Efficacy and safety profile of xanthines in COPD: a network meta-analysis

Theophylline derivatives promote primordial follicle activation via cAMP-PI3K/Akt pathway and ameliorate fertility deficits in naturally aged mice

In elderly women and patients with premature ovarian insufficiency (POI), activating their remaining dormant primordial follicles in vivo is challenging. In this study, we found that phosphodiesterase (PDE) subtypes were expressed mainly in primordial follicle oocytes. The specific PDE inhibitors and theophylline derivatives (aminophylline, dyphylline, and enprofylline) activated primordial follicles in neonatal mice by ovary culture and intraperitoneal injection. These inhibitors also increased the levels of ovarian cyclic adenosine monophosphate (cAMP) and oocyte phosphorylated protein kinase B (p-Akt). The blockade of gap junctions using carbenoxolone (CBX) increased the levels of ovarian cAMP and pre-granulosa cell phosphorylated mammalian target of rapamycin (p-mTOR), suggesting that oocyte PDEs hydrolyze cAMP from pre-granulosa cells through gap junctions to maintain primordial follicle dormancy. Importantly, oral aminophylline improved ovulated oocyte quantity and quality, and increased offspring numbers in naturally aged mice. In addition, theophylline derivatives also activated human primordial follicles and increased p-Akt levels. Thus, theophylline derivatives activate primordial follicles by accumulating cAMP levels and activating phosphatidylinositol 3-kinase (PI3K)/Akt pathway in oocytes, and oral aminophylline increased fertility in naturally aged female mice by improving ovulated oocyte quantity and quality. As oral medications, theophylline derivatives may be used to improve fertility in elderly women and patients with POI.

A narrative review of theophylline: is there still a place for an old friend?

Background and Objective

Theophylline has been used for decades in human medicine for its psychostimulant, anti-inflammatory, and bronchodilator effects. Historically, in pulmonary medicine, theophylline has been used in the treatment of obstructive pulmonary diseases such as bronchial asthma (BA) or chronic obstructive pulmonary disease (COPD). This review aims to determine whether theophylline still has its place in the therapy of obstructive pulmonary diseases or whether we can even extend its use to other diagnoses such as atropine-resistant cardiac arrests, apnea of prematurity, or others. Moreover, we also aim to determine if there is a rationale for using low-dose theophylline due to its immunomodulatory and anti-inflammatory effect, or if the future of methylxanthines lies in newly synthesized derivates of theophylline such as bamifylline, or doxofylline.

Methods

The narrative review is based on a literature search of the articles indexed in the PubMed database in 2023. We searched the database since the year 2009 using the MeSH terms "theophylline", "aminophylline", and "methylxanthines" and we included original articles in the English language.

Key Content and Findings

Theophylline has a number of adverse drug reactions (ADRs), the most serious of which is its effect on the cardiovascular system. It can cause severe arrhythmias or even cardiac arrest when overdosed. On the other hand, there is still a substantial amount of its applications in current clinical practice.

Conclusions

There is considerable controversy associated with its use in current medicine, which can be attributed both to its narrow therapeutic range and its mentioned cardiotoxic effect. Herein, we summarize the current state-of-art of theophylline and its use in human medicine.

Impact of the cAMP efflux and extracellular cAMP-adenosine pathway on airway smooth muscle relaxation induced by formoterol and phosphodiesterase inhibitors

β2-adrenoceptors agonists and phosphodiesterase (PDE) inhibitors are effective bronchodilators, due to their ability to increase intracellular cyclic AMP (cAMP) levels and induce airway smooth muscle (ASM) relaxation. We have shown that increment of intracellular cAMP induced by β2-adrenoceptors agonist fenoterol is followed by efflux of cAMP, which is converted by ecto-PDE and ecto-5'-nucleotidases (ecto-5'NT) to adenosine, leading to ASM contraction. Here we evaluate whether other classical bronchodilators used to treat asthma and chronic obstructive pulmonary disease (COPD) could induce cAMP efflux and, as consequence, influence the ASM contractility. Our results showed that β2-adrenoceptor agonists formoterol and PDE inhibitors IBMX, aminophylline and roflumilast induced cAMP efflux and a concentration-dependent relaxation of rat trachea precontracted with carbachol. Pretreatment of tracheas with MK-571 (MRP transporter inhibitor), AMP-CP (ecto-5'NT inhibitor) or CGS-15943 (nonselective adenosine receptor antagonist) potentiated the relaxation induced by β2-adrenoceptor agonists but did not change the relaxation induced by PDE inhibitors. These data showed that all bronchodilators tested were able to induce cAMP efflux. However, only β2-adrenoceptor-induced relaxation of tracheal smooth muscle was affected by cAMP efflux and extracellular cAMP-adenosine pathway.

