasonal AR symptoms, given out-of-season in the Denmark Environmental Exposure Unit. EEUs are controlled, replicable models that provide valuable insight into the efficacy, onset and duration of action, and dose-related impacts of AR therapeutics, with direct clinical relevance.

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.

Onset of action for loratadine tablets for the symptomatic control of seasonal allergic rhinitis in adults challenged with ragweed pollen in the Environmental Exposure Unit: a post hoc analysis of total symptom score

Background

Loratadine is a second-generation, non-sedating antihistamine used for the relief of allergic rhinitis symptoms. Previous studies reported that when loratadine was encapsulated, the onset of action for symptom relief was 180 min. However, unmodified loratadine tablets were not evaluated at that time. Using data from a previously published Environmental Exposure Unit (EEU) study comparing azelastine nasal spray with loratadine tablets, cetirizine tablets, and placebo, this post hoc analysis determines the onset of action of loratadine tablets (i.e. unmodified) by analyzing the total symptom score for the relief of nasal and ocular seasonal allergic rhinitis (SAR) symptoms.

Methods

A Phase IV, randomized, single-center, double-blind, placebo-controlled, double-dummy, four-way crossover study was conducted in the EEU. Seventy participants were randomized sequentially into one of the four treatments during ragweed pollen exposure. Nasal and ocular symptom scores were self-reported by the participants and recorded. The original study analysis was carried out by evaluating the nasal symptom scores only. For this post hoc analysis, both nasal and ocular data from the loratadine and placebo treatment arms were analyzed. The primary endpoint for this analysis was the onset of action of loratadine as measured by the change in total symptom score (TSS) from baseline in comparison to placebo. The onset of ocular symptom relief using the total ocular symptom score (TOSS) was also reported.

Results

Loratadine tablets demonstrated a significant and durable improvement in both TSS (P = .005) and TOSS (P = .013) at 75 min post-treatment administration compared to placebo. The mean proportion of participants reporting none or mild for all component symptoms of TSS and TOSS at 75 min and thereafter was significantly higher in the loratadine (TSS, P = .0005; TOSS, P ≤ .0001) vs. placebo treatment arm.

Conclusions

The onset of action of loratadine tablets was 75 min for the relief of nasal and ocular symptoms in adults with SAR. These results suggest a faster onset of action for loratadine tablets (75 min) compared to previously reported studies which were conducted with modified (i.e. gelatin-encapsulated) loratadine tablets (180 min).

Trial registration Clinicaltrials.gov identifier NCT00561717

Electronic supplementary material

The online version of this article (10.1186/s13223-017-0227-4) contains supplementary material, which is available to authorized users.

Efficacy and safety of sublingual tablets of house dust mite allergen extracts: Results of a dose-ranging study in an environmental exposure chamber

BACKGROUND

In a natural field study, sublingual tablets of house dust mite (HDM) allergen extracts (STG320) were efficacious in treating HDM-associated allergic rhinitis.

OBJECTIVES

We sought to assess the efficacy and safety of 3 doses of STG320 in an environmental exposure chamber.

METHODS

In this randomized, double-blind study, adults with HDM-associated allergic rhinitis were given a daily sublingual tablet containing placebo or STG320 at a dose of 500IR, 300IR, or 100IR (IR, index of reactivity) for 6 months. Participants recorded their rhinitis symptoms during 4-hour HDM EEC challenges at randomization and months 1, 2, 4, and 6. The primary efficacy end point was the change from baseline to end of treatment in the area under the curve of the rhinitis total symptom score (ChBLAUCRTSS 0-4h). Differences from the placebo group were analyzed by analysis of covariance. Adverse events (AEs) and routine safety parameters were recorded.

RESULTS

A total of 355 subjects were randomized to 1 of 4 groups: 500IR (n = 93), 300IR (n = 86), 100IR (n = 89), or placebo (n = 87). The least squares mean differences from placebo in ChBLAUCRTSS 0-4h for the 500IR, 300IR, and 100IR groups indicated a dose-dependent effect, with reductions in symptom scores of 33%, 29%, and 20%, respectively. The most frequent AEs were throat irritation and oral pruritus. There were no reports of anaphylaxis or reports consistent with severe laryngopharyngeal disorders and no use of epinephrine. AEs leading to premature discontinuations were more common in the 500IR group.

CONCLUSIONS

A dose-dependent effect of sublingual HDM immunotherapy was demonstrated in this environmental exposure chamber study, supporting further development of this treatment.

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.

