Inhaled Beta 2-adrenergic Agonist Research Articles

Pharmacological treatment of asthma and allergic diseases in pregnancy

Allergy incidence in pregnancy is about 20% and frequently observed as rhinitis and asthma. Asthma often coexists with allergic rhinitis in adults, and severe nasal findings are present in one out of every three pregnant women. Asthma and allergic rhinitis may worsen or remain unchanged in pregnancy. Allergic reactions can also worsen the course of pregnancy. Appropriate drug selection should be made for asthma and other allergic diseases, and possible risks should be explained to the pregnant woman. Increased risk perception of drug use may cause the pregnant woman to stop taking the drug suddenly and the disease to worsen. The purpose of the treatment in pregnancy is controlling the mother's disease while ensuring a normal course of fetal development. Treatment should be started with the least number of drugs and the lowest dose possible. Inhaled beta-2 adrenergic agonists and theophylline can be used as bronchodilators during pregnancy. Chlorpheniramine, loratadine and cetirizine may be preferred in allergic conditions requiring antihistamine use. Prednisone and also pseudoephedrine can be used during pregnancy, if necessary. The use of alpha-adrenergic drugs other than pseudoephedrine and epinephrine should be avoided except for anaphylaxis.

Effect of Montelukast 10 mg in Elderly Patients with Mild and Moderate Asthma Compared with Young Adults. Results of a Cohort Study

Background:The clinical characteristics and physio-pathogenic mechanisms of asthma in patients older than 60 years appear to differ from the behavior described for other age groups. Therefore, the effectiveness of medications for elderly patients with asthma should not be extrapolated from studies conducted on teenagers or young adults.Objective: The study aimed to establish the clinical effect of montelukast 10 mg in elderly patients with mild and moderate asthma compared to its effect on young adults.Method:A prospective cohort study was conducted during 12 weeks of follow-up, which consecutively included the total population of adult patients attended by a group of 21 general practitioners, between July and December 2016. Young adults (18-59 years) and older adults were included (60 years or older) with mild or moderate asthma, which, according to the criteria of his treating physician, had been prescribed montelukast 10 mg/day. The variables of interest were: use of inhaled corticosteroids during the last month, use of inhaled beta-2 adrenergic agonists as a rescue in the last month, having attended the emergency service during the last month due to an asthma attack, presence of wheezing in the physical examination, the number of attacks in the last month and the number of days without symptoms in the last month.Results:A total of 126 patients entered the cohort and 104 completed the follow-up, of which 29% were older adults. On admission, 65.4% of patients (68/104) had used rescue inhaled beta2 in the last month and had been using schemes with corticosteroids. After 12 weeks of follow-up, 58.1% (43/74) of the young adults required treatment schedules with corticosteroids, while in the elderly, only 36.7% of the patients (11/30) required this treatment scheme (p-value: 0.047). Regarding the use of rescue inhaled beta-2 at 12 weeks, 55% of young adults reported using them, compared to 33.3% of older adults (p-value: 0.041).Conclusion:In this cohort of patients, treated with montelukast 10 mg/day for 12 weeks, there was a reduction of broncho-obstructive symptoms and exacerbations of the disease. In older adults compared to young adults, a greater reduction in the use of beta2 agonists rescue medications and in the concomitant use of inhaled corticosteroid schemes was documented.

