Immunomodulation by theophylline in asthma. Demonstration by withdrawal of therapy

Possible Treatment Approaches of Sulfur Mustard-Induced Lung Disorders, Experimental and Clinical Evidence, an Updated Review

Sulfur mustard (SM) is one of the major potent chemical warfare that caused the death of victims in World War I and the Iraq-Iran conflict (1980-1988). The respiratory system is the main target of SM exposure and there are no definitive therapeutic modalities for SM-induced lung injury. The effects of the new pharmaceutical drugs on lung injury induced by SM exposure were summarized in this review. Literature review on PubMed, ScienceDirect, and Google Scholar databases was performed to find papers that reported new treatment approach on SM-exposure-induced injury in the respiratory system until October 2019. The search was restricted to sulfur mustard AND induced injury (in vitro studies, animal experiments, and clinical trials) AND respiratory system OR lung, AND treatment in all fields. Two hundred and eighty-three relevant articles were identified that 97 retrieved articles were eligible and were included in the review. Some new pharmaceutical drugs have shown therapeutic potential in controlling various characteristics of lung injury due to SM exposure. Recent studies showed therapeutic effects of mucolytic drugs, non-steroidal drugs, and antibiotics on reducing lung inflammation, oxidative stress responses, and modulating of the immune system as well as improving of respiratory symptoms and pulmonary function tests. Studies on the therapeutic effects of new agents with amelioration or treatment of SM-induced lung injury were reviewed and discussed.

A Disposable Sensor Chip Using a Paste Electrode with Surface-Imprinted Graphite Particles for Rapid and Reagentless Monitoring of Theophylline

This work focuses on a carbon-based imprinted polymer composite, employed as a molecular recognition and sensing interface in fabricating a disposable electrochemical sensor. The carbon-paste electrode was made of a molecularly imprinted polymer comprising a copolymer of methacrylic acid as the functional monomer and blended crosslinking monomers of N,N′-methylenebisacrylamide, and ethylene glycol dimethacrylate, with theophylline as the template. The analytical properties of the proposed theophylline sensor were investigated, and the findings revealed an increase in differential pulse voltammetric current compared to the non-imprinted electrode. Under optimized conditions, the sensor has shown high sensitivity, high selectivity, lower detection limit (2.5 µg/mL), and satisfactory long-term stability. Further, the sensor was tested in whole bovine blood and validated without any matrix effect and cross-reactivity. Additionally, chronoamperometry of the sensor chip supported a rapid determination of THO with a short response time of 3 s. This carbon-paste electrode is highly specific for theophylline and may be applied as a drug sensor for clinical use.

Effect of Liver Cirrhosis on Theophylline Trough Concentrations: A Comparative Analysis of Organ Impairment Using Child-Pugh and MELD Scores

AIMS

Theophylline clearance is known to be reduced in patients with chronic liver diseases (CLDs) such as chronic hepatitis (CH) and liver cirrhosis (LC). The Child-Pugh (CP) score is generally used for pharmacokinetic evaluation, whilst a model for end-stage liver disease (MELD) has not yet been fully evaluated. This study aimed to predict theophylline clearance in patients with LC classified based on CP and MELD scores by population pharmacokinetic (PPK) analysis.

METHODS

PPK analysis included 433 steady-state trough concentrations from 192 Japanese bronchial asthma patients with and without CLDs and was performed using NONMEM. The severity of LC was assessed by CP and MELD scores.

RESULTS

The final CP and MELD models which described apparent theophylline clearance (CL/F) were obtained. The CP model showed that the mean CL/F in patients without CLDs, CH patients, and LC patients with CP class A, B, and C was 0.0473, 0.0413, 0.0330, 0.0280, and 0.0209 L/h kg-1, respectively. The MELD model predicted that CL/F in patients without CLDs, CH patients, and LC patients with MELD scores of < 10, 10-14, 15-19, 20-24, and ≥ 25 was 0.0472, 0.0413, 0.0324, 0.0268, 0.0230, 0.0197, and 0.0155 L/h kg-1, respectively.

CONCLUSIONS

CL/F in various stages of LC was evaluated, and a change in CL/F was highly dependent on the severity of CLDs in both models. The MELD model provided a more accurate and precise description of theophylline clearance in LC than the CP model, which may be due to the wider dynamic range of the MELD score.

Reduced theophylline clearance due to hepatic congestion secondary to right heart failure - A population pharmacokinetic study

Theophylline, a beneficial drug with bronchodilatory and anti-inflammatory effects, is used for the treatment of respiratory diseases. Pulmonary (PC) and hepatic congestion (HC) are secondary to the development of left- and right-sided heart failure (HF), respectively. This study aimed to evaluate the effects of PC and HC on theophylline clearance (CL) by population pharmacokinetic (PPK) analysis with consideration of the severity of HF assessed by the New York Heart Association (NYHA) functional classification. We obtained 710 minimum steady-state concentrations from 201 Japanese bronchial asthma patients with and without HF. PPK analysis was performed by NONMEM. In the analysis, the left ventricular ejection fraction, smoking (SMK), clarithromycin (CAM), sex, and age were also considered as covariates. The final model of apparent theophylline clearance (CL/F) was as follows: CL/F (L/hr/kg) = 0.0465 × 1.40^SMK × 0.870^CAM × 0.863^{HC(+)NYHA II} × 0.634^{HC(+)NYHA III} × 0.586^{HC(-)NYHA IV} × 0.467^{HC(+)NYHA IV}. SMK is a well-known factor that markedly enhances theophylline clearance through the induction of CYP1A enzymes, while CAM has been reported to inhibit CYP3A4. The final model indicates that HF patients with HC show reduced clearance of theophylline depending on the severity of HF. In this study, no effects of PC were observed.

Differences in Theophylline Clearance Between Patients With Chronic Hepatitis and Those With Liver Cirrhosis

BACKGROUND

Theophylline, a xanthine derivative drug, is used for the treatment of respiratory diseases, such as asthma, and is primarily eliminated by hepatic metabolism. There is marked interindividual variability in theophylline clearance. Therefore, the aim of this study was to evaluate the influence of chronic hepatitis (CH), liver cirrhosis (LC), and other covariates on theophylline clearance by population pharmacokinetic (PPK) analysis.

METHODS

The authors retrospectively obtained 496 trough concentrations of theophylline at steady state from 226 adult patients with bronchial asthma. The liver functions of the patients were classified into 3 categories: normal hepatic function, CH, and LC. The PPK analysis was performed using the NONMEM program. CH, LC, age, smoking status, coadministration of clarithromycin (CAM), and sex were considered as covariates that affected theophylline clearance.

RESULTS

Theophylline clearance (CL/F per kg) was significantly influenced by CH, LC, smoking, and CAM. The final model of theophylline clearance was as follows: CL/F (L/h·kg) = 0.0484 × 1.40 × 0.861 × 0.889 × 0.557. Smoking is a well-known factor that markedly enhances CL/F through the induction of CYP1A enzymes, whereas CAM has been reported to inhibit CYP3A4. The final model for hepatic function showed that CL/F in CH and LC patients was 0.043 and 0.027 L/h/kg, respectively, and it was lower than that in patients with normal hepatic function. As theophylline clearance depends on intrinsic hepatic clearance, lower CL/F in patients with LC than in those with CH may be due to a decrease in the metabolic enzymatic capability of LC patients.

CONCLUSIONS

Differences exist in theophylline clearance between CH and LC patients as per the PPK analysis.

