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

Combining desloratadine and pseudoephedrine in the treatment of seasonal allergic rhinitis

Nonsedating antihistamines are a first-line therapy in the management of allergic rhinitis. They relieve the majority of the histamine-mediated symptoms of the condition, including rhinorrhea, sneezing, and pruritus. The nonsedating antihistamine desloratadine is effective in alleviating the symptoms of both seasonal and perennial allergic rhinitis. It may also have some decongestant properties, and thus help to alleviate nasal congestion. Administering desloratadine in combination with the decongestant pseudoephedrine may offer allergic rhinitis patients with moderate-to-severe nasal congestion the benefits of desloratadine's effectiveness for alleviating histamine-mediated symptoms plus pseudoephedrine's relief from nasal congestion. This drug profile reviews a combination therapy containing desloratadine and pseudoephedrine, approved in the USA for the relief of the symptoms of seasonal allergic rhinitis, including nasal congestion.

Efficacy of diphenhydramine vs desloratadine and placebo in patients with moderate-to-severe seasonal allergic rhinitis

BACKGROUND

Previous studies have shown that diphenhydramine and desloratadine effectively relieve symptoms of seasonal allergic rhinitis (SAR).

OBJECTIVE

To compare the relative efficacy of 50 mg of diphenhydramine hydrochloride, 5 mg of desloratadine, and placebo in relieving symptoms in patients with moderate-to-severe SAR.

METHODS

In this 1-week, multicenter, parallel-group, randomized, double-blind, double-dummy, placebo-controlled study, 610 patients with moderate-to-severe SAR received 50 mg of diphenhydramine hydrochloride 3 times daily, 5 mg of desloratadine once daily, or placebo. Daily 24-hour reflective total nasal symptom scores (TNSSs) (primary end point), total symptom scores, and individual symptom scores were evaluated. A global evaluation of response to treatment was conducted at 2 posttreatment visits.

RESULTS

The mean reduction from baseline in 24-hour reflective TNSSs relative to the placebo response was 77.6% for the diphenhydramine group (P < .001) and 21.0% for the desloratadine group (P = .12). A TNSS between-treatment difference of -1.81 (46.7%; P < .001) was observed when comparing diphenhydramine with desloratadine. A similar between-treatment difference was observed for the 24-hour reflective total symptom score comparing diphenhydramine to desloratadine (-3.35; 45.5%; P < .001). Diphenhydramine provided clinically and statistically significant reductions vs placebo and desloratadine in all individual symptoms, including nasal congestion. Desloratadine had a tendency toward improvement compared with placebo for most individual symptom scores. However, a statistically significant result was reached only for sneezing (-0.27; 33.9%; P = .04).

CONCLUSIONS

Diphenhydramine, 50 mg, given for 1 week provided statistically significant and clinically superior improvements in symptoms compared with 5 mg of desloratadine in patients with moderate-to-severe SAR. Somnolence occurred more frequently with diphenhydramine (22.1%) compared with desloratadine (4.5%) and placebo (3.4%).

Review of desloratadine for the treatment of allergic rhinitis, chronic idiopathic urticaria and allergic inflammatory disorders

Desloratadine is a once-daily, non-sedating, non-impairing, selective histamine H1-receptor antagonist. It relieves the symptoms of seasonal allergic rhinitis (including nasal obstruction and congestion, and morning symptoms), perennial allergic rhinitis and chronic idiopathic urticaria by blocking multiple critical steps in the systemic allergic cascade and downregulating key allergy-induced inflammatory mediators. It also relieves asthma symptoms and decreases rescue medication use in patients with seasonal allergic rhinitis and comorbid asthma. Numerous clinical studies have demonstrated that desloratadine is safe, well tolerated and free of serious cardiac effects. Pharmacokinetic studies have demonstrated a low propensity for drug-drug or drug-food interactions. This review outlines the mechanism of action, efficacy and safety of desloratadine for the treatment of allergic inflammatory disorders.

Emerging anti-inflammatory agents for allergic rhinitis

Allergic rhinitis (AR) is a high-prevalence disease, affecting 10-15% of the general population. AR is sustained by an IgE-mediated reaction, and by a complex inflammatory network of cells, mediators and cytokines that becomes chronic when exposure to allergen persists. A T helper 2 (TH2)-biased immune response is the basis for the allergic inflammation. The current therapeutic strategy is mainly based on drugs (antihistamines, nasal corticosteroids, cromones, decongestants) and allergen immunotherapy. Drugs are overall effective in controlling symptoms, but do not modify the immune background that leads to allergic inflammation, and safety concerns may be present especially for prolonged treatments. Immunotherapy can modify the allergic response, but there is still space for improvement. Nowadays, several approaches are under investigation to optimise the management of AR. On one hand, new drugs and antimediators are being developed; on the other hand, attempts are made to selectively block relevant signal pathways of allergic reaction. Finally, one of the major goals is to modify the TH2-biased immune response by improving the characteristics and modes of action of allergen immunotherapy.

