Long acting beta-agonists versus theophylline for maintenance treatment of asthma

Aerosol deposition and airflow dynamics in healthy and asthmatic human airways during inhalation

Inhalation of aerosols such as pharmaceutical aerosols or virus aerosol uptake is of great concern to the human population. To elucidate the underlying aerosol dynamics, the deposition fractions (DFs) of aerosols in healthy and asthmatic human airways of generations 13-15 are predicted. The Navier-stokes equations governing the gaseous phase and the discrete phase model for particles' motion are solved using numerical methods. The main forces responsible for deposition are inertial impaction forces and complex secondary flow velocities. The curvatures and sinusoidal folds in the asthmatic geometry lead to the formation of complex secondary flows and hence higher DFs. The intensities of complex secondary flows are strongest at the generations affected by asthma. The DF in the healthy airways is 0%, and it ranges from 1.69% to 52.93% in the asthmatic ones. From this study, the effects of the pharmaceutical aerosol particle diameters in the treatment of asthma patients can be established, which is conducive to inhibiting the inflammation of asthma airways. Furthermore, with the recent development of COVID-19 which causes pneumonia, the predicted physics and effective simulation methods of bioaerosols delivery to asthma patients are vital to prevent the exacerbation of the chronic ailment and the epidemic.

The Treatment of Mild and Moderate Asthma in Adults

BACKGROUND

Asthma is a chronic inflammatory airway disease that usually causes variable airway obstruction. It affects 5-10% of the German population.

METHODS

This review is based on relevant publications retrieved by a selective search, as well as on national and international guidelines on the treatment of mild and moderate asthma in adults.

RESULTS

The goal of treatment is to attain optimal asthma control with a minimal risk of exacerbations and mortality, loss of pulmonary function, and drug side effects. This can be achieved with a combination of pharmacotherapy and non-drug treatment including patient education, exercise, smoking cessation, and rehabilitation. Pharmacohterapy is based on inhaled corticosteroids (ICS) and bronchodilators. It is recommended that mild asthma should be treated only when needed, either with a fixed combination of ICS and formoterol or with short-acting bronchodilators. For moderate asthma, maintenance treatment is recommended, with an inhaled fixed combinations of ICS and long-acting beta-mimetics, possibly supplemented with longacting anticholinergic agents. Allergen immunotherapy, i.e., desensitization treatment, should be considered if the allergic component of asthma is well documented and the patient is not suffering from uncontrolled asthma. Asthma control should be monitored at regular intervals, and the treatment should be adapted accordingly.

CONCLUSION

The treatment of asthma in adults should be individually tailored, with anti-inflammatory treatment as its main component.

Janeva E, Arsovska A, Isjanovski V. The influence of inhaled corticosteroids on asthma control test in smokers and non-smokers with asthma

Smoking in asthmatics is responsible for the worsening of asthma symptoms, more frequent asthma exacerbations and hospitalizations and lowered quality of life. In smoking asthmatics the designated doses of the inhaled corticosteroid treatment are usually insufficient to accomplish total asthma control. Out of 54 screened adult patients up to 50 years old with mild asthma, 38 were involved in the study. They were divided in two groups: smokers and non-smokers. They received a total daily dosage of 500 µg of inhaled fluticasone propionate. A rescue medication, a short-acting ß2 agonist (salbutamol) in a dosage of 0.1 mg/per inhaled dose, was used when needed. Asthma was diagnosed by a positive metacholine provocation test and/or a positive bronchodilatator response. An asthma control test i.e. the ACT-TM questionnaire was performed before the beginning of the study and 6 weeks after the treatment with fluticasone propionate of the previous corticosteroid-naive patients. A statistically positive response (p<0.05) was reached in favor of non-smoking asthmatics. It can be concluded that ACT is a reliable tool to assess the effect of the topical corticosteroid treatment in non-smoking and smoking asthmatics. An achievement of better asthma control could be expected among both of the examined groups, but the effect of the intervention in the therapy is estimated to be more expressed within the group of asthmatic non-smokers. In smoking asthmatics there is a need for other therapeutic modalities such as increasing the dosage of inhaled corticosteroids, usage of combination therapy and/or adding low doses of aminophylline.

