Intranasal azelastine. A review of its efficacy in the management of allergic rhinitis

Asymmetric Dearomatization of Phthalazines by Anion-Binding Catalysis

A straightforward methodology for the enantioselective synthesis of 1,2-dihydrophthalazines via dearomatization of phthalazines by anion-binding catalysis has been developed. The process involves the Mannich-type addition of silyl ketene acetals to in situ generated N-acylphthalazinium chlorides using a tert-leucine derived thiourea as a H-bond donor catalyst. Ensuing selective and high-yielding transformations provide appealing dihydro- and tetrahydro-phthalazines, phthalazones, and piperazic acid homologues, en route to biologically relevant molecules.

The Multidirectional Effect of Azelastine Hydrochloride on Cervical Cancer Cells

A major cause of cancer cell resistance to chemotherapeutics is the blocking of apoptosis and induction of autophagy in the context of cell adaptation and survival. Therefore, new compounds are being sought, also among drugs that are commonly used in other therapies. Due to the involvement of histamine in the regulation of processes occurring during the development of many types of cancer, antihistamines are now receiving special attention. Our study concerned the identification of new mechanisms of action of azelastine hydrochloride, used in antiallergic treatment. The study was performed on HeLa cells treated with different concentrations of azelastine (15-90 µM). Cell cycle, level of autophagy (LC3 protein activity) and apoptosis (annexin V assay), activity of caspase 3/7, anti-apoptotic protein of Bcl-2 family, ROS concentration, measurement of mitochondrial membrane potential (Δψm), and level of phosphorylated H2A.X in response to DSB were evaluated by cytometric method. Cellular changes were also demonstrated at the level of transmission electron microscopy and optical and fluorescence microscopy. Lysosomal enzyme activities-cathepsin D and L and cell viability (MTT assay) were assessed spectrophotometrically. Results: Azelastine in concentrations of 15-25 µM induced degradation processes, vacuolization, increase in cathepsin D and L activity, and LC3 protein activation. By increasing ROS, it also caused DNA damage and blocked cells in the S phase of the cell cycle. At the concentrations of 45-90 µM, azelastine clearly promoted apoptosis by activation of caspase 3/7 and inactivation of Bcl-2 protein. Fragmentation of cell nucleus was confirmed by DAPI staining. Changes were also found in the endoplasmic reticulum and mitochondria, whose damage was confirmed by staining with rhodamine 123 and in the MTT test. Azelastine decreased the mitotic index and induced mitotic catastrophe. Studies demonstrated the multidirectional effects of azelastine on HeLa cells, including anti-proliferative, cytotoxic, autophagic, and apoptotic properties, which were the predominant mechanism of death. The revealed novel properties of azelastine may be practically used in anti-cancer therapy in the future.

Synthesis and Chemistry of 1,2,3-Benzothiadiazine 1,1-Dioxide Derivatives: A Comprehensive Overview

1,2,4-Benzothiadiazine 1,1-dioxide derivatives (e.g., chlorothiazide, hydrochlorothiazide) have been long used in the human therapy as diuretic and antihypertensive agents. Marketed drugs containing the structurally related phthalazinone scaffold are applied for the treatment of various diseases ranging from ovarian cancer to diabetes and allergy. 1,2,3-Benzothiadiazine 1,1-dioxides combine the structural features of these two compound families, which led to their more intensive research since the 1960s. In the present review, we summarize the literature of this period of more than half a century, including all scientific papers and patent applications dealing with the synthesis and reactions of this compound family, briefly hinting at their potential therapeutic application as well.

Azelastine potentiates antiasthmatic dexamethasone effect on a murine asthma model

Glucocorticoids are among the most effective drugs to treat asthma. However, the severe adverse effects associated generate the need for its therapeutic optimization. Conversely, though histamine is undoubtedly related to asthma development, there is a lack of efficacy of antihistamines in controlling its symptoms, which prevents their clinical application. We have reported that antihistamines potentiate glucocorticoids' responses in vitro and recent observations have indicated that the coadministration of an antihistamine and a synthetic glucocorticoid has synergistic effects on a murine model of allergic rhinitis. Here, the aim of this work is to establish if this therapeutic combination could be beneficial in a murine model of asthma. We used an allergen-induced model of asthma (employing ovalbumin) to evaluate the effects of the synthetic glucocorticoid dexamethasone combined with the antihistamine azelastine. Our results indicate that the cotreatment with azelastine and a suboptimal dose of dexamethasone can improve allergic lung inflammation as shown by a decrease in eosinophils in bronchoalveolar lavage, fewer peribronchial and perivascular infiltrates, and mucin-producing cells. In addition, serum levels of allergen-specific IgE and IgG1 were also reduced, as well as the expression of lung inflammatory-related genes IL-4, IL-5, Muc5AC, and Arginase I. The potentiation of dexamethasone effects by azelastine could allow to reduce the effective glucocorticoid dose needed to achieve a therapeutic effect. These findings provide first new insights into the potential benefits of glucocorticoids and antihistamines combination for the treatment of asthma and grants further research to evaluate this approach in other related inflammatory conditions.