Phosphodiesterase inhibitors and lung diseases

Phosphodiesterase enzymes (PDE) have long been known as regulators of cAMP and cGMP, second messengers involved in various signaling pathways and expressed in a variety of cell types implicated in respiratory diseases such as airway smooth muscle and inflammatory cells making them a key target for the treatment of lung diseases as chronic obstructive pulmonary disease (COPD), asthma, cystic fibrosis, and pulmonary hypertension (PH). The first reported PDE inhibitor was the xanthine, theophylline, described as a non-specific PDE inhibitor and whilst this drug is effective, it also has a range of unwanted side effects. In an attempt to improve the therapeutic window of xanthines, a number of selective PDE inhibitors have been developed for the treatment of respiratory diseases with only the selective PDE 4 inhibitor, roflumilast, being approved for the treatment of severe COPD. However, roflumilast also has a very narrow therapeutic window due to a number of important doses limiting side effects, particularly in the gastrointestinal tract. However, there continues to be research carried out in this field to identify improved selective PDE inhibitors, both by targeting other PDE subtypes (e.g., PDE 7 found in a number of inflammatory and immune cells) and through development of selective PDE inhibitors for pulmonary administration to reduce systemic exposure and improve the side effect profile. This approach has been exemplified by the development of ensifentrine, a dual PDE 3-PDE 4 inhibitor, an inhaled drug that has recently completed two successful Phase III clinical trials in patients with COPD.

Inhaled pan-phosphodiesterase inhibitors ameliorate ovalbumin-induced airway inflammation and remodeling in murine model of allergic asthma

Asthma is a heterogeneous, chronic respiratory disease characterized by airway inflammation and remodeling. Phosphodiesterase (PDE) inhibitors represent one of the intensively studied groups of potential anti-asthmatic agents due to their affecting both airway inflammation and remodeling. However, the effect of inhaled pan-PDE inhibitors on allergen induced asthma has not been reported to date. In this study we investigated the impact of two, representative strong pan-PDE inhibitors from the group of 7,8-disubstituted derivatives of 1,3-dimethyl-3,7-dihydro-1H-purine-2,6-dione: compound 38 and 145, on airway inflammation and remodeling in murine model of ovalbumin (OVA)-challenged allergic asthma. Female Balb/c mice were sensitized and challenged with OVA, 38 and 145 were administrated by inhalation, before each OVA challenge. The inhaled pan-PDE inhibitors markedly reduced the OVA-induced airway inflammatory cell infiltration, eosinophil recruitment, Th2 cytokine level in bronchoalveolar lavage fluid, as well as both, total and OVA-specific IgE levels in plasma. In addition, inhaled 38 and 145 decreased many typical features of airway remodeling, including goblet cell metaplasia, mucus hypersecretion, collagen overproduction and deposition, as well as Tgfb1, VEGF, and α-SMA expression in airways of allergen challenged mice. We also demonstrated that both 38 and 145 alleviate airway inflammation and remodelling by inhibition of the TGF-β/Smad signaling pathway activated in OVA-challenged mice. Taken together, these results suggest that the investigated pan-PDE inhibitors administered by inhalation are dual acting agents targeting both airway inflammation and remodeling in OVA-challenged allergic asthma and may represent promising, anti-asthmatic drug candidates.

The Impact of Corticosteroids on Human Airway Smooth Muscle Contractility and Airway Hyperresponsiveness: A Systematic Review

Classically, the effects elicited by corticosteroids (CS) are mediated by the binding and activation of cytosolic glucocorticoid receptors (GR). However, several of the non-genomic effects of CS seem to be mediated by putative non-classic membrane receptors characterized by pharmacological properties that are different from those of classic cytosolic GR. Since pre-clinical findings suggest that inhaled CS (ICS) may also regulate the bronchial contractile tone via putative CS membrane-associate receptors, the aim of this review was to systematically report and discuss the impact of CS on human airway smooth muscle (ASM) contractility and airway hyperresponsiveness (AHR). Current evidence indicates that CS have significant genomic/non-genomic beneficial effects on human ASM contractility and AHR, regardless of their anti-inflammatory effects. CS are effective in reducing either the expression, synthesis or activity of α-actin, CD38, inositol phosphate, myosin light chain kinase, and ras homolog family member A in response to several pro-contractile stimuli; overall these effects are mediated by the genomic action of CS. Moreover, CS elicited a strong bronchorelaxant effect via the rapid activation of the Gsα-cyclic-adenosine-monophosphate-protein-kinase-A pathway in hyperresponsive airways. The possibility of modulating the dose of the ICS in a triple ICS/long-acting β₂-adrenoceptor agonist/long-acting muscarinic antagonist fixed-dose combination supports the use of a Triple MAintenance and Reliever Therapy (TriMART) in those asthmatic patients at Step 3-5 who may benefit from a sustained bronchodilation and have been suffering from an increased parasympathetic tone.

Respiratory questionnaire-based analysis of awareness of COPD in a large multicenter rural population-based study in India

Background

Chronic obstructive pulmonary disease (COPD) is a more prevalent chronic lung disease with a significant health burden, and the majority of these cases receive inadequate treatment.

Methods

Prospective, observational, interview (questionnaire) based complete workup COPD study, screened 12,000 cases with chronic respiratory symptoms with cough, sputum production, and shortness of breath. A total of 6000 COPD cases were enrolled after the spirometry test. COPD cases were assessed as disease knowledge and methods of treatment offered by applying questionnaires to patients and treating physicians.

