Anticholinergic agents in asthma: chronic bronchodilator therapy, relief of acute severe asthma, reduction of chronic viral inflammation and prevention of airway remodeling

Banhahubak-Tang Tablet, a Standardized Medicine Attenuates Allergic Asthma via Inhibition of Janus Kinase 1 (JAK1)/ Signal Transducer and Activator of Transcription 6 (STAT6) Signal Pathway

Exposure to particulate matter (PM) has been known to be one of the risk factors to cause allergic asthma, leading to development of respiratory disease. Banhahubak-tang tablet (BHT), a standardized Korean Medicine, is prescribed for neurasthenia, laryngopharyngitis and asthma. In this study, we investigated therapeutic effects of BHT on airway inflammation in ovalbumin (OVA) and PM smaller than 10 μm (PM10)-induced allergic asthma mice. To establish allergic asthma with airway hyper-responsiveness by PM10, BALB/c mice were sensitized and challenged with OVA and PM10, and orally administered BHT. Histological staining was performed to assess airway remodeling. Serum and bronchoalveolar lavage fluid (BALF) was collected for measuring immunoglobulin levels and counting inflammatory cells, respectively. Expression levels of Janus kinase 1 (JAK1)/signal transducer and activator of transcription 6 (STAT6), pro-inflammatory cytokines and type 2 T-helper (Th2)-related cytokines were analyzed in vivo and in vitro models. Histopathological analysis demonstrated that BHT suppressed inflammatory cell infiltration, mucus hypersecretion and collagen deposition in the airway. BHT administration effectively decreased number of inflammatory cells in BALF. BHT reduced total serum Immunoglobulin E (IgE) and Immunoglobulin G (IgG) levels. In addition, BHT significantly inhibited the phosphorylation of JAK1 and STAT6 expressions. Release of pro-inflammatory cytokines and Th2-related cytokines were down-regulated by BHT. In conclusion, BHT mitigated airway inflammation by down-regulating pro-inflammatory and Th2-related cytokines via JAK1/STAT6 signaling. BHT might be a promising herbal medicine for preventing airway inflammation. Moreover, an intervention study among humans is needed to further evaluate the possible beneficial effects of BHT in allergic asthma.

Efficacy and safety profile of doxofylline compared to theophylline in asthma: a meta-analysis

Background

Oral methylxanthines are effective drugs for the treatment of chronic obstructive respiratory disorders. The novel methylxanthine doxofylline, that has bronchodilator and anti-inflammatory activities, is not affected by the major drawback of theophylline. Nowadays large-scale quantitative synthesis comparing the efficacy and safety profile of doxofylline vs. theophylline in the treatment of asthma is still lacking. Therefore, we performed a quantitative synthesis to compare the efficacy/safety profile of doxofylline and theophylline in asthma.

Methods

A pairwise and network meta-analyses were performed to assess the impact of doxofylline vs. theophylline and placebo on the change in asthma events, risk of adverse events (AEs), forced expiratory volume in 1 s (FEV₁), and salbutamol use.

Results

Data obtained from 696 asthmatic patients were extracted from 4 randomized controlled trials published between 2015 and 2018. Doxofylline was significantly (P < 0.05) more effective than theophylline in reducing the daily asthma events (mean difference − 0.14, 95%CI -0.27 – 0.00) and risk of AEs (relative risk 0.76, 95%CI 0.59–0.99). Doxofylline was as effective as theophylline in improving FEV₁, and a trend of superiority (P = 0.058) was detected for doxofylline over theophylline with respect to the reduction in the use of salbutamol as rescue medication. The rank of effectiveness was doxofylline>theophylline> > placebo, and the rank of safety was placebo>doxofylline> > theophylline.

Conclusions

Doxofylline is an effective and safe methylxanthine for the treatment of asthma, with an efficacy/safety profile greater than that of theophylline.

Trial registration

Meta-analysis registration: CRD42019119849.