House Dust Mite Respiratory Allergy: An Overview of Current Therapeutic Strategies

Although house dust mite (HDM) allergy is a major cause of respiratory allergic disease, specific diagnosis and effective treatment both present unresolved challenges. Guidelines for the treatment of allergic rhinitis and asthma are well supported in the literature, but specific evidence on the efficacy of pharmacotherapy treatment for known HDM-allergic patients is weaker. The standard diagnostic techniques--skin prick test and specific IgE testing--can be confounded by cross-reactivity. However, component-resolved diagnosis using purified and recombinant allergens can improve the accuracy of specific IgE testing, but availability is limited. Treatment options for HDM allergy are limited and include HDM avoidance, which is widely recommended as a strategy, although evidence for its efficacy is variable. Clinical efficacy of pharmacotherapy is well documented; however, symptom relief does not extend beyond the end of treatment. Finally, allergen immunotherapy has a poor but improving evidence base (notably on sublingual tablets) and its benefits last after treatment ends. This review identifies needs for deeper physician knowledge on the extent and impact of HDM allergy in respiratory disease, as well as further development and improved access to molecular allergy diagnosis. Furthermore, there is a need for the development of better-designed clinical trials to explore the utility of allergen-specific approaches, and uptake of data into guidance for physicians on more effective diagnosis and therapy of HDM respiratory allergy in practice.

Bilastine: new insight into antihistamine treatment

Bilastine is a new second generation H1-antihistamine recently approved for the symptomatic treatment of allergic rhinitis (AR) and chronic urticaria (CU). Bilastine epitomizes the evolution of research on antihistamines concerning both efficacy and safety. In AR treatment, a number of large controlled clinical trials documented its efficacy, as assessed by improvement of all nasal and ocular symptoms and quality of life. These outcomes show that bilastine meets current EAACI/ARIA criteria for medications used in the treatment of AR. Also in CU, the review of the literature indicates that once-daily treatment with bilastine 20 mg was effective in managing symptoms and improving patient's quality of life. Concerning safety and tolerability, the profile of bilastine is very similar to placebo and in particular the adverse effects on central nervous system are insignificant. The balance of efficacy and safety of bilastine is particularly helpful when dosages higher than standard are needed to control the symptoms, as frequently occurs in patients with urticaria, in whom antihistamines doses up to four times the standard dose may be administered.

Onset and dose-related efficacy of house dust mite sublingual immunotherapy tablets in an environmental exposure chamber

BACKGROUND

The magnitude of effect of sublingual immunotherapy for house dust mite (HDM)-induced allergic rhinitis with or without conjunctivitis is uncertain, partly because there are few well-controlled trials with well-defined doses.

OBJECTIVE

We sought to determine the dose-related efficacy and onset of action of the HDM sublingual immunotherapy tablet MK-8237 (Merck/ALK-Abelló) using the Vienna Challenge Chamber.

METHODS

In this randomized, double-blind, single-site trial, adults with HDM-induced allergic rhinitis with or without conjunctivitis and with or without asthma (n = 124) received 12 developmental units (DU) of MK-8237, 6 DU of MK-8237, or placebo daily for 24 weeks. Subjects underwent 6-hour exposure challenges at screening and weeks 8, 16, and 24. The total nasal symptom score (TNSS) during chamber challenge at week 24 was the primary end point. The TNSS was the sum of 4 nasal symptom scores (maximum = 12). Total ocular symptom scores (TOSSs; 2 symptoms; maximum = 6) and total symptom scores (TSSs; TSS = TNSS plus TOSS; maximum = 18) were secondary end points.

RESULTS

Dose- and time-dependent improvements with MK-8237 versus placebo were observed. At week 24, TNSS improvement relative to placebo was 48.6% (95% CI, 35.3% to 60.2%) with 12 DU of MK-8237 and 26.6% (95% CI, 11.2% to 39.6%) with 6 DU of MK-8237. Statistically significant improvements for TNSSs were also observed at weeks 8 (12 DU of MK-8237) and 16 (6 and 12 DU of MK-8237) and for TOSSs and TSSs by both doses at week 24. MK-8237 was well tolerated. No investigator-assessed anaphylactic allergic reactions or reactions requiring epinephrine were observed.

CONCLUSIONS

MK-8237, 12 DU, reduced nasal and ocular symptoms and exceeded World Allergy Organization-established clinical efficacy criteria (≥20% improvement vs placebo). The onset of action for 12 DU of MK-8237 was week 8. MK-8237, 12 DU, is appropriate for further evaluation to determine the magnitude of effect in an uncontrolled allergen exposure environment.

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.

Efficacy of fluticasone furoate nasal spray and levocetirizine in patients with Japanese cedar pollinosis subjected to an artificial exposure chamber

OBJECTIVE

This study investigated the clinical efficacy of a combination therapy of levocetirizine (LCTZ) and fluticasone furoate nasal spray (FFNS), compared with LCTZ monotherapy, for the suppression of seasonal allergic rhinitis (SAR) symptoms induced in an artificial exposure chamber.