Fluoropolymer-associated illness

Context: Isolated outbreaks of respiratory illness associated with fluoropolymer-containing products, such as waterproofing agents and sealants, have occurred for many years in many different countries. Despite this, an assured mechanism of illness is not defined, representing a barrier to the prevention of future occurrences. Objective: To discuss the epidemiology of the respiratory illness outbreaks, proposed mechanisms of toxicity and clinical outcomes from exposure to these products. Methods: We performed a literature review using OVID Medline (January 1946 through December 2012) and PubMed (January 1950 through December 2012) using the search terms “fluoropolymer”, “fluorochemical”, “leather proofing”, “leather protectant”, “weatherproofing agent”, and “waterproofing agent”. Bibliographies of identified articles were screened for additional relevant studies, including non-indexed reports. Results: Fluoropolymer-associated respiratory illnesses often resemble polymer fume fever: acute respiratory symptoms predominate and are accompanied by flu-like symptoms. Outbreaks occasionally follow marketing of a new or reformulated product. Treatment with basic and supportive measures is sufficient in many cases, including fresh air and supplemental oxygen. Inhaled beta-2 adrenergic agonists and corticosteroids have been used. Toxicity may result from the fluoropolymer itself or the solvent in which it is delivered. Factors which may influence toxicity include fluoropolymer particle size, emission rate, methods of application, environmental conditions, and personal health. Conclusion: Exposure to fluoropolymer-containing waterproofing agents can cause lung injury and usually produce abrupt onset of respiratory and flu-like symptoms. Most victims improve with supportive care and supplemental oxygen. Serious outcomes, including acute respiratory distress syndrome and death, are uncommon. Proprietary information on the exact composition of most fluoropolymer-containing products is often unavailable, and this hinders identification of an exact cause of disease. The etiology is most likely multifactorial. Future research should focus on determining the exact mechanism of illness and establishing safe exposure limits.

The 167th Scientific Meeting of the Taiwan Pediatric Association and Continuing Medical Education-Clinical Use of Long-Acting Selective Beta-2 Adrenergic Agonists in the Treatment of Asthmatic Patient

The introduction of long-acting β2-agonists, salmeterol and formoterol, represents a significant milestone in anti-asthma treatment. Both are highly selective, potent, long-acting inhaled beta-2 adrenergic agonists indicated for the long-term maintenance treatment of asthma and prevention of bronchospasm in patients with reversible obstructive airway disease. Salmeterol is a partial agonist and formoterol is a full agonist. Formoterol has a rapid onset of action than salmeterol after aerosol delivery and has prolonged bronchodilator action only after inhalation. When given orally, it has the same duration of action as salbutamol. Monotherapy with long-acting, β2-agonists has limited or no anti-inflammatory effect in asthma. The two long-acting β2-agonists should be used in patients when inhaled steroids do not give them a good symptomatic control. The long-acting β2-agonists also have a protective effect on nocturnal asthma and a prolonged protection on exercise induced asthma.

Management of asthma exacerbations

The 1997 Expert Panel Report 2 from the National Asthma Education and Prevention Program details principles and goals for managing asthma exacerbations, based on scientific literature and the opinion of the panel. The panel's recommendations are summarized here, along with approaches to the evaluation and management of patients with asthma exacerbations. Methods to assess and classify the severity of asthma exacerbations are discussed, and treatment objectives for mild, moderate, and severe exacerbations are presented, along with a discussion of postinfectious acute airway hyperresponsiveness. A review of pharmacologic agents used in the treatment of asthma exacerbations is also included. Key points in the management of asthma exacerbations include the notion that early treatment is the best strategy for management. Important elements of early treatment include recognition of early signs of worsening asthma, a written action plan to guide patient self-management, appropriate intensification of therapy, and prompt communication between patient and provider about deterioration in asthma control. Other key points include the use of inhaled beta 2-adrenergic agonists to provide prompt relief of airflow obstruction, the early use of systemic corticosteroids for patients with moderate to severe exacerbations or for patients who fail to respond promptly and completely to an inhaled beta 2-adrenergic agonist, and monitoring response to therapy with serial measurements of lung function.

Potential for Tolerance, Morbidity, and Mortality Resulting From Regular Use of β2-Adrenergic Agonists in Asthma

The inhaled beta 2-adrenergic agonists form the mainstay of therapy for mild to moderate asthma. They are also highly effective for the management of exercise-induced asthma and nocturnal symptoms of the disease. Mounting evidence suggests that these agents may have the potential for the development of tolerance, particularly to their bronchodilating effects, and this tolerance may be associated with increases in asthma-related morbidity and mortality, though this link remains controversial. However, experience to date indicates that the beta-agonists do not share the same propensity to cause tolerance. Instead, tolerance appears to be more closely associated with the regular use of these drugs rather than their PRN use. Furthermore, clinically relevant tolerance is more likely in patients who are treated regularly with high doses of a bronchodilator for long periods. Current therapeutic recommendations suggest that inhaled beta-agonists should be used on a PRN basis when possible and that the lowest effective doses should be administered.