Platelet-Activating Factor (PAF) in Allergic Rhinitis: Clinical and Therapeutic Implications

Platelet-activating factor (PAF) is a lipid mediator involved in several allergic reactions. It is released from multiple cells of the immune system, such as eosinophils, neutrophils, and mast cells, and also exerts its effect on most of them upon specific binding to its receptor, becoming a pleiotropic mediator. PAF is considered a potential relevant mediator in allergic rhinitis, with a key role in nasal congestion and rhinorrhoea due to its effect on vascular permeability. Interestingly, despite its potential relevance as a therapeutic target, no specific PAF inhibitors have been studied in humans. However, rupatadine, a second-generation antihistamine with dual antihistamine and anti-PAF effects has shown promising results by both blocking nasal symptoms and inhibiting mast cell activation induced by PAF, in comparison to antihistamine receptor drugs. In conclusion, the inhibition of PAF may be an interesting approach in the treatment of allergic rhinitis as part of a global strategy directed at blocking as many relevant inflammatory mediators as possible.

Update on local allergic rhinitis

We here provide an update on the literature regarding local allergic rhinitis (LAR). In reviewing LAR, we have included an updated definition, classifications, mechanisms, comorbidities, and recommendations for diagnosis and treatment for LAR, as well as the defined research areas for future evidence-based studies. LAR is a localised nasal allergic response in the absence of systemic atopy characterised by local production of specific IgE (sIgE) antibodies, a TH2 pattern of mucosal cell infiltration during natural exposure to aeroallergens, and a positive nasal allergen provocation test response, with the release of inflammatory mediators. The localised allergic response of LAR is an important topic for the study of allergies. This review provides an update on the current knowledge of LAR.

An assessment of the onset and duration of action of olopatadine nasal spray

Objective

Seasonal allergic rhinitis (SAR) is a highly prevalent disease. This study was conducted to evaluate the onset and duration of action of three concentrations of olopatadine nasal spray.

METHODS

This was a randomized, double-blind, single-dose, placebo-controlled study, conducted in an environmental exposure chamber in patients with SAR. A total of 320 patients were exposed to ragweed allergen in the chamber and randomized to olopatadine nasal spray 0.2%, 0.4%, 0.6%, or placebo nasal spray. Symptoms (sneezing, runny, itchy, and stuffy nose) were self-assessed during a 12-hour study period.

RESULTS

All concentrations of olopatadine nasal spray provided clinically meaningful reductions in total nasal symptom scores at 30 minutes compared to the placebo. Olopatadine nasal spray 0.6% was significantly more effective ( P <0.05) than placebo nasal spray at all time-points starting at 90 minutes postdose and continuing over 12 hours.

CONCLUSIONS

Olopatadine nasal spray 0.6% demonstrated a fast onset of action and maintained an effect for at least 12 hours after dosing.

Azelastine and budesonide (nasal sprays): Effect of combination therapy monitored by acoustic rhinometry and clinical symptom score in the treatment of allergic rhinitis