The Saudi Initiative for Asthma - 2016 update: Guidelines for the diagnosis and management of asthma in adults and children

This is an updated guideline for the diagnosis and management of asthma, developed by the Saudi Initiative for Asthma (SINA) group, a subsidiary of the Saudi Thoracic Society. The main objective of SINA is to have guidelines that are up to date, simple to understand and easy to use by nonasthma specialists, including primary care and general practice physicians. SINA approach is mainly based on symptom control and assessment of risk as it is the ultimate goal of treatment. The new SINA guidelines include updates of acute and chronic asthma management, with more emphasis on the use of asthma control in the management of asthma in adults and children, inclusion of a new medication appendix, and keeping consistency on the management at different age groups. The section on asthma in children is rewritten and expanded where the approach is stratified based on the age. The guidelines are constructed based on the available evidence, local literature, and the current situation in Saudi Arabia. There is also an emphasis on patient-doctor partnership in the management that also includes a self-management plan.

The Saudi initiative for asthma - 2012 update: Guidelines for the diagnosis and management of asthma in adults and children

This an updated guidelines for the diagnosis and management of asthma, developed by the Saudi Initiative for Asthma (SINA) group, a subsidiary of the Saudi Thoracic Society. The main objective of SINA is to have updated guidelines, which are simple to understand and easy to use by non-asthma specialists, including primary care and general practice physicians. This new version includes updates of acute and chronic asthma management, with more emphasis on the use of Asthma Control Test in the management of asthma, and a new section on "difficult-to-treat asthma." Further, the section on asthma in children was re-written to cover different aspects in this age group. The SINA panel is a group of Saudi experts with well-respected academic backgrounds and experience in the field of asthma. The guidelines are formatted based on the available evidence, local literature, and the current situation in Saudi Arabia. There was an emphasis on patient-doctor partnership in the management that also includes a self-management plan. The approach adopted by the SINA group is mainly based on disease control as it is the ultimate goal of treatment.

An integrative review of systematic reviews related to the management of breathlessness in respiratory illnesses

BACKGROUND

Breathlessness is a debilitating and distressing symptom in a wide variety of diseases and still a difficult symptom to manage. An integrative review of systematic reviews of non-pharmacological and pharmacological interventions for breathlessness in non-malignant disease was undertaken to identify the current state of clinical understanding of the management of breathlessness and highlight promising interventions that merit further investigation.

METHODS

Systematic reviews were identified via electronic databases between July 2007 and September 2009. Reviews were included within the study if they reported research on adult participants using either a measure of breathlessness or some other measure of respiratory symptoms.

RESULTS

In total 219 systematic reviews were identified and 153 included within the final review, of these 59 addressed non-pharmacological interventions and 94 addressed pharmacological interventions. The reviews covered in excess of 2000 trials. The majority of systematic reviews were conducted on interventions for asthma and COPD, and mainly focussed upon a small number of pharmacological interventions such as corticosteroids and bronchodilators, including beta-agonists. In contrast, other conditions involving breathlessness have received little or no attention and studies continue to focus upon pharmacological approaches. Moreover, although there are a number of non-pharmacological studies that have shown some promise, particularly for COPD, their conclusions are limited by a lack of good quality evidence from RCTs, small sample sizes and limited replication.

CONCLUSIONS

More research should focus in the future on the management of breathlessness in respiratory diseases other than asthma and COPD. In addition, pharmacological treatments do not completely manage breathlessness and have an added burden of side effects. It is therefore important to focus more research on promising non-pharmacological interventions.

Theophylline

Theophylline (3-methyxanthine) has been used to treat airway diseases for over 70 years. It was originally used as a bronchodilator but the relatively high doses required are associated with frequent side effects, so its use declined as inhaled β₂-agonists became more widely used. More recently it has been shown to have anti-inflammatory effects in asthma and COPD at lower concentrations. The molecular mechanism of bronchodilatation is inhibition of phosphodiesterase(PDE)3 and PDE4, but the anti-inflammatory effect may be due to histone deacetylase (HDAC) activation, resulting in switching off of activated inflammatory genes. Through this mechanism theophylline also reverses corticosteroid resistance and this may be of particular value in severe asthma and COPD where HDAC2 activity is markedly reduced. Theophylline is given systemically (orally as slow-release preparations for chronic treatment and intravenously for acute exacerbations of asthma) and blood concentrations are determined mainly by hepatic metabolism, which may be increased or decreased in several diseases and by concomitant drug therapy. Theophylline is now usually used as an add-on therapy in asthma patients not well controlled on inhaled corticosteroids and in COPD patients with severe disease not controlled by bronchodilator therapy. Side effects are related to plasma concentrations and include nausea, vomiting and headaches due to PDE inhibition and at higher concentrations to cardiac arrhythmias and seizures due to adenosine A₁-receptor antagonism.

