Theophylline: potential antiinflammatory effects in nocturnal asthma

Attenuating Effect of Peruvian Cocoa Populations on the Acute Asthmatic Response in Brown Norway Rats

Cocoa contains bioactive components, which vary according to genetic and environmental factors. The present study aimed to ascertain the anti-allergic properties of native Peruvian cocoa populations ("Blanco de Piura" or BPC, "Amazonas Peru" or APC, "Criollo de Montaña" or CMC, "Chuncho" or CCC, and an ordinary cocoa or OC). To do so, after an initial in vitro approach, an in vivo study focused on the induction of an anaphylactic response associated with allergic asthma in Brown Norway rats was carried out. Based on their polyphenol content, antioxidant activity and in vitro effects, the APC and CMC were selected to be included in the in vivo study. Cocoa diets were tested in a model of allergic asthma in which anaphylactic response was assessed by changes in body temperature, motor activity and body weight. The concentration of specific immunoglobulin E (IgE), mast cell protease and leukotrienes was also quantified in serum and/or bronchoalveolar lavage fluid. CMC and OC populations exhibited a protective effect on the allergic asthma rat model as evidenced by means of a partial protection against anaphylactic response and, above all, in the synthesis of IgE and the release of mast cell protease.

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.

Neutrophilic inflammation in asthma: mechanisms and therapeutic considerations

INTRODUCTION

Neutrophilic airway inflammation represents a pathologically distinct form of asthma and frequently appears in symptomatic adulthood asthmatics. However, clinical impacts and mechanisms of the neutrophilic inflammation have not been thoroughly evaluated up to date. Areas covered: Currently, distinct clinical manifestations, triggers, and molecular mechanisms of the neutrophilic inflammation (namely Toll-like receptor, Th1, Th17, inflammasome) are under investigation in asthma. Furthermore, possible role of the neutrophilic inflammation is being investigated in respect to the airway remodeling. We searched the related literatures published during the past 10 years on the website of Pub Med under the title of asthma and neutrophilic inflammation in human. Expert commentary: Epidemiologic and experimental studies have revealed that the neutrophilic airway inflammation is induced by a wide variety of stimuli including ozone, particulate matters, cigarette smoke, occupational irritants, endotoxins, microbial infection and colonization, and aeroallergens. These triggers provoke diverse immune and inflammatory responses leading to progressive and sometimes irreversible airway obstruction. Clinically, neutrophilic airway inflammation is frequently associated with severe asthma and poor response to glucocorticoid therapy, indicating the need for other treatment strategies. Accordingly, therapeutics will be targeted against the main mediators behind the underlying molecular mechanisms of the neutrophilic inflammation.

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.

Chronotherapeutics--a chronopharmaceutical approach to drug delivery in the treatment of asthma

Bronchial asthma is a chronic inflammatory disorder of the airways associated with airflow obstruction that is reversible spontaneously or with treatment. Bronchial asthma is a disease based on established circadian rhythm. The symptoms of asthma worsen during midnight to early morning and therefore it is required to deliver the drug in such fashion that effective treatment can be obtained during the time of asthma attacks. Chronotherapy is an approach that fulfills the criteria of drug delivery at a specific time as per the pathophysiological need of the disease, to improve patient compliance. The current article focuses on the chronotherapy of bronchial asthma, methodologies involved for the existing systems, recent updates and different chronopharmaceutical technologies currently available in the market. Chronotherapy with different categories of bronchial asthma medications also has been reviewed.

Comparative monitoring of oral theophylline treatment in blood serum, saliva, and nasal mucus

BACKGROUND

Theophylline, used in the treatment for various pulmonary pathologies, is usually given orally with drug levels measured primarily in blood serum and occasionally in saliva. Although theophylline treatment is now not commonly used it has been effective to correct smell loss (hyposmia). This is important because 21 million people in the United States exhibit hyposmia and oral theophylline has corrected hyposmia in about 50% of these patients. This result suggests that oral theophylline may result in the drug not only appearing in the serum but also in nasal mucus, thereby playing a role in correcting hyposmia. No prior report of theophylline in nasal mucus has been made and no comparison of levels in nasal mucus, blood serum, or saliva has been previously reported.

PURPOSE

The aim was to determine, after oral theophylline treatment, if it is present in nasal mucus and, if present, to compare the levels with those in serum and saliva.

METHODS

Oral theophylline was given to 23 hyposmic patients at daily doses of 200, 300, 400, 600, and 800 mg for periods of 2-10 months. During each period, blood serum, saliva, and nasal mucus were collected and theophylline measured in each fluid.

RESULTS

Theophylline was found in nasal mucus and in saliva and blood serum at each drug dose in each patient to whom it was given. The mean level of theophylline in nasal mucus was 74% that of serum; mean level in saliva was 67% of serum; mean level in nasal mucus was 111% that in saliva.

CONCLUSIONS

Theophylline is present in nasal mucus after oral administration. Levels in nasal mucus reflect blood and saliva levels in a consistent manner and offer a simple convenient noninvasive method to monitor theophylline doses of the oral drug.

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.