Effect of desloratadine therapy on symptom scores and measures of nasal patency in seasonal allergic rhinitis: results of a single-center, placebo-controlled trial

BACKGROUND

Desloratadine reduces symptoms and maintains nasal airflow in patients with seasonal allergic rhinitis (SAR) during experimental allergen exposure.

OBJECTIVE

To compare the effects of desloratadine and placebo on symptom scores, quality of life (QOL), and nasal airway patency in patients with SAR during the allergy season.

METHODS

Adults with symptomatic SAR were randomized in a double-blind manner to receive desloratadine, 5 mg, or placebo for 14 days. Patient-rated SAR symptoms were recorded twice daily (morning and evening). On days 1 and 15, SAR symptoms were scored jointly (investigator and patient), nasal airflow was measured using 4-phase rhinomanometry, and QOL and the overall condition of SAR were rated. Overall treatment response was scored on day 15. Adverse events were recorded.

RESULTS

At day 15, total symptom (P = .03) and total nasal symptom (P = .02) scores and patient morning-rated individual nasal symptom scores (except nasal stuffiness) (P < or = .04) decreased significantly from baseline with desloratadine vs placebo. Flow in the descending expiratory nasal airflow phase was significantly greater (P = .046) and the percentage increase in total inspiratory nasal airway resistance was less (P = .03) in the desloratadine group vs the placebo group. The overall condition of SAR was less severe (P = .045), the therapeutic response was greater (P = .004), and the nasal symptom domain of the QOL score was significantly better (P = .03) in the desloratadine group. Adverse event rates were similar in both groups.

CONCLUSION

Desloratadine treatment for 14 days improved nasal airflow and resistance as well as symptom and QOL scores in patients with symptomatic SAR during the allergy season.

Allergic rhinitis: treatment based on patient profiles

Allergic rhinitis is a common medical condition characterized by nasal, throat, and ocular itching; rhinorrhea; sneezing; nasal congestion; and, less frequently, cough. The treatment of allergic rhinitis should control these symptoms without adversely affecting daily activities or cognitive performance and should prevent sequelae such as asthma exacerbation or sinusitis. This review describes a stepwise approach to treatment of allergic rhinitis derived from a synthesis of clinical trial results, patient preferences, and real-world tolerability data. Key clinical considerations include frequency and intensity of symptoms, patient age, comorbidities, compliance with treatment regimens (influenced by formulation, route and frequency of administration), and effects on quality of life. Oral second-generation antihistamines, versus first-generation agents and inhaled corticosteroids, should be considered first-line treatment because they provide rapid relief of most allergic rhinitis symptoms without safety and tolerability issues. Additional therapeutic agents can then be added or substituted based on individual symptom response.

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.

Azelastine nasal spray and desloratadine tablets in pollen-induced seasonal allergic rhinitis: a pharmacodynamic study of onset of action and efficacy

OBJECTIVE

To assess the efficacy and onset of action of azelastine nasal spray and desloratadine tablets in patients with allergen-induced seasonal allergic rhinitis (SAR).

RESEARCH DESIGN AND METHODS

46 adult patients with a history of SAR were exposed to a controlled grass pollen concentration for 6 h in the Vienna Challenge Chamber (VCC) in each treatment period according to a randomised, double-blind (double-dummy), three-period, three-sequence crossover design (wash-out period of 12 days). Single doses of study medication (one puff nasal spray into each nostril of azelastine, 0.2 mg, or placebo before swallowing one encapsulated tablet of desloratadine, 5 mg) were administered 2 h after the start of the allergen challenge. Results of subjective and objective assessments were recorded throughout the challenge.

RESULTS

Efficacy of azelastine nasal spray was significantly superior compared to desloratadine tablets (p = 0.005) and placebo (p < 0.001). Desloratadine was significantly better than placebo (p < 0.001). Decrease both in Major Nasal Symptom Score (MNSS) and in Total Nasal Symptom Score (TNSS) was fastest after azelastine treatment. Improvement of nasal symptom severity was most pronounced after azelastine treatment for all nasal symptoms including nasal congestion. Onset of action was 15 min for azelastine compared to 150 min for desloratadine. Both active preparations were safe and well tolerated.

CONCLUSIONS

This study confirms the usefulness of azelastine nasal spray for the symptomatic treatment of seasonal allergic rhinitis. Concerning onset of action in particular, the results favour the topical treatment over systemic therapy.

Desloratadine reduces systemic allergic inflammation following nasal provocation in allergic rhinitis and asthma patients

BACKGROUND

Preclinical studies have demonstrated that some second-generation antihistamines have anti-inflammatory effects. It is not known whether these effects are also demonstrable in vivo. In this study we investigated the effect of treatment with desloratadine (DL) on systemic inflammation and on nasal and bronchial mucosal inflammation after nasal allergen provocation (NP) in subjects with grass-pollen-allergic rhinitis and asthma.

METHODS

Twenty-six subjects with grass-pollen-allergic rhinitis and asthma were randomly allocated to 8 days of treatment with DL (n = 13) or placebo (n = 13) outside the grass pollen season. On day 7 they underwent nasal provocation with grass pollen allergen. Nasal and bronchial biopsies were taken for immunohistochemical evaluation, and blood samples were analysed. Rhinitis and asthma symptoms, peak nasal inspiratory flow and peak expiratory flow, were also measured at specified times.

