Comparison of the bronchodilatory effects of cetirizine, albuterol, and both together versus placebo in patients with mild-to-moderate asthma

Cetirizine use in childhood: an update of a friendly 30-year drug

Cetirizine is a second-generation antihistamine, derived from the metabolism of hydroxyzine, highly specific for the H1 receptors, and with marked antiallergic properties. Although its history began more than 30 years ago, it remains one of the most used drugs in children with a leading role in the medical care of children with allergic diseases. Cetirizine use is licensed for paediatric patients for the treatment of allergic rhinitis, and chronic spontaneous urticaria, in Europe in children older than 2 years old and in the USA in children older than 6 months old. This review provides a practical update on the use of cetirizine in children and adolescents.

Focus on the cetirizine use in clinical practice: a reappraisal 30 years later

Antihistamines are currently one of the most commonly administered categories of drugs. They are used to treat symptoms that are secondary to histamine release, which is typical of certain allergic conditions, including rhinitis, conjunctivitis, asthma, urticaria, and anaphylaxis. Cetirizine belongs to the second-generation family, so, it is very selective for peripheral H1 receptors, is potent and quickly relieves symptoms, exerts additional anti-allergic/anti-inflammatory effects, and is usually well-tolerated. It has been marketed 30 years ago. In these years, a remarkable body of evidence has been built. The current review provides a practical update on the use of cetirizine in clinical practice.

Antipruritic Placebo Effects by Conditioning H1-antihistamine

OBJECTIVE

Allergic rhinitis symptoms can be reduced by behaviorally conditioning antihistamine. It is unclear whether these findings extend to histamine-induced itch or work when participants are informed about the conditioning procedure (open-label conditioning). The current study aims to investigate the efficacy of (open-label) antipruritic behavioral conditioning for histamine-induced itch.

METHODS

Healthy participants (n = 92; 84% female) were randomized to I) an open-label conditioned, II) closed-label conditioned, III) conditioned-not-evoked control, or IV) nonconditioned control group. A two-phase conditioning paradigm was used. During acquisition, a conditioned stimulus (CS; distinctively tasting beverage) was repeatedly paired with the H1-antihistamine levocetirizine (groups I-III). During evocation, the CS was paired with placebo (I, II), or instead of the CS, water was paired with placebo (III). The nonconditioned control group (IV) received CS with placebo in both phases. Itch after histamine iontophoresis and physiological data (i.e., spirometry, heart rate, skin conductance) were assessed. Combined conditioned and combined control groups were first compared, and analyses were repeated for separate groups.

RESULTS

Marginally lower itch was reported in the combined conditioned compared with the control groups (F(1,88) = 2.10, p = .076, ηpartial = 0.02); no differences between separate groups were found. No effects on physiological data were found, except for heart rate, which reduced significantly and consistently for control groups, and less consistently for conditioned groups (group by time interaction: F(7,80) = 2.35, p = .031, ηpartial = 0.17).

CONCLUSION

Limited support was found for the efficacy of antipruritic behavioral conditioning, regardless of whether participants were informed about the conditioning procedure. The application of open-label conditioning in patient populations should be further researched.

TRIAL REGISTRATION

www.trialregister.nl; ID NTR5544.

A practical guide to the sublingual immunotherapy tablet adverse event profile: implications for clinical practice

OBJECTIVES

Treatment with allergy immunotherapy improves allergic rhinoconjunctivitis, but can also improve comorbidities associated with allergic rhinitis such as asthma. Sublingual immunotherapy (SLIT)-tablets are a convenient and efficacious method of allergy immunotherapy. They are self-administered after the first tablet has been provided under medical supervision. Therapy may elicit local reactions or, rarely, systemic allergic reactions. The objective of this report is to inform healthcare practitioners about the safety and tolerability profile of SLIT-tablets and use this information to provide practical guidance that may inform patients regarding potential adverse reactions and how to manage them.

METHODS

Pooled analyses of safety data from completed randomized, multicenter, double-blind, placebo-controlled phase 2 and phase 3 US and EU trials of timothy grass, short ragweed, and SQ house dust mite SLIT-tablets were conducted to characterize safety and tolerability.

RESULTS

SLIT-tablets are generally well tolerated. No life-threatening events, serious systemic allergic reactions, or events that compromised the airway have been reported. The most common treatment-related adverse events (AEs) are oral site reactions, most of which begin on day 1 of treatment, recur for less than 2 weeks, and resolve after approximately 30-60 minutes. Systemic allergic reactions have been managed with conventional pharmacotherapy. Reactions treated with epinephrine are uncommon, but have been reported. Treatment of AEs, treatment discontinuation considerations, and patient FAQs regarding SLIT-tablet safety/tolerability are discussed.

CONCLUSIONS

This report gives healthcare providers valuable information to educate patients regarding what to expect in terms of SLIT-tablet safety and tolerability. Practical guidance is also provided to ensure proper treatment of any adverse reactions.