Progress in the management of childhood asthma

Asthma has become the most common chronic disease in childhood. Significant advances in epidemiological research as well as in therapy of pediatric asthma have been made over the past 2 decades. In this review, we look at certain aspects therapy of childhood asthma, both in the past and present. Literature review on allergen avoidance (including mites, cockroach and cat), intensive therapy with β(2)-agonists in acute asthma (administering via continuous nebulization and intravenous routes), a revisit of theophylline use and its action, the use of inhaled corticosteroids in various phases of childhood asthma and sublingual immunotherapy in asthma are examined. Recent facts and dilemmas of these treatments are identified along with expression of our opinions, particularly on points of childhood asthma in the Asia-Pacific, are made in this review.

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 in asthma

Methylxanthines represent a unique class of drugs for the treatment of asthma. The methylxanthine theophylline has demonstrated efficacy in attenuating the three cardinal features of asthma - reversible airflow obstruction, airway hyperresponsiveness, and airway inflammation. At doses achieving relatively high serum levels in which toxic side effects are sometimes observed, direct bronchodilatory effects of theophylline are recognized. At lower serum concentrations, theophylline is a weak bronchodilator but retains its capacity as an immunomodulator, anti-inflammatory, and bronchoprotective drug. Intense investigation into the molecular mechanisms of action of theophylline has identified several different points of action. Phosphodiesterase inhibition and adenosine receptor antagonism have both been implicated in promoting airway smooth muscle relaxation and bronchodilation. Similar mechanisms of action may explain the inhibitory effects of theophylline on immune cells. At lower concentrations that fail to inhibit phosphodiesterase, effects on histone deacetylase activity are believed to contribute to the immunomodulatory actions of theophylline. Since anti-inflammatory and immunomodulatory effects of methylxanthines are realized at lower serum concentrations than are required for bronchodilation, theophylline's predominant role in asthma treatment is as a controller medication for chronic, persistent disease.

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

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.

Influence of the Circadian System on Disease Severity

The severity of many diseases varies across the day and night. For example, adverse cardiovascular incidents peak in the morning, asthma is often worse at night and temporal lobe epileptic seizures are most prevalent in the afternoon. These patterns may be due to the day/night rhythm in environment and behavior, and/or endogenous circadian rhythms in physiology. Furthermore, chronic misalignment between the endogenous circadian timing system and the behavioral cycles could be a cause of increased risk of diabetes, obesity, cardiovascular disease and certain cancers in shift workers. Here we describe the magnitude, relevance and potential biological basis of such daily changes in disease severity and of circadian/behavioral misalignment, and present how these insights may help in the development of appropriate chronotherapy.

Asthma

Asthma has been recognized as a disease since the earliest times. In the Corpus Hippocraticum, Hippocrates used the term “ασθμα” to indicate any form of breathing difficulty manifesting itself by panting. Aretaeus of Cappadocia, a well-known Greek physician (second century A.D.), is credited with providing the first detailed description of an asthma attack [13], and to Celsus it was a disease with wheezing and noisy, violent breathing. In the history of Rome, we find many members of the Julio-Claudian family affected with probable atopic respiratory disorders: Caesar Augustus suffered from bronchoconstriction, seasonal rhinitis as well as a highly pruritic skin disease. Claudius suffered from rhinoconjunctivitis and Britannicus was allergic to horse dander [529]. Maimonides (1136–1204) warned that to neglect treatment of asthma could prove fatal, whereas until the 19th century, European scholars defined it as “nervous asthma,” a term that was given to mean a defect of conductivity of the ninth pair of cranial nerves.

Targeting systemic inflammation: novel therapies for the treatment of chronic obstructive pulmonary disease

The increasing evidence that inflammation in the lungs leads to the structural changes observed in chronic obstructive pulmonary disease, whereas extrapulmonary symptoms and comorbidities may be systemic manifestations of these inflammatory processes, highlights an urgent need to discover novel, effective anti-inflammatory treatments for this disease. Some studies are suggesting that, by decreasing dynamic hyperinflation, bronchodilators might reduce systemic inflammation; inhaled corticosteroids and their combination with long-acting beta2-agonists might contribute to this goal. Even so, the opinion that suppression of the inflammatory response might improve systemic complications is stimulating a search for novel anti-inflammatory therapies. Many drugs include those that inhibit the recruitment and activation of inflammatory cells and/or antagonise their products. However, many of these therapeutic strategies are not specific for neutrophilic inflammation because they affect other cell types, thus, it is difficult to interpret whether any clinical benefit observed is a result of a reduction in airway neutrophils. In any case, there is some evidence that drugs used to treat a co-morbid condition, such as statins, angiotensin converting enzyme (ACE) inhibitors and angiontensin II type 1 (AT1) receptor blockers as well as glycosaminoglycans and peroxisome proliferator-activated receptor (PPAR) agonists, might benefit chronic obstructive pulmonary disease patients because they deal with the extrapulmonary, systemic component of chronic obstructive pulmonary 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.

Different bronchodilator combinations have similar effects on health status in COPD

BACKGROUND

The main treatment in COPD consists of bronchodilator agents. As the severity of disease increases, combined bronchodilators are preferred in place of single agents. Since there is a weak correlation between well being and spirometric parameters, additional life quality questionnaires are used.

OBJECTIVES

The main aim of this study was to investigate whether different bronchodilator combinations have similar effects on quality of life measures in COPD.