METHODS

This study was a single-center, placebo-controlled, randomized, 3-way cross-over comparative study performed in 42 Japanese cedar pollinosis patients. These subjects received (1) LCTZ plus FFNS (combination group), (2) LCTZ plus FFNS placebo (monotherapy group), or (3) LCTZ placebo plus FFNS placebo (placebo group) once on the night prior to exposure, with a 1-week washout period between exposures. Nasal (sneezing, rhinorrhea, nasal congestion, and itchy nose) and ocular (eye itching and tearing) symptoms were recorded every 15 min, and the number of sneezes, nose blowing events, and the amount of nasal secretions were measured during exposure. The primary end-point was the cumulative incidence of SAR symptoms during exposure and the 'ime to occurrence of symptoms'. The secondary end-points were the total nasal symptom score, the ocular symptom score, the amount of nasal discharge, and the number of sneezes and nose blowing events.

RESULTS

At all the measurement points, the lowest cumulative incidences for the nasal symptoms were observed in the combination group, followed by the monotherapy and placebo groups. All the subjects in the placebo group developed nasal symptoms within 2 h after pollen exposure, while three and eight subjects in the monotherapy and combination groups, respectively, did not develop any nasal symptoms during exposure. In addition, combination therapy delayed the onset of symptoms.

CONCLUSIONS

The results demonstrated that combination therapy with FFNS and LCTZ significantly suppressed the induced SAR symptoms and delayed the onset of symptoms compared with LCTZ monotherapy and placebo. Although the conditions of the allergen challenge study using an exposure chamber are different from those in real life, combination therapy with FF and LCTZ was confirmed to be an effective treatment for SAR.

Allergic rhinitis

Familiarity with the diagnosis and management of allergic rhinitis is important for physicians concerned with the nasal airway. Allergic rhinitis is a common and manageable condition that may cause persistent or intermittent symptoms that vary as to duration and severity. Allergic rhinitis impairs quality of life, sleep, school performance, and productivity on a scale that compares with other chronic diseases. Diagnosis is primarily clinical, but supported by allergy testing. Therapeutic options for allergic rhinitis include pharmacotherapy, environmental control, and immunotherapy. More recently, a role for sublingual immunotherapy and turbinate reduction has been reported.

The allergen challenge chamber: a valuable tool for optimizing the clinical development of pollen immunotherapy

The clinical development of allergen immunotherapy for allergic rhinoconjunctivitis because of pollen is complicated by seasonal, geographical and subject-related variability in allergen exposure. Using an allergen challenge chamber (ACC), a room that enables reproducible challenges with controlled levels of inhalant allergens for several hours, these factors can be controlled. The ACC has often been used to evaluate symptomatic medications but is underexploited in the field of allergen immunotherapy. When used in conjunction with a programme of natural-exposure trials, the ACC enables researchers to (i) facilitate the allergen immunotherapy dose-finding process, (ii) accelerate the transition from Phase I/II to Phase III trials, (iii) characterize the onset and maintenance of action, (iv) avoid the confounding effects of rescue medication, (v) better characterize the baseline or pretreatment characteristics of trial subjects, (vi) perform better-standardized physical and laboratory measurements during an acute challenge, (vii) simplify trial logistics and use smaller numbers of subjects than would be required in equivalent natural-exposure studies and (viii) support (but not replace) Phase III natural-exposure trials for the investigation into long-term and disease-modifying effects. ACC studies can further increase levels of evidence for allergen immunotherapy--the only current therapy potentially capable of modifying the underlying allergic disease.

Improving SAR symptoms with levocetirizine: evaluating active and placebo effects in pollen challenge vs. natural exposure studies

OBJECTIVE

Despite a plethora of published data on levocetirizine, no meta-analyses exist on the effect of study design, and covariates like age, gender, and baseline symptom severity on treatment response. The objective of this study was the efficacy of levocetirizine 5  mg tablets and matching placebo at reducing allergy symptoms in adult subjects with seasonal allergic rhinitis under various pollen exposure study conditions and by age, gender and baseline symptom severity.

METHODS

This was a meta-analysis of original reports from randomized, double-blind, placebo-controlled studies. Clinical studies without detailed reports, open-label, non-randomized and non-controlled studies, or paediatric studies, were excluded. Study subjects were divided into an environmental exposure (EE) group or a natural exposure (NE) group.