Results

In the present study, 3% of study cases were aware of their COPD illness, 54% were not having knowledge about the disease, and 43% cases were not accepting the COPD diagnosis (p < 0.0001). A total of 58% of cases received inhalation treatment as levosalbutamol monotherapy in 31% cases, levosalbutamol plus beclometasone in 18% cases, and formoterol plus budesonide or salmeterol plus fluticasone only in 9% of COPD cases (p < 0.0001). Total 42% cases received oral treatment as theophylline in 16% cases, salbutamol in 7% cases, oral steroids in 19% cases (p < 0.0001).

Conclusion

"Doctor-patient-drug trio" discordance clubbed as "difficult doctor, difficult patient, and difficult treatment" is a very crucial issue observed during diagnosis and management of COPD in peripheral settings in India.

An Unexpected Deuterium-Induced Metabolic Switch in Doxophylline

Precision deuteration has become part of the medicinal chemist's toolbox, but its usefulness can be undermined by unpredictable metabolic switch effects. Herein we report the deuteration of doxophylline, a drug used in the treatment of asthma and COPD that undergoes extensive oxidative metabolism. Labeling of the main metabolic soft spots triggered an unexpected multidirectional metabolic switch that, while not improving the pharmacokinetic parameters, changed the metabolic scenario and, in turn, the pharmacodynamic features in two murine models of lung injury.

An audit of patients admitted to hospital in Nepal for COPD exacerbation

Objectives:

Chronic obstructive pulmonary disease is a large and increasing problem in low- and middle-income countries; Nepal is no exception. We aimed to obtain information on patient characteristics and the level of care provided to patients admitted for acute exacerbation of chronic obstructive pulmonary disease in two Nepalese hospitals and to compare the given care with the Global Initiative for Chronic Obstructive Lung Disease guidelines.

Methods:

This was a cross-sectional, observational, descriptive study. All patients admitted to two Nepalese hospitals due to acute exacerbation of chronic obstructive pulmonary disease between 18 February and 5 April 2019 were asked to participate.

Results:

In total, 108 patients with a median age of 70 years participated. Fifty-three (42.7%) were male, 80 (74.8%) were former smokers, and 46 (45.1%) were farmers. Using the Global Initiative for Chronic Obstructive Lung Disease A-D classification, 97 (90.6%) of the patients were classified in group D. All the patients received supplementary oxygen treatment and 103 (95.4%) were treated with short-acting beta2 agonists. A total of 105 (97.2%) patients received antibiotics, and 80 (74.5%) received systemic corticosteroids. The majority was discharged with triple therapy including long-acting muscarinic antagonist, long-acting beta2 agonist, and inhaled corticosteroids, and 72 (75.8%) were discharged with long-term oxygen treatment.

Conclusion:

All elements of the Global Initiative for Chronic Obstructive Lung Disease guidelines were applied. However, due to a lack of information, it cannot be concluded whether the treatment was provided on the correct indications. The average patient received almost all the treatment alternatives available. This might indicate a very sick population or over-treatment.

Methylxanthine Treatment in Patients Hospitalized for Acute Exacerbation of Chronic Obstructive Pulmonary Disease in China: A Real-World Study Using Propensity Score Matching Analysis

Background: Although medical guidelines discourage the use of methylxanthines in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD), they are still widely used in clinical practice. This study investigated the real-world use of methylxanthines in the management of AECOPD.

Methods: Patient data from the Acute exacerbation of Chronic obstructive pulmonary disease Using REgistry data (ACURE, NCT02657525) study database were screened. Enrolled patients were divided into treatment and control groups. Propensity score (PS) matching and Cox regression analyses were used to minimize confounding factors and determine the association between methylxanthine treatment and the length of stay (LOS).

Results: Among the 2088 eligible patients, 1,563 (74.9%) were in the methylxanthine treatment group. Patients treated with methylxanthines had more severe respiratory symptoms and worse lung function than those in the control group. Doxophylline was the most commonly used methylxanthine in both secondary and tertiary hospitals. After PS matching, 966 patients were equally divided into two groups. The LOS of patients in the two groups was similar [median: 8 days, interquartile range (IQR): 7–11 days, p = 0.730]. Patients in the treatment group (median: 8, IQR: 4–12) had a more significant decrease in the COPD Assessment Test score from admission to discharge than those in the control group (median: 6, IQR: 2–10, p &lt; 0.001). Among all matched patients, the LOS was not significantly associated with methylxanthine treatment [adjusted hazard ratio (HR): 1.02, 95% confidence intervals (CIs): 0.89–1.16]. However, in the subgroup analysis, methylxanthines were significantly associated with a short LOS in patients with blood eosinophil count &gt;4% (adjusted HR: 1.56, 95% CIs: 1.12–2.17).

Conclusion: This study revealed that methylxanthines, especially doxophylline, are widely used in China. Methylxanthines were effective in improving symptoms in AECOPD patients. Higher blood eosinophil count may be associated with a better efficacy of methylxanthine treatment.