Effects of aminophylline on airway epithelial-mesenchymal transition in brown Norway rats after repeated allergen challenge

Purpose: Chronic asthma is characterized by airway inflammation and remodeling. The aim of this study is to evaluate the effects of aminophylline on airway epithelial-mesenchymal transition (EMT). Materials and methods: Two experimental groups of brown Norway rats that were repeatedly challenged with aerosolized ovalbumin (OA) were given oral aminophylline (OA-aminophylline group) or saline only (OA-saline group). A third group was challenged by saline as a control. The rats were anesthetized and pulmonary function were performed. Immuno-histochemical staining of epithelial markers (zonula occludens-1 (ZO-1)) and mesenchymal markers (vimentin) in the airway were performed. The protein expressions of ZO-1, E-cadherin, vimentin, fibronectine, TGF-ß1, SMAD 2/3, JNK, and p38 MAPK were examined by western blot. Results: Aminophylline had beneficial effects on airway inflammation, and airway remodeling in the OA-aminophylline group compared to the OA-saline group. The OA-saline group had decreased ZO-1 but increased vimentin according to immuno-histochemical staining. The protein expression indicated decreases in ZO-1 and E-cadherin but increases in vimentin, fibronectine, TGF-ß1, SMAD 2/3, JNK, and p38 MAPK in comparison to the other two groups. The OA-aminophylline group had higher ZO-1 but lower vimentin in immuno-histochemical staining compared to the OA-saline group. The protein expression showed higher ZO-1 and E-cadherin but lower vimentin, fibronectine, TGF-ß1, SMAD 2/3, JNK, and p38 MAPK when compared to the OA-saline group. Conclusions: Ovalbumin increases airway remodeling and airway EMT. Aminophylline is effective in preventing airway remodeling and airway EMT in Brown Norway rats after repeated allergen challenge.

Effects of Tiotropium Combined with Theophylline on Stable COPD Patients of Group B, D and its Impact on Small Airway Function: A Randomized Controlled Trial

INTRODUCTION

Tiotropium bromide has been widely used in clinical practice, while theophylline is another treatment option for chronic obstructive pulmonary disease (COPD). However, only a few relevant studies have investigated the long-term outcomes and efficacy of both in patients with COPD. We evaluated the effects of tiotropium and low-dose theophylline on stable COPD patients of groups B and D.

METHODS

Eligible participants (n = 170) were randomized and received either tiotropium 18 µg once daily with theophylline 100 mg twice daily (Group I) or tiotropium 18 µg once daily (Group II) for 6 months. COPD assessment test (CAT), modified Medical Research Council (mMRC) dyspnea scores and pulmonary function tests were measured before randomization and during the treatment.

RESULTS

After 6 months of treatment, the CAT scores in both groups decreased significantly (11.41 ± 3.56 and 11.08 ± 3.05, p < 0.0001). The changes of CAT (p = 0.028) and mMRC scores (p = 0.049) between the two groups differed after 1 month of treatment. In Group I, forced expiratory flow after 25% of the FVC% predicted (MEF₂₅% pred) was significantly improved after 3 months (4.84 ± 8.73%, p < 0.0001) and 6 months (6.21 ± 8.65%, p < 0.0001). There was a significant difference in small airway function tests (MEF₅₀% pred, MEF₂₅% pred, and MMEF% pred) between the two groups after 6 month of treatment (p = 0.003, p < 0.0001, and p = 0.021, respectively).

CONCLUSIONS

Tiotropium combined with low-dose theophylline significantly improved the symptoms and general health of patients with stable COPD of groups B and D after 6 months of follow-up. Additionally, this therapy also improved the indicators of small airway function.

TRIAL REGISTRATION

Chinese Clinical Trial Registry (Registry ID: ChiCTR1800019027).

Traditional Therapies for Severe Asthma

Severe asthma is a complex and heterogeneous disease. The European Respiratory Society and American Thoracic Society guidelines define severe asthma for patients 6 years or older as "asthma which requires treatment with high-dose inhaled corticosteroids…plus a second controller or systemic corticosteroids to prevent it from becoming 'uncontrolled' or which remains 'uncontrolled' despite this therapy." This article reviews available traditional therapies, data behind their uses in severe asthma, and varying recommendations. As various asthma endotypes and phenotypes are better understood and characterized, targeted therapies should help improve disease outcomes, efficacy, and cost-effectiveness.

Bifunctional Drugs for the Treatment of Respiratory Diseases

Over the last decade, there has been a steady increase in the use of fixed dose combinations for the treatment of a range of diseases, including cancer, AIDS, tuberculosis and other infectious diseases. It is now evident that patients with asthma or chronic obstructive pulmonary disease (COPD) can also benefit from the use of fixed dose combinations, including combinations of a long-acting β₂-agonist (LABA) and an inhaled corticosteroid (ICS), and combinations of LABAs and long-acting muscarinic receptor antagonists (LAMAs). There are now also "triple inhaler" fixed dose combinations (containing a LABA, LAMA and ICS) under development and already being made available in clinical practice, with the first such triple combination having been approved in India. The use of combinations containing drugs with complementary pharmacological actions in the treatment of patients with asthma or COPD has led to the discovery and development of drugs having two different primary pharmacological actions in the same molecule that we have called "bifunctional drugs". In this review we have discussed the state of the art of bifunctional drugs that can be categorized as bifunctional bronchodilators, bifunctional bronchodilator/anti-inflammatory drugs, bifunctional anti-inflammatory drugs and bifunctional mucolytic and anti-inflammatory drugs.

Association of pre-hospital theophylline use and mortality in chronic obstructive pulmonary disease patients with sepsis

BACKGROUND

Although theophylline has been shown to have anti-inflammatory effects, the therapeutic use of theophylline before sepsis is unknown. The aim of our study was to determine the effect of theophylline on COPD patients presenting with sepsis.

METHODS

This nationwide, population-based, propensity score-matched analysis used data from the linked administrative databases of Taiwan's National Health Insurance program. Patients with COPD who were hospitalized for sepsis between 2000 and 2011 were divided into theophylline users and non-users. The primary outcome was 30-day mortality. The secondary outcome was in-hospital death, intensive care unit admission, and need for mechanical ventilation. Cox proportional hazard model and conditional logistic regression were used to calculate the risk between groups.

RESULTS

A propensity score-matched cohort of 51,801 theophylline users and 51,801 non-users was included. Compared with non-users, the 30-day (HR 0.931, 95% CI 0.910-0.953), 180-day (HR 0.930, 95% CI 0.914-0.946), 365-day (HR 0.944, 95% CI 0.929-0.960) and overall mortality (HR 0.965, 95% CI 0.952-0.979) were all significantly lower in theophylline users. Additionally, the theophylline users also had lower risk of in-hospital death (OR 0.895, 95% CI 0.873-0.918) and need for mechanical ventilation (OR 0.972, 95% CI 0.949-0.997).

CONCLUSIONS

Theophylline use is associated with a lower risk of sepsis-related mortality in COPD patients. Pre-hospital theophylline use may be protective to COPD patients with sepsis.