Tiotropium in asthma: From bench to bedside

OBJECTIVE

Tiotropium is a long-acting muscarinic antagonist approved for maintenance treatment of asthma in children, adolescents, and adults in the United States, and recommended as add-on treatment for uncontrolled asthma despite treatment with inhaled corticosteroids and/or long-acting beta-2 agonists. This review traces the journey of tiotropium from its historical origins through early preclinical testing to human clinical trials and real-life studies.

DATA SOURCES

A search was performed in PubMed using search terms 'tiotropium' and 'asthma.' Relevant references cited in those articles were reviewed.

STUDY SELECTIONS

English language articles published from December 2008-December 2018 were screened. Articles evaluating the efficacy, cost-effectiveness, real-life evidence, and steroid-sparing effect of tiotropium with inadequately controlled asthma were included.

RESULTS

Anticholinergics have a long history of use in the treatment of obstructive airway diseases. Evidence indicates that tiotropium's mechanism of action consists of bronchodilation and diminished mucus secretion, with preclinical evidence suggesting an anti-inflammatory effect as well. Phase 2 and 3 clinical trials have demonstrated that tiotropium is efficacious and safe, resulting in significant improvements in lung function in adults, adolescents, and children across asthma severities. Emerging evidence suggests that add-on tiotropium might potentially enable reductions in inhaled corticosteroid dose in patients with uncontrolled asthma. Further, tiotropium is a cost-effective treatment option that is also effective in the clinical practice setting.

CONCLUSIONS

An increasing body of evidence indicates that tiotropium can play a significant role in the treatment of patients with uncontrolled asthma.

Crosstalk between mAChRM3 and β2AR, via acetylcholine PI3/PKC/PBEP1/Raf-1 MEK1/2/ERK1/2 pathway activation, in human bronchial epithelial cells after long-term cigarette smoke exposure

BACKGROUND

Cigarette smoke extract (CSE) affects the expression of non-neuronal components of cholinergic system in bronchial epithelial cells and, as PEBP1/Raf-mediated MAPK1/2 and ERK1/2 pathway, promotes inflammation and oxidative stress.

AIMS

We studied whether Acetylcholine (ACh) is involved in the mechanism of crosstalk between mAChRM3 and β2Adrenergic receptors (β2AR) promoting, via PI3/PKC/PBEP1/Raf/MEK1/2/ERK1/2 activation, β2AR desensitization, inflammation and, oxidative stress in a bronchial epithelial cell line (16HBE) after long-term exposure to cigarette smoke extract (LECSE).

METHODS

We evaluated mAChRM3 and Choline Acetyltransferase (ChAT) expression, ACh production, PEBP1, ERk1/2, and β2AR phosphorylation, as well as NOX-4, ROS production and IL-8 release in 16HBE after LECSE. The inhibitory activity of Hemicholinium (HCh-3) (a potent choline uptake blocker), LY294002 (a highly selective inhibitor of PI3 kinase), Tiotropium (Spiriva®) (anticholinergic drug) and Olodaterol (β2AR agonist), were tested in 16HBE after LECSE.

RESULTS

mAChRM3, ChAT, ACh activity, pPEBP1, pβ2AR, pERK1/2, ROS, NOX-4 and IL-8 increased after LECSE in 16HBE LECSE compared to untreated cells. HCh-3 and LY294002 (alone or in combination) as well as Tiotropium (Spiriva®) or Olodaterol (alone or in combination) all reduced the levels of pPEBP1, pβ2AR, pERK1/2, ROS, NOX-4, and IL-8 in 16HBE LECSE compared to untreated cells.

CONCLUSIONS

LECSE promotes ACh production which enhances PI3/PKC/PEBP1/Raf-ERK1/2 pathway activation, heterologous β2AR desensitization, as well as release of inflammatory and oxidative mediators in bronchial epithelial cells. The use of anticholinergic drugs and long-acting β2-agonists, alone or in combination may be dampen these inflammatory mechanisms when used in combination in some epithelial cell types.