METHODS

Sixty male patients with COPD were randomized into three groups. After a two-week run-in period, life quality scores were determined using the Turkish version of St George's Respiratory Questionnaire (SGRQ). Group 1 was given ipratropium + theophylline (IP + THEO); Group 2 formoterol + theophylline (FOR + THEO) and Group 3 ipratropium + formoterol (IP + FOR). After a 12-week treatment period, symptom, activity and impact scores were again determined.

RESULTS

When compared with baseline, all component scores and total scores improved significantly (Delta total score: 16, 15 and 17 units in Groups I, II, and III, respectively), but there was no significant change between groups (p > 0.05).

CONCLUSIONS

According to these results, combined bronchodilator treatments have a significant effect on life quality in COPD, but the effects were observed to be similar between the three different combinations tested.

Aminophilline suppress the release of chemical mediators in treatment of acute asthma

BACKGROUND

The control of airway inflammation is crucial for management of asthma. Theophylline has been demonstrated to have an anti-inflammatory effect as a long-term-medication for asthma in various studies. In the present study we attempted to clarify if aminophylline, a theophylline derivative, could act as an anti-inflammatory agent as well as a bronchodilator in the treatment for acute asthma exacerbations.

METHODS

Patients are initially treated either with an intravenous infusion of aminophylline or with inhalation of salbutamol. Pro-inflammatory mediators such as eosinophil cationic protein (ECP), histamine, serotonin, thromboxane B2, leukotriene C4 were measured before and one hour after the initial treatment. Clinical parameters such as peak expiratory flow (PEF) and SpO2 were also checked during the studies.

RESULTS

Significant improvements of PEF and SpO2 with both aminophylline and salbutamol treatment were seen. Furthermore, significant decreases of ECP, histamine, and serotonin were observed with aminophylline but not with salbutamol.

CONCLUSIONS

Suppressing the release of pro-inflammatory mediators may play a role, at least in part, in the beneficial effects of aminophylline in the treatment of acute exacerbations in asthma. Additionally, this study indicated that treatment with aminophylline is at least as beneficial as nebulized salbutamol in the restoration of lung function.

Comparison of the effect of aminophylline and low PEEP vs. high PEEP on EGF concentration in critically ill patients with ALI/ARDS

BACKGROUND

Acute respiratory distress syndrome (ARDS) remains a serious, often fatal, condition, despite progress in modern critical care treatment. Cytokines play important roles in the pathogenesis of the syndrome, although their roles in the evaluation and outcome have not been clearly elucidated yet.

OBJECTIVES

We tested whether serum concentration of epidermal growth factor (EGF), as one of the important inflammatory mediators, changes with time and administration of mechanical ventilation and aminophylline.

PATIENTS AND METHODS

Thirty patients [mean (SD): age = 56.6 (17.4) years] with ARDS were enrolled. After diagnosis based on inclusion and exclusion criteria, the patients were intubated and mechanically ventilated. Two hours after ventilation with definite positive end-expiratory pressure (PEEP), aminophylline with a specific dose was started. Serum samples were obtained at five time points of 0, 2, 2.5, 4 and 8 h post-starting PEEP.

RESULTS

Serum EGF concentration decreased after mechanical ventilation with PEEP (P < 0.05). The serum EGF concentrations 8 h after intervention was statistically lower in the low PEEP group than in the high PEEP group. The Acute Physiology and Chronic Health Evaluation (APACHE) Pi score and PaO2/FiO2 improved significantly after 8 h (P < 0.05).

CONCLUSION

Beneficial effects of mechanical ventilation and aminophylline on APACHE Pi score and PaO2/FiO2 influence serum EGF levels. These findings may have relevance to the development of multisystem organ failure.

Phosphodiesterase-4 inhibitors in the treatment of inflammatory lung disease

Phosphodiesterases (PDE) belong to an important family of proteins that regulate the intracellular levels of cyclic nucleotide second messengers. Targeting PDE with selective inhibitors may offer novel therapeutic strategies in the treatment of various conditions, and in the context of respiratory disease these include asthma and chronic obstructive pulmonary disease (COPD). The rationale for such an approach stems, in part, from the clinical efficacy of theophylline, an orally active drug that is purportedly a nonselective PDE inhibitor. In addition, intracellular cyclic adenosine monophosphate (cAMP) levels regulate the function of many of the cells thought to contribute to the pathogenesis of respiratory diseases such as asthma and COPD, and these cells also selectively express PDE4. This has offered pharmaceutical companies the opportunity to selectively targeting these enzymes for the treatment of these diseases. Finally, the success of targeting PDE5 in the treatment of erectile dysfunction provides clinical proof of concept for the targeting of PDE in disease. Whether a 'Viagra' of the airways can be found for the treatment of asthma and COPD remains to be seen, but positive results from recent clinical studies examining the efficacy of selective PDE4 inhibitors such as cilomilast and roflumilast offer some optimism. However, one of the major issues to be resolved is the tolerability profile associated with this drug class that is a consequence of PDE4 inhibition. While cilomilast and roflumilast have low emetic potential they are not free from emesis and various strategies are being investigated in the hope of developing a PDE4 inhibitor without this adverse effect.