Xanthines and Phosphodiesterase Inhibitors

Theophylline is an orally acting xanthine that has been used since 1937 for the treatment of respiratory diseases including asthma and chronic obstructive pulmonary disease (COPD). However, in most treatment guidelines, xanthines have now been consigned to third-line therapy because of their narrow therapeutic window and propensity for drug-drug interactions. However, lower than conventional doses of theophylline considered to be bronchodilator are now known to have anti-inflammatory actions of relevance to the treatment of respiratory disease. The molecular mechanism(s) of action of theophylline are not well understood, but several potential targets have been suggested including non-selective inhibition of phosphodiesterases (PDE), inhibition of phosphoinositide 3-kinase, adenosine receptor antagonism and increased activity of certain histone deacetylases. Although theophylline has a narrow therapeutic window, other xanthines are in clinical use that are claimed to have a better tolerability such as doxofylline and bamifylline. Nonetheless, xanthines still play an important role in the treatment of asthma and COPD as they can show clinical benefit in patients who are refractory to glucocorticosteroid therapy, and withdrawal of xanthines from patients causes worsening of disease, even in patients taking concomitant glucocorticosteroids.More recently the orally active selective PDE4 inhibitor, roflumilast, has been introduced into clinical practice for the treatment of severe COPD on top of gold standard treatment. This drug has been shown to improve lung function in patients with severe COPD and to reduce exacerbations, but is dose limited by a range side effect, particularly gastrointestinal side effects.

Anti-inflammatory dosing of theophylline in the treatment of status asthmaticus in children

BACKGROUND

Low-dose theophylline has been recognized for its ability to restore histone deacetylase-2 activity which leads to improved steroid responsiveness and thus improved clinical outcome. We retrospectively evaluated the effect of low-dose theophylline therapy in pediatric patients hospitalized for an acute asthma exacerbation as a proof of concept study.

METHODS

We compared patients who received low-dose theophylline (5-7 mg/kg/day) in addition to current standard of care to patients who were treated with current standard of care alone. The primary outcome of the study was hospital length of stay (LOS). Generalized linear mixed-effects modeling (GLMM) was used to test whether receiving theophylline independently predicted outcomes. A Cox (proportional hazards) regression model was also developed to examine whether theophylline impacted LOS.

RESULTS

After adjustment for illness severity measures, theophylline significantly reduces LOS (β=-21.17, P<0.001), time to discontinue oxygen (β=-15.88, P=0.044), time to spirometric improvement (β=-16.60, P=0.014), and time to space albuterol (β=-23.2, P<0.001) as well as reduced costs (β=-US$2,746, P<0.001). Furthermore, theophylline significantly increased the hazards of being discharged from the hospital (hazards ratio =1.75, 95% confidence interval 1.20-2.54, P=0.004). There was no difference in side effects between patients who receive low-dose theophylline and those who did not.

CONCLUSION

The results of this retrospective study suggest low-dose theophylline may have a positive effect in acute status asthmaticus. This study suggests that further research with a prospective, randomized, double-blinded, placebo controlled trial may be warranted to confirm and extend our findings.

Contemporary treatment of children with critical and near-fatal asthma

Asthma is the most common chronic illness in childhood. Although the vast majority of children with acute asthma exacerbations do not require critical care, some fail to respond to standard treatment and require escalation of support. Children with critical or near-fatal asthma require close monitoring for deterioration and may require aggressive treatment strategies. This review examines the available evidence supporting therapies for critical and near-fatal asthma and summarizes the contemporary clinical care of these children. Typical treatment includes parenteral corticosteroids and inhaled or intravenous beta-agonist drugs. For children with an inadequate response to standard therapy, inhaled ipratropium bromide, intravenous magnesium sulfate, methylxanthines, helium-oxygen mixtures, and non-invasive mechanical support can be used. Patients with progressive respiratory failure benefit from mechanical ventilation with a strategy that employs large tidal volumes and low ventilator rates to minimize dynamic hyperinflation, barotrauma, and hypotension. Sedatives, analgesics and a neuromuscular blocker are often necessary in the early phase of treatment to facilitate a state of controlled hypoventilation and permissive hypercapnia. Patients who fail to improve with mechanical ventilation may be considered for less common approaches, such as inhaled anesthetics, bronchoscopy, and extracorporeal life support. This contemporary approach has resulted in extremely low mortality rates, even in children requiring mechanical support.

Therapeutic approaches to asthma-chronic obstructive pulmonary disease overlap syndromes

The recognition that there are some patients with features of asthma and chronic obstructive pulmonary disease (COPD) has highlighted the need to develop more specific treatments for these clinical phenotypes. Some patients with COPD have predominantly eosinophilic inflammation and might respond to high doses of inhaled corticosteroids and newly developed specific antieosinophil therapies, including blocking antibodies against IL-5, IL-13, IL-33, and thymic stromal lymphopoietin, as well as oral chemoattractant receptor-homologous molecule expressed on TH2 cells antagonists. Other patients have severe asthma or are asthmatic patients who smoke with features of COPD-induced inflammation and might benefit from treatments targeting neutrophils, including macrolides, CXCR2 antagonists, phosphodiesterase 4 inhibitors, p38 mitogen-activating protein kinase inhibitors, and antibodies against IL-1 and IL-17. Other patients appear to have largely fixed obstruction with little inflammation and might respond to long-acting bronchodilators, including long-acting muscarinic antagonists, to reduce hyperinflation. Highly selected patients with severe asthma might benefit from bronchial thermoplasty. Some patients with overlap syndromes can be conveniently treated with triple fixed-dose combination inhaler therapy with an inhaled corticosteroid, long-acting β2-agonist, and long-acting muscarinic antagonist, several of which are now in development. Corticosteroid resistance is a feature of asthma-COPD overlap syndrome, and understanding the various molecular mechanisms of this resistance has identified novel therapeutic targets and presented the prospect of therapies that can restore corticosteroid responsiveness.

Pharmacotherapy of critical asthma syndrome: current and emerging therapies

The critical asthma syndrome (CAS) encompasses the most severe, persistent, refractory asthma patients for the clinician to manage. Personalized pharmacotherapy is necessary to prevent the next acute severe asthma exacerbation, not just the control of symptoms. The 2007 National Asthma Education and Prevention Program Expert Panel 3 provides guidelines for the treatment of uncontrolled asthma. The patient's response to recommended pharmacotherapy is highly variable which risks poor asthma control leading to frequent exacerbations that can deteriorate into CAS. Controlling asthma symptoms and preventing acute exacerbations may be two separate clinical activities with their own unique demands. Clinicians must be prepared to use the entire spectrum of asthma medications available but must concurrently be aware of potential drug toxicities some of which can paradoxically worsen asthma control. Medications normally prescribed for COPD can potentially be useful in the CAS patient, particularly those with asthma-COPD overlap syndrome. Immunomodulation with drugs like omalizumab in IgE-mediated asthma syndromes is one important approach. New and emerging drugs address unique aspects of airway inflammation and biology but at a significant financial cost. The pharmacology and toxicities of the agents that may be used in the treatment of CAS to control asthma symptoms and prevent severe exacerbations are reviewed.

Refractory asthma: mechanisms, targets, and therapy

Asthma is a common medical condition affecting 300 million people worldwide. Airway inflammation, smooth muscle bronchoconstriction leading to airflow obstruction, and mucous hypersecretion are clinical hallmarks of asthma. The NHLBI Expert Panel Report 3 recommends inhaled corticosteroids (ICS) for patients with moderate to severe persistent asthma. Inhaled corticosteroids (ICS) target gene transcription through their interactions with the glucocorticoid (GC) receptor (GR) at the glucocorticoid response element (GRE). The GC/GR complex enhances anti-inflammatory but inhibits pro-inflammatory mediator production. Classically, asthma has been described as a Th2-associated eosinophil-predominant disease, but recently alternative models have been described including a Th17-mediated neutrophil-predominant phenotype resulting in patients with more severe disease who may be less responsive to steroids. Additional mechanisms of steroid resistance include increased activity of GR phosphorylating kinases which modify the interactions of GR with transcription factors to inhibit the ability of GR to bind with GRE, leading to an increase in pro-inflammatory gene transcription. Oxidative stress also affects the balance between pro-inflammatory and anti-inflammatory gene transcription through the modification of transcription factors and cofactors (such as PI3K) leading to the inhibition of histone deacetylase 2. Continued investigations into the mechanisms behind glucocorticoid resistance will lead to novel treatments that improve control of severe refractory asthma.