RESULTS

The number of circulating eosinophils decreased during DL treatment, and there was a reduced increase in circulating eosinophils after NP in these subjects. There was also a significant reduction in early bronchial clinical response. There was no significant lessening in the severity of the nasal symptoms. Nasal and bronchial mucosal inflammation parameters did not alter under DL treatment.

CONCLUSION

These data suggest that treatment with DL reduces systemic eosinophilia and prevents the increase in circulating eosinophils after NP. DL also significantly reduces the early bronchial clinical response to NP. However, airway mucosal inflammation is not altered by 1 week of treatment.

Evaluation of the optimal oral antihistamine for patients with allergic rhinitis

Because of its bothersome symptoms, allergic rhinitis (AR) is 1 of the top 10 reasons for patient visits to primary care physicians. This highly prevalent disease also results in loss of productivity, both at work and in school. Oral antihistamines are one of the most frequently prescribed medications for the management of AR and, with several agents available, it is important to discern the specific benefits and detriments of each. To assess the differences in efficacy and safety factors among antihistamines, the Individual therapeutic window of each agent can be used as a comparative reference tool because it defines the dose range over which an antihistamine is efficacious and free of adverse effects. As such, the therapeutic window includes both undesired effects, such as sedation, and desired properties, such as rapid onset of action, long duration of efficacy, broad age range of applicability, and potential to Improve quality of life. Therefore, agents with broad therapeutic windows, based on both efficacy and safety, are expected to be more favorable; this therapeutic window should be understood by the primary care physician when prescribing a medication.

A Review of the Evidence from Comparative Studies of Levocetirizine and Desloratadine for the Symptoms of Allergic Rhinitis

BACKGROUND

Levocetirizine and desloratadine are newer antihistamines indicated for the treatment of allergic rhinitis and chronic idiopathic urticaria.

OBJECTIVE

This article discusses the pharmacokinetics and pharmacodynamics of levocetirizine and desloratadine and reviews studies that have directly compared the effects of these 2 drugs in allergic rhinitis and urticaria.

METHODS

Relevant articles were identified through a search of MEDLINE from 1999 through 2004 using the main search terms levocetirizine and desloratadine.

RESULTS

Levocetirizine is absorbed rapidly and reaches a steady-state plasma concentration more quickly than does desloratadine. It is also metabolized to a lesser extent than desloratadine, has a lower V(d), and has higher specificity for histamine(1) receptors. Eight well-controlled trials were identified that directly compared the effects of levocetirizine and desloratadine in the skin and nose of healthy individuals and patients with allergic rhinitis. Drug activity was measured in terms of wheal, flare, and itch reactions; nasal symptoms or symptom scores; increases in concentrations of inflammatory markers; or facial thermography. In most of these trials, levocetirizine had a faster onset and greater consistency of effect than desloratadine. The differences in the pharmacokinetic and pharmacodynamic profiles of the 2 drugs may partially explain these clinical findings.

CONCLUSIONS

Levocetirizine may be preferred to desloratadine as a treatment option for allergic rhinitis because of its faster onset of action and greater consistency of effect. Although comparative studies in chronic idiopathic urticaria are not available, data from histamine-induced wheal and flare studies in healthy volunteers suggest that levocetirizine may be more effective in preventing itching than desloratadine.

Desloratadine and levocetirizine improve nasal symptoms, airflow, and allergic inflammation in patients with perennial allergic rhinitis: a pilot study

BACKGROUND

Nasal obstruction is the main symptom in patients with perennial allergic rhinitis. Some new antihistamines have been demonstrated to be capable of improving this symptom.

OBJECTIVE

The aim of this pilot study was to evaluate nasal symptoms, nasal airflow, eosinophils, and IL-4 in patients with perennial allergic rhinitis, before and after treatment with two new antihistamines: desloratadine and levocetirizine.

METHODS

Thirty patients with perennial allergic rhinitis were evaluated, 26 males and 4 females (mean age 26+/-7.1 years). All of them received either desloratadine (5 mg/daily) or levocetirizine (5 mg/daily) or placebo for 4 weeks. The study was double-blind, parallel-group, placebo-controlled, and randomized. Total symptom score (including: rhinorrhea, nasal itching, sneezing, and nasal obstruction) was assessed before and after treatment. Rhinomanometry and decongestion test, nasal lavage, and nasal scraping were performed in all subjects before and after treatment. Eosinophils were counted by conventional staining; IL-4 was measured by immunoassay of fluids recovered from nasal lavage.

RESULTS

Desloratadine and levocetirizine treatment induced significant symptom relief and significant reduction of IL-4. Both antihistamines significantly affected all parameters in comparison with placebo.

CONCLUSIONS

This pilot study demonstrates the effectiveness of antihistaminic treatment in: i) relieving nasal symptoms, including obstruction, ii) improving nasal airflow, iii) exerting decongestant activity, iv) reducing eosinophil infiltration, and v) diminishing IL-4 levels.