β2-Integrin adhesion caused by eotaxin but not IL-5 is blocked by PDE-4 inhibition and β2-adrenoceptor activation in human eosinophils

We investigated the effect and mechanism(s) of PDE-4 treatment with concurrent beta2-adrenoceptor stimulation on human eosinophil adhesion mediated by beta2-integrin in vitro. Eosinophils were pretreated with either rolipram, a PDE-4 inhibitor, alone or combined with salmeterol, a beta2-adrenoceptor agonist, before activation with either eotaxin or IL-5. Beta2-integrin mediated adhesion was assessed as adherence to BSA, an established surrogate for ICAM-1. Rolipram caused progressive blockade (77.7 +/- 6.2%) of adhesion elicited by eotaxin. Maximal blockade of IL-5-activated adhesion by rolipram was substantially less (29.9 +/- 5.2%). Salmeterol + rolipram synergistically enhanced the blockade of eotaxin-activated adhesion. Eotaxin also caused approximately 50% increase in surface CD11b expression, which was blocked additively by rolipram + salmeterol. By contrast, CD11b upregulation caused by IL-5 was not blocked by rolipram + salmeterol. Rolipram also attenuated cPLA2 phosphorylation caused by eotaxin but did not block IL-5-induced phosphorylation. We conclude that rolipram blocks expression of CD11b and inhibits cPLA2 phosphorylation in human eosinophils, thus blocking eotaxin-induced adhesion of beta2-integrin. IL-5-induced adhesion likely utilizes a different upstream mechanism in regulation of integrin adhesion.

Pharmacology of airway inflammation in asthma and COPD

The current asthma therapies are not cures and symptoms return soon after treatment is stopped even after long term treatment. Although inhaled glucocorticoids are highly effective in controlling airway inflammation in asthma, they are ineffective in the small group of patients with glucocorticoid-dependent and -resistant asthma. With very few exceptions, COPD is caused by tobacco smoking, and smoking cessation is the only truly effective treatment of COPD available. Current pharmacological treatment of COPD is unsatisfactory, as it does not significantly influence the severity of the disease or its natural course. Glucocorticoids are scarcely effective in COPD patients without concomitant asthma. Bronchodilators improves symptoms and quality of life, in COPD patients, but, with the exception of tiotropium, they do not significantly influence the natural course of the disease. Theophylline is the only drug which has been demonstrated to have a significant effect on airway inflammation in patients with COPD. Here we review the pharmacology of currently used antiinflammatory therapies for asthma and COPD and their proposed mechanisms of action. Recent understanding of disease mechanisms in severe steroid-dependent and -resistant asthma and in COPD, has lead to the development of novel compounds, which are in various stages of clinical development. We review the current status of some of these new potential drugs.

Theophylline and PDE4 inhibitors in asthma

Over the past three decades, beta -adrenoceptor agonists and glucocorticosteroids have formed the mainstay of treatment for patients with asthma; during this time, only one new drug class, leukotriene receptor antagonists, have been introduced. Theophylline has also been used in the treatment of patients with asthma, although there is a perception that this drug does not offer the patient any advantages over conventional therapeutic strategies. However, a number of clinical studies have documented the efficacy of this orally active drug. The mechanism by which theophylline exerts its well recognized antiinflammatory activity remains to be established but, if explained, could lead to newer drug development with greater efficacy. The development of phosphodiesterase (PDE)4 inhibitors is one such approach, and recent studies have demonstrated the potential utility of this new drug class for the treatment of patients with asthma.(2)

Synergistic effect of theophylline and procaterol on interleukin-5-induced degranulation from human eosinophils

Inhibiting the release of toxic granule proteins from eosinophils is a possible means of treating allergic inflammation. This study was performed to examine whether procaterol and theophylline, commonly used bronchodilators in asthma, inhibit eosinophil degranulation induced by interleukin (IL)-5. Purified eosinophils from patients with asthma were incubated with IL-5 for 24 hr in the presence of theophylline, procaterol, combinations of theophylline and procaterol, or dexamethasone. Levels of eosinophil-derived neurotoxin (EDN) in the supernatants were measured with radioimmunoassay. Theophylline inhibited IL-5-induced release of EDN in a concentration-dependent manner. Procaterol inhibited degranulation only at high concentrations. However, procaterol at 10(-9) M and 10(-8) M, which are physiologic concentrations, together with theophylline at 10(-5) M, which is a concentration commonly found in the serum of patients receiving low-dose theophylline, inhibited degranulation by 43.8%. This finding indicates that theophylline and procaterol have synergistic effects. The inhibition was comparable to that with dexamethasone at 10(-9) M. Our results suggest that a combination of low-dose theophylline and procaterol exhibits antiinflammatory effects in asthma by inhibiting eosinophil-effector functions.

New clinical applications of xanthine derivatives: modulatory actions on leukocyte survival and function

The use of theophylline in the treatment of obstructive pulmonary diseases has diminished with the advent of new medications. However, its use as a second-line bronchodilator has been reconsidered in recent years. Theophylline is reported to have immunomodulatory actions that may account for its clinical effectiveness in the control of airway inflammation. Theophylline, even at low plasma concentrations, inhibits the late asthmatic reaction following allergen challenge. The apparent suppression of airway inflammation by theophylline reinforces findings from in vitro experiments (including our recent studies). Its immunomodulatory actions include inhibition of cytokine synthesis and release, inhibition of inflammatory cell activation, and acceleration of granulocyte apoptosis. On the basis of these findings, theophylline has been re-evaluated as a key drug for the long-term management of bronchial asthma, and new applications are proposed for the clinical use of xanthine derivatives. Here, we review some recent advances in the understanding of pharmacological actions and new applications of xanthine derivatives.