Study of pharmacokinetic interaction of paroxetine and roxithromycin on bencycloquidium bromide in healthy subjects

PURPOSE

The aim of this study was to investigate the potential drug-drug interaction between Bencycloquidium bromide (BCQB) and paroxetine, and between BCQB and roxithromycin.

METHODS

Two studies were conducted on healthy male Chinese volunteers. Study A was an open-label, two-period, one-sequence crossover study (n=21). Each participant received a single nasal spray dose of BCQB 180μg on day 1. After a 7-day wash-out period, subjects received 20mg of paroxetine from day 8 to 17, and were co-administered 20mg of paroxetine and BCQB 180μg on day 18. In study B, participants (n=12) were randomly assigned to two groups. In period I, group A received BCQB 180μg on day 1, followed by the same dose four times daily from day 4 to 10, then, on day 11 a single dose of 150mg roxithromycin with BCQB 180μg were co-administered. In parallel, group B received a single dose of roxithromycin 150mg on day 1, followed by 300mg of roxithromycin from day 4 to 10, then, on day 11 a single dose of BCQB 180μg with roxithromycin 300mg were co-administered. After a wash-out time of 7days the respective treatments of each group (A and B) were swapped in period II. Blood samples were collected for pharmacokinetic analysis. Statistical comparison of pharmacokinetic parameters was performed to identify a possible drug interaction between treatments. Tolerability was evaluated by recording adverse events.

RESULTS

Study A: Geometric mean AUC0-36 for BCQB alone and co-administered with paroxetine were 474.3 and 631.3pgh/ml, respectively. The geometric mean ratio (GMR) of AUC0-36 was 1.33 (1.13-1.46), 90% C.Is, and was out the predefined bioequivalence interval (90% C.Is, 0.80-1.25). Geometric mean Cmax were 187.0 and 181.2pg/ml. Study B: The GMR of AUC0-36 was 0.98 (0.90-1.07), 90% C.Is for BCQB, and the GMR of AUC0-72 was 0.98 (0.87-1.11), 90% C.Is for roxithromycin. Both GMRs were within the predefined bioequivalence interval (90% C.Is, 0.80-1.25). Other pharmacokinetic parameters were within the predefined interval. No serious adverse events were reported and no significant clinical changes were observed in laboratory test results, vital signs and ECGs in any of the studies. All treatments were well tolerated.

CONCLUSION

The co-administration of BCQB with paroxetine showed a moderate increase in BCQB exposure, but was not clinically relevant. Also, no drug interaction was found between BCQB and roxithromycin.

Refractory asthma - beyond step 5, the role of new and emerging adjuvant therapies

A small percentage of asthmatics have 'severe refractory asthma', where there is suboptimal response to currently available therapies. A number of novel therapies targeting key biological targets are becoming available. Asthma is a heterogeneous disease, and systematic evaluation of patients is important to target therapies to the underlying inflammatory subtype and clinical features. This review article outlines new and emerging treatments for severe asthma, including monoclonal antibodies targeting eosinophilic disease, anti-neutrophil strategies, novel bronchodilators and bronchial thermoplasty. We highlight the importance of individualized investigation, treatment and management of severe asthmatics.

Anticholinergics/antimuscarinic drugs in asthma

Anticholinergic alkaloids have been used for thousands of years for the relief of bronchoconstriction and other respiratory symptoms, and their use in the treatment of chronic obstructive pulmonary disease is well established. Acetylcholine, acting through muscarinic receptor (M) receptor, modulates multiple physiologic functions pertinent to asthma including airway muscle tone, mucus gland secretion, and various parameters of inflammation and remodeling. In addition, activation of M receptors may inhibit beta2 adrenoreceptor. These observations offer the rationale for the use of M receptors antagonists in the treatment of asthma. Short-acting antimuscarinic agents may be effective alone or in combination with short-acting beta agonists for the relief of acute symptoms. Long-acting antimuscarinic agents have emerged as potentially useful in the long-term treatment of difficult-to-control asthma. This review will analyze the mechanisms of action and therapeutic role of antimuscarinic agents on asthma including current guidelines regarding antimuscarinic drugs, recent studies in asthma, special populations to consider, and possible predictors of response.