Theophylline

Theophylline (dimethylxanthine) has been used to treat airway diseases for more than 80 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 antiinflammatory effects in asthma and chronic obstructive pulmonary disease (COPD) at lower concentrations. The molecular mechanism of bronchodilatation is inhibition of phosphodiesterase (PDE)3, but the antiinflammatory effect may be due to inhibition of PDE4 and histone deacetylase-2 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, wherein histone deacetylase-2 activity is reduced. Theophylline is given systemically (orally as slow-release preparations for chronic treatment and intravenously for acute exacerbations of asthma). Efficacy is related to blood concentrations, which 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 patients with asthma not well controlled on inhaled corticosteroids with or without long-acting β2-agonists and in patients with COPD 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. In the future, low-dose theophylline may be useful in reversing corticosteroid resistance in COPD and severe asthma.

Severe acute asthma exacerbation in children: a stepwise approach for escalating therapy in a pediatric intensive care unit

OBJECTIVES

An increasing prevalence of pediatric asthma has led to increasing burdens of critical illness in children with severe acute asthma exacerbations, often leading to respiratory distress, progressive hypoxia, and respiratory failure. We review the definitions, epidemiology, pathophysiology, and clinical manifestations of severe acute asthma, with a view to developing an evidence-based, stepwise approach for escalating therapy in these patients.

METHODS

Subject headings related to asthma, status asthmaticus, critical asthma, and drug therapy were used in a MEDLINE search (1980-2012), supplemented by a manual search of personal files, references cited in the reviewed articles, and treatment algorithms developed within Le Bonheur Children's Hospital.

RESULTS

Patients with asthma require continuous monitoring of their cardiorespiratory status via noninvasive or invasive devices, with serial clinical examinations, objective scoring of asthma severity (using an objective pediatric asthma score), and appropriate diagnostic tests. All patients are treated with β-agonists, ipratropium, and steroids (intravenous preferable over oral preparations). Patients with worsening clinical status should be progressively treated with continuous β-agonists, intravenous magnesium, helium-oxygen mixtures, intravenous terbutaline and/or aminophylline, coupled with high-flow oxygen and non-invasive ventilation to limit the work of breathing, hypoxemia, and possibly hypercarbia. Sedation with low-dose ketamine (with or without benzodiazepines) infusions may allow better toleration of non-invasive ventilation and may also prepare the patient for tracheal intubation and mechanical ventilation, if indicated by a worsening clinical status.

CONCLUSIONS

Severe asthma can be a devastating illness in children, but most patients can be managed by using serial objective assessments and the stepwise clinical approach outlined herein. Following multidisciplinary education and training, this approach was successfully implemented in a tertiary-care, metropolitan children's hospital.

Outpatient management of asthma in children

The principal aims of asthma management in childhood are to obtain symptom control that allows individuals to engage in unrestricted physical activities and to normalize lung function. These aims should be achieved using the fewest possible medications. Ensuring a correct diagnosis is the first priority. The mainstay of asthma management remains pharmacotherapy. Various treatment options are discussed. Asthma monitoring includes the regular assessment of asthma severity and asthma control, which then informs decisions regarding the stepping up or stepping down of therapy. Delivery systems and devices for inhaled therapy are discussed, as are the factors influencing adherence to prescribed treatment. The role of the pediatric health care provider is to establish a functional partnership with the child and their family in order to minimize the impact of asthma symptoms and exacerbations during childhood.

Efficacy of theophylline plus salmeterol/fluticasone propionate combination therapy in patients with asthma

OBJECTIVE

To compare the efficacy of theophylline plus salmeterol/fluticasone propionate combination product (SFC) with SFC plus placebo in asthmatic patients.

METHODS

In this randomized, stratified, parallel-group study, 325 patients were randomized to receive either 200 mg theophylline plus 50/250 μg SFC or placebo tablet plus 50/250 μg SFC twice daily for 24 weeks. Outcome variables included the level of asthma control (assessed by the Asthma Control Test) and the number of patients experiencing ≥1 exacerbations during the 24-week treatment period. Testing of lung function as well as measurement of the levels of inflammatory markers in induced sputum was performed.

RESULTS

There were significantly fewer patients with ≥1 asthma exacerbation in the theophylline plus SFC group (29.6%) when compared with the SFC plus placebo group (46.9%) (p = 0.004). Theophylline plus SFC improved the FEF(25-75%) value, which indicates enhanced small airway function, to a greater extent than SFC plus placebo (66.9 ± 18.8% and 57.4 ± 17.6%, respectively; p < 0.001). A significant decrease in eosinophil count and concentration of eosinophil cationic protein in induced sputum was also seen in the theophylline plus SFC group when compared with the SFC plus placebo group (4.1 ± 2.2% and 6.3 ± 2.7%, 63.6 ± 39.5 μg/L and 89.4 ± 45.6 μg/L, respectively; all p < 0.01).

CONCLUSION

The combination of theophylline plus SFC may provide greater protection against asthma exacerbations, and its administration is accompanied by significant improvements in small airway function and airway inflammation.

Childhood asthma: diagnosis and treatment

Many children suffer from recurrent coughing, wheezing and chest tightness. In preschool children one third of all children have these symptoms before the age of six, but only 40% of these wheezing preschoolers will continue to have asthma. In older school-aged children the majority of the children have asthma. Quality of life is affected by asthma control. Sleep disruption and exercised induced airflow limitation have a negative impact on participation in sports and social activities, and may influence family life. The goal of asthma therapy is to achieve asthma control, but only a limited number of patients are able to reach total control. This may be due to an incorrect diagnosis, co-morbidities or poor inhalation technique, but in the majority of cases non-adherence is the main reason for therapy failures. However, partnership with the parents and the child is important in order to set individually chosen goals of therapy and may be of help to improve control. Non-pharmacological measures aim at avoiding tobacco smoke, and when a child is sensitised, to avoid allergens. In pharmacological management international guidelines such as the GINA guideline and the British Guideline on the Management of Asthma are leading.

Severe asthma: advances in current management and future therapy

Effective treatment of severe asthma is a major unmet need because patients' symptoms are not controlled on maximum treatment with inhaled therapy. Asthma symptoms can be poorly controlled because of poor adherence to controller therapy, and this might be addressed by using combination inhalers that contain a corticosteroid and long-acting β(2)-agonist as reliever therapy in addition to maintenance treatment. New bronchodilators with a longer duration of action are in development, and recent studies have demonstrated the benefit of a long-acting anticholinergic bronchodilator in addition to β(2)-agonists in patients with severe asthma. Anti-IgE therapy is beneficial in selected patients with severe asthma. Several new blockers of specific mediators, including prostaglandin D(2), IL-5, IL-9, and IL-13, are also in clinical trials and might benefit patients with subtypes of severe asthma. Several broad-spectrum anti-inflammatory therapies that target neutrophilic inflammation are in clinical development for the treatment of severe asthma, but adverse effects after oral administration might necessitate inhaled delivery. Macrolides might benefit some patients with infection by atypical bacteria, but recent results are not encouraging, although there could be an effect in patients with predominant neutrophilic asthma. Corticosteroid resistance is a major problem in patients with severe asthma, and several molecular mechanisms have been described that might lead to novel therapeutic approaches, including drugs that could reverse this resistance, such as theophylline and nortriptyline. In selected patients with severe asthma, bronchial thermoplasty might be beneficial, but thus far, clinical studies have not been encouraging. Finally, several subtypes of severe asthma are now recognized, and in the future, it will be necessary to find biomarkers that predict responses to specific forms of therapy.