Acute severe asthma.

Preview How can the severity of an acute episode of asthma be assessed? What is a reasonable approach to corticosteroid administration in acute severe asthma? For which patients should mechanical ventilation be considered? The answers to these and other questions can be found in this guide to the evaluation and management of potentially fatal exacerbations of asthma.

Exercise-induced asthma

Bronchoconstriction associated with exercise can occur in nearly all individuals with asthma and in 35-40% of those with allergic rhinitis/hay fever symptoms. This represents approximately 12-15% of the population. Exercise-induced asthma (EIA) is a clinical syndrome characterized by transient airflow obstruction typically 5-15 min after cessation of physical exertion. Symptoms may include chest tightness, breathlessness, coughing, and/or wheezing. Some individuals may experience delayed bronchoconstriction (late phase response) 6-10 h after completing exercise. Approximately 40-50% of those with asthma exhibit a "refractory period", i.e., diminished bronchoconstriction to exercise performed within 2 h. The pathophysiology of EIA is related to thermal events within the intrathoracic airways. Alterations in the temperature of the airways and/or osmolarity in the epithelial lining fluid cause release of mediators in the airways and the development of bronchoconstriction. Although EIA can be strongly suspected by an appropriate history, pulmonary function testing is necessary to make a specific diagnosis. Measurement of lung function is an important first diagnostic test. If there is no evidence of airflow obstruction at rest, then either bronchoprovocation testing or exercise challenge testing is indicated. Nonpharmacologic therapy includes "warm-up" exercise prior to training or competition to induce a "refractory period" and to prevent/reduce bronchoconstriction. An inhaled beta 2-adrenergic agonist, e.g., albuterol, is usually effective for preventing/treating EIA. Cromolyn sodium is an alternative class of medication that inhibits both the early and late phase responses. Other bronchodilator agents are available if combination therapy with an inhaled beta 2-adrenergic agonist and cromolyn sodium is not effective.(ABSTRACT TRUNCATED AT 250 WORDS)

A Placebo-controlled Dose-finding Study With Bambuterol in Elderly Patients With Asthma

A new long-acting bronchodilator prodrug, bambuterol hydrochloride, was tested in a randomized, crossover, and double-blind study in elderly asthmatic patients (aged 64 to 82 years). They received placebo and 5-mg, 10-mg, and 20-mg tablets once daily for a week at each dose. The plasma concentration of the active metabolite, terbutaline, increased linearly with the dose of drug (p < 0.001). Peak expiratory flow rate increased with dose in the morning (p < 0.001 for 10-mg and 20-mg doses) and afternoon (p < 0.05 for 10 mg; p < 0.001 for 20 mg) and was different from placebo for the 10-mg/d and 20-mg/d regimens. The use of supplemental inhaled beta 2-adrenergic agonist therapy was reduced during the night for the 10-mg (p < 0.05) and 20-mg (p < 0.01) doses in comparison to placebo. No significant effects of treatment on blood pressure and pulse were demonstrated. Tremor and palpitations were mild and related to the dose. These data suggest that treatment once daily with bambuterol hydrochloride in a dose of 10 or 20 mg improves pulmonary function and is well tolerated as bronchodilator therapy in elderly patients with asthma.