RESULTS

Data from 3640 subjects were analysed (n = 2174 for levocetirizine, n = 1466 for placebo). The overall results confirmed the efficacy of levocetirizine 5  mg, with an approximately 40% symptom score improvement from baseline, in both the EE and NE groups. While levocetirizine showed no gender- or age-related differences in efficacy, female subjects responded better to placebo in the EE, but not in the NE group; younger subjects (<30 years of age) responded less favourably to placebo compared with older subjects (≥ 50 years of age). Levocetirizine was consistently superior to placebo regardless of baseline symptom score levels. The highest significance levels between the active and placebo groups were observed in subjects sensitized to animal dander and grass.

CONCLUSIONS

Differences between an oral antihistamine and placebo in clinical studies of allergic rhinitis might be due to a different response to placebo rather than to the active drug. Levocetirizine seems to have consistent efficacy regardless of age, gender, and baseline scores.

Levocetirizine: a modern H1-antihistamine for the treatment of allergic rhinitis

Levocetirizine is the latest of the H(1)-antihistamines indicated for adults and children (as young as 2 years old) suffering from allergic rhinitis and chronic idiopathic urticaria. Currently, it is the only therapy registered for treatment of persistent allergic rhinitis, as defined by the Allergic Rhinitis & its Impact on Asthma guidelines. Pharmacologic studies have shown levocetirizine to have a more favorable pharmacokinetic/pharmacodynamic profile than other commonly employed H(1)-antihistamines. This reflects its superiority in controlling the symptoms of seasonal, perennial and persistent allergic rhinitis in well-controlled trials. Clinical trials and postmarketing surveillance have indicated that levocetirizine is safe and well tolerated, and leads to clinically significant improvements in the quality of life of patients. It is also reported to reduce comorbidities as well as overall treatment costs when administered continuously over the longterm.

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.

From pharmacokinetics to therapeutics

Whilst pharmacokinetics describe the relationship between dose levels and concentration-time profiles of a drug in the body and pharmacodynamics describe the concentration-response relationships, pharmacokinectics-pharmacodynamics(PK-PD) models link these two items providing a framework for modelling the time course of drug response. In this chapter, PK-PD models, describing the therapeutic effects of drugs used for the therapy of allergic diseases have been reviewed. Emphasis was given also to the description of the receptor occupancy, which is tightly related to the downstream clinical response. PK - PD models describing unwanted effects were also commented. An integrated use of these models allows choosing appropriate dosing regimens and providing an objective evaluation of the benefit/risk balance.

Efficacy comparison of levocetirizine vs montelukast in ragweed sensitized patients

BACKGROUND

To date, no adequate data are available on direct comparison of the efficacy of levocetirizine, a recently approved histamine1-antihistamine, with that of a leukotriene antagonist in the treatment of seasonal allergic rhinitis (SAR) symptoms.

OBJECTIVE

To compare the efficacy of therapeutic doses of 5 mg of levocetirizine and 10 mg of montelukast in ragweed sensitized patients.

METHODS

A randomized, double-blind, placebo-controlled, parallel-group study was conducted between July and October 2006. Symptomatic patients with SAR were exposed to ragweed pollen under controlled conditions in an environmental exposure chamber for 4 to 5 hours after treatment with 5 mg of levocetirizine, 10 mg of montelukast, or matched placebo on 2 consecutive days. The mean change from baseline in pollen-induced rhinitis symptoms, expressed as a major symptoms complex (MSC) score (sum of scores for rhinorrhea, itchy nose, sniffles, nose blows, sneezes, and watery eyes), in period 1 (first 5 hours after first drug intake) was the primary efficacy outcome.

RESULTS

A total of 611 patients were screened, of whom 403 were randomized to receive treatment (102 placebo, 152 levocetirizine, and 149 montelukast). The MSC score in period 1 was progressively decreased to a significantly greater extent in the levocetirizine group compared with the montelukast and placebo groups (adjusted mean differences, -2.18 [95% confidence interval, -3.35 to -1.01; P < .001] and -2.22 [95% confidence interval, -3.51 to -0.92; P < .001] for levocetirizine vs montelukast and vs placebo, respectively). The effect of 10 mg of montelukast was not significantly different compared with placebo. Levocetirizine also achieved a significantly faster onset of action within 2.5 hours of administration. Both products were well tolerated.

CONCLUSIONS

This study in an environmental exposure chamber confirms the therapeutic efficacy of 5 mg of levocetirizine in improving symptoms of SAR, which was superior to 10 mg of montelukast.

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.

Pharmacoeconomics of levocetirizine in allergic rhinitis and chronic idiopathic urticaria: considerations for the USA

BACKGROUND

Levocetirizine, a recent, second-generation oral antihistamine, was approved by the US FDA in May 2007 to treat symptoms of allergic rhinitis and chronic idiopathic urticaria.

OBJECTIVE

To review the economic literature for levocetirizine.