Fluvastatin combined with corbrin capsule can improve depression and anxiety in the treatment of chronic obstructive pulmonary disease

OBJECTIVE

To investigate the effect of fluvastatin (Flu) combined with corbrin capsule (CC) on the pulmonary function (PF) in patients with chronic obstructive pulmonary disease (COPD).

METHODS

Totally, 156 patients with COPD treated in our hospital were assigned: 86 patients in the research group (RG), who were treated with Flu plus CC, and 70 patients in the control group (CG), who were treated with CC plus conventional drugs. The changes in inflammatory factors, including interleukin-6 (IL-6), interleukin-8 (IL-8), tumor necrosis factor-α (TNF-α) and procalcitonin (PCT), of the two groups before and after treatment were compared. The complications, psychological status, quality of life (QOL) and recurrence rate of the two groups were analyzed.

RESULTS

The total effective rate in the RG was dramatically higher than that in the CG (P<0.05). Compared with the factors in the CG, the PF in the RG notably increased after treatment (P<0.05); the blood gas levels were noticeably better (P<0.05); and the level of inflammatory factors decreased (P<0.05). The incidence of complications in the RG was noticeably lower than that in the CG (P<0.05). The psychological status and QOL in the RG were remarkably better than those in the CG (P<0.05), and the recurrence rate within one year of diagnosis was lower than that in the CG (P<0.05).

CONCLUSION

Flu combined with CC is effective and safe in the treatment of COPD and can effectively improve the PF and the QOL of patients.

Effect of Doxofylline on Reducing the Inflammatory Response in Mechanically Ventilated Rats with Chronic Obstructive Pulmonary Disease

Objective

To evaluate the effect of doxofylline on reducing the inflammatory response in mechanically ventilated rats with chronic obstructive pulmonary disease (COPD).

Methods

A total of 40 eight-week-old male Sprague Dawley rats were randomly divided into four groups of 10 rats each: a control group (group C), a model group (group M), a model + natural saline group (group N), and a doxofylline group (group D). Then mechanical ventilation, drug intervention, and the extraction of the experimental material were performed in each group. Pulmonary tissue samples were taken after 120 minutes of mechanical ventilation and the pulmonary histopathological changes and the wet/dry (W/D) weight ratio of the pulmonary tissue were identified. The levels of tumor necrosis factor α (TNF-α) and interleukin 10 (IL-10) were detected using an enzyme-linked immunosorbent assay, and the expression levels of c-Jun-N-terminal kinase (JNK) and phosphorylated c-Jun N-terminal kinase (p-JNK) were detected using immunohistochemistry.

Results

Compared with group C, the pulmonary histopathology in groups M, N, and D showed typical changes associated with COPD. Furthermore, the W/D weight ratio and levels of TNF-α, JNK, and p-JNK in the pulmonary tissue increased in groups M, N, and D (P < 0.05), while the levels of IL-10 decreased (P < 0.05). Compared with group M, no statistically significant changes in the above indicators were detected in the pulmonary tissue of group N (P > 0.05). Compared with group N, the W/D weight ratio and levels of TNF-α, JNK, and p-JNK in the pulmonary tissue decreased in group D (P < 0.05), while the levels of IL-10 increased (P < 0.05).

Conclusion

Doxofylline might attenuate pulmonary inflammatory responses in mechanically ventilated rats with COPD, and the JNK/stress-activated protein kinase signaling pathway is involved in doxofylline’s inhibition of inflammatory responses in the pulmonary tissue of rats with COPD.

Systemic Medications in Chronic Obstructive Pulmonary Disease: Use and Outcomes

Inhaled therapy remains the cornerstone of chronic obstructive pulmonary disease pharmacologic care, but some systemic treatments can be of help when the burden of the disease remains high. Azithromycin, phosphodiesterase-4 inhibitors, and mucoactive agents can be used in such situations. The major difficulty remains in the identification of the optimal target populations. Another difficulty is to determine how these treatments should be positioned in the global treatment algorithm. For instance, should they be prescribed in addition to other antiinflammatory agents or should they replace them in some cases? Research is ongoing to identify new therapeutic targets.

Effect of terbutaline plus doxofylline on chronic obstructive pulmonary disease

OBJECTIVES

This study focused on patients with chronic obstructive pulmonary disease (COPD) and aimed at investigating the effect of terbutaline plus doxofylline on their pulmonary function and quality of life.

METHODS

Ninety COPD patients were divided by using a random number table into a control group (administration of doxofylline) and experimental group (administration of terbutaline combined with doxofylline), with 45 patients in each group. The therapeutic efficacy, pre- and post-treatment pulmonary function and the quality of life were compared between the control and experimental groups.

RESULTS

After treatment, patients in the experimental group had lower levels of interleukin-8, tumor necrosis factor α and C-reactive protein (all P<0.001), higher forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), and FEVl/FVC (all P<0.001), and lower total score of COPD assessment test (P<0.05) compared with the control group.