Desloratadine partially inhibits the augmented bacterial responses in the sinuses of allergic and infected mice

BACKGROUND

Allergic rhinitis (AR) is considered a major predisposing factor for the development of acute bacterial rhinosinusitis. How AR augments a bacterial infection is unknown.

OBJECTIVE

Our purpose in this study was to test whether an H1 receptor antagonist, desloratadine, could reduce the augmented effect of an ongoing allergic reaction on acute bacterial rhinosinusitis.

METHODS

Three groups of infected and ovalbumin (OVA)-sensitized mice were studied: (1) infected and allergic mice treated with desloratadine, (2) infected and allergic mice treated with placebo, and (3) infected mice. A fourth group of uninfected, non-sensitized mice served as a control for the cellular changes. BALB/c mice were sensitized by two intraperitoneal injections of OVA given 8 days apart. One day after the second injection, the mice were nasally exposed daily to 6% OVA (the groups treated with desloratadine or placebo) or phosphate-buffered saline (PBS) (the infection-only group) for 5 days. After the second OVA exposure, the mice were intranasally inoculated with Streptococcus pneumoniae. Desloratadine or placebo was given daily throughout the OVA exposure period. Nasal allergic symptoms were observed by counting of nasal rubbing and sneezing for 10 min after OVA or PBS nasal challenge. On day 5 post-infection, nasal lavage culture was done, and the inflammatory cells in the sinuses were evaluated by flow cytometry.

RESULTS

Mice that were made allergic, infected, and treated with placebo showed more organisms and phagocytes than did only infect mice. They also manifested allergic nasal symptoms and eosinophil influx into the sinuses. Desloratadine treatment during allergen exposure reduced allergic symptoms and reduced sinonasal infection (P<0.05). There tended to be less myeloid cell and neutrophil influx (P=0.09 both), but not eosinophil influx (P=0.85) compared with that in the placebo-treated group.

CONCLUSION

Desloratadine treatment during nasal challenge inhibited allergic symptoms and reduced sinonasal infection, suggesting that histamine via an H1 receptor plays a role in the augmented infection in mice with an ongoing allergic reaction.

Second-Generation Antihistamines

Antihistamines are useful medications for the treatment of a variety of allergic disorders. Second-generation antihistamines avidly and selectively bind to peripheral histamine H1 receptors and, consequently, provide gratifying relief of histamine-mediated symptoms in a majority of atopic patients. This tight receptor specificity additionally leads to few effects on other neuronal or hormonal systems, with the result that adverse effects associated with these medications, with the exception of noticeable sedation in about 10% of cetirizine-treated patients, resemble those of placebo overall. Similarly, serious adverse drug reactions and interactions are uncommon with these medicines. Therapeutic interchange to one of the available second-generation antihistamines is a reasonable approach to limiting an institutional formulary, and adoption of such a policy has proven capable of creating substantial cost savings. Differences in overall efficacy and safety between available second-generation antihistamines, when administered in equivalent dosages, are not large. However, among the antihistamines presently available, fexofenadine may offer the best overall balance of effectiveness and safety, and this agent is an appropriate selection for initial or switch therapy for most patients with mild or moderate allergic symptoms. Cetirizine is the most potent antihistamine available and has been subjected to more clinical study than any other. This agent is appropriate for patients proven unresponsive to other antihistamines and for those with the most severe symptoms who might benefit from antihistamine treatment of the highest potency that can be dose-titrated up to maximal intensity.

The ARIA/EAACI criteria for antihistamines: an assessment of the efficacy, safety and pharmacology of desloratadine

BACKGROUND

The definition of allergic rhinitis and the classification of its severity and treatment have advanced in recent years following the publication of the Allergic Rhinitis and its Impact of Asthma (ARIA) document. The ARIA and the European Academy of Allergology and Clinical Immunology (ARIA/EAACI) have published a set of recommendations that outline the pharmacological and clinical criteria to be met by medications commonly used in the treatment of allergic rhinitis.

METHODS

An international group of experts met to assess the profile of the antihistamine, desloratadine, under the ARIA/EAACI criteria. Data on desloratadine were collected from peer-reviewed clinical studies and review articles, which were corroborated and augmented by comprehensive public access documents from the European Medicines Evaluation Agency (EMEA).

RESULTS AND CONCLUSION

Based on this systematic review, it was concluded that the efficacy, safety and pharmacology of desloratadine broadly meet the ARIA/EAACI criteria for antihistamines.

Levocetirizine improves nasal obstruction and modulates cytokine pattern in patients with seasonal allergic rhinitis: a pilot study

BACKGROUND

Allergic rhinitis is characterized by an IgE-dependent inflammation. Nasal obstruction is related to allergic inflammation. Some antihistamines have been demonstrated to be capable of improving this nasal symptom.

OBJECTIVE

The aim of this pilot study was to evaluate nasal symptoms, nasal airflow, inflammatory cells, and cytokine pattern in patients with seasonal allergic rhinitis (SAR), before and after treatment with levocetirizine, desloratadine, or placebo.