Inhaled Corticosteroids

Inhaled corticosteroids (ICS) are the most effective controllers of asthma. They suppress inflammation mainly by switching off multiple activated inflammatory genes through reversing histone acetylation via the recruitment of histone deacetylase 2 (HDAC2). Through suppression of airway inflammation ICS reduce airway hyperresponsiveness and control asthma symptoms. ICS are now first-line therapy for all patients with persistent asthma, controlling asthma symptoms and preventing exacerbations. Inhaled long-acting β₂-agonists added to ICS further improve asthma control and are commonly given as combination inhalers, which improve compliance and control asthma at lower doses of corticosteroids. By contrast, ICS provide much less clinical benefit in COPD and the inflammation is resistant to the action of corticosteroids. This appears to be due to a reduction in HDAC2 activity and expression as a result of oxidative stress. ICS are added to bronchodilators in patients with severe COPD to reduce exacerbations. ICS, which are absorbed from the lungs into the systemic circulation, have negligible systemic side effects at the doses most patients require, although the high doses used in COPD has some systemic side effects and increases the risk of developing pneumonia.

Potential adverse effects of bronchodilators in the treatment of airways obstruction in older people: recommendations for prescribing

Asthma and chronic obstructive pulmonary disease (COPD) are common disorders that are associated with increasing morbidity and mortality in older people. Bronchodilators are used widely in patients with these conditions, but even when used in inhaled form can have systemic as well as local effects. Older people experience more adverse drug effects because of pharmacodynamic and pharmacokinetic changes and particularly drug-drug and drug-disease interactions. Cardiovascular disease is common in older people and beta-adrenoceptor agonists (beta-agonists) have inotropic and chronotropic effects that can increase arrhythmias and cardiomyopathy. They can also worsen or induce myocardial ischaemia and cause electrolyte disturbances that contribute to arrhythmias. Tremor is a well known distressing adverse effect of beta-agonist administration. Long-term beta-agonist use can be associated with tolerance, poor disease control, sudden life-threatening exacerbations and asthma-related deaths. Functional beta2-adrenoceptors are present in osteoblasts, and chronic use of beta-agonists has been implicated in osteoporosis. Inhaled anticholinergics are usually well tolerated but may cause dry mouth, which can be troublesome in older people. Pupillary dilatation, blurred vision and acute glaucoma can occur from escape of droplets from loosely fitting nebulizer masks. Although ECG changes have not been seen in randomized controlled trials of long-acting inhaled anticholinergics, supraventricular tachycardias have been observed in a 5-year randomized controlled trial of ipratropium bromide. Paradoxical bronchoconstriction can occur with inhaled anticholinergics as well as with beta-agonists, but tolerance has not been reported with anticholinergics. Anticholinergic drugs also cause central effects, most notably impairment of cognitive function, and these effects have been noted with inhaled agents. Use of theophylline is limited by its adverse effects, which range from commonly occurring gastrointestinal symptoms to palpitations, arrhythmias and reports of myocardial infarction. Seizures have been reported, but are rare. Theophylline is metabolized primarily by the liver, and commonly interacts with other medications. Its concentration in plasma should be monitored closely, especially in older people. Although many clinical trials have been conducted on bronchodilators in obstructive airways disease, the results of these clinical trials need to be interpreted with caution as older people are often under-represented and subjects with co-morbidities actively excluded from these trials.