The aim of this study was to objectively evaluate the effects of intranasal therapy with azelastine (AZE), budesonide (BUD), and combined AZE plus BUD (AZE/BUD) using a nasal provocation test (NPT) and acoustic rhinometry in patients with allergic rhinitis. A randomized, single-blind, crossover study with three treatment sequences was used. Thirty patients with persistent AR received the three treatments using a nasal spray twice daily for 30 days and were evaluated by an NPT with histamine before and after each period of treatment. The treatment comparison, assessed by the nasal responsiveness to histamine, was monitored based on subjective (symptom score) and objective parameters (acoustic rhinometry). The minimal cross-area 2 (MCA2) was measured by acoustic rhinometry at 1, 4, 8, and 12 minutes after NPT for each histamine concentration administered (0.5, 1, 2, 4, and 6 mg/mL) up to at least a 20% reduction in the MCA2 from baseline (NPT₂₀). The subjects were scored regarding nasal response encompassing histamine dose and time after histamine administration that caused nasal obstruction (NPT₂₀ score) to assess the treatments' effects. Combination therapy produced a significant increase in baseline MCA2, viz., the improvement of nasal patency (p = 0.005). The symptoms score was significantly decreased after treatment with AZE (p = 0.03), BUD (p < 0.0001), and AZE/BUD (p < 0.0001), compared with pretreatment. The NPT₂₀ score was significantly higher (p = 0.0009) after AZE/BUD, compared with AZE and BUD on their own. Thus, AZE therapy combined with BUD might provide more therapeutic benefits than the isolated drugs for improving nasal patency.

Effectiveness of twice daily azelastine nasal spray in patients with seasonal allergic rhinitis

Azelastine nasal spray (Allergodil^®, Lastin^®, Afluon^®; Meda AB, Stockholm, Sweden) is a fast-acting, efficacious and well-tolerated H1-receptor antagonist for the treatment of rhinitis. In addition it also has mast-cell stabilizing and anti-inflammatory properties, reducing the concentration of leukotrienes, kinins and platelet activating factor in vitro and in vivo, as well as inflammatory cell migration in rhinitis patients. Well-controlled studies in patients with seasonal allergic rhinitis (SAR), perennial rhinitis (PR) or vasomotor rhinitis (VMR) confirm that azelastine nasal spray has a rapid onset of action, and improves nasal symptoms associated with rhinitis such as nasal congestion and post-nasal drip. Azelastine nasal spray is effective at the lower dose of 1 spray as well at a dose of 2 sprays per nostril twice daily, but with an improved tolerability profile compared to the 2-spray per nostril twice daily regimen. Compared with intranasal corticosteroids, azelastine nasal spray has a faster onset of action and a better safety profile, showing at least comparable efficacy with fluticasone propionate (Flonase^®; GSK, USA), and a superior efficacy to mometasone furoate (Nasonex^®; Schering Plough, USA). In combination with fluticasone propionate, azelastine nasal spray exhibits greater efficacy than either agent used alone, and this combination may provide benefit for patients with difficult to treat seasonal allergic rhinitis. In addition, azelastine nasal spray can be used on an as-needed basis without compromising clinical efficacy. Compared with oral antihistamines, azelastine nasal spray also demonstrates superior efficacy and a more rapid onset of action, and is effective even in patients who did not respond to previous oral antihistamine therapy. Unlike most oral antihistamines, azelastine nasal spray is effective in alleviating nasal congestion, a particularly bothersome symptom for rhinitis sufferers. Azelastine nasal spray is well tolerated in both adults and children with allergic rhinitis. Bitter taste which seems to be associated with incorrect dosing technique is the most common side effect reported by patients, but this problem can be minimized by correct dosing technique.

Rhinitis in the geriatric population

The current geriatric population in the United States accounts for approximately 12% of the total population and is projected to reach nearly 20% (71.5 million people) by 20301. With this expansion of the number of older adults, physicians will face the common complaint of rhinitis with increasing frequency. Nasal symptoms pose a significant burden on the health of older people and require attention to improve quality of life. Several mechanisms likely underlie the pathogenesis of rhinitis in these patients, including inflammatory conditions and the influence of aging on nasal physiology, with the potential for interaction between the two. Various treatments have been proposed to manage this condition; however, more work is needed to enhance our understanding of the pathophysiology of the various forms of geriatric rhinitis and to develop more effective therapies for this important patient population.

The pathophysiology, diagnosis and treatment of allergic rhinitis

Treatment of AR requires a stepwise approach depending on the severity and duration of symptoms. Treatment options for AR consist of allergen avoidance, pharmacotherapy, immunotherapy and surgery. For the mechanisms of AR, anti-IgE antibody and specific antibody to cytokines such as IL-4 or IL-5 that correlate with allergic inflammation have recently emerged. SLIT is currently widely used due to its efficacy, safety and convenience, which replaces subcutaneous immunotherapy. Although allergen avoidance and immunotherapy are theoretically ideal, antihistamines and intranasal corticosteroids will play the main role in the management of AR until an innovative treatment develops. However, patients' main symptom, the duration and severity of AR, patients' compliance, safety of medication and cost-effectiveness should be considered when treatment options are chosen. In conclusion, physicians should be aware of etiology, pathophysiology, symptoms, signs and diseases related to AR in order to make a correct diagnosis and choose a proper treatment option for each patient.