The role of antihistamines in asthma management

Histamine is an important mediator in airway inflammation. It is elevated in the airways of asthmatic patients and is responsible for many of the pathophysiological features in asthma. Antihistamines block the actions of histamine and also have effects on inflammation which is independent of histamine-H(1)-receptor antagonism. Antihistamines have been shown to have bronchodilatory effects, effects on allergen-, exercise-, and adenosine-monophosphate-challenge testing, and also to prevent allergen-induced nonspecific airways hyperresponsiveness. Clinical studies have shown mixed results, and some studies have reported beneficial effects of azelastine, cetirizine, desloratadine, and fexofenadine on asthma symptoms or physiological measures in patients with asthma. The combination of an antihistamine and a leukotriene receptor antagonist has been shown to have additive effects in certain studies. Antihistamines have also been shown to delay or prevent the development of asthma in a subgroup of atopic children. These data suggest that antihistamines may have beneficial effects in the management of asthma.

Improvement and prevention of asthma with concomitant treatment of allergic rhinitis and allergen-specific therapy

BACKGROUND

Asthma and allergic rhinitis are 2 of the most prevalent chronic medical diseases. Asthma is estimated to affect 8% of adults and 9% of children, with nearly 300 million people affected worldwide. Poorly controlled allergic rhinitis may be associated with worsening asthma symptoms over time. Various treatments have been proposed in the improvement and prevention of asthma in children and adults with allergic symptoms, which have included pharmacotherapy with antihistamines and topical intranasal corticosteroids, as well as allergen-specific immunotherapy.

METHODS

Articles were selected through PubMed and personal knowledge of the authors based on a comprehensive literature review examining whether treatment of allergic rhinitis improves and/or prevents concomitant symptoms of asthma. The largest and highest-quality studies were included in the literature review. The search selection was not standardized. Articles written in a language other than English were excluded.

RESULTS

Clinical trials have showed improvement in asthma symptoms with concomitant treatment of allergic rhinitis with antihistamines and topical intranasal corticosteroids, though improvement in objective pulmonary function parameters has not been uniformly demonstrated with antihistamine use alone. There is very strong evidence to suggest that subcutaneous and sublingual immunotherapy may in addition prevent the progression of asthma in high-risk atopic patients by inducing immunological tolerance.

CONCLUSION

Traditional pharmacotherapy with antihistamines and topical intranasal steroids has been shown to improve allergic rhinitis symptoms with concomitant allergic asthma; however, only allergen-specific immunotherapy offers long-term control in improving asthma symptoms, exacerbations, and likely ultimate prevention in developing asthma.

Sphingolipids: a potential molecular approach to treat allergic inflammation

Allergic inflammation is an immune response to foreign antigens, which begins within minutes of exposure to the allergen followed by a late phase leading to chronic inflammation. Prolonged allergic inflammation manifests in diseases such as urticaria and rhino-conjunctivitis, as well as chronic asthma and life-threatening anaphylaxis. The prevalence of allergic diseases is profound with 25% of the worldwide population affected and a rising trend across all ages, gender, and racial groups. The identification and avoidance of allergens can manage this disease, but this is not always possible with triggers being common foods, prevalent air-borne particles and only extremely low levels of allergen exposure required for sensitization. Patients who are sensitive to multiple allergens require prophylactic and symptomatic treatments. Current treatments are often suboptimal and associated with adverse effects, such as the interruption of cognition, sleep cycles, and endocrine homeostasis, all of which affect quality of life and are a financial burden to society. Clearly, a better therapeutic approach for allergic diseases is required. Herein, we review the current knowledge of allergic inflammation and discuss the role of sphingolipids as potential targets to regulate inflammatory development in vivo and in humans. We also discuss the benefits and risks of using sphingolipid inhibitors.

The united allergic airway: connections between allergic rhinitis, asthma, and chronic sinusitis

BACKGROUND

The united allergic airway is a theory that connects allergic rhinitis (AR), chronic rhinosinusitis, and asthma, in which seemingly disparate diseases, instead of being thought of separately, are instead viewed as arising from a common atopic entity.

OBJECTIVE

This article describes patients with such diseases; explores ideas suggesting a unified pathogenesis; elucidates the various treatment modalities available, emphasizing nasal corticosteroids and antihistamines; and provides an update of the literature.

METHODS

A literature review was conducted.

CONCLUSION

The aggregation of research suggests that AR, asthma, and chronic rhinosinusitis are linked by the united allergic airway, a notion that encompasses commonalities in pathophysiology, epidemiology, and treatment.

Comparison of leukotriene receptor antagonists and anti-histamines as an add-on therapy in patients with asthma complicated by allergic rhinitis

Patients with asthma are often complicated by allergic rhinitis, and the intimate pathophysiological association between allergic rhinitis and asthma often imposes a significant morbidity on affected individuals. The present study was conducted to assess the clinical efficacies of leukotriene receptor antagonists (LTRAs) and anti-histamines on asthma as an add-on therapy in patients with asthma complicated by allergic rhinitis. Consecutive patients with asthma were recruited to fill in systematic self-administered questionnaires concerning symptoms and conditions related to asthma and allergic rhinitis. The questionnaire was conducted twice, one month apart, and the attending physicians gave detailed information on disease control and medications on both occasions. In the study 3,140 patients with asthma participated, and 634 had concomitant allergic rhinitis (mean age: 53.1, 389 female). The second survey disclosed that treatment with LTRAs or anti-histamines had been added in 26 patients and 19 patients, respectively, without any changes in other medications. There were no significant differences in age, gender, severity of disease, or baseline treatments. The initial survey indicated that the patients who were treated with LTRAs had significantly more severe asthma-related symptoms (i.e. wheeze, cough and sleep disturbance) and experienced greater dissatisfaction with the treatment than did those who were treated with anti-histamines. The second survey disclosed significant reductions in sneezing (p=0.03), rhinorrhea (p=0.01), dyspnea (p=0.046), sleep disturbance (p=0.02), over-all asthma symptoms (p=0.013), and an improvement in satisfaction with treatment (p=0.019) in patients to whom LTRAs were added-on, whereas the patients receiving anti-histamines reported no significant changes in these symptoms. These results suggest that LTRAs are more effective than anti-histamines as an add-on therapy in symptomatic patients with asthma complicated by allergic rhinitis.