CONCLUSION

Terbutaline combined with doxofylline for the treatment of COPD patients can efficiently decrease inflammatory factor levels, and bring them better pulmonary function and quality of life.

Systemic Medications in Chronic Obstructive Pulmonary Disease: Use and Outcomes

Inhaled therapy remains the cornerstone of chronic obstructive pulmonary disease pharmacologic care, but some systemic treatments can be of help when the burden of the disease remains high. Azithromycin, phosphodiesterase-4 inhibitors, and mucoactive agents can be used in such situations. The major difficulty remains in the identification of the optimal target populations. Another difficulty is to determine how these treatments should be positioned in the global treatment algorithm. For instance, should they be prescribed in addition to other antiinflammatory agents or should they replace them in some cases? Research is ongoing to identify new therapeutic targets.

Pharmacology and Therapeutics of Bronchodilators Revisited

Bronchodilators remain the cornerstone of the treatment of airway disorders such as asthma and chronic obstructive pulmonary disease (COPD). There is therefore considerable interest in understanding how to optimize the use of our existing classes of bronchodilator and in identifying novel classes of bronchodilator drugs. However, new classes of bronchodilator have proved challenging to develop because many of these have no better efficacy than existing classes of bronchodilator and often have unacceptable safety profiles. Recent research has shown that optimization of bronchodilation occurs when both arms of the autonomic nervous system are affected through antagonism of muscarinic receptors to reduce the influence of parasympathetic innervation of the lung and through stimulation of β ₂-adrenoceptors (β ₂-ARs) on airway smooth muscle with β ₂-AR-selective agonists to mimic the sympathetic influence on the lung. This is currently achieved by use of fixed-dose combinations of inhaled long-acting β ₂-adrenoceptor agonists (LABAs) and long-acting muscarinic acetylcholine receptor antagonists (LAMAs). Due to the distinct mechanisms of action of LAMAs and LABAs, the additive/synergistic effects of using these drug classes together has been extensively investigated. More recently, so-called "triple inhalers" containing fixed-dose combinations of both classes of bronchodilator (dual bronchodilation) and an inhaled corticosteroid in the same inhaler have been developed. Furthermore, a number of so-called "bifunctional drugs" having two different primary pharmacological actions in the same molecule are under development. This review discusses recent advancements in knowledge on bronchodilators and bifunctional drugs for the treatment of asthma and COPD. SIGNIFICANCE STATEMENT: Since our last review in 2012, there has been considerable research to identify novel classes of bronchodilator drugs, to further understand how to optimize the use of the existing classes of bronchodilator, and to better understand the role of bifunctional drugs in the treatment of asthma and chronic obstructive pulmonary disease.

The effect of doxofylline in asthma and COPD

Theophylline is still one of the most widely prescribed drugs for the treatment of asthma and COPD in developing countries because the majority of asthma and COPD medicines are largely unavailable and also because it is a cheap option. In any case, its anti-inflammatory effects and capacity to reverse corticosteroid resistance deserve consideration, but it can induce numerous side effects and drug-drug interactions and frequently requires measurement of drug levels in plasma. In order to overcome the problems posed by theophylline, other xanthines have been developed. Doxofylline is a newer generation xanthine with both bronchodilating and anti-inflammatory activities and for this reason it has been called "novofylline". It differs substantially from theophylline at the pharmacological level. Clinical studies have shown substantial differences between doxofylline and theophylline. In particular, efficacy/safety profile of doxofylline is better than that of theophylline.

Anthelminthic medicinal plants in veterinary ethnopharmacology: A network meta-analysis following the PRISMA-P and PROSPERO recommendations

Medicinal plants may be effective against helminthic infestation in animals, but to date few studies have investigated the real impact of anthelminthic medicinal plants in veterinary ethnopharmacology. The aim of this study was to assess the geographical use of anthelminthic medicinal plants in livestock in European Union (EU), and to quantify the anthelminthic efficacy of medicinal plants in comparison with anthelminthic drugs. Surveys on the use of anthelminthic traditional medicinal plants in livestock in the EU were included in the qualitative synthesis. Studies that investigated the efficacy of anthelminthic traditional medicinal plants in animals, compared with negative control and/or anthelminthic drugs, were included in the quantitative synthesis (network meta-analysis). Twelve surveys (9 in Italy, 2 in Spain, 1 in Austria) reported the use of anthelminthic medicinal plants in livestock living in EU Countries. Data obtained from 256 animals and extracted from 6 studies were included in the network meta-analysis. Medicinal plants and drugs were more effective than negative control (standardized mean difference [SMD]: -0.60 95%CrI -0.88 to -0.31, -0.73 95%CrI -1.08 to -0.38, respectively, P < 0.001). Overall, no difference was detected between anthelminthic medicinal plants and anthelminthic drugs, namely albendazole, ivermectin, fenbendazole, and doramectin (SMD: 0.26 95%CrI -0.02 to 0.55, P > 0.05). The most effective anthelminthic medicinal plants were Artemisia absintihium, Allium sativum, and Duranta erecta. There is the strong medical need of performing adequately powered randomized controlled trials in different livestock species aimed to improve the quality of the current evidence concerning the anthelminthic efficacy of medicinal plants compared to that of the currently available antiparasitic drugs.