In vitro study on the interaction of ketotifen fumarate with anhydrous theophylline

The purpose of the present study was to investigate the interaction between ketotifen fumarate and anhydrous theophylline in aqueous media of various pH (1.2 and 6.8). Using Job's continuous-variation analysis and Ardon's spectrophotomeric measurement methods, the values of the stability constants of theophylline with ketotifen were determined at a fixed temperature (37 ºC) at various pH. The stability constants, ranging between 5.66 and 9.92, were derived from Ardon's plot, indicating that comparatively stable complexes had formed as a result of an interaction between the drugs. However, following the interaction of theophylline with ketotifen, stability constants were <1 at gastric pH (1.2) and intestinal pH (6.8). Concurrent administration of ketotifen and theophylline could result in the formation of a stable complex and this is likely to reduce the therapeutic activities of both drugs.

Selective PDE inhibitors as novel treatments for respiratory diseases

Phosphodiesterases (PDEs) are a family of enzymes which catalyse the metabolism of the intracellular cyclic nucleotides, c-AMP and c-GMP that are expressed in a variety of cell types and in the context of respiratory diseases, It is now recognised that the use of PDE3, PDE4 and mixed PDE3/4 inhibitors can provide clinical benefit to patients with asthma or chronic obstructive pulmonary disease (COPD). The orally active PDE4 inhibitor Roflumilast-n-oxide has been approved for treatment of severe exacerbations of COPD as add-on therapy to standard drugs. This review discusses the involvement of PDEs in airway diseases and various strategies that are currently being pursued to improve efficacy and reduce side-effects of PDE4 inhibitors, including delivery via the inhaled route, mixed PDE inhibitors and/or antisense biologicals targeted towards PDE4.

Histone deacetylases and their role in asthma

OBJECTIVE

The aim of this article is to provide an overview of the classical histone deacetylase (HDAC) enzymes and HDAC inhibitors. The discussion is focused on the potential anti-asthmatic effects of this group of compounds.

METHODS

Medline was used with the search terms, "asthma and HDAC," "asthma and Trichostatin A," "asthma and valproic acid," "allergic airways disease and HDAC," "allergic airways disease and Trichostatin A," and "allergic airways disease and valproic acid." Manuscripts from the past decade were accessed. Historical literature dating from the 1960s was accessed for the use of anti-epileptics in the treatment of asthma.

RESULTS

Preliminary clinical trials with anti-epileptic drugs including the well-known HDAC inhibitor, valproic acid, have shown long-lasting anti-asthmatic effects providing the basis for the evaluation of this class of compounds in asthma. Studies using the prototypical HDAC inhibitor, Trichostatin A, in well-established murine models of allergic airways disease have also indicated beneficial effects.

CONCLUSION

Although the precise mechanisms are still controversial, inhibition of airway hyperresponsiveness and agonist-induced contraction as well as anti-inflammatory effects have been described for HDAC inhibitors in asthma.

Addition of theophylline or increasing the dose of inhaled corticosteroid in symptomatic asthma: a meta-analysis of randomized controlled trials

PURPOSE

Low-dose theophylline has anti-inflammatory effects. The aim of this study was to evaluate the effects of adding theophylline compared with increasing the dose of inhaled corticosteroid (ICS) on symptomatic asthma.

MATERIALS AND METHODS

The associated literature was acquired through deliberate searching and selected based on the established inclusion criteria for publications. The extracted data were further analyzed by a meta-analysis.

RESULTS

Four randomized, controlled, parallel studies were selected. Addition of theophylline produced a greater increase of forced expiratory volume in one second as %predicted (FEV₁pred) by 2.49% [95% confidence interval (CI) 1.99-3.00; z = 9.70; p < 0.001], compared with increasing the dose of ICS. There was no difference between the two treatments in terms of peak expiratory flow (PEF).

CONCLUSION

Addition of theophylline to ICS has similar therapeutic effects on improving lung function as increasing the dose of ICS in the treatment of symptomatic asthma.

Methylxanthines and drug dependence: a focus on interactions with substances of abuse

This chapter examines the psychostimulant actions of methylxanthines, with a focus on the consequences of their excessive use. Consumption of methylxanthines is pervasive and their use is often associated with that of substances known to produce dependence and to have abuse potential. Therefore, the consequences of this combined use are taken into consideration in order to evaluate whether, and to what extent, methylxanthines could influence dependence on or abuse of other centrally active substances, leading to either amplification or attenuation of their effects. Since the methylxanthine that mostly influences mental processes and readily induces psychostimulation is caffeine, this review mainly focuses on caffeine as a prototype of methylxanthine-produced dependence, examining, at the same time, the risks related to caffeine use.

Roflumilast: first phosphodiesterase 4 inhibitor approved for treatment of COPD

In April 2010, the European Medicines Agency Committee for Medicinal Products for Human Use recommended approval of roflumilast, a selective phosphodiesterase 4 inhibitor, for the “maintenance treatment of severe chronic obstructive pulmonary disease (COPD, FEV₁ postbronchodilator less than 50% predicted) associated with chronic bronchitis in adult patients with a history of frequent exacerbations as add-on to bronchodilator treatment”. This decision was based, in part, on the results of several large, international, multicenter, randomized, placebo-controlled trials of either six or 12 months’ duration that had been undertaken in COPD patients. Roflumilast 500 μg daily improved lung function and reduced exacerbations in patients with more severe COPD, especially those with chronic bronchitis, frequent exacerbations, or who required frequent rescue inhaler therapy in the placebo-controlled trials. It also improved lung function and reduced exacerbations in patients with moderately severe COPD treated with salmeterol or tiotropium. Advantages of roflumilast over inhaler therapy are that it is an oral tablet and only needs to be taken once daily. While taking roflumilast, the most common adverse effects patients experienced were gastrointestinal upset and headache. Weight loss, averaging 2.2 kg, occurred in patients treated with roflumilast. Patients taking roflumilast were more likely to drop out of the trials than patients in the control groups. Patients who discontinued therapy usually did so during the first few weeks and were more likely to have experienced gastrointestinal side effects. Roflumilast is the first selective phosphodiesterase 4 inhibitor and will offer physicians another treatment option for patients with more severe COPD.

Aminophylline for treating asthma and chronic obstructive pulmonary disease

Aminophylline is a complex of theophylline and ethylenediamine. Its main pharmacological action is relaxation of bronchial smooth muscle. Two meta-analyses examining the efficacy of aminophylline in acute asthma attacks in children and in adults have been reported by the Cochrane Collaboration. In the meta-analysis reporting results from studies in children, it was concluded that aminophylline does not add any benefit to standard care. Yet one study, which has the largest patient population, reports that aminophylline improves lung functions within 6-8 h and reduces the risk of intubation. The meta-analysis examining adult studies revealed that there is no outstanding difference between aminophylline and standard therapy in the management of adult acute asthma. In conclusion, aminophylline may be an alternative to intravenous infusion of beta-agonists, heliox or magnesium sulfate administration in children in whom respiratory fatigue begins to develop and intensive-care unit admission and mechanical ventilation seems to be the next treatment in line. However, in adults, it is not recommended for use in the treatment of acute asthma owing to its possible adverse effects.

Should treatments for asthma be aimed at the airway smooth muscle?