MK-0873, a PDE4 inhibitor, does not influence the pharmacokinetics of theophylline in healthy male volunteers

BACKGROUND

MK-0873 is a novel selective phosphodiesterase-4 inhibitor, which has been in development for the treatment of chronic obstructive pulmonary disease (COPD). In this indication, theophylline is still an important treatment, despite its relatively small therapeutic window. In view of this, it is important to investigate whether MK-0873 could affect the pharmacokinetics, safety and tolerability of theophylline, when both drugs are given concomitantly.

AIM

The objective of this study was to investigate the effect of multiple doses of oral MK-0873, a selective phosphodiesterase-4 inhibitor, on the pharmacokinetics, safety and tolerability profile of orally administered theophylline in healthy volunteers.

METHODS

Eight healthy, non-smoking male subjects participated in this randomized, open-label, 2-period, cross-over study. In one period subjects received an oral dose of 2.5mg MK-0873 for 6 days co-administered with a single oral dose of 250 mg theophylline on day 5. The other period consisted of a single dose of 250 mg theophylline on day 1. In each period, blood samples were collected at predefined time points to evaluate theophylline pharmacokinetics.

RESULTS

All subjects completed the study. The study medications were generally well tolerated and no clinically relevant changes were observed in either treatment periods. No significant difference was found in the AUC 0-infinity (77.7 vs. 83.8h ng/ml; p=0.280) and Cmax (6.70 vs. 7.77 ng/ml; p=0.125) of theophylline between the MK-0873+theophylline and theophylline only treatment, and bioequivalence was demonstrated for AUC0-infinity (geometric mean ratio with 90% confidence interval: 0.930 (0.826, 1.047)).

CONCLUSION

In this study, in a limited number of subjects, co-administration of oral MK-0873 did not affect the pharmacokinetics, safety, and tolerability of oral theophylline in non-smoking healthy male subjects.

Long-acting beta2-agonists versus theophylline for maintenance treatment of asthma

BACKGROUND

Theophylline and long acting beta-2 agonists are bronchodilators used for the management of persistent asthma symptoms, especially nocturnal asthma. They represent different classes of drug with differing side-effect profiles.

OBJECTIVES

To assess the comparative efficacy, safety and side-effects of long-acting beta-2 agonists and theophylline in the maintenance treatment of adults and adolescents with asthma.

SEARCH STRATEGY

We searched the Cochrane Airways Group trials register and reference lists of articles. We also contacted authors of identified RCTs for other relevant published and unpublished studies and pharmaceutical manufacturers. Most recent search: November 2006.

SELECTION CRITERIA

All included studies were RCTs involving adults and children with clinical evidence of asthma. These studies must have compared oral sustained release and/or dose adjusted theophylline with an inhaled long-acting beta-2 agonist.

DATA COLLECTION AND ANALYSIS

In original review, two reviewers independently assessed trial quality and extracted data, similarly in this update two reviewers undertook this. Study authors were contacted for additional information.

MAIN RESULTS

Thirteen studies with a total of 1344 participants met the inclusion criteria of the review. They were of varying quality. There was no significant difference between salmeterol and theophylline in FEV(1) predicted (6.5%; 95% CI -0.84 to 13.83). However, salmeterol treatment led to significantly better morning PEF (mean difference 16.71 L/min, 95% CI 8.91 to 24.51) and evening PEF (mean difference 15.58 L/min, 95% CI 8.33 to 22.83). Salmeterol also reduced the use of rescue medication. Formoterol, used in two studies was reported to be as effective as theophylline. Bitolterol, used in only one study, was reported to be less effective than theophylline. Participants taking salmeterol experienced fewer adverse events than those using theophylline (Parallel studies: Relative Risk 0.44; 95% CI 0.30 to 0.63, Risk Difference -0.11; 95% CI -0.16 to -0.07, Numbers Needed to Treat (NNT) 9; 95% CI 6 to 14). Significant reductions were reported for central nervous system adverse events (Relative Risk 0.50; 95% CI 0.29 to 0.86, Risk Difference -0.07; 95% CI -0.12 to -0.02, NNT 14; 95% CI 8 to 50) and gastrointestinal adverse events (Relative Risk 0.30; 95% CI 0.17 to 0.55, Risk Difference -0.11; 95% CI -0.16 to -0.06, NNT 9; 95% CI 6 to 16).