METHODS

Thirty patients with SAR were evaluated, 27 males and three females (mean age 26.9+/-5.4 years). All of them received levocetirizine (5 mg/day), desloratadine (5 mg/day), or placebo for 2 weeks. The study was double-blind, parallel-group, placebo-controlled, and randomized. Total symptom score (TSS) (including: rhinorrhea, nasal itching, sneezing, and nasal obstruction) was assessed before and after treatment. Rhinomanometry, nasal lavage, and nasal scraping were performed in all subjects before and after treatment. Inflammatory cells were counted by conventional staining; IL-4 and IL-8 were measured by immunoassay on fluids recovered from nasal lavage.

RESULTS

Levocetirizine treatment induced significant symptom relief (P=0.0009) and improved nasal airflow (P=0.038). Desloratadine also relieved TSS (P=0.01), but did not affect nasal airflow. Levocetirizine significantly reduced eosinophils (P=0.029), neutrophils (P=0.005), IL-4 (P=0.041), and IL-8 (P=0.02), whereas desloratadine diminished IL-4 only (P=0.044). Placebo treatment did not significantly affect any evaluated parameters.

CONCLUSIONS

This pilot study demonstrates the effectiveness of levocetirizine in: (i) relieving nasal symptoms, (ii) improving nasal airflow, (iii) reducing leucocyte infiltration, and (iv) diminishing cytokine levels. These findings are the first evidence of the effectiveness of levocetirizine in SAR.

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)

OBJECTIVE

The Vienna Challenge Chamber (VCC) is an established method for the controlled exposure of patients to specific allergens, used to make valid comparisons between antihistamines. The aim of the significantly more than loratadine at all time two placebo-controlled, randomised studies reported here was to compare the efficacy and safety of levocetirizine 5 mg od and loratadine 10 mg od in subjects suffering from seasonal allergic rhinitis (SAR) or perennial allergic rhinitis (PAR).

SUBJECTS AND METHODS

During each study period, SAR and PAR subjects were exposed to grass pollen or house-dust mite allergens, respectively for 6 h on 2 consecutive days in the VCC. Each day, medications were administered 2 h after the start of the challenge; with a washout of at least 5 days between each period. The main criterion for evaluation of efficacy was the major symptom complex (MSC) for SAR and the complex symptom score (CSS) for PAR.

RESULTS

The pattern of patients' response was similar in SAR and PAR. Both levocetirizine and loratadine were superior to placebo in alleviating SAR and PAR symptoms at all time intervals evaluated during the two study days. Levocetirizine decreased the mean MSC score intervals in SAR subjects, with the most marked difference observed on day 2 (p = 0.002). In PAR patients, although with borderline significance (p = 0.08), levocetirizine decreased the mean CSS more than loratadine. Levocetirizine appeared to have a faster onset of action than loratadine in SAR (45 min versus 1 h 15 min) and PAR (1 h versus 1 h 30 min). However, these apparent differences were not tested for statistical significance. Both medications were well tolerated and no treatment-related adverse events were reported. This level of antihistamine efficacy was maintained regardless of whether the subjects' rhinitis was seasonal or perennial.

CONCLUSION

This study demonstrated that levocetirizine is superior to loratadine in improving symptoms in SAR and that there is a similar trend in PAR.

Levocetirizine better protects than desloratadine in a nasal provocation with allergen

BACKGROUND

Direct comparisons of antihistamines are rare but very much needed. Newly available antihistamine preparations, levocetirizine, the R-enantiomer of racemate cetirizine, and desloratadine, an active metabolite of loratadine, have been recently released for allergic rhinitis.

OBJECTIVE

We sought to compare levocetirizine and desloratadine in a nasal provocation test (NPT) with grass pollen.

METHODS

Twenty-four volunteers with grass pollen allergy and a history of rhinitis were enrolled in a double-blind, placebo-controlled, crossover study. Three NPTs were performed in a dose-escalating manner during the out-of-season period 4 hours after a single dose of levocetirizine (5 mg), desloratadine (5 mg), or placebo.

RESULTS

CONCLUSIONS

This study demonstrates a better overall protection of a single dose of levocetirizine compared with desloratadine in an NPT with grass pollen allergen. In contrast to late-phase inflammatory markers, which were unaffected, extravascular leakage of the early-phase marker albumin was significantly limited by levocetirizine.