Pulmonary and cardiac drugs: clinically relevant interactions

Chronic heart and lung diseases are very common in the elderly population. The combination of chronic heart failure and chronic obstructive pulmonary disease (COPD) is also common and, according to current guidelines, these patients should be treated for both diseases. In patients with heart failure, beta-blockers are very important drugs because their use is associated with significantly improved morbidity and mortality. These beneficial effects were documented in patients with and without COPD, although theoretically there is a risk for bronchoconstriction, particularly with non-beta1 selective blockers. In COPD patients, long-acting sympathomimetics (LABA) improve lung function, dyspnea, and quality of life and their combination with a beta-blocker makes sense from a pharmacological and a clinical point of view, because any potential arrhythmogenic effects of the LABA will be ameliorated by the beta-blocker. Inhaled tiotropium, a long-acting muscarinic antagonist (LAMA), has been extensively investigated and no safety concerns were reported in terms of cardiac adverse effects. The same applies for the other approved LAMA preparations and LAMA-LABA combinations. Severe COPD causes air-trapping with increasing pressures in the thorax, leading to limitations in blood return into the thorax from the periphery of the body. This causes a decrease in stroke volume and cardiac index and is associated with dyspnea. All these adverse effects can be ameliorated by potent anti-obstructive therapy as recently shown by means of a LABA-LAMA combination.

Pharmacological treatment and current controversies in COPD

Bronchodilators, corticosteroids, and antibiotics are still key elements for treating chronic obstructive pulmonary disease in the 2019 Global Initiative for Chronic Obstructive Lung Disease (GOLD) recommendations and this is due in part to our current inability to discover new drugs capable of decisively influencing the course of the disease. However, in recent years, information has been produced that, if used correctly, can allow us to improve the use of the available therapies.

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.

Clinical efficacy of bronchodilators in equine asthma: Looking for minimal important difference

BACKGROUND

Airway obstruction is the main trait of severe equine asthma that affects respiratory function and elicits detrimental effects on clinical presentation. Only few and underpowered clinical studies have investigated the impact of improvement in lung function induced by bronchodilators on the clinical signs of asthma-affected horses.

OBJECTIVES

To identify the minimal important difference (MID) in lung function elicited by bronchodilator leading to a meaningful improvement in clinical signs.

STUDY DESIGN

Pairwise meta-analysis and meta-regression analysis.

METHODS

Literature searches were performed for studies that investigated the effect of bronchodilator therapy on lung function and clinical condition of asthmatic horses. The relationship between the change in lung function variables and clinical score was analysed via random-effect meta-regression. One-point change of the Improved clinically Detectable Equine Asthma Scoring System (IDEASS) score was used to identify the MID.

RESULTS

A significant (P<0.05) relationship was found between the changes in IDEASS score and maximum change in transpulmonary pressure (ΔPpl_max ) or pulmonary resistance (R_L ). Since only the model resulting for R_L passed through the origin (Y-intercept when X = 0: -0.31, 95% CI -0.75 to 0.14), this variable was used to identify the MID correlated with a meaningful improvement in clinical signs. The resulting MID value was a change in R_L of 0.63 cm H₂ O/L/s (95% CI 0.33-0.94), representing the slope of meta-regression model (high quality of evidence).

MAIN LIMITATIONS

No long-term studies investigated the effect of bronchodilator agents on both lung function and clinical signs in asthmatic horses.

CONCLUSIONS

In conclusion, bronchodilator pharmacotherapy in equine asthma elicits clinically meaningful effect when R_L increases ≥1 cm H₂ O/L/s, a value indicating the MID. Assessing the MID based on change in R_L may improve the quality of evidence and the scientific impact of future clinical trials as it extends beyond the simple, and limiting, evaluation of statistical significance.

Long-term observational study on the impact of GLP-1R agonists on lung function in diabetic patients

INTRODUCTION

Preclinical research suggests a role of Glucagon Like Peptide-1 Receptors (GLP-1R) on the regulation of human bronchial tone. We investigated the effect of GLP-1R agonists on lung function of Type 2 Diabetes Mellitus (T2DM) population without co-existing chronic obstructive respiratory disorders.

METHODS

This was a prospective cohort study that examined change in lung function measurements over two years of T2DM patients (n = 32) treated with metformin monotherapy (control cohort), metformin plus GLP-1R agonists (GLP-1R agonists cohort), or metformin plus insulin (insulin cohort).