C-027 inhibits IgE-mediated passive sensitization bronchoconstriction and acts as a histamine and serotonin antagonist in human airways

Atopic asthma is poorly controlled by current therapies. Newer therapies and novel antihistamines are, therefore, required to treat patients whose atopic asthma is not controlled. For the first time, C-027 is shown to antagonize histamine, IgE-mediated and serotonin-induced contraction in human airways and vessels. Human precision-cut lung slices (PCLS, 250 μm thick), containing an airway or blood vessel, were pretreated with either C-027 (2 hours) or with vehicle alone and were contracted with histamine or serotonin. Known antihistamine was used as a comparator in antihistamine studies. Also, human airways were contracted via IgE passive sensitization in the presence or absence of C-027 or fexofenadine. Affinity of C-027 toward human G-protein coupled receptors was also determined, as well as the drug's biodistribution in murine model. C-027 was shown to have the highest affinity toward human histamine and serotonin receptors. Subsequently, C-027 was shown to antagonize histamine- and serotonin-induced airway and vascular smooth muscle contraction, respectively, and histamine-released bronchocontraction mediated by IgE passive sensitization in human small airways. C-027 also inhibited histamine-mediated single-cell calcium ion release. Low levels of C-027 were found in murine brain tissue. Collectively, these data suggest that C-027 markedly inhibits IgE-induced bronchoconstriction and antagonizes histamine and serotonin-contraction with little biodistribution in the brain. The compound may offer a future therapy for allergen-induced airway hyperresponsiveness in patients with asthma.

The role of histamine in asthma

Histamine is a ubiquitous inflammatory mediator intimately associated with the pathology of allergy. Traditional antihistamines, targeting the histamine H1 receptor, have failed to demonstrate a significant role for histamine in asthma. Novel immunomodulatory roles for histamine and the discovery of a novel histamine receptor, the histamine H4 receptor, have resulted in a reassessment of its importance in asthma.

Computer-based decision support for pediatric asthma management: description and feasibility of the Stop Asthma Clinical System

Clinical guidelines can assist in the management of asthma. Decision support systems (DSSs) can enhance adherence to clinical guidelines but tend not to provide clinicians with cues for behavioral change strategies to promote patient self-management. The Stop Asthma Clinical System (SACS) is a DSS designed for this purpose. To assess feasibility, seven clinicians used SACS to guide well visits with 26 predominantly persistent pediatric asthma patients. Data were collected via survey and in-depth semi-structured interviews. SACS improved assessment of asthma severity and control, classification of and intervention in medicine and environmental trigger management problems, and development of an action plan (all p < 0.05). Clinician-patient communication was enhanced. The primary challenge was that SACS increased clinic visit time. SACS can enhance clinician behavior to improve patient asthma self-management, but more studies are indicated to mitigate temporal constraints and evaluate impact on clinician and patient communication and behavior as well as clinical outcomes.

Comparison of cetirizine-pseudoephedrine and placebo in patients with seasonal allergic rhinitis and concomitant mild-to-moderate asthma: randomized, double-blind study

BACKGROUND

Allergic rhinitis (AR) and asthma are common concurrent conditions.

OBJECTIVES

To evaluate the effects of cetirizine hydrochloride (5 mg)-pseudoephedrine hydrochloride (120 mg) (cetirizine-D) twice daily on AR and asthma symptoms, pulmonary function, and asthma-related quality of life in 274 patients with confirmed seasonal AR and concomitant mild-to-moderate asthma.

METHODS

In this multicenter, randomized, double-blind, placebo-controlled study, after a 1-week screening period, patients took cetirizine-D or placebo for 4 weeks. The primary efficacy variable, AR total symptom severity complex score, was derived from patient daily diary ratings of sneezing, runny nose, itchy nose, postnasal drip, and nasal congestion. Asthma symptom severity total scores were derived from twice-daily diary ratings of wheezing, coughing, shortness of breath, and chest tightness. Pulmonary function was tested at clinic visits and by patients each morning and evening. Patients completed the Asthma Quality of Life Questionnaire at each visit. All tests were 2-sided, with statistical significance at the .05 level.

RESULTS

Cetirizine-D reduced total symptom severity complex scores by 42.3% overall vs 23.6% with placebo (P < .001). Asthma symptom severity total scores were significantly improved with cetirizine-D at most times vs placebo. Cetirizine-D treatment was also associated with significantly improved Asthma Quality of Life Questionnaire overall scores. Pulmonary function test results were neutral. Cetirizine-D was well tolerated, with discontinuation and adverse event rates similar to placebo. Somnolence occurred in 8 patients (5.8%) taking cetirizine-D and in 1 (0.7%) taking placebo.