The airway smooth muscle (ASM) cell is an important part of the airway wall of asthma patients because of its increased contractile properties, which appear to be enhanced in this condition and which contribute to airflow obstruction and bronchial hyper-responsiveness. ASM cells are also abnormal in asthma with increased expression of certain chemokines, with increased proliferation rate, numbers and size. beta-adrenergic agonists and corticosteroids are the two most important treatments for asthma; other drugs used are leukotriene receptor antagonists and theophylline. Combination therapy of beta-adrenergic agonists and corticosteroids has become the treatment of choice for moderate-to-severe asthma. beta-adrenergic agonists cause relaxation of ASM cells, leading to a decrease in airflow obstruction of asthma and acute relief of symptoms. Corticosteroids also have direct effects on ASM cells. It is postulated that the effect of anti-inflammatory agents on ASM cells is the most important determinant of the therapeutic effects of these agents. Targeting the ASM cell in asthma could be the focus of therapies for asthma. Specific delivery of active agents to ASM cells may also be part of this strategy.

Airway remodelling in asthma: from benchside to clinical practice

Airway remodelling refers to the structural changes that occur in both large and small airways relevant to miscellaneous diseases including asthma. In asthma, airway structural changes include subepithelial fibrosis, increased smooth muscle mass, gland enlargement, neovascularization and epithelial alterations. Although controversial, airway remodelling is commonly attributed to an underlying chronic inflammatory process. These remodelling changes contribute to thickening of airway walls and, consequently, lead to airway narrowing, bronchial hyper-responsiveness, airway edema and mucous hypersecretion. Airway remodelling is associated with poor clinical outcomes among asthmatic patients. Early diagnosis and prevention of airway remodelling has the potential to decrease disease severity, improve control and prevent disease expression. The relationship between structural changes and clinical and functional abnormalities clearly deserves further investigation. The present review briefly describes the characteristic features of airway remodelling observed in asthma, its clinical consequences and relevance for physicians, and its modulation by therapeutic approaches used in the treatment of asthmatic patients.

Aspirin attenuates the anti-inflammatory effects of theophylline via inhibition of cAMP production in mice with non-eosinophilic asthma

Theophylline is commonly used to treat severe asthma and chronic obstructive pulmonary disease (COPD) characterized by non-eosinophilic inflammation. Acetyl salicylic acid (ASA) is one of the most widely used medications worldwide, but up to 20% of patients with asthma experience aggravated respiratory symptoms after taking ASA. Here we evaluated the adverse effect of ASA on the therapeutic effect of theophylline in mice with non-eosinophilic asthma. A non-eosinophilic asthma mouse model was induced by airway sensitization with lipopolysaccharide-containing allergen and then challenged with allergen alone. Therapeutic intervention was performed during allergen challenge. Theophylline inhibited lung inflammation partly induced by Th1 immune response. ASA attenuated the beneficial effects of theophylline. However, co-administration of the ASA metabolite salicylic acid (SA) showed no attenuating effect on theophylline treatment. The therapeutic effect of theophylline was associated with increase in cAMP levels, which was blocked by co-treatment of theophylline and ASA. ASA co-treatment also attenuated the anti-inflammatory effects of a specific phosphodiesterase 4 inhibitor. These results demonstrate that ASA reverses anti-inflammatory effects of theophylline, and that ASA exerts its adverse effects through the inhibition of cAMP production. Our data suggest that ASA reverses lung inflammation in patients taking theophylline, although clinical evidence will be needed.

Theophylline inhibits the differentiation of human monocyte into dendritic cell potentially via adenosine receptor antagonism

BACKGROUND

Theophylline has an anti-inflammatory action that may account for its clinical effectiveness in the reduction of inflammatory cells in the airways. Dendritic cells (DCs) are professional antigen-presenting cells, capable of priming naïve T cells, and play key roles in the activation of immune responses in asthma.

OBJECTIVE

The purpose of this study was to investigate the effects of theophylline on human monocyte differentiation into DCs and whether this involved antagonism of adenosine receptors.

METHODS

Peripheral human blood monocytes were cultured in the presence of granulocyte/macrophage-colony stimulating factor and IL-4 to induce DC differentiation. The cells were incubated with theophylline, KF17837 (a selective A2a receptor antagonist) and enprofylline (A2b receptor antagonist) and co-incubated with selective adenosine A1 and A2a receptor agonists, a phosphodiesterase inhibitor (rolipram) and adenosine deaminase (ADA) to determine their effects on DC differentiation. In addition, depletion of adenosine receptors by small interfering RNA (siRNA) was also examined.

RESULTS

Monocytes differentiated into myeloid DCs in the culture system. The number of DCs was remarkably reduced by 60-70% when theophylline was administered at a therapeutic concentration. This effect was concentration-dependently exacerbated, was partly mediated by cellular apoptosis and was effectively reversed by the addition of the A1 agonists [2-chloro-N(6)-cyclopentyladenosin, N(6)-cyclohexyladenosine, and N-ethylcarboxamidoadenosine (NECA)] or the A2a agonist (CGS-21680, NECA). The depletion of the adenosine A1 receptor by siRNA and addition of ADA remarkably reduced DC differentiation. Meanwhile, both enprofylline and rolipram had little effect.

CONCLUSION

Our findings suggest that the adenosine A1 (and possibly coordinated with A2a) receptors contribute to DC differentiation and survival. These findings provide further evidence that theophylline has an anti-inflammatory action in bronchial asthma.

Interactions between theophylline and salbutamol on cytokine release in human monocytes

The combination of beta(2)-adrenoceptor agonists (beta(2)-agonists) with inhaled steroids has become the standard treatment for mild to moderate asthma. Theophylline has also been combined successfully with inhaled steroids. However, the possible interaction between theophylline and beta(2)-agonists, with regard to their anti-inflammatory effects, has not been clarified. The aim of this study was to investigate the in vitro interaction between theophylline and salbutamol on cytokine generation from human monocytes and compare it with a similar interaction between dexamethasone and salbutamol. Purified monocytes from normal donors were pretreated with the drugs (alone or in combination) and stimulated with lipopolysaccharide for 24 h. Released tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6), and their corresponding mRNA expressions, were determined and analyzed. Salbutamol (>or= 0.1 microM) significantly inhibited the release of TNF-alpha, but also significantly enhanced that of IL-6. In contrast, theophylline (50 microM) and dexamethasone (0.1 microM) strongly inhibited the generation of both cytokines. It is noteworthy that when the drugs were used in combination the effects of theophylline and salbutamol were additive in inhibiting TNF-alpha release, but theophylline blocked the IL-6-enhancing effect of salbutamol. A similar effect was seen when dexamethasone was combined with salbutamol. These results show that beta(2)-agonists have opposing effects on the generation of TNF-alpha and IL-6, but that when they were combined with clinically relevant concentrations of theophylline, theophylline, like dexamethasone, was capable of augmenting the anti-inflammatory effects of the beta(2)-agonists while at the same time preventing their proinflammatory effect. Thus, theophylline may have a potentially useful steroid-sparing effect.

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.

[Asthma therapy: combination of topical glucocorticosteroids and theophylline]

In addition to its bronchodilatory effects, theophylline has anti-inflammatory and immunomodulatory effects. Since theophylline and corticosteroids act via different molecular mechanisms, they may be used in combination. Two recently completed trials have demonstrated that with respect to asthma control the combination of inhaled steroid (400 - 800 microg/d) plus theophylline is at least as effective as doubling the dose of inhaled steroid in patients who remain symptomatic on a dosage of 400 - 800 microg daily.