Tiotropium sustains the anti-inflammatory action of olodaterol via the cyclic AMP pathway

Mesenchymal cells (fibroblasts) of the airway wall respond to cholinergic stimulation by releasing pro-inflammatory and chemotactic cytokines and may thus contribute to chronic inflammation of the lung. Here, we studied the anti-inflammatory potential of olodaterol, a long acting β2-adrenergic receptor agonist, and tiotropium, a long-acting muscarinic receptor antagonist, and whether they interact at the level of the cyclic AMP dependent signaling pathway. Pulmonary fibroblasts of asthmatic (n = 9) and non-asthmatic (n = 8) subjects were stimulated with the muscarinic receptor agonist carbachol and interleukin-1β (IL-1 beta) in presence or absence of tiotropium or olodaterol alone, or their combination. We also measured cAMP levels and phosphorylation of the cAMP response element binding protein (CREB). As single components, carbachol, olodaterol and tiotropium did not affect IL-6 and IL-8 release. Carbachol concentration-dependently enhanced the production of IL-1β-induced IL-6 and IL-8, which was blocked by the simultaneous addition of tiotropium. The combination of olodaterol plus tiotropium further reduced IL-6 and IL-8 release. Olodaterol induced cAMP and the phosphorylation of CREB, an effect counteracted by carbachol, but rescued by tiotropium. We conclude that olodaterol plus tiotropium cooperate to decrease the inflammatory response in pulmonary fibroblasts in vitro.

The emerging role of tiotropium for patients with asthma

OBJECTIVE

To review clinical data on the use of the long-acting anticholinergic agent tiotropium in patients with asthma.

DATA SOURCES

A literature search was performed via EMBASE and MEDLINE (1966-November 2012). The search was limited to human data published in the English language. Search terms included asthma, tiotropium, and long-acting anticholinergics.

STUDY SELECTION AND DATA EXTRACTION

Relevant information related to the use of tiotropium in patients with asthma was reviewed. Randomized controlled trials and open-label trials were included. The references of published articles identified in the search were also examined for additional studies appropriate to include in the review. Data were prioritized if they originated from human studies, especially if derived from randomized, placebo-controlled trials. Trials and case reports involving the use of long-acting anticholinergic tiotropium in asthma patients were included; conversely, trials involving ipratropium were not.

DATA SYNTHESIS

Two large randomized controlled trials support the safety and efficacy of adding tiotropium to the treatment regimen of select patients with poorly controlled asthma already receiving combination high-dose glucocorticosteroid/long-acting β-agonist (LABA) therapy. Pharmacogenomic studies have shown that patients with polymorphisms of the β2-adrenoreceptor (ADRB2; 16 Arg/Arg and 16 Arg/Gly) are particularly responsive to treatment with tiotropium. Smaller studies indicate that the advantages may be most pronounced in patients with a predominance of sputum neutrophils and that tiotropium can assist with decreasing the inhaled corticosteroid (ICS) dose. An increased risk of cardiovascular events was not identified.

CONCLUSIONS

Tiotropium should be considered in patients with asthma who remain symptomatic while receiving high-dose ICS and LABA therapy. Specifically, patients with high sputum neutrophil levels or with 16 Arg/Arg or 16 Arg/Gly polymorphism of the ADRB2 gene appear to respond best.

Nicotinic acetylcholine receptor variants associated with susceptibility to chronic obstructive pulmonary disease: a meta-analysis

Background

Only 10-15% of smokers develop chronic obstructive pulmonary disease (COPD) which indicates genetic susceptibility to the disease. Recent studies suggested an association between COPD and polymorphisms in CHRNA coding subunits of nicotinic acetylcholine receptor. Herein, we performed a meta-analysis to clarify the impact of CHRNA variants on COPD.