CONCLUSIONS

Treatment with cetirizine-D twice daily significantly reduced rhinitis and asthma symptoms and improved overall asthma quality of life in patients with seasonal AR and concomitant mild-to-moderate asthma.

Addition of fexofenadine to inhaled corticosteroid therapy to reduce inflammatory biomarkers in atopic asthma

BACKGROUND

We previously showed that H1-antihistamines may shift the PC20 (provocation concentration that caused a decrease in forced expiratory volume in 1 second of 20%) threshold to adenosine monophosphate (AMP) challenge but may paradoxically prolong recovery.

OBJECTIVES

To measure AMP recovery using a constant predetermined AMP PC20 and to evaluate whether fexofenadine use confers add-on effects to treatment with either fluticasone propionate alone or combined fluticasone propionate-salmeterol.

METHODS

Fourteen atopic patients with mild-to-moderate asthma (forced expiratory volume in 1 second of 76%) completed a double-blind, randomized, crossover study consisting of 3-week treatment blocks of either fluticasone propionate-salmeterol, 250 microg twice daily, or fluticasone propionate alone, 250 microg twice daily, in conjunction with either fexofenadine, 180 mg once daily, or matched placebo. Recovery after a predetermined AMP PC20 challenge was measured (primary outcome), along with exhaled nitric oxide levels, plasma eosinophil cationic protein levels, peripheral eosinophil counts, pulmonary function, diary card outcomes, and quality of life (all secondary outcomes).

RESULTS

There were no differences in any of the primary or secondary outcomes when fexofenadine was added to treatment with either fluticasone propionate-salmeterol or fluticasone propionate alone. The mean AMP recovery time was 25.0 vs 23.4 minutes for fexofenadine and placebo, respectively, as add-on to fluticasone-salmeterol and 22.5 vs 23.9 minutes, respectively, as add-on to fluticasone alone.

CONCLUSION

Fexofenadine did not affect recovery to a fixed dose of AMP challenge or any other surrogate inflammatory markers when given as add-on therapy to corticosteroid-treatedatopic asthmatic patients.

Second-generation antihistamines in asthma therapy: is there a protective effect?

Second-generation histamine H(1) receptor antagonists are recognized as being highly effective treatments for allergic-based disease and are among the most frequently prescribed drugs in the world. The newer antihistamines represent a heterogeneous group of compounds with markedly different chemical structures, a spectrum of antihistaminic properties, adverse effects, half-life, tissue distribution, metabolism and varying degrees of anti-inflammatory effects. Histamine is an important mast cell- and basophil-derived mediator that has been implicated in the pathogenesis of asthma, resulting in smooth muscle contraction, mucus hypersecretion, and increased vascular permeability leading to mucosal edema. Antihistamines should never be used as monotherapy for asthma but there is evidence that these drugs give a measure of protection in histamine-induced bronchoconstriction. Furthermore, several studies have demonstrated that the use of second-generation antihistamines, as adjunct therapy, may benefit those patients whose allergic asthma co-exists with allergic rhinitis. Indeed, many patients present with both allergic rhinitis and asthma. The link between the upper and lower respiratory airways is now well established and there is increasing evidence that allergic rhinitis is a risk factor for the development of asthma. More recently, a number of novel antihistamines have been developed which are either metabolites of active drugs or enantiomers and there is emerging evidence that at least one of these drugs, desloratadine, may give significant symptomatic benefit in some types of asthma. It is of interest to note that cetirizine provides a primary pharmacological intervention strategy to prevent the development of asthma in specifically-sensitized high risk groups of infants. Moreover, the documented anti-inflammatory activities of antihistamines may provide a novel mechanism of action for the therapeutic control of virus-induced asthma exacerbations by inhibiting the expression of intercellular adhesion molecule-1 (ICAM-1) by airway epithelial cells. Finally, several well-conducted studies suggest that combination therapy with antihistamines and antileukotrienes may be as effective as corticosteroid use in patients with allergic asthma and seasonal allergic rhinitis.

Histamine in allergic inflammation and immune modulation

Histamine, originally considered as a mediator of acute inflammatory and immediate hypersensitivity responses has also been demonstrated to affect chronic inflammation and regulate several essential events in the immune response. On the other hand, various cytokines control histamine synthesis, release and expression of histamine receptors (HRs). The cells involved in the regulation of immune response and hematopoiesis express HRs and also secrete histamine, which can selectively recruit the major effector cells into tissue sites and affect their maturation, activation, polarization and effector functions leading to chronic inflammation. Histamine, acting through its receptor type 2, positively interferes with the peripheral antigen tolerance induced by T regulatory cells in several pathways. Histamine also regulates antigen-specific Th1 and Th2 cells, as well as related antibody isotype responses. The diverse effects of histamine on immune regulation are due to differential expression and regulation of four HRs and their distinct intracellular signals. In addition, differences in affinities of these receptors are highly decisive on the biological effects of histamine and agents that target HRs. This article highlights the findings leading to a change of perspective in histamine immunobiology.