AUTHORS' CONCLUSIONS

Long-acting beta-2 agonists, particularly salmeterol, are more effective than theophylline in improving morning and evening PEF, but are not significantly different in their effect on FEV1. There is evidence of decreased daytime and nighttime short-acting beta-2 agonist requirement with salmeterol. Fewer adverse events occurred in participants using long-acting beta-2 agonists (salmeterol and formoterol) as compared to theophylline.

The mechanisms, diagnosis, and management of severe asthma in adults

There has been a recent increase in the prevalence of asthma worldwide; however, the 5-10% of patients with severe disease account for a substantial proportion of the health costs. Although most asthma cases can be satisfactorily managed with a combination of anti-inflammatory drugs and bronchodilators, patients who remain symptomatic despite maximum combination treatment represent a heterogeneous group consisting of those who are under-treated or non-adherent with their prescribed medication. After excluding under-treatment and poor compliance, corticosteroid refractory asthma can be identified as a subphenotype characterised by a heightened neutrophilic airway inflammatory response in the presence or absence of eosinophils, with evidence of increased tissue injury and remodelling. Although a wide range of environmental factors such as allergens, smoking, air pollution, infection, hormones, and specific drugs can contribute to this phenotype, other features associated with changes in the airway inflammatory response should be taken into account. Aberrant communication between an injured airway epithelium and underlying mesenchyme contributes to disease chronicity and refractoriness to corticosteroids. The importance of identifying underlying causative factors and the recent introduction of novel therapeutic approaches, including the targeting of immunoglobulin E and tumour necrosis factor alpha with biological agents, emphasise the need for careful phenotyping of patients with severe disease to target improved management of the individual patient's needs.

Inhaled beta2-adrenoceptor agonists: cardiovascular safety in patients with obstructive lung disease

Although large surveys have documented the favourable safety profile of beta(2)-adrenoceptor agonists (beta(2)-agonists) and, above all, that of the long-acting agents, the presence in the literature of reports of adverse cardiovascular events in patients with obstructive airway disease must induce physicians to consider this eventuality. The coexistence of beta(1)- and beta(2)-adrenoceptors in the heart clearly indicates that beta(2)-agonists do have some effect on the heart, even when they are highly selective. It should also be taken into account that the beta(2)-agonists utilised in clinical practice have differing selectivities and potencies. beta(2)-agonist use has, in effect, been associated with an increased risk of myocardial infarction, congestive heart failure, cardiac arrest and sudden cardiac death. Moreover, patients who have either asthma or chronic obstructive pulmonary disease may be at increased risk of cardiovascular complications because these diseases amplify the impact of these agents on the heart and, unfortunately, are a confounding factor when the impact of beta(2)-agonists on the heart is evaluated. Whatever the case may be, this effect is of particular concern for those patients with underlying cardiac conditions. Therefore, beta(2)-agonists must always be used with caution in patients with cardiopathies because these agents may precipitate the concomitant cardiac disease.

Sleep and medical disorders

Extensive evidence links cardiovascular disease and sleep disordered breathing. OSA has adverse effects on blood pressure, cardiovascular status,and mortality. Effective CPAP therapy can improve blood pressure and cardiac function in patients who have OSA. Patients who have congestive heart failure have a high prevalence of sleep-disordered breathing, with OSA occurring in 30% of such patients and Cheyne-Stokes respiration in 40%.CPAP is the preferred mode of therapy for both types of sleep-disordered breathing in patients who have coexistent congestive heart failure. Nocturnal worsening of asthma is a common manifestation of this disease that indicates increased disease severity. Therapy focuses on judicious use of long-acting bronchodilators, and the presence of OSA should also be considered. COPD is frequently associated with impaired sleep, likely because of chronic dyspnea and sleep-associated hypoxemia. Appropriate therapy again includes long-acting bronchodilators and possibly nocturnal supplemental oxygen. Gastroesophageal reflux during sleep may lead to prolonged episodes of esophageal acid exposure and may be a common sequela of OSA, perhaps triggering nocturnal worsening of asthma. Endstage renal disease and chronic dialysis are commonly associated with a host of troublesome sleep problems,including OSA, RLS, PLMD, and daytime sleepiness.