Desloratadine: an update of its efficacy in the management of allergic disorders

Desloratadine (Clarinex, Neoclarityn, Aerius, Azomyr, Opulis, Allex), the principal metabolite of loratadine, is itself an orally active, nonsedating, peripheral histamine H(1)-receptor antagonist. It is indicated in the US and Europe for the treatment of seasonal allergic rhinitis (SAR), perennial allergic rhinitis (PAR) and chronic idiopathic urticaria (CIU). It has a rapid onset of effect, efficacy throughout a 24-hour dosage interval, and sustained efficacy in these allergic conditions, as demonstrated in placebo-controlled trials of up to 6 weeks' duration in adult and adolescent patients. At present, there are no published direct comparisons of desloratadine and other H(1)-antihistamines; however, the principal, potential clinical advantages of desloratadine over late-generation H(1)-antihistamines are the drug's decongestant activity, which has been corroborated in several studies of patients with allergic rhinitis, and its anti-inflammatory effects. Indeed, the decongestant activity of desloratadine did not differ from that of pseudoephedrine in a trial in patients with SAR, and in patients with SAR and coexisting asthma, desloratadine reduced asthma symptoms and beta(2)-agonist use, and improved forced expiratory flow in 1 second. However, these issues warrant further study. Desloratadine is generally well tolerated. The overall incidence of adverse events in adults, adolescents and children was not significantly different to that with placebo, and similar proportions of desloratadine or placebo recipients reported events such as pharyngitis, dry mouth, myalgia, somnolence, dysmenorrhoea or fatigue. Desloratadine does not cause sedation or prolong the corrected QT (QTc) interval, can be administered without regard to concurrent intake of food and grapefruit juice, and appears to have negligible potential for drug interactions mediated by several metabolic systems.

CONCLUSION

Although comparative studies with second-generation and other recently developed H(1)-antihistamines are needed to define the drug's clinical profile more clearly, desloratadine can be expected to claim a prominent place in the management of allergic disorders in general, and in the amelioration of specific symptoms of allergy (e.g. nasal congestion) in patients with such disorders.

Comparison of the combinations of fexofenadine-pseudoephedrine and loratadine-montelukast in the treatment of seasonal allergic rhinitis

BACKGROUND

Antihistamine-decongestant combinations are used routinely for the treatment of seasonal allergic rhinitis. Recently, the combination of an antihistamine and a leukotriene receptor antagonist has been shown to be efficacious.

OBJECTIVE

To compare the 2 combinations in the treatment of seasonal allergic rhinitis.

METHODS

This was a randomized, double-blind, double-dummy, parallel study in which patients with seasonal allergic rhinitis received either fexofenadine, 60 mg, and pseudoephedrine, 120 mg, twice daily, or loratadine, 10 mg, and montelukast, 10 mg, once daily, for 2 weeks. The Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ) was completed at the beginning and end of the study. Patients recorded nasal symptoms and measured nasal peak inspiratory flow (NPIF) twice daily. Baseline measurements were obtained before initiation of treatment.

RESULTS

Compared with baseline, both treatments resulted in statistically and clinically meaningful reductions of overall and individual RQLQ domain scores (P < .01) except for the sleep domain, for which only loratadine-montelukast led to significant improvement. There was a significant reduction in total symptoms (P < or = .05) compared with baseline on most treatment days in patients receiving both combinations. When the change from baseline was analyzed, there were no statistically significant differences in total symptoms between fexofenadine-pseudoephedrine and loratadine-montelukast (median, -28.5 vs -22.5; P = .33). There was a significant improvement in NPIF from baseline on all treatment days in both groups (P < .05), with no significant difference between treatments.

CONCLUSIONS

Fexofenadine-pseudoephedrine and loratadine-montelukast have comparable efficacy in improving symptoms, RQLQ scores, and nasal obstruction in seasonal allergic rhinitis. The lack of improvement in sleep in the fexofenadine-pseudoephedrine group is probably related to insomnia, a known adverse effect of pseudoephedrine.

Comparative clinical efficacy, onset and duration of action of levocetirizine and desloratadine for symptoms of seasonal allergic rhinitis in subjects evaluated in the Environmental Exposure Unit (EEU)

The Environmental Exposure Unit, an indoor pollen challenge system to test anti-allergic medications, was used to compare the onset and duration of action and the efficacy of levocetirizine and desloratadine, two recently developed H1-antagonists. In this double-blind, placebo-controlled, parallel-group study, qualified subjects were randomised to once-daily levocetirizine 5 mg (n = 141), desloratadine 5 mg (n = 140) or placebo (n = 92) and exposed to ragweed pollen on two consecutive days (7 h and 6 h). Symptoms were self-rated every 30 min. On both days, levocetirizine produced a greater improvement in the major symptom complex score (primary efficacy variable) than desloratadine (p = 0.015); both were better than placebo (p < 0.001). Levocetirizine acted earlier (1 h vs. 3 h) and produced greater symptom relief at 24 h than desloratadine (p = 0.003). Levocetirizine also alleviated nasal obstruction better than desloratadine (p = 0.007) on day 1; and better than placebo (p = 0.014) after the second dose on day 2, which was not observed with desloratadine. Levocetirizine and desloratadine were safe and well tolerated.

Validation of an environmental exposure unit for controlled human inhalation studies with grass pollen in patients with seasonal allergic rhinitis

BACKGROUND

There is an increasing need for allergen inhalation systems to perform basic clinical research and test anti-allergic drugs under well-controlled conditions. This requires stability of environmental conditions like temperature and humidity, as well as allergen concentration and reproducible induction of allergic symptoms.

OBJECTIVE

The aim of this study was to validate an environmental exposure unit for controlled human pollen inhalation studies in participants with seasonal allergic rhinitis.