Pediatric allergy medications: review of currently available formulations

BACKGROUND

Allergy affects about 50% of the pediatric population globally. Allergic rhinitis (AR), one form of allergy, causes considerable impairment in quality of life, including disruption of sleep and, in children, interference with school attendance and performance.

SCOPE

Traditional formulations and delivery systems - tablets, capsules, or intranasal sprays - successfully used by adults for treatment of AR may not be as easily administered in children. Liquid oral medications are more readily taken by children but contain sugars and excipients; they can also be inconvenient with less accurate dosing and are associated with dental caries and gastrointestinal upset.

METHODOLOGY

This review evaluated medications for treatment of AR currently available for pediatric patients and identified the attitudes of parents and health care professionals toward these medications. Guidelines from international organizations and governmental websites were reviewed for recommendations and product labeling requirements. A Medline search was conducted using the terms dyes, excipients, palatability, prescribing habits, sugar, among others.

FINDINGS

In recent years, governmental regulatory agencies and professional organizations in Europe and the United States have recommended avoidance of sugar in pediatric medicines and required stricter labeling of their ingredients. Public awareness about the adverse effects of sugar and some excipients has also increased, and parents more frequently express the desire for safer and more convenient medicines for their children. In response, more sugar-free, dye-free liquid medicines and other formulations, such as granules, filmstrips, chewable tablets, fast-dissolving tablets, and drops, are becoming available for pediatric use.

LIMITATIONS

Data from well-designed trials conducted in children for the treatment of AR are lacking. In addition, the possibility of a social response bias may exist for parents and physicians about sugar and other ingredients in children's medications.

CONCLUSION

Treatment for AR is often long-term, particularly in persistent AR; therefore, safety, tolerability, convenience, and patient/parental acceptance are important considerations when deciding which medication to prescribe.

Validation of guinea pig model of allergic rhinitis by oral and topical drugs

Ovalbumin-induced guinea pig model of rhinitis was assessed for its utility in the studies of rhinitis. Systemic sensitization and challenge with ovalbumin-induced rhinitis symptoms and an increase in anti-OVA-IgE and IgG titers, positive skin reactions and nasal lavage IL-4 concentration. Histopathology of nasal mucosa showed infiltration of eosinophils and other inflammatory cells consistent with the symptoms. Topical sensitization of ovalbumin yielded inconsistent symptoms of rhinitis. In systemic sensitization model, repeated challenge of ovalbumin caused similar response for at least 3 consecutive challenges. The symptoms were affected by relative humidity in the air and dosing volume of topical drugs. Sneezing and lacrimation were reduced by acute oral administration of the H1 receptor antagonists and steroids or the prophylactic oral administration of cysteinyl leukotriene (CysLT1) receptor antagonist montelukast or acute topical antihistamines, mast cell stabilizer sodium cromoglycate and anticholinergic agent ipratropium bromide, but not by a topical steroid. Nose rubbing was reduced significantly by some oral and topical antihistamines. Oral steroids offered excellent protection against all symptoms. Dexamethasone and montelukast also inhibited nasal lavage IL-4 concentration and inflammatory cell infiltration. Treatment with topical steroid fluticasone for 2 weeks had no effect on sneezing or rubbing. However, it caused complete inhibition of congestion. The cyclooxygenase inhibitor indomethacin had no effect on symptoms of rhinitis. The adrenergic alpha receptor agonist-decongestant oxymetazoline caused reduction in congestion. These results suggest that differential responsiveness to symptoms of rhinitis by a new agent can be very well profiled in the model in congruence with the mediation pathways and mechanism of action of drugs. The model provides complete symptomatic characterization of rhinitis and is a good tool for its study.