Methods

We searched Web of Knowledge and Medline from 1990 through June 2011 for COPD gene studies reporting variants on CHRNA. Pooled odds ratios (ORs) were calculated using the major allele or genotype as reference group.

Results

Among seven reported variants in CHRNA, rs1051730 was finally analyzed with sufficient studies. Totally 3460 COPD and 11437 controls from 7 individual studies were pooled-analyzed. A-allele of rs1051730 was associated with an increased risk of COPD regardless of smoking exposure (pooled OR = 1.26, 95% CI 1.18-1.34, p < 10^-5). At the genotypic level, the ORs gradually increased per A-allele (OR = 1.27 and 1.50 for GA and AA respectively, p < 10^-5). Besides, AA genotype exhibited an association with reduced FEV1% predicted (mean difference 3.51%, 95%CI 0.87-6.16%, p = 0.009) and increased risk of emphysema (OR 1.93, 95%CI 1.29-2.90, p = 0.001).

Conclusions

Our findings suggest that rs1051730 in CHRNA is a susceptibility variant for COPD, in terms of both airway obstruction and parenchyma destruction.

Analytic review: management of life-threatening asthma in adults

Asthma remains a troubling health problem despite the availability of effective treatment. A small but significant number of asthmatics experience life-threatening attacks culminating in intensive care unit admission. Standard treatment includes high dose systemic corticosteroids and inhaled bronchodilators. Patients with especially severe attacks may develop respiratory failure and need endotracheal intubation and mechanical ventilation. Severe airway obstruction may lead to dynamic hyperinflation and the possibility of hemodynamic collapse and barotrauma. Fortunately, most intubated asthmatics survive if physicians adhere to key management principles intended to avoid or minimize hyperinflation. The purpose of this review is to discuss the pathogenesis of life-threatening asthma and to provide practical guidance to promote rationale, safe, and effective management.

M(3) muscarinic receptor antagonist bencycloquidium bromide attenuates allergic airway inflammation, hyperresponsiveness and remodeling in mice

M(3) muscarinic receptors are localized on inflammatory cells, airway smooth muscle, and submucosal glands, known to mediate bronchoconstriction, mucus secretion, and airway remodeling. It is hypothesized bencycloquidium bromide (BCQB), a novel M(3) receptor antagonist, might have potential effects on airway hyperresponsiveness, inflammation and airway remodeling in a murine model of asthma. Mice sensitized and challenged with ovalbumin developed airway inflammation. Bronchoalveolar lavage fluid was examined to determine the total and differential cell counts, and cytokine levels. Lung tissues were evaluated for cell infiltration, mucus hypersecretion, airway remodeling, and the expression of inflammatory biomarkers. Airway hyperresponsiveness was monitored by direct airway resistance analysis. Inhalation administration of BCQB significantly not only reduced ovalbumin-induced airway hyperresponsiveness comparing to methacholine, and prevented the ovalbumin-induced increase in total cell counts and eosinophil counts. Reverse transcriptase polymerase chain reaction analysis of whole lung lysates revealed that BCQB markedly suppressed ovalbumin-induced mRNA expression of eotaxin, IL-5, IL-4 and MMP-9, and increased mRNA expression of IFN-γ and TIMP-1 in a dose-dependent manner. Substantial IFN-γ/IL-4 (Th1/Th2) levels were recovered in bronchoalveolar lavage fluid after BCQB treatment. In addition, histological studies showed that BCQB dramatically inhibited ovalbumin-induced lung tissue eosinophil infiltration, airway mucus production and collagen deposition in lung tissues. Results reported in current paper suggest that M(3) receptors antagonist may provide a novel therapeutic approach to treat airway inflammation, hyperresponsiveness and remodeling.