Nocturnal asthma uncontrolled by inhaled corticosteroids: theophylline or long-acting beta2 agonists?

Asthma is an inflammatory disease of the airways that is frequently characterised by marked circadian rhythm. Nocturnal and early morning symptoms are quite common among patients with asthma. Increased mortality and decreased quality of life are associated with nocturnal asthma. Although numerous mechanisms contribute to the pathophysiology of nocturnal asthma, increasing evidence suggests the most important mechanisms relate to airway inflammation. According to international guidelines, patients with persistent asthma should receive long term daily anti-inflammatory therapy. A therapeutic trial with anti-inflammatory therapy alone (without a long-acting bronchodilator) should be assessed to determine if this therapy will eliminate nocturnal and early morning symptoms. If environmental control and low to moderate doses of inhaled corticosteroids do not eliminate nocturnal symptoms, the addition of a long-acting bronchodilator is warranted. Long-acting inhaled beta2 agonists (e.g. salmeterol, formoterol) are effective in managing nocturnal asthma that is inadequately controlled by anti-inflammatory agents. In addition, sustained release theophylline and controlled release oral beta2 agonists are effective. In patients with nocturnal symptoms despite low to high doses of inhaled corticosteroids, the addition of salmeterol has been demonstrated to be superior to doubling the inhaled corticosteroid dose. In trials comparing salmeterol with theophylline, 3 studies revealed salmeterol was superior to theophylline (as measured by e.g. morning peak expiratory flow, percent decrease in awakenings, and need for rescue salbutamol), whereas 2 studies found the therapies of equal efficacy. Studies comparing salmeterol to oral long-acting beta2 agonists reveal salmeterol to be superior to terbutaline and equivalent in efficacy to other oral agents. Microarousals unrelated to asthma are consistently increased when theophylline is compared to salmeterol in laboratory sleep studies. In addition to efficacy data, clinicians must weigh benefits and risks in choosing therapy for nocturnal asthma. Long-acting inhaled beta2 agonists are generally well tolerated. If theophylline therapy is to be used safely, clinicians must be quite familiar with numerous factors that alter clearance of this drug, and they must be prepared to use appropriate doses and monitor serum concentrations. Comparative studies using validated, disease specific quality of life instruments (e.g. Asthma Quality of Life Questionnaire) have shown long-acting inhaled beta2 agonists are preferred to other long-acting bronchodilators. Examination of costs for these therapeutic options reveals that evening only doses of long-acting oral bronchodilators are less expensive than multiple inhaled doses. However, costs of monitoring serum concentrations, risks, quality of life and otheroutcome measures must also be considered. Long-acting inhaled beta2 agonists are the agents of choice for managing nocturnal asthma in patients who are symptomatic despite anti-inflammatory agents and other standard management (e.g. environmental control). These agents offer a high degree of efficacy along with a good margin of safety and improved quality of life.

Salmeterol plus theophylline combination therapy in the treatment of COPD

BACKGROUND

Patients with COPD often require multiple therapies to improve lung function and decrease symptoms and exacerbations. Salmeterol and theophylline are indicated for the treatment of COPD, but the use of these agents in combination has not been extensively studied.

OBJECTIVES

To compare the efficacy and safety of salmeterol plus theophylline vs either agent alone in COPD.

METHODS

Randomized, double-blind, double-dummy, parallel-group trial in 943 patients with COPD. After an open-label theophylline titration period (serum levels, 10 to 20 microg/mL), patients were randomly assigned to receive salmeterol (42 microg bid) plus theophylline, salmeterol (42 microg bid), or theophylline for 12 weeks. Serial pulmonary function tests were completed on day 1 and treatment week 12. Patients kept diary cards and noted their peak flow rates, symptom scores, and albuterol use, and periodically completed quality-of-life and dyspnea questionnaires.

RESULTS

All three groups significantly improved compared with baseline. Combination treatment with salmeterol plus theophylline provided significantly (p < or = 0.045) greater improvements in pulmonary function; significantly (p < or = 0.048) greater decreases in symptoms, dyspnea, and albuterol use; and significantly fewer COPD exacerbations (p = 0.023 vs theophylline). In general, treatment with salmeterol provided greater improvement in lung function and satisfaction with treatment compared with theophylline. Salmeterol treatment was also associated with significantly fewer drug-related adverse events (p < or = 0.042) than either treatment that included theophylline. The safety profile (adverse events, vital signs, and ECG findings) of the two treatments that included theophylline were similar.

CONCLUSION

Patients with COPD may benefit from combination treatment with salmeterol plus theophylline, without a resulting increase in adverse events or other adverse sequelae.

Decreased steroid responsiveness at night in nocturnal asthma. Is the macrophage responsible?