BSACI guidelines for the management of allergic and non-allergic rhinitis

This guidance for the management of patients with allergic and non‐allergic rhinitis has been prepared by the Standards of Care Committee (SOCC) of the British Society for Allergy and Clinical Immunology (BSACI). The guideline is based on evidence as well as on expert opinion and is for use by both adult physicians and paediatricians practicing in allergy. The recommendations are evidence graded. During the development of these guidelines, all BSACI members were included in the consultation process using a web‐based system. Their comments and suggestions were carefully considered by the SOCC. Where evidence was lacking, consensus was reached by the experts on the committee. Included in this guideline are clinical classification of rhinitis, aetiology, diagnosis, investigations and management including subcutaneous and sublingual immunotherapy. There are also special sections for children, co‐morbid associations and pregnancy. Finally, we have made recommendations for potential areas of future research.

Caring for patients with allergic rhinitis

PURPOSE

Allergic rhinitis (AR) affects up to 40 million Americans, with an estimated cost of $2.7 billion per annum. This review discusses several therapeutic options that reduce the symptoms of AR, including allergen avoidance, antihistamines, intranasal corticosteroids (INS), leukotriene receptor antagonists, and immunotherapy.

DATA SOURCES

The articles included in this review were retrieved by a search of Medline literature on the subjects of AR, antihistamines, INS, leukotriene antagonists, and immunotherapy, as well as current published guidelines for the treatment of AR.

CONCLUSIONS

Allergen avoidance is recommended for all patients prior to pharmacologic therapy. Oral and nasal H(1)-antihistamines are recommended to alleviate the mild and intermittent symptoms of AR, and INS are recommended as the first-line treatment choice for mild persistent and more moderate-to-severe persistent AR.

IMPLICATIONS FOR PRACTICE

There are a number of different types of therapy for the management of AR; with so many options available, successful tailoring of treatment to suit individual requirements is realistically achievable.

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.

Allergic rhinitis in children : diagnosis and management strategies

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

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.

Treatment of nonallergic perennial rhinitis

Nonallergic perennial rhinitis (also commonly referred to as vasomotor rhinitis) is a chronic non-IgE-mediated condition that is characterized by symptoms which are similar to those seen in allergic rhinitis, but which persist for over nine months each year. Although treatment of vasomotor rhinitis involves the use of either intranasal corticosteroids or antihistamines, the corticosteroids are generally not effective in treatment of all the symptoms of vasomotor rhinitis and have generally been shown to be effective in patients with eosinophilia. With the exception of azelastine, the only topical antihistamine to be approved by the FDA for the treatment of nonallergic rhinitis, the antihistamines have also produced inconsistent results. While clinical studies of azelastine have demonstrated that this drug is highly efficacious in the treatment of all the symptoms of vasomotor rhinitis, mechanistic studies have demonstrated that azelastine has potent anti-inflammatory effects (in particular attenuation of the expression and synthesis of pro-inflammatory cytokines, leukotrienes, and cell adhesion molecules), which are likely to contribute to its clinical efficacy. Furthermore, pharamacokinetic studies have suggested that since azelastine has a more rapid onset of action, compared to most other antihistamines and intranasal corticosteroids, then azelastine nasal spray may be considered as primary therapy for patients with symptoms of both allergic and/or vasomotor (nonallergic perennial) rhinitis.

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 intranasal corticosteroids and antihistamines in allergic rhinitis: a review of randomized, controlled trials

For several years there has been discussion of whether first-line pharmacological treatment of allergic rhinitis should be antihistamines or intranasal corticosteroids. No well documented, clinically relevant differences seem to exist for individual nonsedating antihistamines in the treatment of allergic rhinitis. Likewise, the current body of literature does not seem to favor any specific intranasal corticosteroid. When comparing efficacy of antihistamines and intranasal corticosteroids in allergic rhinitis, present data favor intranasal corticosteroids. Interestingly, data do not support antihistamines as superior in treating conjunctivitis associated with allergic rhinitis. Safety data from comparative studies in allergic rhinitis do not indicate differences between antihistamines and intranasal corticosteroids. Combining antihistamines and intranasal corticosteroids in the treatment of allergic rhinitis does not provide additional beneficial effects to intranasal corticosteroids alone. Considering present data, intranasal corticosteroids seem to offer superior relief in allergic rhinitis, when compared with antihistamines.