METHODS

Two reviewers conducted a systematic review of the literature to identify abstracts that met the inclusion criteria. Abstracts that were considered acceptable were retrieved with full text for further assessment.

RESULTS

A total of 82 potential studies were identified. After reviewing abstracts, 11 articles were preselected for potential inclusion. Of the 11 full-text articles, three articles met the inclusion criteria.

CONCLUSION

The pharmacoeconomic literature for levocetirizine was limited. The findings were consistent across the literature, suggesting levocetirizine improved outcomes, leading to incremental cost savings and cost-effectiveness. Since many of the available levocetirizine data come from European studies, differences in practice patterns and medical resources should be considered when extrapolating data to a US clinical setting.

Onset of Action of Ciclesonide Once Daily in the Treatment of Seasonal Allergic Rhinitis

Ciclesonide is an intranasal corticosteroid approved for the treatment of allergic rhinitis. We conducted a randomized, double-blind, parallel-group, placebo-controlled study to evaluate the time to onset of action of ciclesonide 200 μg once daily in 502 adults with seasonal allergic rhinitis of at least 2 years’ duration. To trigger immunologic priming, patients underwent between one and five priming sessions with exposure to 3,500 grains/m3 (±500) of ragweed pollen in an environmental exposure chamber. The criteria for a successful priming session was a patient-assessed instantaneous total nasal symptom score of at least 6 (of a possible 12) and a nasal congestion or rhinorrhea score of at least 2 (of a possible 3) 90 minutes after allergen exposure during at least two consecutive priming sessions. Patients were then randomly assigned to receive either a single dose of ciclesonide 200 μg (n = 251) or placebo (n = 251) administered intranasally. The difference in the change from baseline total nasal symptom scores in the two groups was assessed hourly for 12 hours after administration. Onset of action was determined to have taken place the first time that the effects of ciclesonide, as reflected in the total nasal symptom score, were significantly greater than those of placebo at a particular hourly assessment, provided that the subsequent hourly assessment also showed a statistically significant difference. The onset of action of ciclesonide occurred within 1 hour of administration (p = 0.01 vs. placebo), and the significant difference in total nasal symptom scores between ciclesonide and placebo was maintained through post-treatment hour 12 (p ≤ 0.018).

Inhibition of the histamine-induced weal and flare response: a valid surrogate measure for antihistamine clinical efficacy?

Histamine plays a central role in allergic responses. Inhibition of the weal and flare response to histamine is a traditional pharmacodynamic tool to measure the activity of H(1)-receptor antagonists. The time course and duration of cutaneous weal and flare inhibition are often used as surrogate measures of clinical efficacy. Pharmacodynamic differences among antihistamines are often interpreted to indicate differences in clinical efficacy. A systematic review of literature from 1980 to 2006 regarding the histamine induced weal and flare was undertaken. Search terms included 'histamine', 'skin test', 'weal', 'flare', and 'antihistamine'; retrieved articles were searched for relevant studies not identified initially. Data from human studies on the inhibition of the weal and flare by second-generation antihistamines were extracted and assessed. A literature search from 1980 to 2006 was undertaken for comparative studies of second-generation antihistamines in the clinical settings of allergic rhinitis (AR) and chronic idiopathic urticaria; data extracted from these studies underwent systematic review. Differences were noted among second-generation antihistamines in terms of their ability to inhibit the histamine-induced weal and flare. Corresponding differences in terms of clinical efficacy in AR and chronic urticaria were not identified following a systematic review. The reasons for the disconnect between pharmacodynamic effects and clinical efficacy may include differences between the route and concentration of histamine, the involvement of mediators other than histamine in the allergic response, and the short time course of pharmacodynamic studies. The histamine-induced weal and flare response is a pharmacodynamic test that should not be used to compare the clinical efficacy of different antihistamines, and is not an adequate alternative to clinical end-point assessments in AR or chronic idiopathic urticaria.

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.

Clinical efficacy of probiotic Bifidobacterium longum for the treatment of symptoms of Japanese cedar pollen allergy in subjects evaluated in an environmental exposure unit

BACKGROUND

Japanese cedar pollinosis (JCPsis) affects nearly one in six Japanese. Oral administration of Bifidobacterium longum BB536 has been shown to be effective in relieving JCPsis symptoms during the pollen season.

METHODS

This double- two-way crossover study was designed to evaluate the efficacy of BB536 on reducing symptoms in JCPsis patients exposed to Japanese cedar pollen (JCP) in an environmental exposure unit (EEU) outside of the normal JCP season. After a 1-week run-in period, subjects (n=24) were randomly allocated to receive BB536 powder (approximately 5x1010) or placebo twice a day for 4 weeks. After a 2-week washout period, subjects were crossed over to another 4 weeks of intake. At the end of each intake period, subjects received controlled JCP exposure for 4 hours in the EEU. Symptoms were self-rated 30 minutes before and every 30 minutes during the exposures. From the first day of exposure through the next 5 successive days, participants self-rated their delayed symptoms and medication uses. Blood samples were taken before the exposures. The mean JCP levels for exposures were 6500 to 7000 grains/m3 air.