As peripheral blood mononuclear cells from patients with nocturnal asthma (NA) exhibit reduced steroid responsiveness at 4:00 A.M. as compared with 4:00 P.M., we hypothesized that NA is associated with increased nocturnal airway cell expression of GRbeta, an endogenous inhibitor of steroid action. Ten subjects with NA and seven subjects with nonnocturnal asthma (NNA) underwent bronchoscopy with bronchoalveolar lavage (BAL) at 4:00 P.M. and 4:00 A.M. BAL lymphocytes and macrophages were incubated with dexamethasone (DEX) at 10(-5) to 10(-8) M. DEX suppressed proliferation of BAL lymphocytes similarly at 4:00 P.M. and 4:00 A.M. in both groups. However, BAL macrophages from NA exhibited less suppression of IL-8 and TNF-alpha production by DEX at 4:00 A.M. as compared with 4:00 P.M. (p = 0.0001), whereas in the NNA group DEX suppressed IL-8 and TNF-alpha production equally at both time points. GRbeta expression was increased at night only in NA, primarily due to significantly increased expression by BAL macrophages (p = 0.008). IL-13 mRNA expression was increased at night, but only in the NA group and addition of neutralizing antibodies to IL-13 reduced GRbeta expression by BAL macrophages. We conclude that the airway macrophage may be the airway inflammatory cell driving the reduction in steroid responsiveness at night in NA, and this function is modulated by IL-13.

Drug treatment of airway inflammation in asthma

Several methods are available for assessing drug effects on airway inflammation and the antiinflammatory effects of drugs for asthma. Cromolyn and theophylline are well-established drugs for the treatment of asthma, and each has antiinflammatory properties. Drugs in development include those aimed at inhibiting inflammatory mediators and immunoglobulin E function; clinical studies, however, have been conducted largely in patients with moderate to severe asthma.

Effect of a 4-week treatment with theophylline on sputum eosinophilia and sputum eosinophil chemotactic activity in steroid-naive asthmatics

BACKGROUND

The precise mechanism of action of theophylline in asthma is not fully understood but recent data have drawn attention to its potential anti-inflammatory effect.

OBJECTIVE

The purpose of this study was to assess the effect of theophylline on sputum eosinophilia and sputum eosinophil chemotactic activity in steroid-naive asthmatics.

METHOD

We performed a 4-week randomized double-blind, placebo-controlled, parallel group study in 21 mild to moderate steroid-naive asthmatics whose sputum eosinophilia was found twice > 5% during the run in period. Eleven subjects received 600 mg/24 h theophylline for the first 2 weeks and 900 mg/24 h for the last 2 weeks while 10 subjects took a placebo for 4 weeks. Sputum was induced after 2 and 4 weeks of treatment and 1 week after stopping the treatment. The sputum samples were compared for their cell counts, eosinophil cationic protein (ECP) levels and eosinophil chemotactic activity using micro-Boyden chambers.

RESULTS

Serum theophylline concentrations reached 7 and 11 microg/mL at V3 and V4, respectively. Intragroup comparisons showed that theophylline, but not placebo, caused a significant reduction in sputum eosinophil counts at V3 (62 +/- 10% from baseline, P < 0.01) and a strong trend at V4 (67 +/- 16% from baseline, P = 0.07) when compared to baseline. The intergroup difference obtained after comparing the area under the curve over the 4 week treatment period only approached the statistical significance (P = 0.08). At baseline the fluid phase of the sputum contained a significant eosinophil chemotactic activity which was inhibited after a 4-week treatment by theophylline (P < 0. 01) but not by placebo. The mean sputum theophylline levels after 4 weeks of treament (1.7 microg/mL) was lower than that required to cause significant inhibition of eosinophil chemotaxis in vitro.

CONCLUSION

Theophylline decreases the natural sputum eosinophil chemotactic activity present in asthmatics. However, when using a small sample size, the 35% reduction in sputum eosinophilia achieved by theophylline failed to reach statistical significance when compared to that seen after placebo.

The pathobiologic implications for treatment. Old and new strategies in the treatment of chronic asthma

An increased understanding of the pathobiology of asthma has led to improved treatment for chronic asthma. This article discusses the old and new strategies of asthma therapy based on a pathobiologic approach. Therapeutic agents discussed include beta-adrenergic agonists, methylxanthines, corticosteroids, cromolyn, nedocromil, leukotriene modifiers, and new investigational agents.

Circadian rhythms in the pharmacokinetics and clinical effects of beta-agonist, theophylline, and anticholinergic medications in the treatment of nocturnal asthma

Published asthma consensus reports now acknowledge that asthma is a nocturnal disease in as many as 75% of those afflicted by this medical condition. Nonetheless, the treatment of this chronic obstructive pulmonary disease in the clinic continues to be based primarily on homeostatic considerations in that it relies on long-acting bronchodilator and other therapies formulated and scheduled to ensure constant or near-constant levels of medication during the 24h. The need of asthma patients prone to nighttime attacks is not the same during the day and night; the therapeutic requirements of patients who experience nocturnal asthma, especially ones with the more severe forms of the disease, are often not satisfied by conventional medications. The therapeutic response and patient tolerance to bronchodilator medications can be improved markedly when the medications are proportioned during the 24h as a chronotherapy, that is, when more medication is delivered during nighttime sleep than daytime activity, as verified by numerous studies. This article reviews how the body's circadian rhythms influence the pharmacokinetics and effects of commonly prescribed asthma therapies and addresses why and how they must be taken into consideration to increase the effectiveness of asthma treatment.