Cetirizine: a review of its use in allergic disorders

Cetirizine is a selective, second-generation histamine H1 receptor antagonist, with a rapid onset, a long duration of activity and low potential for interaction with drugs metabolised by the hepatic cytochrome P450 system. Cetirizine was generally more effective than other H1 receptor antagonists at inhibiting histamine-induced wheal and flare responses. Cetirizine is an effective and well tolerated agent for the treatment of symptoms of seasonal allergic rhinitis (SAR), perennial allergic rhinitis (PAR) and chronic idiopathic urticaria (CIU) in adult, adolescent and paediatric patients. In adults with these allergic disorders, cetirizine was as effective as conventional dosages of ebastine (SAR, PAR, CIU), fexofenadine (SAR), loratadine (SAR, CIU) or mizolastine (SAR). This agent was significantly more effective, and with a more rapid onset of action, than loratadine in 2-day studies in environmental exposure units (SAR). In paediatric patients, cetirizine was as at least as effective as chlorphenamine (chlorpheniramine) [SAR], loratadine (SAR, PAR) and oxatomide (CIU) in the short term, and more effective than oxatomide and ketotifen (PAR) in the long term. Cetirizine was effective in reducing symptoms of allergic asthma in adults and reduced the relative risk of developing asthma in infants with atopic dermatitis sensitised to grass pollen or house dust mite allergens. It had a corticosteroid-sparing effect in infants with severe atopic dermatitis and was effective in ameliorating reactions to mosquito bites in adults. Cetirizine was well tolerated in adults, adolescents and paediatric patients with allergic disorders. In adult, adolescent and paediatric patients aged 2-11 years, the incidence of somnolence with cetirizine was dose related and was generally similar to that with other second-generation H1 receptor antagonists. Although, its sedative effect was greater than that of fexofenadine in some clinical trials and that of loratadine or fexofenadine in a postmarketing surveillance study. In infants aged 6-24 months, the tolerability profile of cetirizine was similar to that of placebo. Cetirizine did not have any adverse effects on cognitive function in adults, or cognitive function, behaviour or achievement of psychomotor milestones in paediatric patients. Cetirizine was not associated with cardiotoxicity.

CONCLUSION

Cetirizine is well established in the treatment of symptoms of SAR, PAR or CIU. It demonstrated a corticosteroid-sparing effect and reduced the relative risk of developing asthma in sensitised infants with atopic dermatitis. Cetirizine was effective in the treatment of allergic cough and mosquito bites; however, its precise role in these indications has yet to be clearly established. On the basis of its favourable efficacy and tolerability profile and rapid onset of action, cetirizine provides an important option for the treatment of a wide range of allergic disorders.

Development of an expert system knowledge base: a novel approach to promote guideline congruent asthma care

Existing guidelines for the clinical management of asthma provide a good framework for such tasks as diagnosing asthma, determining severity, and prescribing pharmacological treatment. Guidance is less explicit, however, about establishing a patient-provider partnership and overcoming barriers to asthma management by patients in a way that can be easily adopted in clinical practice. We report herein the first developmental phase of the "Stop Asthma" expert system. We describe the establishment of a knowledge base related to both the clinical management of asthma and the enhancement of patient and family self-management (including environmental management). The resultant knowledge base comprises 142 multilayered decision rules that describe clinical and behavioral management in three domains: 1) determination of asthma severity and control; 2) pharmacotherapy, including prescription of medicine for chronic maintenance, acute exacerbation, exercise pretreatment, and rhinitis relief; and 3) patient self-management, including the process of intervening to facilitate the patient's asthma medication management, environmental control, and well-visit scheduling. The knowledge base provides a systematic and accessible approach for intervening with family asthma-related behaviors.

Rhinitis therapy and the prevention of hospital care for asthma: a case-control study

BACKGROUND

Although clinical trials have demonstrated that rhinitis therapy improves subjective and objective measures of asthma, it is uncertain whether treatment of allergic rhinitis significantly affects the frequency of asthma exacerbations.

OBJECTIVE

The objective of this study was to determine whether treatment with intranasal corticosteroids and/or second-generation antihistamines is associated with changes in rates of asthma exacerbations resulting in emergency room visits and/or hospitalizations in patients with asthma and allergic rhinitis.

METHODS

This was a nested, case-control study.

RESULTS

Treatment with either nasal corticosteroids or second-generation antihistamines was associated with a lower risk of asthma-related emergency room treatment and hospitalization (adjusted odds ratio [OR], 0.51; 95% CI, 0.34 to 0.77 and 0.34, 0.18 to 0.62, respectively). Patients who used nasal corticosteroids had a significantly lower risk of both asthma-related emergency room treatment and hospitalization (adjusted OR, 0.75; 95% CI, 0.62 to 0.91 and 0.56, 0.42 to 0.76, respectively), whereas there was a trend toward lower risk of emergency room treatment and hospitalization in patients who used second-generation antihistamines (adjusted OR, 0.88; 95% CI, 0.62 to 1.26 and 0.68, 0.40 to 1.14, respectively). Combined treatment with both medications was associated with a further lowering of the risk of both emergency room treatment and hospitalization (adjusted OR, 0.37; 95% CI, 0.19 to 0.73 and 0.22, 0.07 to 0.63).