RESULTS

In comparison with placebo, BB536 intake significantly reduced the ocular symptom scores during JCP exposures. Evaluating delayed symptoms after exposures indicated that scores for disruption of normal activities were significantly lower in the BB536 group compared with the placebo group. Prevalence of medication use was markedly reduced by BB536 intake.

CONCLUSIONS

These results suggest the potential beneficial effect of BB536 in relieving symptoms of JCP allergy.

Onset of action of fexofenadine hydrochloride 60 mg/pseudoephedrine hydrochloride 120 mg in subjects aged 12 years with moderate to severe seasonal allergic rhinitis: a pooled analysis of two single-dose, randomized, double-blind, placebo-controlled allergen exposure unit studies

BACKGROUND

The onset of action of antihistamine-decongestant combinations is an important factor in the treatment of subjects with seasonal allergic rhinitis (SAR).

OBJECTIVE

This was a pooled analysis of 2 published studies with identical designs investigating the onset of action of the combination of fexofenadine hydrochloride 60 mg/pseudoephedrine hydrochloride 120 mg (FEX60/PSE120) in subjects with moderate to severe SAR.

METHODS

Subjects aged 12 years received single doses of FEX60/PSE120 or placebo in 2 randomized, double-blind, placebo-controlled, parallel-group, allergen exposure unit studies and recorded their SAR symptoms on diary cards before dosing, at 15-minute intervals for 2 hours after dosing, and at 30-minute intervals for the next 4 hours. The primary efficacy end point was onset of action, assessed in terms of absolute change in the major symptom complex (MSC) score, which was the sum of scores for the individual symptoms of stuffy nose, itchy nose, runny nose, watery eyes, itchy eyes, itchy ears/throat, and sneezing. Secondary end points included the absolute and percent change in the total symptom complex (TSC) score (the sum of the MSC score plus the scores for nose blowing, sniffles, postnasal drip, and cough) and individual symptom scores. Treatment-emergent adverse events (TEAEs) were recorded. Analyses were performed on the modified intention-to-treat (mITT) population, which included all subjects who were randomized to treatment and took the single dose of study medication according to the protocol.

RESULTS

A total of 1693 subjects were screened in the 2 studies, and 786 were randomized (298 in study 1, 488 in study 2). Two subjects withdrew from study 2; therefore, the mITT population consisted of 784 subjects. Subjects' mean age was 33.4 years, and 64.4% were female. The onset of action of FEX60/PSE120 was 45 minutes; the least squares mean (SD) treatment difference in the change from baseline in absolute MSC score was 0.8 (0.31) (95% CI, 0.2-1.4; P = 0.008). All subsequent changes from baseline in MSC scores were statistically significant for FEX60/PSE120 compared with placebo (P < 0.001). The absolute and percent change in TSC score and the percent change in MSC score were significantly decreased at all time points from 45 minutes after dosing for FEX60/PSE120 compared with placebo (all, P < 0.05). Individual symptoms (mean of hours 1 to 5) also were significantly improved with FEX60/PSE120 compared with placebo (all, P < 0.05). TEAEs were reported by 2.3% (9/391) and 4.3% (17/393) of subjects receiving FEX60/PSE120 and placebo, respectively. The most commonly occurring TEAS in the FEX60/PSE120 and placebo groups was somnolence (n = 4 and n = 6, respectively).

CONCLUSION

In this pooled analysis of 2 allergen exposure unit studies, FEX60/PSE120 had an onset of action of 45 minutes and a sustained effect throughout the 6-hour study period in subjects with moderate to severe SAR.

Effects of levocetirizine as add-on therapy to fluticasone in seasonal allergic rhinitis

BACKGROUND

Addition of H(1) antagonists to intranasal corticosteroid treatment of allergic rhinitis (AR) is common in clinical practice and recommended by guidelines, despite some evidence that the additive benefits are negligible.

OBJECTIVE

To assess additional benefits of 5 mg levocetirizine dihydrochloride in seasonal AR patients using 200 mcg fluticasone propionate nasal spray once daily.

METHODS

In a double-blind placebo-controlled crossover study of 27 patients, following 2 weeks without treatment, subjects used fluticasone with levocetirizine or identical placebo for 2 weeks each. Assessments were the Juniper mini Rhinoconjunctivitis Quality-of-Life Questionnaire (mini-RQLQ), domiciliary peak nasal inspiratory flow (PNIF), total nasal symptoms (TNS) scores and nasal nitric oxide concentrations. Effects were interpreted and tested against minimal clinically important differences.