The role of theophylline in asthma management

Views on the appropriate use of theophylline in asthma management have varied substantially over the past decades. The recent emphasis on potential anti-inflammatory effects of theophylline has only added to the debate. In current guidelines, theophylline has been positioned mainly as a form of "add-on" therapy in moderate to severe persistent asthma. The purpose of this review is to analyze whether recent developments have been made that allow for a further positioning of theophylline in the treatment of asthma.

Reduction in health care resource utilization associated with extended-release theophylline

BACKGROUND

People with airway disease are high utilizers of health care resources. Few studies document the value of alternative therapies in reducing utilization. Studies examining theophylline, which demonstrate reduction in resource utilization, have been primarily of short duration in hospitalized settings with small samples.

OBJECTIVE

The purpose of this study was to examine the role of oral extended-release theophylline in reducing health care utilization over an extended period of time when added to existing inhaler therapy for ambulatory patients with airway disease.

METHODS

We used a retrospective, pretest/posttest design in examining the 1990-1993 South Carolina Medicaid database to compare health care utilization of 455 ambulatory patients for 4 months before and 6 months after extended-release theophylline was added to their treatment regimen. We assessed the following three outcomes: inhaler use, physician office visits, and emergency department visits, all measured in units/person/month.

RESULTS

Our sample consisted of patients taking beta2-agonist only (n = 393), steroid only (n = 25), and beta2-agonist plus steroid (n = 37). Inhaler use and physician office visits declined significantly among beta2-agonist users, as well as within the entire sample. Initiation of extended-release theophylline therapy was associated with a 30% decline in utilization of inhaler and physician office visits, influenced mostly by the decline with the beta2-agonist group.

CONCLUSION

The results of this effectiveness study using an administrative claims database are consistent with the published randomized clinical trials that document the value of extended-release theophylline when added to existing inhaler therapy.

Anti-oxidative effects of theophylline on human neutrophils involve cyclic nucleotides and protein kinase A

The effects were studied of the non-specific phosphodiesterase inhibitor, theophylline (37.5-300 microM), on intracellular levels of cyclic adenosine monophosphate (cAMP) and superoxide generation following exposure of human neutrophils to four different stimuli of neutrophil membrane-associated oxidative metabolism, each of which utilizes a different transductional mechanism to activate NADPH-oxidase, in vitro. Exposure of neutrophils to FMLP (1 microM), the calcium ionophore A23187 (1 microM), and opsonized zymosan (OZ, 0.5 mg/ml) was accompanied by activation of superoxide production and increased concentrations of intracellular cAMP. Inclusion of theophylline resulted in augmentation of cAMP and inhibition of superoxide production by these stimuli. These negative effects of theophylline on neutrophil superoxide generation were mimicked by dibutyryl cAMP and 8-bromo-cGMP, while the inhibitory activity of all 3 agents was antagonized by the protein kinase A inhibitor KT 5720, but not by the G-kinase inhibitor KT 5823. Unlike FMLP, OZ and A23187, intracellular cAMP levels did not increase in cells activated with phorbol-12-myristate-13-acetate (PMA, 25 ng/ml), while oxidant production activated by this stimulus was insensitive to the inhibitory effects of theophylline. These observations suggest that the beneficial, anti-inflammatory interactions of theophylline with human neutrophils are related to the phosphodiesterase inhibitory properties of this agent, and are selective for those pro-inflammatory stimuli which elevate cAMP, resulting in enhanced activity of protein kinase A and inhibition of the production of potentially harmful reactive oxidants by these cells.

Theophylline. A review of its potential steroid sparing effects in asthma

Theophylline is generally considered to be a bronchodilatory drug. However, recent pharmacodynamic studies indicate that it has anti-inflammatory effects. It reduced eosinophil survival rates in vitro, and reduced eosinophil accumulation in bronchial tissue in patients with atopic asthma. Theophylline has also been shown to reduce T cell proliferation and accumulation. These changes were mirrored by improved pulmonary function in patients with asthma in studies that evaluated this parameter. Three randomised double-blind studies have evaluated the potential role of theophylline as an anti-inflammatory treatment in patients with asthma not controlled by low doses of inhaled corticosteroids. Patients were randomised to receive low dose theophylline (400 to 750 mg daily) plus low dose inhaled corticosteroids, or an increased dose of inhaled corticosteroids. Clinical pulmonary function improved to the same or a greater extent in patients who received low dose inhaled corticosteroids plus theophylline than in those treated with high dose inhaled corticosteroids plus placebo. Where reported, the dosages of theophylline used in these studies resulted in serum theophylline concentrations of approximately 9 to 10 mg/L. Approximate monthly costs were provided in one study: these were $60 (year and currency not specified) for theophylline plus budesonide 800 micrograms/day, compared with $100 for budesonide 1600 micrograms/day, and $155 for a regimen of budesonide 800 micrograms/day and salmeterol 100 micrograms/day.

CONCLUSIONS

Low dose theophylline has been shown to reduce requirements for inhaled corticosteroid therapy in patients with asthma and may reduce overall treatment costs.

Theophylline inhibits the late asthmatic response to nighttime antigen challenge in patients with mild atopic asthma

BACKGROUND

Inhaled antigen at night causes a more pronounced late asthmatic response (LAR) when compared with daytime challenges. Chronopharmacology with controlled-release theophylline given in the evening leads to a peak serum theophylline concentration (STC) in early morning which coincides with LAR that follows an evening challenge.