Metabolic Effects of Inhaled Fenoterol in Normal Subjects

Although the hypokalemic effect of inhaled beta 2-adrenergic agonists has been well documented, little is known as to their effect on plasma magnesium. We therefore examined in ten healthy young volunteers the effect of the inhalation of 2 mg of nebulized fenoterol on plasma potassium (Kpl), plasma magnesium (Mgpl), and intraerythrocytic magnesium (MgIE) levels, as well as on plasma insulin and C peptide concentrations, measured before and serially up to 110 min after fenoterol inhalation. In all subjects, fenoterol inhalation caused a reversible reduction in Kpl (range, 0.2 to 1.1 mEq/L), which was progressive, reaching a statistically significant nadir 30 to 60 min following fenoterol inhalation (largest dip in Kpl, 0.55 +/- 0.29 mEq/L; p < 0.05). The nadir in Kpl levels was preceded by a peak in plasma insulin levels in all subjects. No significant changes in Mgpl or MgIE were observed in any of the subjects. We conclude that fenoterol inhaled at a dosage used in clinical practice significantly reduces Kpl but not Mgpl nor MgIE levels in healthy subjects, indicating a lower sensitivity of Mg++ ions to beta 2-adrenergic stimulation than K+ ions. Beta 2-adrenergic-induced insulin secretion probably contributes to the hypokalemic effect of inhaled fenoterol.

Salmeterol, a new inhaled beta 2-adrenergic agonist, has a longer blocking effect than albuterol on hyperventilation-induced bronchoconstriction

The duration of the blocking effect of salmeterol (50 μg), albuterol (200 μg), and a placebo were compared in a double-blind study in 12 adult subjects with asthma who underwent hyperventilation tests with cold dry air (−20°C) on 4 study days. On the first day, the hyperventilation test was performed at various time intervals (baseline, 1,4, 6, 8, 12, and 24 hours) with spontaneous functional recovery between each test to determine the within-day within-subject variability of the response. The response was assessed by interpolating the dose of cold dry air causing a 20% fall in FEV 1. On the 3 remaining days, separated by an interval of at least 5 days, the active or placebo medication was administered after spontaneous recovery from the first hyperventilation test. Spirometry was assessed 15 minutes and 1 hour later. The hyperventilation test was then performed and repeated 4 hours after administration of the drug. The test was repeated 6, 8, 12, and 24 hours later to detect any significant blocking effect. The improvement in FEV 1 15 minutes and 1 hour after the drug was administered was 19.8% and 20.4%, as compared to baseline for albuterol, and 16.3% and 16.8% for salmeterol (not significant). The mean duration of the blocking effect was 0.25 hour for the placebo, 3.5 hours for albuterol, and 15.9 hours for salmeterol ( F = 24.5; p < 0.001; Newman-Keul's test was significant for every contrast). Eight of the 12 subjects still demonstrated some blocking effect 8 hours after taking salmeterol; this was true for only one subject receiving albuterol. We conclude that salmeterol has a significantly longer effect than albuterol on bronchoconstriction induced by hyperventilation.

629 Formoterol a new inhaled beta-2 adrenergic agonist has a longer blocking effect than albuterol on bronchoconstriction induced by hyperventilation

BACKGROUND: Medications can modulate the results of skin prick tests (SPTs). Short-term corticosteroid therapy does not alter IgE-mediated skin tests, but the impact of long-term oral corticosteroid therapy on SPT results is unclear. A prospective study was carried out in patients with steroid-dependent asthma who received oral corticosteroids for a long period to determine whether this treatment reduced skin test reactivity. METHODS: Thirty-three patients with steroid-dependent asthma (median age, 59 years) were compared with 66 patients with asthma who served as a control group, matched for age, sex, and atopic status. SPTs with codeine phosphate and a screening battery of standardized allergen extracts were performed before commencement and after at least 1 year of daily oral prednisone treatment (median duration, 2 years; median daily dose, 20 mg). RESULTS: Fifteen patients with corticosteroid-dependent asthma were allergic before treatment, and their sensitization was not changed by long-term treatment with oral corticosteroids. The median wheal diameters induced by codeine phosphate were similar in both groups. The median wheal diameters induced by allergens, and more specifically, by Dermatophagoides pteronyssinus and D. farinae were similar in both groups and did not change in the steroid group after treatment. CONCLUSIONS: Systemic corticosteroid therapy (prednisone, 10 to 60 mg/day) for 2 or more years does not seem to alter SPT reactivity. (J ALLERGY CLIN IMMUNOL 1996;98:522-7.)