Long-acting beta2-agonists in asthma: an overview of Cochrane systematic reviews

According to major asthma management guidelines, long-acting beta2-agonists (LABAs) should be used only when asthma remains symptomatic in patients already receiving regular inhaled corticosteroids (ICSs). A large Cochrane systematic review provides evidence that LABAs are safe and beneficial in control of asthma; sub-group analyses indicating that this is true when ICSs are used and in their absence. Two other Cochrane systematic reviews have found that LABAs are more effective than regular short-acting beta2-agonists, and are as effective as theophylline with fewer side-effects. These reviews support guidelines in the use of LABA as additional therapy when asthma is inadequately controlled by ICS at moderate dose. However, guidelines may be too conservative, and more studies in stable mild asthma comparing their use and safety with placebo and ICS are required.

Management of paediatric asthma

Paediatric asthma best practice not only includes prescribing the correct therapeutic mix based on consensus guidelines, but also reducing therapy once control has been achieved. Clinicians should also be aware that asthma in young children is a heterogeneous entity, and a beneficial response to bronchodilators and/or inhaled steroids is not inevitable. In general, preschool children and infants should not be prescribed inhaled corticosteroids above 200 microg beclometasone dipropionate equivalent twice a day, or regular oral steroids, or long acting beta2-adrenoceptor agonists. New therapies such as anti-IgE antibodies are on the horizon, but these are unlikely to replace the established drug combinations. More likely is that the delivery of established drugs will become more convenient (for example, once a day inhaled corticosteroids, or season dependent prophylactic therapy).

Newer drugs for asthma

Several new drugs have resulted from innovative pharmacological and immunomodulatory approaches towards treatment of asthma. Diverse therapeutic targets have provided new agents. The new classes of drugs available are newer "on site activated inhaled corticisteroids" and soft steroids, anti IgE compounds, leukotriene inhibitors and single isomer agents which are available for clinical use. Anti interleukin agents and phosphodiesterase inhibitors are in the stage of clinical trials. Antisense therapy and pharmacogenetics are the on horizon for treatment of asthma.

Long-acting beta2-agonists or leukotriene receptor antagonists as add-on therapy to inhaled corticosteroids for the treatment of persistent asthma

It is well accepted that the combination of inhaled corticosteroids (ICSs) and long-acting beta2-agonists (LABAs) is effective in achieving asthma control, as it treats both components of asthma pathophysiology, namely inflammation and smooth muscle dysfunction of the airways. Leukotriene receptor antagonists (LTRAs) can also be used as add-ons to ICS therapy in patients whose asthma is not controlled by ICSs alone. The purpose of this review is to compare the effectiveness of ICSs plus LABAs with that of ICSs plus LTRAs for the treatment of persistent asthma that is not controlled by ICSs alone. Several studies have shown that, in comparison with an ICS plus an LTRA, the addition of an LABA to ICS therapy provides greater improvements in pulmonary function and overall control of asthma as measured by use of rescue medication and the number of exacerbations of the asthma, symptom-free days and symptom-free nights. The greater improvements in pulmonary function observed with an ICS plus the LABA, salmeterol, occurred within the first week of treatment (at first treatment assessment), and remained significantly greater than those achieved with an ICS plus an LTRA over the duration of the treatment. Moreover, the salmeterol-fluticasone propionate combination (SFC) produces consistently greater improvements in pulmonary lung function and control of asthma than does the addition of an LTRA to fluticasone propionate. In addition, SFC is a more cost-effective treatment option than fluticasone propionate plus montelukast for patients with asthma that is uncontrolled by ICSs alone. Important cost savings can be made with SFC in clinical practice compared with other combinations of ICSs plus salmeterol or ICSs plus LTRAs.

Management of asthma in adults: current therapy and future directions

Asthma is increasing in prevalence worldwide and results in significant use of healthcare resources. Although most patients with asthma can be adequately treated with inhaled corticosteroids, an important number of patients require additional therapy and an increasing number of options are available. A further minority of patients develop severe persistent asthma which remains difficult to manage despite current pharmacological therapies. This review discusses the various treatment options currently available for each stage of asthma severity, highlights some of the limitations of current management, and outlines directions which may improve the management of asthma in the future.