RESULTS

Add-on effects for levocetirizine vs. placebo excluded any clinically significant benefits: mean effects (one sided 95% confidence intervals) were mini-RQLQ -0.11 (-0.34), PNIF +0.57 (+5.23), and TNS -0.11 (-0.60). Numbers needed to treat (95% confidence intervals) by outcome were mini-RQLQ 14 (5 to 49), PNIF 4 (3-7), and TNS 3 (2-6). No significant within or between treatment effects were seen for nasal nitric oxide.

CONCLUSION

Contrary to current practice, the present results demonstrate that for the majority of patients, antihistamine add-on to effective nasal steroid treatment is inappropriate. Further work is required to confirm that this is also true in the most severe cases, and the available evidence needs to be put into guidelines and implemented.

Levocetirizine: a review of its use in the management of allergic rhinitis and skin allergies

Levocetirizine (Xyzal) is a selective, potent, oral histamine H(1) receptor antagonist of the latest generation that is licensed for the symptomatic treatment of allergic rhinitis (including persistent allergic rhinitis [PER]) and chronic idiopathic urticaria (CIU). Large, well designed trials indicate that levocetirizine is effective and generally well tolerated in the treatment of allergic rhinitis and CIU. Its pharmacological profile offers many positive aspects: a rapid onset and long duration of antihistaminic effect; rapid absorption and high bioavailability; a low potential for drug interactions; a low volume of distribution; and a lack of effect on cognition, psychomotor function and the cardiovascular system. Allergen challenge chamber studies suggest that levocetirizine has better efficacy than desloratadine, loratadine or fexofenadine. Well controlled, long-term studies with other later-generation H(1) receptor antagonists are required to fully define its clinical profile relative to other agents in this class. Overall, levocetirizine is a valuable addition to the oral H(1) receptor antagonists available for the treatment of allergic rhinitis and as first-line therapy in patients with CIU.

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.

Influence of short-term exposure to airborne Der p 1 and volatile organic compounds on skin barrier function and dermal blood flow in patients with atopic eczema and healthy individuals

BACKGROUND

Epidemiological studies indicate environmental pollutants to be involved in the increase in the prevalence of allergic diseases. In human exposure studies, volatile organic compounds (VOCs) have been shown to cause exacerbations of allergic asthma whereas, no data concerning atopic eczema (AE) are available.

OBJECTIVE

We investigated the effect of airborne VOCs on the skin of patients with AE and controls in the presence or absence of house dust mite allergen, Der p 1.

METHODS

In a double-blind crossover study, 12 adults with AE and 12 matched healthy volunteers were exposed on their forearms to Der p 1 and subsequently to a mixture of 22 VOCs (M22, 5 mg/m(3)) in a total body exposure chamber for 4 h. Transepidermal water loss (TEWL) and skin blood flow were measured in all subjects before, during and after exposure. Additionally, an atopy patch test (APT) with Der p 1 was applied to the skin after exposure.

RESULTS

A significant increase in transepidermal water loss was observed 48 h after exposure to VOCs as compared with exposure with filtered air in all individuals (mean difference: +34%; 95% Confidence Interval: 7-69%). Prior Der p 1 exposure resulted in a significant rise of dermal blood flow after 48 h in patients with AE but not in controls. Six out of seven patients showed enhanced atopy patch test (APT) reactions to HDM allergen after previous exposure to VOCs.

CONCLUSION

Our results show that exposure to VOCs - at concentrations commonly found in indoor environments - can damage the epidermal barrier and enhance the adverse effect of Der p 1 on sensitized subjects with AE. These findings may contribute to a better understanding of the mechanisms underlying the increase in prevalence and exacerbation of AE.

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.

Experimental models for the evaluation of treatment of allergic rhinitis

OBJECTIVE

To review the experimental models used for the clinical evaluation of treatments for allergic rhinitis.

DATA SOURCES

Peer-reviewed clinical studies and review articles were selected from the PubMed database using the following relevant keywords: allergic rhinitis in combination with efficacy, wheal and flare, nasal challenge, park, cat room, or exposure unit. Regulatory guidance documents on allergic rhinitis were also included.

STUDY SELECTION

The authors' knowledge of the field was used to limit references with emphasis on recent randomized and controlled studies. References of historical significance were also included.