Safety and tolerability profiles of intranasal antihistamines and intranasal corticosteroids in the treatment of allergic rhinitis

Intranasal corticosteroids and intranasal antihistamines are efficacious topical therapies in the treatment of allergic rhinitis. This review addresses their relative roles in the management of this disease, focusing on their safety and tolerability profiles. The intranasal route of administration delivers drug directly to the target organ, thereby minimising the potential for the systemic adverse effects that may be evident with oral therapy. Furthermore, the topical route of delivery enables the use of lower doses of medication. Such therapies, predominantly available as aqueous formulations following the ban of chlorofluorocarbon propellants, have minimal local adverse effects. Intranasal application of therapy can induce sneezing in the hyper-reactive nose, and transient local irritation has been described with certain formulations. Intranasal administration of corticosteroids is associated with minor nose bleeding in a small proportion of recipients. This effect has been attributed to the vasoconstrictor activity of the corticosteroid molecules, and is considered to account for the very rare occurrence of nasal septal perforation. Nasal biopsy studies do not show any detrimental structural effects within the nasal mucosa with long-term administration of intranasal corticosteroids. Much attention has focused on the systemic safety of intranasal application. When administered at standard recommended therapeutic dosage, the intranasal antihistamines do not cause significant sedation or impairment of psychomotor function, effects that would be evident when these agents are administered orally at a therapeutically relevant dosage. The systemic bioavailability of intranasal corticosteroids varies from <1% to up to 40-50% and influences the risk of systemic adverse effects. Because the dose delivered topically is small, this is not a major consideration, and extensive studies have not identified significant effects on the hypothalamic-pituitary-adrenal axis with continued treatment. A small effect on growth has been reported in one study in children receiving a standard dosage over 1 year, however. This has not been found in prospective studies with the intranasal corticosteroids that have low systemic bioavailability and therefore the judicious choice of intranasal formulation, particularly if there is concurrent corticosteroid inhalation for asthma, is prudent. There is no evidence that such considerations are relevant to shorter-term use, such as in intermittent or seasonal disease. Intranasal therapy, which represents a major mode of drug delivery in allergic rhinitis, thus has a very favourable benefit/risk ratio and is the preferred route of administration for corticosteroids in the treatment of this disease, as well as an important option for antihistaminic therapy, particularly if rapid symptom relief is required.

Emerging treatments for allergic rhinitis

Allergic rhinitis has increased in prevalence and afflicts almost a fourth of the younger population in westernised countries. Recent discoveries concerning the pathophysiology of the allergic reaction have led to an increase in research for new and improved remedies for allergic rhinitis. Pharmacological research in the field of allergic rhinitis concentrates on selective agents that may block or inhibit the release or actions of certain mediators or cytokines. The complexity of the allergic inflammatory process, however, may question the benefit of this research, unless the drug interferes early in allergic processes. Current treatments such as antihistamines and intranasal steroids can also be improved, displaying better clinical potency with fewer side effects. All novel treatments, however, must measure up with the present ones, in terms of both clinical and cost effectiveness.

Recognizing And Treating Non-Infectious Rhinitis

PURPOSE

To increase clinicians' familiarity with nonallergic and mixed rhinitis and to differentiate these from allergic rhinitis, thus providing for an accurate diagnosis and facilitating a successful initial treatment program.

DATA SOURCES

A Medline search of published journal articles was supplemented with known books and proceedings pertaining to rhinitis.

CONCLUSIONS

Although there is significant overlap of symptoms among the three types of rhinitis (i.e., allergic, nonallergic, and mixed), the patient history often contains clues that can aid in establishing a correct diagnosis. The new Patient Rhinitis Screen, a questionnaire developed for use in the primary care arena, facilitates the diagnostic process.

IMPLICATIONS FOR PRACTICE

As the most common condition in the outpatient practice of medicine, rhinitis is frequently treated by primary care practitioners. Recent guidelines for the diagnosis and management of rhinitis suggest that a specific diagnosis of allergic, nonallergic, or mixed rhinitis leads to more effective treatment strategies. The result is successful and efficient care utilizing, as appropriate, broad-based and symptom-specific therapies.

Topical immunopharmacology of ocular allergies

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

Ocular allergy guidelines: a practical treatment algorithm

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

Clinical prescribing of allergic rhinitis medication in the preschool and young school-age child: what are the options?