RESULTS

After 24 months of treatment, the forced expiratory volume in 1 s (FEV₁) significantly (p < 0.05) increased from baseline in the GLP-1R agonists cohort (218 ml [95%CI 88-246]), but not in the control and insulin cohorts (94 ml [95%CI -28 - 216] and 26 ml [95%CI -174 - 226], respectively; p > 0.05 vs. baseline). The average increase in FEV₁ in the GLP-1R agonists cohort was significantly greater than that in the control and insulin cohorts (delta: 110 ml [95%CI 18-202] and 177 ml [95%CI 85-270], respectively, p < 0.05). The forced vital capacity (FVC) also increased significantly more in the GLP-1R agonists cohort than in the control and insulin cohorts (overall delta FVC: 183 ml [95%CI 72-295], p < 0.05). The maximal expiratory flow at 50-75% significantly (p < 0.05) improved from baseline in the GLP-1R agonists cohort, but not in the control and insulin cohorts (p > 0.05).

CONCLUSION

Our preliminary results suggest a potential new therapeutic perspective to treat airway disorders with GLP-1R agonists.

Efficacy and safety profile of mucolytic/antioxidant agents in chronic obstructive pulmonary disease: a comparative analysis across erdosteine, carbocysteine, and N-acetylcysteine

Background

To date there are no head-to-head studies comparing different mucolytic/antioxidant agents. Considering the inconsistent evidence resulting from the pivotal studies on mucolytic/antioxidant agents tested in chronic obstructive pulmonary disease (COPD), and the recent publication of Reducing Exacerbations and Symptoms by Treatment with ORal Erdosteine in COPD (RESTORE) study, we have performed a meta-analysis to compare the efficacy and safety of erdosteine 600 mg/day, carbocysteine 1500 mg/day, and N-acetylcysteine (NAC) 1200 mg/day in COPD.

Methods

A pairwise and network meta-analyses were performed to assess the efficacy of erdosteine, carbocysteine, and NAC on acute exacerbation of COPD (AECOPD), duration of AECOPD, and hospitalization. The frequency of adverse events (AEs) was also investigated.

Results

Data obtained from 2753 COPD patients were extracted from 7 RCTs published between 2004 and 2017. In the pairwise meta-analysis mucolytic/antioxidant agents significantly reduced the risk of AECOPD (RR 0.74 95%CI 0.68–0.80). The network meta-analysis provided the following rank of effectiveness: erdosteine>carbocysteine>NAC. Only erdosteine reduced the risk of experiencing at least one AECOPD (P < 0.01) and the risk of hospitalization due to AECOPD (P < 0.05). Erdosteine and NAC both significantly reduced the duration of AECOPD (P < 0.01). The AEs induced by erdosteine, carbocysteine, and NAC were mild in severity and generally well tolerated. The quality of evidence of this quantitative synthesis is moderate.

Conclusions

The overall efficacy/safety profile of erdosteine is superior to that of both carbocysteine and NAC. Future head-to-head studies performed on the same COPD populations are needed to definitely confirm the results of this meta-analysis.

Trial registration

CRD42016053762.

Formulation and Characterization of New Polymeric Systems Based on Chitosan and Xanthine Derivatives with Thiazolidin-4-One Scaffold

In the past many research studies have focused on the thiazolidine-4-one scaffold, due to the important biological effects associated with its heterocycle. This scaffold is present in the structure of many synthetic compounds, which showed significant biological effects such as antimicrobial, antifungal, antioxidant, anti-inflammatory, analgesic, antidiabetic effects. It was also identified in natural compounds, such as actithiazic acid, isolated from Streptomyces strains. Starting from this scaffold new xanthine derivatives have been synthetized and evaluated for their antibacterial and antifungal effects. The antibacterial action was investigated against Gram positive (Staphyloccoccus aureus ATCC 25923, Sarcina lutea ATCC 9341) and Gram negative (Escherichia coli ATCC 25922) bacterial strains. The antifungal potential was investigated against Candida spp. (Candida albicans ATCC 10231, Candida glabrata ATCC MYA 2950, Candida parapsilosis ATCC 22019). In order to improve the antimicrobial activity, the most active xanthine derivatives with thiazolidine-4-one scaffold (XTDs: 6c, 6e, 6f, 6k) were included in a chitosan based polymeric matrix (CS). The developed polymeric systems (CS-XTDs) were characterized in terms of morphological (aspect, particle size), physic-chemical properties (swelling degree), antibacterial and antifungal activities, toxicity, and biological functions (bioactive compounds loading, entrapment efficiency). The presence of xanthine-thiazolidine-4-one derivatives into the chitosan matrix was confirmed using Fourier transform infrared (FT-IR) analysis. The size of developed polymeric systems, CS-XTDs, ranged between 614 µm and 855 µm, in a dry state. The XTDs were encapsulated into the chitosan matrix with very good loading efficiency, the highest entrapment efficiency being recorded for CS-6k, which ranged between 87.86 ± 1.25% and 93.91 ± 1.41%, depending of the concentration of 6k. The CS-XTDs systems showed an improved antimicrobial effect with respect to the corresponding XTDs. Good results were obtained for CS-6f, for which the effects on Staphylococcus aureus ATCC 25923 (21.2 ± 0.43 mm) and Sarcina lutea ATCC 9341 (25.1 ± 0.28 mm) were comparable with those of ciprofloxacin (25.1 ± 0.08 mm/25.0 ± 0.1 mm), which were used as the control. The CS-6f showed a notable antifungal effect, especially on Candida parapsilosis ATCC 22019 (18.4 ± 0.42 mm), the effect being comparable to those of nystatin (20.1 ± 0.09 mm), used as the control. Based on the obtained results these polymeric systems, consisting of thiazolidine-4-one derivatives loaded with chitosan microparticles, could have important applications in the food field as multifunctional (antimicrobial, antifungal, antioxidant) packaging materials.