METHODS

Temperature, relative humidity, and air flow rate were kept constant with an air conditioning system. Pollen atmosphere was generated using a specially designed feeding system and monitored online by laser counter and offline using rotating rod samplers. Efficacy (total nasal symptom score, nasal air flow rate, nasal secretion) and safety (lung function) parameters were evaluated at different pollen concentrations and repeated allergen challenges.

RESULTS

Temperature, humidity, and air flow rate in the environmental exposure unit remained constant within a range of <2%. The spatial distribution and the temporal stability of the pollen concentration varied only slightly over 4 h (+/-10% and <4%, respectively). Dose-dependent induction of allergic rhinitis symptoms, reduction in nasal air flow rate, and increase in nasal secretion were observed over time. These effects were reproducible from day to day. Lung function remained clinically normal at all concentrations and from day to day.

CONCLUSIONS

Thus, pollen exposure in the environmental exposure unit is an effective, reproducible, safe, and suitable method for single-centre clinical studies on the efficacy of anti-allergic treatment or basic clinical research.

Asthma and rhinosinusitis

Allergic rhinoconjunctivitis and asthma are becoming more common in industrialized societies, particularly in the second and third decades of life, when those affected are at a vital stage of their education and career. It is therefore of paramount importance that the treatment options available be effective, improve quality of life, and above all, they must be without any significant unwanted effects. National and international guidelines for the treatment of both allergic rhinitis and asthma have been released recently that put forward recommendations based on an extensive evidence-based review of the literature for the care of these diseases that would meet these goals of disease management.

Comparison of the effects of desloratadine 5-mg daily and placebo on nasal airflow and seasonal allergic rhinitis symptoms induced by grass pollen exposure

BACKGROUND

Nasal congestion is a chronic symptom of seasonal allergic rhinitis (SAR) that is often difficult to treat with antihistamines. Desloratadine, a new, potent, H1-receptor antagonist has been shown to decrease nasal congestion in clinical trials and to maintain nasal airflow in response to grass pollen exposure. We compared the effects of desloratadine 5 mg and placebo on nasal airflow, nasal secretion weights and SAR symptoms, including nasal congestion, in patients exposed to grass pollen in an environmental exposure unit.

METHODS

Forty-six grass pollen allergic SAR patients received desloratadine or placebo for 7 days, followed by a 10-day washout, and then crossed over to the other treatment for 7 days. A 6-h allergen exposure was performed at the end of each treatment period.

RESULTS

Desloratadine was significantly superior to placebo in maintaining nasal airflow (P <or= 0.014) and lessening the increase in nasal secretion weights (P < 0.001) throughout allergen exposure. SAR symptom scores, including nasal congestion, were significantly less with desloratadine than placebo (P <or= 0.001). Desloratadine was well tolerated.

CONCLUSIONS

This study confirms that, compared with placebo, desloratadine can maintain nasal airflow and reduce nasal secretion weights and the severity of SAR symptoms, including nasal congestion, in SAR patients exposed to grass pollen allergen.

Advances in allergy management

Our understanding of the pathophysiology of allergy has moved to the molecular level, while study of epidemiology and genetics has revealed risks of developing allergies based on environmental and genetic profiles, and pharmacoeconomic data have enabled accurate measurement of the immense burden of allergic disease. These advances in allergy research have affected its management, particularly the search for new antiallergy therapies. New therapies should intervene in the systemic allergy inflammatory cascade and provide clinical efficacy that extends to multiple allergic disease states. In addition, these new therapies should present no additional safety issues, offer improvements over existing therapies, and have an impact on disease-impaired quality of life. In vitro studies show that desloratadine, a new, once-daily, nonsedating, selective histamine H1-receptor antagonist, blocks the systemic allergy cascade at multiple points. Desloratadine 5 mg once daily relieves the symptoms of chronic idiopathic urticaria and of both seasonal (SAR) and perennial allergic rhinitis. In patients with concomitant asthma and SAR, asthma symptoms are relieved and beta2-agonist medication use is decreased by desloratadine. Unlike many other second-generation histamine H1-receptor antagonists, desloratadine provides the added benefit of efficacy against nasal obstruction in SAR. Desloratadine improves quality of life by decreasing the impact of allergic symptoms on sleep and on daily activities.

Impact and modulation of nasal obstruction

Nasal obstruction, the leading symptom of allergic rhinitis, results from the combined activity of early- and late-phase allergic reactions. Desloratadine inhibits both early- and late-phase inflammatory mediators in vitro. Thus, double-blind, placebo-controlled, randomized, crossover trials were conducted to assess the efficacy of desloratadine against nasal obstruction, measured objectively and subjectively, during controlled exposure of patients with seasonal allergic rhinitis to allergen. Positive results were obtained in three single-dose studies; desloratadine 5 mg resulted in a greater improvement from baseline than did placebo in the total symptom score and the nasal obstruction symptom score (P </= 0.02). Desloratadine was more effective than placebo in a multiple-dose study; desloratadine 5 mg was given once daily for 7 days, and a 6-h allergen challenge was administered at the end of treatment compared with placebo. Desloratadine treatment was associated with less deterioration from baseline in the mean nasal airflow (P < 0.05) and in the mean severity score for the symptom of nasal obstruction (P < 0.03). Desloratadine significantly reduces the severity of nasal obstruction in patients with seasonal allergic rhinitis.