CONCLUSIONS

In patients with asthma, treatment of concomitant allergic rhinitis was associated with significant reductions in risk of emergency room treatment and hospitalization for asthma.

Practice parameters in pediatric allergy

The primary role of practice parameter/guidelines and other boundaries developed for the field of medicine is to improve the quality of patient care. Practice parameters/guidelines are also important for education, interaction with managed care and third-party payers, establishing appropriate variables for outcome assessment, reducing inappropriate variation in clinical practice, and resolving medical-legal issues. National specialty organizations, the American Medical Association, and government agencies have been actively involved in developing and promoting practice parameters. These documents provide a framework within which pediatricians can provide the best quality of care for their patients.

Prospects for antihistamines in the treatment of asthma

Antihistamines have been evaluated as potential therapies for asthma for more than 50 years. With first-generation compounds, side effects prevented effective dosing. By reviewing published studies of the effectiveness of terfenadine, cetirizine, and loratadine in clinical asthma, evidence for the relevant effect of the second-generation antihistamines on bronchial asthma can be found. Terfenadine, at doses of 120 or 180 mg twice a day, reduced symptoms and improved pulmonary function in mild and moderate allergic asthma but was ineffective in severe perennial asthma. Fexofenadine at doses used for allergic rhinitis had little effect on seasonal allergic asthma. Research is ongoing to determine the effects of higher doses of fexofenadine. In 5 studies, cetirizine at doses of 10 to 20 mg, once or twice daily, consistently improved asthma symptoms compared with placebo or terfenadine 60 mg twice a day in 2 cases, whereas in 2 studies, loratadine at doses of 10 to 20 mg daily has not produced significant improvement in asthma. However, loratadine 5 mg combined with 60 mg of pseudo-ephedrine twice a day significantly improved both asthma symptoms and peak expiratory flow. Similarly, the combination of loratadine 20 mg and the leukotriene-receptor antagonist montelukast improved asthma symptoms, peak expiratory flow, and beta-agonist use over montelukast alone. Therefore, there might be a role for second- and third-generation antihistamines in treating mild and moderate asthma, which might require administering doses greater than those commonly used to treat allergic rhinitis. If higher doses are sedative, the addition of decongestants or leukotriene-receptor antagonists might enhance the effects of lower doses of the antihistamines.

H1-receptors: localization and role in airway physiology and in immune functions

Histamine H(1)-receptors are involved in the pathologic processes of allergy. Clinical trials of H(1)-receptor antagonists have demonstrated the efficacy of these agents in reducing the sneezing, pruritus, and rhinorrhea associated with allergic rhinitis. In the lung, H(1)-receptors mediate the bronchoconstrictive effects of histamine and increase vascular permeability, which lead to plasma exudation. H(1)-receptors are present on T cells, B cells, monocytes, and lymphocytes, and stimulation of these receptors induces pro-inflammatory effects. It has been suggested that a signal from the H(1)-receptor contributes to the antigen receptor-mediated signaling pathways that induce proliferative responses and lead to the production of cytokines and antibodies by T cells and B cells, respectively. It would appear, therefore, that the H(1)-receptor has a wider role in inflammatory processes than simply mediating the actions of histamine.

Efficacy and safety of budesonide inhalation powder (Pulmicort Turbuhaler) during 52 weeks of treatment in adults and children with persistent asthma

BACKGROUND

Inhaled corticosteroids are the agents of choice for treating persistent asthma.

OBJECTIVE

To evaluate the long-term efficacy and safety of budesonide inhalation powder (Pulmicort Turbuhaler) in patients with mild to severe persistent asthma.

METHODS

Patients (n=1133) received open-label budesonide (dose range, 100-800 microg b.i.d.) for 52 weeks following 2 weeks to 5 months of treatment in one of four double-blind, placebo-controlled studies. Patients, identified before the double-blind studies, included adults (n=249) not receiving corticosteroids, adults (n=384) and children (n=356) previously maintained on inhaled corticosteroids, and adults (n=144) previously maintained on oral corticosteroids.

RESULTS

Mean forced expiratory volume in 1 sec was 68.2% of predicted normal (n=1133) at baseline (mean from two visits before randomization), 74.4% (n=1132) at the end of double-blind treatment, 81.3% (n=971) at week 52, and 80.1% (n=1125) at last observation (including patients who discontinued early). Sixty-four patients maintained on oral corticosteroids before double-blind treatment entered the open-label study off oral corticosteroids, 58 of whom (91%) remained oral corticosteroid-free throughout the study. There was no evidence of basal or cosyntropin-stimulated hypothalamic-pituitary-adrenal axis function suppression, and the most commonly occurring adverse events were respiratory infection, sinusitis, and pharyngitis.

CONCLUSIONS

During this 52-week, open-label study, budesonide maintained the improved pulmonary function and decreased oral corticosteroid use observed during previous double-blind treatment and was well tolerated, supporting its long-term use in adults and children with mild to severe persistent asthma.