RESULTS

Traditional outpatient studies are universally accepted in the evaluation of treatment for allergic rhinitis. Experimental models provide ancillary information on efficacy at different stages of treatment development. Skin histamine and allergen challenge, as well as direct nasal challenge with histamine and allergen, are often used as early steps in assessing drug efficacy. Exposure units, park settings, and cat rooms better approximate real life by drawing on the natural mode of allergen exposure and delivering the sensitizing allergen to allergic individuals in the ambient air. Park studies make use of allergens in the outdoors, whereas cat rooms and exposure units present the sensitizing allergens indoors, with the latter providing consistent predetermined allergen levels. Exposure unit and park studies are acknowledged for the determination of onset of action and are also suited to the measurement of duration of effect and other measures of efficacy. Onset and duration of effect are 2 important pharmacodynamic properties of antihistamines and nasal corticosteroids as determined by the Allergic Rhinitis and Its Impact on Asthma and the European Academy of Allergology and Clinical Immunology workshop group.

CONCLUSIONS

All challenge models serve as important instruments in the evaluation of antiallergic medications and provide additional information to complement traditional studies.

Effects of rupatadine vs placebo on allergen-induced symptoms in patients exposed to aeroallergens in the Vienna Challenge Chamber

BACKGROUND

Rupatadine is a novel compound with potent dual antihistamine and platelet-activating factor antagonist activities and no sedative effects.

OBJECTIVE

To evaluate the efficacy of rupatadine, 10 mg once daily, and placebo on allergen-induced symptoms (including nasal congestion), nasal airflow, nasal secretion, and subjective tolerability in response to grass pollen in a controlled allergen-exposure chamber.

METHODS

In a randomized, double-blind, placebo-controlled, crossover trial, 45 patients with a history of seasonal allergic rhinitis received rupatadine or placebo every morning for 8 days in 2 different periods separated by a 14-day washout interval. On day 8 of each crossover period, patients underwent a 6-hour allergen exposure in the Vienna Challenge Chamber, where a constant and homogeneous concentration of aeroallergens was maintained. Subjective and objective assessments were performed online during the exposure.

RESULTS

Subjective single and composite nasal and nonnasal symptoms were consistently less severe with rupatadine use than with placebo use starting from the first evaluation at 15 minutes to the end of the 6-hour Vienna Challenge Chamber challenge, with the most significant effects seen for nasal rhinorrhea, nasal itching, sneezing attacks, and total nasal symptoms (P < .001 for all). All the other symptoms (including nasal congestion, P < or = .005) were also significantly reduced with active treatment compared with placebo use. Mean secretion weights and overall feeling of complaint were significantly lower with rupatadine therapy than with placebo use (P < or = .001). Overall, rupatadine treatment was well tolerated.

CONCLUSION

Rupatadine treatment is effective and well tolerated in patients with allergen-induced symptoms exposed to aeroallergens in a controlled exposure chamber.

Levocetirizine has a longer duration of action on improving total nasal symptoms score than fexofenadine after single administration

AIMS

To compare the onset and duration of action of the new antihistamine levocetirizine with that of the second-generation antihistamine fexofenadine using the Vienna Challenge Chamber (VCC). The latter is an environment where subjects can be exposed to specific aeroallergens in controlled and reproducible conditions allowing for precise comparisons of anti-allergic drugs.

METHODS

Ninety-four subjects received a single dose of levocetirizine 5 mg, fexofenadine 120 mg or placebo in a random order using a three-way cross-over design. On day 1, subjects were exposed to grass pollens (1500 grains/m(3)) in the VCC over a period of 4 h. Treatment was given 2 h after the start of challenge. On day 2, 22 h after drug intake, subjects were again exposed to pollens for 6 h. Specified symptoms were assessed by the subjects every 15 min using 5-point scales. The main efficacy parameter was the change from baseline in the Major Symptom Complex Score (MSCS = sum of rhinorrhea, sneezing, itchy nose and eyes).

RESULTS

Baseline characteristics, including symptoms scores, were similar in the three study groups. During the first 2 h after drug intake both antihistamines achieved clinically relevant and significant (P < 0.001) improvements in symptom scores. Twenty-two to 24 h after drug intake, mean (SEM) MSCS reductions were: 1.9 (0.3) after placebo (baseline of 9.7), 3.8 (0.3) after fexofenadine (baseline of 9.9), and 5.1 (0.3) after levocetirizine (baseline of 9.8). Levocetirizine was significantly (P < 0.001) more effective than fexofenadine with a score difference of 1.3 (95% CI 0.7, 1.9). This was maintained until the end of the study (up to 28 h).

CONCLUSIONS

A rapid onset of action in alleviating seasonal allergic rhinitis (SAR) symptoms of subjects exposed to grass pollens in the VCC was observed after levocetirizine and fexofenadine. Levocetirizine was more effective than fexofenadine at and later than 22 h after drug intake, an indication of the longer-duration of action of levocetirizine.