Novel approaches in the treatment of allergic rhinitis

PURPOSE OF REVIEW

The increasing prevalence of allergic rhinitis, its impact on individual quality of life and social costs, as well as its role as a risk factor for asthma, underline the need for improved treatment options for this disorder. We reviewed the recent literature published in English, dealing with relevant and appropriately controlled clinical trials on the treatment of allergic rhinitis.

RECENT FINDINGS

In addition to well established pharmacological therapies with antihistamines, corticosteroids, decongestants and mast cell stabilizers, new therapeutic options become increasingly important, including leukotriene modifiers, anti-immunoglobulin E antibodies, phosphodiesterase inhibitors and intranasal heparin; there also exist new developments in appropriate allergen specific immunotherapy.

SUMMARY

Promising results, both with established and novel treatment options, are communicated, but further studies are still necessary to confirm these data.

Desloratadine: a nonsedating antihistamine

OBJECTIVE

To review information on desloratadine, a nonsedating antihistamine.

DATA SOURCES

An English-language MEDLINE search was conducted (1966-July 2002). References of identified articles were subsequently reviewed for additional data. Schering Corporation provided unpublished information.

STUDY SELECTION/DATA EXTRACTION

Articles and abstracts pertaining to desloratadine were considered for inclusion, with emphasis on randomized, placebo-controlled, double-blind trials.

DATA SYNTHESIS

Desloratadine is approved for the treatment of symptoms associated with seasonal allergic rhinitis (SAR), perennial allergic rhinitis (PAR), and chronic idiopathic urticaria (CIU) in patients aged > or =12 years. In placebo-controlled trials, desloratadine demonstrated superior efficacy as a once-daily treatment of SAR, PAR, and CIU. Data suggest that desloratadine has antiinflammatory and decongestant activity.

CONCLUSIONS

Desloratadine appears to be a "me-too" agent, with no major differences compared with other second-generation antihistamines.

Onset and Duration of Action of Ketotifen???0.025%???and???Emedastine???0.05% in Seasonal Allergic Conjunctivitis

OBJECTIVE

To compare the efficacy, onset and duration of action, and the safety of ketotifen fumarate 0.025% ophthalmic solution and emedastine difumarate 0.05% ophthalmic solution in subjects with seasonal allergic conjunctivitis (SAC) induced by allergen exposure, using the Vienna Challenge Chamber model.

DESIGN AND SETTING

This was a double-masked, randomised, comparative, crossover study conducted at an allergy outpatient clinic in Austria.

STUDY PARTICIPANTS

Subjects with an allergy to grass pollen were exposed to the allergen in a pollen chamber for 4 hours, followed by a 3-hour break and then a second exposure for 3 hours.

INTERVENTIONS

Study participants were randomised to a treatment sequence (ketotifen followed by emedastine or emedastine followed by ketotifen), receiving 1 drop per eye of ketotifen or emedastine 2 hours after the initial allergen exposure in the pollen chamber.

OUTCOMES

Individual and composite ocular, individual and composite nasal, and total (ocular + nasal) symptom complex scores were determined by repeated exposure to allergen 0-2 hours and 5-8 hours after dosing. Onset of action was defined as the time to the first observation of a 20% reduction from baseline in the composite ocular symptom score.

RESULTS

All 37 subjects enrolled completed the study. The median time to onset of action was 15 minutes for ketotifen and 30 minutes for emedastine. This difference was significant using the generalised linear model (p = 0.048), but not for the log-rank test analysis. In the initial 2 hours post dose, ketotifen provided significantly greater relief of both composite ocular symptoms (p = 0.026) and total symptom complex (p = 0.014). Both medications were effective in reducing symptoms 5 to 8 hours after dosing. No adverse events were reported for either treatment.

CONCLUSIONS

In the Vienna Challenge Chamber model, ketotifen and emedastine both effectively alleviated ocular symptoms of SAC after single-dose administration. Ketotifen had a faster onset of action and provided better symptom relief than emedastine during the first 2 hours after dosing. The rapid onset of action and symptom control make ketotifen a valuable treatment for SAC.

Treatment of allergic rhinitis

Allergic rhinitis, a common and often debilitating disease marked by rhinorrhea, nasal congestion, nasal itching, and sneezing, is on the increase worldwide. Treatment involves allergen avoidance, pharmacotherapy, and, in selected cases, immunotherapy. This overview describes the characteristics, pathogenesis, and diagnosis of allergic rhinitis. The major contributing allergens of seasonal and perennial allergic rhinitis are identified. Pharmacotherapy is described within the context of treatment guidelines developed by the major asthma and allergy professional organizations. Oral H1 antihistamines are first-line therapy for mild-to-moderate allergic rhinitis. The newer, nonsedating agents are recommended over first-generation antihistamines. Some of the newer oral antihistamines, such as cetirizine, desloratadine, and fexofenadine, have been shown to relieve the symptom of nasal congestion. Intranasal steroids are first-line therapy for patients with more severe symptoms.