Disruption of L-histidine decarboxylase reduces airway eosinophilia but not hyperresponsiveness

Histamine has a variety of airway actions and is considered to be an important mediator in asthma. This study examined the role of endogenous histamine in allergic airway eosinophil recruitment and hyperresponsiveness using L-histidine decarboxylase gene knockout mice. Histamine levels of the airways in L-histidine decarboxylase knockout mice were largely diminished compared with wild-type mice. Inhalation challenge with ovalbumin (OVA) in OVA-sensitized wild-type mice caused eosinophil accumulation in the lung as well as airway hyperresponsiveness to methacholine 3 days after the challenge. The eosinophil recruitment was significantly reduced in the knockout mice. In the bone marrow, the proliferation of eosinophils was enhanced after OVA challenge in the wild-type mice; however, the proliferation was significantly reduced in the knockout mice. The induction of P-selectin in the lung after OVA challenge was also inhibited in the knockout mice. In contrast, airway hyperresponsiveness was not suppressed in the knockout mice. These results suggest that endogenous histamine is involved in the accumulation of eosinophils into the airways after allergic challenge, possibly acting in the bone marrow and producing P-selectin in the airways. Furthermore, allergen-induced airway hyperresponsiveness appeared to occur independently of airway eosinophilia in our present model.

Role of histamine in the pathophysiology of asthma: immunomodulatory and anti-inflammatory activities of H1-receptor antagonists

Cumulative clinical and laboratory evidence on histamine and its actions suggests that it has a pathophysiologic role in asthma. These findings have renewed interest in the potential therapeutic role of H1 antihistamines in this disease. A murine model of allergen-induced airway inflammation and methacholine-induced airway hyperresponsiveness has been used to clarify mechanisms of airway function, to identify potential therapeutic targets, and to investigate the effects of the H1-receptor antagonist fexofenadine. Findings suggest that there may be a role for second-generation antihistamines in treating asthma, with patient selection as well as dosing both important therapeutic considerations. Because high-dose therapy may be required to achieve a clinical response, agents with the widest therapeutic window and the lowest potential for sedation would offer the greatest therapeutic potential.

Are antihistamines useful in managing asthma?

There continues to be a great deal of interest in the anti-asthmatic role of antihistamines. Antihistamines have recently been shown to have anti-inflammatory properties that are more extensive than simply the blocking of histamine receptors. For example, new evidence suggests that the suppression of cell adhesion molecule expression occurs with these drugs. The anti-inflammatory and anti-asthmatic effects of antihistamines have been evaluated in patients with both allergic asthma and rhinitis, given the established association between allergic inflammation of the upper and lower airways, with evidence to suggest that antihistamines have clinically relevant anti-asthmatic properties. As well as conferring benefits in asthma symptom control and the measurement of lung function, studies assessing the effect of histamine receptor antagonists on bronchial hyperresponsiveness suggest that there is bronchoprotection during both methacholine and mannitol challenges. Recently, there has also been considerable interest in the effect of combining an antihistamine with a leukotriene receptor antagonist. This combination has an anti-asthmatic effect that is greater than that of either drug given alone and may be comparable to inhaled corticosteroid therapy.

Rhinitis, sinusitis and asthma: one linked airway disease

Understanding the relationship between upper and lower airways has greatly increased through epidemiological and pharmacological studies. Scientific evidence supports the concept that rhinosinusitis and asthma may be the expression of an inflammatory process which appears in different sites of the respiratory tract at different times. The implications are not only academic but are important for diagnostic and therapeutic purposes.

A self-management program for adult asthma. III. Maintenance and relapse of skills

Patient self-management programs have become an integral part of asthma treatment. The goal of such programs is to strengthen the partnership between patients and health care providers in controlling the condition. The present study analyzed how well patients maintained or relapsed in performing asthma self-management skills over time and across settings. It was conducted by contacting patients who had been involved in a successful self-management program an average of 6 years after their participation or an average of 7 years after they completed training. Seventy percent of the patients agreed to participate and complete, either by themselves or over the telephone, a structured interview regarding their experiences in performing asthma self-management. On the basis of their responses, 53 participants were categorized into two groups: continuers or relapsers, according to previously developed and published criteria for relapse. Characteristics that distinguished the two groups were described. As anticipated, those classified as continuers reportedly exhibited broader repertoires of self-management skills across an array of settings. They credited their performance with maintaining control over their asthma. However, two unexpected findings emerged in the study: First, all patients continued to use self-management skills to one degree or another 7 years after they had acquired these skills. Even patients who were categorized as relapsers regularly performed some self-management skills, often involving self-monitoring of their breathing. Second, half of the patients in the relapse group reported that their asthma was in remission and that they were asymptomatic. The self-management skills they reportedly used were performed to monitor and prevent a return of asthma.

New insights into the second generation antihistamines

Second generation antihistamines are recognised as being highly effective treatments for allergy-based disease and are among the most frequently prescribed and safest drugs in the world. However, consideration of the therapeutic index or the benefit/risk ratio of the H1 receptor antagonists is of paramount importance when prescribing this class of compounds as they are used to treat non-life threatening conditions. There are many second generation antihistamines available and at first examination these appear to be comparable in terms of safety and efficacy. However, the newer antihistamines in fact represent a heterogeneous group of compounds, having markedly differing chemical structures, adverse effects, half-life, tissue distribution and metabolism, spectrum of antihistaminic properties, and varying degrees of anti-inflammatory effects. With regard to the latter, there is growing awareness that some of these compounds might represent useful adjunct medications in asthma therapy. In terms of safety issues, the current second generation grouping includes compounds with proven cardiotoxic effects and others with the potential for adverse drug interactions. Moreover, some of the second generation H1 antagonists have given cause for concern regarding their potential to cause a degree of somnolence in some individuals. It can be argued, therefore, that the present second generation grouping is too large and indistinct since this was based primarily on the concept of separating the first generation sedating compounds from nonsedating H1 antagonists. Although it is too early to talk about a third generation grouping of antihistamines, future membership of such a classification could be based on a low volume of distribution coupled with a lack of sedating effects, drug interactions and cardiotoxicity.