Impact of doxofylline compared to theophylline in asthma: A pooled analysis of functional and clinical outcomes from two multicentre, double-blind, randomized studies (DOROTHEO 1 and DOROTHEO 2)

This pooled analysis of double-blind, randomized, placebo-controlled trials aimed to investigate the impact of DOxofylline compaRed tO THEOphylline (DOROTHEO 1 and DOROTHEO 2 studies) on functional and clinical outcomes in asthma. Asthmatic patients ≥16 years of age with forced expiratory volume in 1 s (FEV₁) ≥50% and <80% and with ≥15% post-bronchodilator increase in FEV₁ were randomized in a 1:1:1:1 ratio in DOROTHEO 1 to receive doxofylline 200 mg, doxofylline 400 mg, theophylline 250 mg, or placebo; in DOROTHEO 2 patients were randomized in a 1:1:1 ratio to receive doxofylline 400 mg, theophylline 250 mg, or placebo. All double-blind treatments were taken orally with immediate release formulations and three times daily. Data evaluating the effect of doxofylline 400 mg, theophylline 250 mg and placebo on FEV₁, asthma events rate, use of salbutamol as rescue medication and adverse events (AEs) were pooled from both studies. The pooled-analysis of 483 patients demonstrated that both doxofylline 400 mg and theophylline 250 mg significantly increased FEV₁, reduced the rate of asthma events and use of salbutamol to relieve asthma symptoms compared to placebo (p < 0.01). No significant differences were detected between doxofylline 400 mg and theophylline 250 mg. Doxofylline 400 mg did not significantly (p > 0.05) increase the risk of AEs compared to placebo, conversely in patients treated with theophylline 250 mg the risk of AEs was significantly (p < 0.05) greater than in those that received placebo. We conclude that doxofylline seems to offer a promising alternative to theophylline with a superior efficacy/safety profile in the management of patients with asthma.

Current challenges in managing comorbid heart failure and COPD

INTRODUCTION

Heart failure (HF) with reduced ejection fraction and chronic obstructive pulmonary disease (COPD) frequently coexist, particularly in the elderly. Given their rising prevalence and the contemporary trend to longer life expectancy, overlapping HF-COPD will become a major cause of morbidity and mortality in the next decade. Areas covered: Drawing on current clinical and physiological constructs, the consequences of negative cardiopulmonary interactions on the interpretation of pulmonary function and cardiopulmonary exercise tests in HF-COPD are discussed. Although those interactions may create challenges for the diagnosis and assessment of disease stability, they provide a valuable conceptual framework to rationalize HF-COPD treatment. The impact of COPD or HF on the pharmacological treatment of HF or COPD, respectively, is then comprehensively discussed. Authors finalize by outlining how the non-pharmacological treatment (i.e. rehabilitation and exercise reconditioning) can be tailored to the specific needs of patients with HF-COPD. Expert commentary: Randomized clinical trials testing the efficacy and safety of new medications for HF or COPD should include a sizeable fraction of patients with these coexistent pathologies. Multidisciplinary clinics involving cardiologists and respirologists trained in both diseases (with access to unified cardiorespiratory rehabilitation programs) are paramount to decrease the humanitarian and social burden of HF-COPD.

Impact of doxofylline in COPD: A pairwise meta-analysis

Doxofylline is an effective bronchodilator for relieving airway obstruction in patients with asthma or chronic obstructive pulmonary disease (COPD), and displays a better safety profile with respect to theophylline. Herein, we performed a pairwise meta-analysis of the currently available data to provide consistent and homogeneous findings on the impact of this xanthine in COPD patients. Results obtained from 820 patients were selected from 20 clinical trials. Meta-regression was performed to examine the source of heterogeneity between-studies and identify potential confounder covariates. The quality of the evidence was assessed by the GRADE system. Doxofylline induced a significant (P < 0.001) increase in forced expiratory volume in 1 s (FEV₁) of 8.20% (95%CI 4.00-12.41; I² 93%) and 317 ml (95%CI 19-439; I² 87%) compared with baseline. The total administered dose of doxofylline significantly (P < 0.001) interacted with the size of the effect estimates detected for FEV₁. Doxofylline induced a significant (P < 0.001), although moderate, increase in adverse events (AEs) frequency (proportion 0.03, 95%CI 0.02-0.04; I² 88%), but only epigastralgia, nausea, dyspepsia and headache were statistically significant (P < 0.05). The GRADE analysis indicated high quality of evidence (++++) for the impact of doxofylline on FEV₁, and moderate quality of evidence (+++) for the safety profile in COPD patients. Doxofylline is an effective and safe medicine when administered to patients with COPD and can be considered as an alternative to theophylline.