Characterization of bencycloquidium bromide, a novel muscarinic M(3) receptor antagonist in guinea pig airways

In this study we have investigated the antagonist affinity, efficacy and duration of action of bencycloquidium bromide (BCQB), a selective muscarinic M(3) receptor antagonist, as a possible clinical bronchodilator for the treatment of chronic obstructive pulmonary disease (COPD) and asthma. In competition studies, BCQB showed high affinity toward the M(3) receptor in Chinese hamster ovary (CHO) cells (M(3) pKi=8.21, M(2) pKi=7.21, and M(1) pKi=7.86); pA(2)=8.85, 8.71 and 8.57 in methacholine-induced contraction of trachea, ileum and urinary bladder, 8.19 in methacholine-induced bradycardia of right atrium in vitro, respectively. In function studies, duration of inhibition of carbachol-induced tonic contraction, BCQB and ipratropium had a very similar onset and offset of action, but onset faster and offset slower than that of tiotropium. After treatment with intratracheally instilled or the inhalation route, BCQB protects against methacholine or antigen-induced bronchoconstriction in a dose-dependent manner in the normal and sensitized guinea pigs in vivo. BCQB and ipratropium-induced inhibitory activity was short lasting, as it declined quickly when compared to tiotropium. These results suggest that BCQB bind muscarinic M(3) receptors with high affinity. On this basis we speculate that a putative BCQB-based therapy for COPD might require more than once-a-day administration to be as effective as the currently employed once-daily therapy with tiotropium. Nevertheless, Inhalable M(3)-selective compounds may spare M(2)-cardiac receptors and reduce the risks of cardiovascular events associated with the long-term treatment of these agents.

An update on the safety of long-acting beta-agonists in asthma patients using inhaled corticosteroids

IMPORTANCE OF THE FIELD

Pooled trial data have shown that long-acting beta-agonists increase the risk for asthma hospitalizations and deaths by two to fourfold compared with placebo. Until recently, it was unclear whether concomitant inhaled corticosteroids (ICSs) could eliminate this risk.

AREAS COVERED IN THIS REVIEW

This review summarizes the available data on the safety of long-acting beta-agonist use in asthma, with and without concomitant ICSs. The results from an updated meta-analysis are presented, with data through December 2008.

WHAT THE READER WILL GAIN

In pooled trial data, catastrophic asthma events (defined as asthma-related intubation or death) were increased fourfold for concomitant treatment with long-acting beta-agonists and ICSs compared with corticosteroids alone (odds ratio 3.7; 95% CI 1.4 - 9.6). It is estimated that the addition of long-acting beta-agonists to ICS therapy is associated with an absolute increase of one catastrophic event per 1500 patient-years.

TAKE HOME MESSAGE

When the available trial data are pooled together, it is clear that long-acting beta-agonists significantly increase the risk for asthma-related intubations and deaths, even when used in a controlled fashion with concomitant ICSs. Clinical guidelines should readdress the role long-acting beta-agonists have in the management of asthma.

Long-acting beta-agonists with and without inhaled corticosteroids and catastrophic asthma events

BACKGROUND

It is unclear whether long-acting beta-agonists with concomitant inhaled corticosteroids increase asthma-related intubations and deaths. We pooled data on long-acting beta-agonists with variable and concomitant inhaled corticosteroids to evaluate the risk for catastrophic asthma events.

METHODS

We conducted searches of electronic databases, the US Food and Drug Administration website, clinical-trials registries, and selected references through December 2008. We analyzed randomized controlled trials in patients with asthma, which lasted at least 3 months, evaluated long-acting beta-agonists compared with placebo or long-acting beta-agonists with inhaled corticosteroids compared with corticosteroids alone, and included at least 1 catastrophic event, defined as asthma-related intubation or death.