New drugs targeting Th2 lymphocytes in asthma

Asthma represents a profound worldwide public health problem. The most effective anti-asthmatic drugs currently available include inhaled beta2-agonists and glucocorticoids and control asthma in about 90-95% of patients. The current asthma therapies are not cures and symptoms return soon after treatment is stopped even after long term therapy. Although glucocorticoids are highly effective in controlling the inflammatory process in asthma, they appear to have little effect on the lower airway remodelling processes that appear to play a role in the pathophysiology of asthma at currently prescribed doses. The development of novel drugs may allow resolution of these changes. In addition, severe glucocorticoid-dependent and resistant asthma presents a great clinical burden and reducing the side-effects of glucocorticoids using novel steroid-sparing agents is needed. Furthermore, the mechanisms involved in the persistence of inflammation are poorly understood and the reasons why some patients have severe life threatening asthma and others have very mild disease are still unknown. Drug development for asthma has been directed at improving currently available drugs and findings new compounds that usually target the Th2-driven airway inflammatory response. Considering the apparently central role of T lymphocytes in the pathogenesis of asthma, drugs targeting disease-inducing Th2 cells are promising therapeutic strategies. However, although animal models of asthma suggest that this is feasible, the translation of these types of studies for the treatment of human asthma remains poor due to the limitations of the models currently used. The myriad of new compounds that are in development directed to modulate Th2 cells recruitment and/or activation will clarify in the near future the relative importance of these cells and their mediators in the complex interactions with the other pro-inflammatory/anti-inflammatory cells and mediators responsible of the different asthmatic phenotypes. Some of these new Th2-oriented strategies may in the future not only control symptoms and modify the natural course of asthma, but also potentially prevent or cure the disease.

Chronobiology and chronotherapy of allergic rhinitis and bronchial asthma

Study of the chronobiology of allergic rhinitis (AR) and bronchial asthma (BA) and the chronopharmacology and chronotherapy of the medications used in their treatment began five decades ago. AR is an inflammatory disease of the upper airway tissue with hypersensitivity to specific environmental antigens, resulting in further local inflammation, vasomotor changes, and mucus hypersecretion. Symptoms include sneezing, nasal congestion, and runny and itchy nose. Approximately 25% of children and 40% of adults in USA are affected by AR during one or more seasons of the year. The manifestation and severity of AR symptoms exhibit prominent 24-h variation; in most persons they are worse overnight or early in the morning and often comprise nighttime sleep, resulting in poor daytime quality of life, compromised school and work performance, and irritability and moodiness. BA is also an inflammatory medical condition of the lower airways characterized by hypersensitivity to specific environmental antigens, resulting in greater local inflammation as well as bronchoconstriction, vasomotor change, and mucus hypersecretion. In USA an estimated 6.5 million children and 15.7 million adults have BA. The onset and worsening of BA are signaled by chest wheeze and/or croupy cough and difficult and labored breathing. Like AR, BA is primarily a nighttime medical condition. AR is treated with H1-antagonist, decongestant, and anti-inflammatory (glucocorticoid and leukotriene receptor antagonist and modifier) medications. Only H1-antagonist AR medications have been studied for their chronopharmacology and potential chronotherapy. BA is treated with some of the same medications and also theophylline and beta2-agonists. The chronopharmacology and chronotherapy of many classes of BA medications have been explored. This article reviews the rather extensive knowledge of the chronobiology of AR and BA and the chronopharmacology and chronotherapy of the various medications used in their treatment.

Oxidative stress and steroid resistance in asthma and COPD: pharmacological manipulation of HDAC-2 as a therapeutic strategy

Insensitivity to corticosteroid treatment in inflammatory conditions, such as asthma and chronic obstructive pulmonary disease, present considerable management problems and cost burdens to health services. Oxidative stress is a major component of chronic inflammation and can have a significant suppressive effect on corticosteroid efficacy. Recent advances in the understanding of both the mechanisms of corticosteroid action and corticosteroid insensitivity have provided hope for a therapeutic strategy of restoring corticosteroid sensitivity. Histone deacetylase 2 (HDAC-2) plays a pivotal role in corticosteroid action and is reduced in many cases of steroid insensitivity. Moreover, it has shown that oxidative stress can be responsible for this reduction in HDAC-2 activity. Two structurally different compounds; methyl-xanthine theophylline and polyphenol curcumin restore HDAC activity, thereby restoring corticosteroid function. Low, subbronchodilator doses of theophylline can also act as corticosteroid-sparing drugs in asthmatics. Although these compounds appear to restore corticosteroid function and may initially provide therapeutic potential, they lack specificity and the mechanism of their action is unknown. Once their mechanisms of action are established, it is likely that derivatives of these compounds may be used as a therapeutic strategy to restore corticosteroid insensitivity in the future.

Anti-inflammatory pharmacotherapy for wheezing in preschool children

Accumulating evidence indicates that there are at least two phenotypes of wheezing in preschool years with distinct natural history. Frequent wheezing in the first 3 years of life with risk factors for asthma (e.g., eczema, maternal asthma) predicts symptoms in older age, while infrequent viral-associated wheezing without risk factors for asthma has a benign prognosis. This systematic review summarizes evidence on the use of anti-inflammatory medications in preschool children with wheezing. Literature search was performed using Medline and the Cochrane Library. Retrieved articles were critically appraised. Episodic use of high-dose inhaled corticosteroids (>1,600 mcg/day of beclomethasone) may ameliorate severity of intermittent viral-associated wheezing. Maintenance inhaled corticosteroids can control symptoms in children with frequent wheezing associated with risk factors for asthma. Inhaled corticosteroids do not alter the natural history of wheezing even when started early in life and could have a negative impact on linear growth rate. Short courses of oral corticosteroids have been proposed as an effective measure to control exacerbations of symptoms although there is little evidence supporting their use. Some studies support the administration of non-steroidal anti-inflammatory medications (leukotriene pathway modifiers, cromones, methylxanthines) for mild frequent wheezing. Maintenance inhaled corticosteroids is the most effective measure for controlling frequent wheezing in preschool children, especially when accompanied by risk factors for asthma. This treatment does not affect the natural history of wheezing, although deceleration of linear growth rate is the most commonly recognized systemic adverse effect.

A prospective survey on safety of sustained-release theophylline in treatment of asthma and COPD

BACKGROUND

Theophylline is a useful drug for the treatment of asthma. The Asthma Prevention and Management Guidelines (JGL) recommend use of sustained-release theophylline products as controllers and of injectable aminophylline products as relievers. The Global Initiative for Asthma: Global Strategy for Asthma Management and Prevention, the NHLB/WHP Workshop Report 1995 (GINA, 1995) and guidelines in Western countries recommend sustained-release theophylline, but not as positively as in the JGL. The aim of this survey was to determine the occurrence of serious adverse reactions.

METHODS

The survey was conducted in 66 institutions staffed by physicians certified by the Japanese Society of Allergology (JSA). The target diseases were asthma and COPD including chronic bronchitis and pulmonary emphysema, which are indications for use of sustained-release theophylline products in Japan.

RESULTS

3,921 patients were included in the safety evaluation. No serious adverse reactions were observed among the patients in this survey, although 54 patients (1.38%) exhibited non-serious adverse reactions. The incidence of adverse reactions was found to be high in patients who had begun use of sustained-release theophylline products at the time of registration in this survey, and in patients who were concomitantly taking macrolide antibiotics.

CONCLUSIONS

The present survey demonstrates that sustained-release theophylline is safe, as long as used appropriately, although adverse reactions tend to develop early after initiation of administration.