Allergic rhinitis (AR) is the most common chronic condition in children and is estimated to affect up to 40% of all children. It is usually diagnosed by the age of 6 years. The major impact in children is due to co-morbidity of sinusitis, otitis media with effusion, and bronchial asthma. AR also has profound effects on school absenteeism, performance and quality of life. Pharmacotherapy for AR should be based on the severity and duration of signs and symptoms. For mild, intermittent symptoms lasting a few hours to a few days, an oral second-generation antihistamine should be used on an as-needed basis. This is preferable to a less expensive first-generation antihistamine because of the effect of the latter on sedation and cognition. Four second-generation antihistamines are currently available for children under 12 years of age: cetirizine, loratadine, fexofenadine and azelastine nasal spray; each has been found to be well tolerated and effective. There are no clearcut advantages to distinguish these antihistamines, although for children under 5 years of age, only cetirizine and loratadine are approved. Other agents include pseudoephedrine, an oral vasoconstrictor, for nasal congestion, and the anticholinergic nasal spray ipratropium bromide for rhinorrhoea. Sodium cromoglycate, a mast cell stabiliser nasal spray, may also be useful in this population. For patients with more persistent, severe symptoms, intranasal corticosteroids are indicated, although one might consider azelastine nasal spray, which has anti- inflammatory activity in addition to its antihistamine effect. With the exception of fluticasone propionate for children aged 4 years and older, and mometasone furoate for those aged 3 years and older, the other intranasal corticosteroids including beclomethasone dipropionate, triamcinolone, flunisolide and budesonide are approved for children aged 6 years and older. All are effective, so a major consideration would be cost and safety. For short term therapy of 1 to 2 months, the first-generation intranasal corticosteroids (beclomethasone dipropionate, triamcinolone, budesonide and flunisolide) could be used, and mometasone furoate and fluticasone propionate could be considered for longer-term treatment. Although somewhat more costly, these second-generation drugs have lower bioavailability and thus would have a better safety profile. In patients not responding to the above programme or who require continuous medication, identification of specific triggers by an allergist can allow for specific avoidance measures and/or immunotherapy to decrease the allergic component and increase the effectiveness of the pharmacological regimen.

Effects of azelastine on contractility, action potentials and L-type Ca(2+) current in guinea pig cardiac preparations

Azelastine is used for symptomatic relief of allergic rhinitis and asthma bronchiale. In vitro studies in smooth muscle cells from guinea pig trachea and ileum demonstrate that the drug blocks L-type Ca(2+) current (I(Ca, L)). However, for safety reasons, it is important to know whether azelastine also affects cardiac I(Ca, L) in therapeutically relevant concentrations. We have therefore studied the effects of azelastine on I(Ca, L) in guinea pig ventricular myocytes using standard whole-cell patch-clamp technique. Force of contraction and action potentials from isolated papillary muscles of the same species were also investigated at physiological temperature (36 degrees C). Azelastine (30 microM) significantly reduced force of contraction, shortened action potential duration, and depressed maximum upstroke velocity. I(Ca, L) was elicited by 200-ms-long clamp steps from -100 to 0 mV (one pulse every 3 s). Azelastine blocked I(Ca, L) reversibly and concentration-dependently with an IC(50) of 20.2+/-1.3 microM and a Hill coefficient of 1.1. At 10 microM, azelastine shifted steady-state inactivation by 5 mV (n=7) to more negative potentials. The time course of I(Ca, L) inactivation could be described by a double exponential function. Azelastine (10 microM) significantly shortened the slow inactivation time constant (tau(s)) from 54.2+/-2.8 ms under control conditions to 38.7+/-2.9 ms (n=16) in the presence of drug. Azelastine also reduced low-voltage-activated Ca(2+) currents with a similar IC(50) value (24 microM, at -35 mV). Since the therapeutic plasma concentrations are in the order of 10-100 nM, we conclude that azelastine does indeed affect also cardiac I(Ca, L), but the concentrations required are at least two orders of magnitude larger than those obtained during drug therapy.

Allergic and immunologic disorders of the eye. Part II: ocular allergy

Allergy affects more than 15% of the world population, and some studies have shown that up 30% of the US population has some form of allergy. Most of these patients have various target organs for their allergies, and most have ocular involvement. The ocular component may be the most prominent and sometimes disabling feature of their allergy. Some are affected for only a few weeks to months, whereas others have symptoms that last throughout the year. The seasonal forms may present to clinical allergists, whereas the more chronic forms may present to ophthalmologists. Thus, in the second of this 2-part review series (Part I: Ocular Immunology appeared in the November issue of the Journal), an overview is provided of the spectrum of ocular allergy that ranges from acute seasonal allergic conjunctivitis to chronic variants of atopic keratoconjunctivitis. With a better understanding of the immunologic mechanisms, we now can develop better treatment approaches and design further research in intervention of allergic eye diseases.