Do antihistamines have a role in asthma therapy?

The coexistence of allergic rhinitis with asthma is widely recognized by clinicians. Histamine, a common mediator for both diseases, has a substantial role in the pathophysiology of asthma through its ability to produce smooth muscle contraction and promote vascular permeability. Because antihistamines often are administered to manage allergic rhinitis symptoms, the effects of antihistamines in asthma should be evaluated. The usefulness of first-generation antihistamines is limited by their side-effect profile, namely sedation and cognitive impairment. Second-generation antihistamines have only a modest effect in attenuating bronchospasm induced by histamine, cold air, exercise, and allergen bronchoprovocation, suggesting that second-generation antihistamines do not have a direct role as a single agent for treating asthma. Studies have shown that controlling allergic rhinitis with antihistamines has a small, indirect effect in improving asthma symptoms. Future work should be directed at improving the potency of antihistamines and defining their antiinflammatory activity.

Allergic inflammation in upper and lower airways

OBJECTIVE

The primary reason for this review is to discuss the relationship between upper and lower airways at various levels with the emphasis on common pathophysiologic mechanisms, and how treatment of the upper airways will benefit the lower airways.

DATA SOURCES

The main source of information is derived from original articles and books, with an extensive bibliography included.

STUDY SELECTION

Studies were derived almost exclusively from articles and reviews in peer-reviewed journals.

RESULTS

The prevalence of rhinitis and asthma are both increasing. Common to both the upper and lower airways are the triggers, many of the inflammatory cells and mediators, and the treatment modalities. By contrast, there are organ-specific differences in the reaction to various stimuli in the nose or lung, with each organ manifesting its own vocabulary of response.

CONCLUSIONS

There are meaningful relationships between upper and lower airways at various levels of our understanding. Differential responses to medications help us better understand pathogenic mechanisms in rhinitis and asthma. Further, treatment of the upper airways provides additional benefit to the lower airways.

Linking upper and lower airways

BACKGROUND

Upper and lower airways are similar in many ways, including common triggers, pathogenic mechanisms, and response to treatment. Explanations for the posed linkage between upper and lower airways include nasal-bronchial reflux, postnasal drainage of inflammatory material into the lower airways, and dry air impinging on the nasal mucosa.

CONCLUSION

Treatment modalities such as antihistamines and corticosteroid aerosols by the nasal route improve both the upper and lower airways.

Impact of cetirizine on the burden of allergic rhinitis

OBJECTIVE

The goals of this article include the reporting of the epidemiology, economic and medical impact of allergic rhinitis. In addition, the pharmacology and clinical profile of the therapeutic agent cetirizine are reviewed.

DATA SOURCES

A detailed literature search was conducted. References are limited to the English language and human subjects and tissues. Studies considered relevant and important over the past 20 years are highlighted.

STUDY SELECTION

Prevalence and morbidity data were chosen from more recent assessments. Because cetirizine is a relatively new compound, studies from the past several years from peer-reviewed journals have been emphasized.

RESULTS

Allergic rhinitis affects between 15% and 25% of the US general population. It shares common pathophysiologic mechanisms with conjunctivitis and asthma and predisposes to nasal infections, otitis media, sinusitis, nasal polyposis, and orthodontic malocclusions. Direct medical care costs amount to up to 3 billion dollars every year. In addition, the quality of life of affected individuals is substantially compromised. Cetirizine is a potent H1-receptor antagonist and has anti-inflammatory properties. It does not interact with concomitantly administered medications, has no cardiac adverse effects, and does not appear to be associated with teratogenicity. Impairment of CNS function is comparable to other low-sedating antihistamines at the recommended dose of 10 mg daily for adults. Its clinical efficacy for allergic respiratory diseases has been established in numerous trials.

CONCLUSIONS

Allergic rhinitis causes considerable suffering. Cetirizine, with a fine risk-benefit ratio, can be a most valuable therapeutic option.

Is antihistamine (H1-receptor antagonist) therapy useful in clinical asthma?

Airway hyperresponsiveness to histamine is a hallmark of asthma, and histamine inhalation reproduces asthma symptoms. Plasma histamine concentrations are elevated during the early and late responses to inhaled allergens, and may also increase during spontaneous acute asthma episodes. Ordinary doses of currently available antihistamines (H1-receptor antagonists) have minimal bronchodilator and bronchoprotective activity. In severe persistent asthma, H1 antagonists have no significant clinical effect. In moderate persistent asthma, clinical benefits of H1 antagonists are apparent, but may not be worth the potential risks of the higher-than-usual doses required. When mild seasonal asthma and allergic rhinitis coexist, however, relief of rhinitis symptoms with H1 antagonists administered in ordinary dose is associated with significant improvement in asthma symptoms.