RESULTS

In pooled trial data that included 36,588 participants, long-acting beta-agonists increased catastrophic events 2-fold (Peto odds ratio [OR] 2.10; 95% confidence interval [CI], 1.37-3.22). Statistically significant increases were seen for long-acting beta-agonists with variable corticosteroids compared with placebo (OR 1.83; 95% CI, 1.14-2.95) and for concomitant treatment with corticosteroids compared with corticosteroids alone (OR 3.65; 95% CI, 1.39-9.55). Similar increases in risk were seen for variable and concomitant corticosteroid use, salmeterol and formoterol, and children and adults. When the analysis was restricted to trials with controlled corticosteroid use, given as part of the study intervention, concomitant treatment still increased catastrophic events compared with corticosteroids alone (OR 8.19; 95% CI, 1.10-61.18).

CONCLUSION

Long-acting beta-agonists increase the risk for asthma-related intubations and deaths, even when used in a controlled fashion with concomitant inhaled corticosteroids.

Tiotropium bromide: an update

Tiotropium bromide is a once-daily inhaled anticholinergic bronchodilator. It works by blocking the muscarinic receptors in airway smooth muscle. Tiotropium has a wide therapeutic margin, due to its poor gastrointestinal absorption and its very low systemic bioavailability. The drug is mainly indicated in COPD patients. Clinically relevant outcomes such as significant improvements in spirometry, hyperinflation, dyspnea, heath status, acute exacerbations and mortality have been consistently observed in tiotropium clinical trials, and the drug has been shown to reduce the risk of mortality due to cardiac-vascular disease and respiratory failure. The main side effect reported is dryness of the mouth. Some subgroups of asthmatics also seem to respond to anticholinergic drugs: among them, those with the Arg/Arg genotype for the beta2-adrenergic receptor and those with a high percentage of neutrophils in sputum.

The effect of tiotropium therapy on markers of elastin degradation in COPD

Background

Desmosine and Isodesmosine (D/I) are cross-linking amino acids which are present only in mature elastin. Changes in their concentration in body fluids indicate changes in elastin degradation and can be a reflection of tissue elastase activity. This study was undertaken to determine whether continuous therapy with the long-acting bronchodilator Tiotropium bromide (TTP) could result in reductions in D/I as measured by mass spectrometry in plasma, urine and sputum.

Methods

Twelve not currently smoking patients with chronic obstructive pulmonary disease (COPD), never on TTP, were selected for study. Levels of D/I, along with measurements of FVC, FEV₁ and FEV₁/FVC. were determined before starting TTP daily, and then one and two months after.

Results

D/I decreased in plasma (10 of 12 patients), in sputum all (12 of 12), and in the percentage of free D/I in urine (10 of 12). Most patients showed slight increases in FVC and FEV₁ percent predicted over two months.

Conclusion

The results are consistent with an effect of prolonged bronchodilitation by anti-cholinergic blockade to also result in reduced lung elastin degradation.

Chronic obstructive pulmonary disease: an evidence-based approach to treatment with a focus on anticholinergic bronchodilation

Chronic obstructive pulmonary disease is a prevalent condition associated with a high societal burden. Despite a decrease in the prevalence of smoking in the United States, the rates of morbidity and mortality associated with chronic obstructive pulmonary disease are expected to continue to increase. Appropriate treatment can have an important impact on many facets of the disease. This article reviews evidence gathered in a PubMed search of papers published from January 1, 2004, to December 31, 2007. The search terms used were chronic obstructive pulmonary disease, epidemiology, practice guidelines, clinical trial, and meta-analysis. Selection of pharmacological therapy is based on severity of disease and differences among the effects of drugs on various end points, including the criterion standard, forced expiratory volume in the first second of expiration. Other important variables, which are closely related to patients' perception of their condition, include reduction in acute exacerbations, improved quality of life, improved exercise performance, and reduced hyperinflation. When maintenance therapy is indicated, clinical evidence suggests initiating treatment with a long-acting agent, either a once-daily anticholinergic or a twice-daily beta2-agonist. If combination therapy is indicated, data support using long-acting drugs from different classes that provide complementary modes of action (beta2-agonist, anticholinergic, inhaled corticosteroid). In this setting, inhaled corticosteroids may further reduce exacerbations when given with a beta2-agonist, an anticholinergic, or both.