Clinical trial of low-dose theophylline and montelukast in patients with poorly controlled asthma

BACKGROUND

Asthma treatment guidelines recommend addition of controller medications for patients with poorly controlled asthma. We compared the effectiveness of once-daily oral controller therapy with either an antileukotriene receptor antagonist (montelukast) or low-dose theophylline added to existing medications in patients with poorly controlled asthma.

METHODS

We conducted a randomized, double-masked, placebo-controlled trial in 489 participants with poorly controlled asthma randomly assigned to placebo, theophylline (300 mg/d), or montelukast (10 mg/d). Participants were monitored for 24 wk to measure the rate of episodes of poor asthma control (EPACs) defined by decreased peak flow, increased beta-agonist use, increased oral corticosteroid use, or unscheduled health care visits.

OBSERVATIONS

There was no significant difference in EPAC rates (events/person/yr) compared with placebo: low-dose theophylline, 4.9 (95% confidence interval [CI], 3.6-6.7; not significant); montelukast, 4.0 (95% CI, 3.0-5.4; not significant); and placebo, 4.9 (95% CI, 3.8-6.4). Both montelukast and theophylline caused small improvements in prebronchodilator FEV(1) of borderline significance. Nausea was more common with theophylline only during the first 4 wk of treatment. Neither treatment improved asthma symptoms or quality of life. However, in patients not receiving inhaled corticosteroids, addition of low-dose theophylline significantly (p < 0.002) improved asthma control and symptoms as well as lung function.

CONCLUSIONS

Neither montelukast nor low-dose theophylline lowered the EPAC rate of poor asthma control in patients with poorly controlled asthma despite improved lung function. For patients not using inhaled corticosteroids, low-dose theophylline improved asthma symptom control more than montelukast or placebo, and provides a safe and low-cost alternative asthma treatment.

Effects of salmeterol in patients with persistent asthma receiving inhaled corticosteroid plus theophylline

BACKGROUND

Patients with severe asthma require multiple therapies to improve lung function and reduce symptoms. The use of long-acting inhaled beta(2)-agonists plus theophylline in addition to high doses of inhaled corticosteroids (ICSs) for the treatment of severe asthma has not been extensively studied.

OBJECTIVE

The purpose of this study was to investigate the efficacy and safety of salmeterol combined with high-dose ICSs plus theophylline in severe asthma.

METHODS

We undertook a randomized, placebo-controlled, crossover study to compare the effect of a single dose of inhaled salmeterol (50 microg) or a placebo in patients with severe asthma whose conditions were not being adequately controlled by therapies with high-dose ICSs plus oral theophylline with or without leukotriene receptor antagonists.

RESULTS

Twenty patients took part in the trial. Compared with the placebo, the inhalation of salmeterol significantly increased the FEV(1). Even in the 9 patients treated with high-dose ICSs plus theophylline plus a leukotriene receptor antagonist, the FEV(1) increased significantly more after salmeterol than after the placebo.

CONCLUSION

Patients with severe asthma receiving high-dose ICSs plus theophylline may benefit from the addition of salmeterol.

Positive benefits of theophylline in a randomized, double-blind, parallel-group, placebo-controlled study of low-dose, slow-release theophylline in the treatment of COPD for 1 year

OBJECTIVE AND BACKGROUND

Increasing evidence suggests that low-dose theophylline has anti-inflammatory benefits and is safe in the treatment of COPD. This study aims to evaluate the efficacy and safety of low-dose, slow-release oral theophylline administered over a 1-year period in patients with COPD.

METHODS

A randomized, double-blind, parallel-group, placebo-controlled trial was carried out. In total, 110 participants with COPD were randomly assigned to receive slow-release theophylline (100 mg b.i.d.) or placebo for 1 year. Use of medicine and symptoms recorded by diary cards; pulmonary function, exacerbations of COPD, quality of life and the use of rescue medicine were evaluated. Superiority test was used to estimate the efficacy.

RESULTS

Of 110 participants, 85 (77.3%) complied with the protocol, with 42 subjects in theophylline and 43 subjects on placebo. In both intention-to-treat and per-protocol population analysis, greater improvement in pre-bronchodilator FEV(1) (P = 0.038 and P = 0.070, respectively), lower frequency of COPD exacerbations (P = 0.047 and P = 0.035, respectively), fewer days of COPD exacerbations (P = 0.045 and P = 0.046, respectively), lower frequency of clinical visits (P = 0.017 and P = 0.039, respectively), greater improvement in satisfaction with treatment (P = 0.014 and P = 0.004, respectively) were found in the theophylline group than in the placebo group. In per-protocol population, greater improvements in quality of life (P = 0.047) were also observed in the theophylline group and the mean time to the first exacerbation was delayed in theophylline group in comparison with placebo group (P = 0.047). Drug-related adverse events such as stomach discomfort (3.51%), headache (3.51%), insomnia (1.75%) and palpitation (1.75%) were found in the theophylline group.

CONCLUSIONS

Low-dose, slow-release oral theophylline is effective and well-tolerated in the long term treatment of stable COPD, although it does not improve post-bronchodilator lung function.

Structural changes in airway diseases: characteristics, mechanisms, consequences, and pharmacologic modulation

In airway diseases such as asthma and COPD, specific structural changes may be observed, very likely secondary to an underlying inflammatory process. Although it is still controversial, airway remodeling may contribute to the development of these diseases and to their clinical expression and outcome. Airway remodeling has been described in asthma in various degrees of severity, and correlations have been found between such features as increase in subepithelial collagen or proteoglycan deposits and airway responsiveness. Although the clinical significance of airway remodeling remains a matter of debate, it has been suggested as a potential target for treatments aimed at reducing asthma severity, improving its control, and possibly preventing its development. To date, drugs used to treat airway diseases have a little influence on airway structural changes. More research should be done to identify key changes, valuable treatments, and proper interventional timing to counteract these changes. The potential of novel therapeutic agents to reverse or prevent airway remodeling is an exciting avenue and warrants further evaluation.

Theophylline as ‘Add-on’ Therapy to Cetirizine in Patients with Chronic Idiopathic Urticaria

BACKGROUND

Chronic urticaria is a prevalent condition associated with substantial disability. Its pathogenesis is not clearly understood and is divided into autoimmune and chronic idiopathic urticaria (CIU). We investigated if the non-specific phosphodiesterase inhibitor theophylline could provide additional benefit to the histamine-1 receptor (H-1R) antagonist cetirizine in CIU.

METHODS

This was a double-blind, placebo-controlled, parallel study. Patients were randomized to receive either cetirizine and theophylline (200 mg twice daily; group A, 67 subjects) or cetirizine and placebo for 6 months (group B, 67 subjects). Group A patients took theophylline for 6 more months. Response was assessed by visual analog scale (VAS) and treatment effectiveness score (TES). Blood theophylline levels were also determined at visit t=1 and t=7.

RESULTS

The study was completed by 54 of the 67 patients (80.6%) in group A and 51 of the 67 patients (76.1%) in group B. The physician VAS values for group A were lower after t=3, while the patient VAS values were decreased after t=2. The physician and patient TES values in group A were statistically higher (p<0.05) at all time points except for t=1. At least 1 month of theophylline addition was necessary to obtain statistically significant benefit over cetirizine, and reducing theophylline by 50% during phase 2 did not alter this benefit. Pruritus values were reduced, but not statistically significant.

CONCLUSIONS

Addition of theophylline to conventional H-1R antagonists was well tolerated without any adverse effects and provided considerable additional benefit in the management of CIU.