OBJECTIVE

To evaluate the effect of controlled-release theophylline given with the evening meal on the immediate asthmatic response (IAR) and LAR following nighttime antigen challenge in patients with mild atopic asthma.

METHODS

To qualify, subjects underwent antigen bronchoprovocation by graded nebulization until the IAR (fall in FEV1 of > or =20%) occurred; spirometry was then measured hourly for 8 hours to establish the presence of LAR (fall in FEV1 > or =15%). After 2 weeks of randomized, double-blind crossover treatment with either theophylline (target STC of 10 to 15 mg/L, (56 to 83 micromol/L)) or placebo, inhaled antigen challenge was performed at 10 PM in each subject. FEV1 values were measured immediately and then hourly for 8 hours following antigen challenge.

RESULTS

Twelve subjects completed the study. During the placebo phase, the maximal fall in FEV1 during LAR was 39 +/- 3% (mean +/- SEM) compared with 31 +/- 4% fall during theophylline treatment phase (P = .01). A reduction in LAR occurred despite higher dose (P <.05) of inhaled antigen during theophylline phase, which would have been expected to result in a more pronounced LAR. Serum theophylline concentration at 8 AM on the day following antigen challenge was 9.6 +/- 1.1 mg/L (53 +/- 6 micromol/L).

CONCLUSION

Nocturnal administration of controlled-release theophylline increases the tolerance to inhaled antigen and reduces severity of LAR. Because the LAR is linked to airway inflammation, these data support the possibility of antiinflammatory effects associated with theophylline use.

Theophylline: recent advances in the understanding of its mode of action and uses in clinical practice

Theophylline, a drug that has been used for several decades, has several different actions at a cellular level, including inhibition of phosphodiesterase isoenzymes, antagonism of adenosine, enhancement of catecholamine secretion, and modulation of calcium fluxes. Recently, theophylline was found to have several immunomodulatory and anti-inflammatory properties, and thus interest in its use in patients with asthma has been renewed. The use of theophylline in the treatment of asthma and chronic obstructive pulmonary disease has diminished with the advent of new medications, but theophylline remains beneficial, especially in the patient with difficult refractory symptoms. In the future, theophylline may be used as treatment for bradyarrhythmias after cardiac transplantation, prophylactic medication to reduce the severity of nephropathy associated with intravenous administration of contrast material, therapy for breathing problems during sleep, and treatment for leukemias.

Disease management of COPD with pulmonary rehabilitation

Pulmonary rehabilitation is a set of tools and disciplines that attends to the multiple needs of the COPD patient. It extends beyond standard care by addressing the disabling features of chronic and progressive lung disease. It centers on self-management, exercise, functional training, psychosocial skills, and contributes to the optimization of medical management. Exercise enables other components by building strength, endurance, confidence, and reducing dyspnea. Patients who have undergone rehabilitation often enjoy a reduced need for health-care utilization. On the downside, rehabilitation is a one-time intervention, the benefits of which dissolve over time. The patient's physician is rarely a participant in the program; thus, the physician is at a disadvantage in being able to support a long-term response. Rehabilitation is available to a small percentage of a large patient population who could benefit. Optimal disease management would entail redesigning standard medical care to integrate rehabilitative elements into a system of patient self-management and regular exercise. It should emphasize physician involvement in self-management, which is essential in developing and maintaining an effective exacerbation protocol. Pulmonary rehabilitation should take its place in the mainstream of disease management through its integrative and reconciliative role in the multidisciplinary continuum of services, as defined by the National Institutes of Health, Pulmonary Rehabilitation Research, Workshop of 1994.

Theophylline infusion modulates prostaglandin and leukotriene production in man

Although theophylline has been used in the treatment of asthma for decades, it is not a first line choice any more. It is a well-known bronchodilator, but was recently discovered also to be an anti-inflammatory, immunomodulatory and bronchoprotective agent. Therefore we wanted to establish the role of theophylline on prostaglandin and leukotriene production, which plays a part in the pathogenesis of asthma. Theophylline was infused (bolus 5 mg/kg in 15 min and infusion 0.4 mg/kg/h for 1 h 45 min) into healthy volunteers. Thromboxane B2, prostaglandin E2 and leukotriene E4 were measured from the A23187-stimulated whole blood samples and stable metabolites of thromboxane A2; prostacyclin and leukotriene E4 were measured from urine. Theophylline increased prostaglandin E2 production and decreased leukotriene E4 production ex vivo in whole blood, thus increasing the prostanoid/leukotriene ratio. It did not change thromboxane B2 production stimulated by either spontaneous clotting or A23187 in the whole blood. Theophylline had hardly any effect on in vivo thromboxane, prostacyclin and leukotriene E4 production measured as urinary metabolites, 11-dehydro-thromboxane B2, 2,3-dinor-6-keto-prostaglandin F1alpha and leukotriene E4, respectively. Serum theophylline concentrations were at the lower level of normal therapeutic range during the infusion. The increase in PGE2 and the decrease in LTE4 synthesis ex vivo may offer a new explanation for the mode of antiasthmatic action of theophylline. It is notable that this phenomenon occurs at low serum theophylline concentrations. These results confirm the idea that theophylline has an anti-inflammatory and bronchoprotective action and support the use of theophylline as a therapeutic agent in asthmatic patients.