Effect of ipratropium bromide on airway mucociliary function

Cough medicines for children- time for a reality check

Cough medicines have been in use for over a century to treat the common and troublesome, but often helpful, symptoms of cough in children. They contain various combinations of "anti-tussive" drugs including opioids, antihistamines, herbal preparations, mucolytics, decongestants and expectorants. Whilst theoretically attractive for symptom relief when children are suffering, as time has passed these popular over the counter medicines have been shown to lack efficacy, delay more serious underlying diagnoses, and can cause complications and sometimes death. This has resulted in clinician concerns, a citizen petition to the American Food and Drug Association in 2007, some self-regulation from manufacturers and escalating restrictions on their use from regulatory agencies across the world over the last twenty years. This article will review the protective role of cough, juxtapose the conflicting treatment goals of suppressing a dry cough and promoting expectoration for a wet cough, consider the evidence basis for prescribing cough medicines in comparison to other more specific treatments such as for asthma [beta agonists] or infection [antibiotics], regulatory interventions, and conclude with the view that over counter cough medicines should not be used in children, especially young children.

Planktonic sea urchin larvae change their swimming direction in response to strong photoirradiation

To survive, organisms need to precisely respond to various environmental factors, such as light and gravity. Among these, light is so important for most life on Earth that light-response systems have become extraordinarily developed during evolution, especially in multicellular animals. A combination of photoreceptors, nervous system components, and effectors allows these animals to respond to light stimuli. In most macroscopic animals, muscles function as effectors responding to light, and in some microscopic aquatic animals, cilia play a role. It is likely that the cilia-based response was the first to develop and that it has been substituted by the muscle-based response along with increases in body size. However, although the function of muscle appears prominent, it is poorly understood whether ciliary responses to light are present and/or functional, especially in deuterostomes, because it is possible that these responses are too subtle to be observed, unlike muscle responses. Here, we show that planktonic sea urchin larvae reverse their swimming direction due to the inhibitory effect of light on the cholinergic neuron signaling>forward swimming pathway. We found that strong photoirradiation of larvae that stay on the surface of seawater immediately drives the larvae away from the surface due to backward swimming. When Opsin2, which is expressed in mesenchymal cells in larval arms, is knocked down, the larvae do not show backward swimming under photoirradiation. Although Opsin2-expressing cells are not neuronal cells, immunohistochemical analysis revealed that they directly attach to cholinergic neurons, which are thought to regulate forward swimming. These data indicate that light, through Opsin2, inhibits the activity of cholinergic signaling, which normally promotes larval forward swimming, and that the light-dependent ciliary response is present in deuterostomes. These findings shed light on how light-responsive tissues/organelles have been conserved and diversified during evolution.

The importance of light for organisms on Earth has led to the extraordinary development of sophisticated light-response systems during evolution. It is likely that light-dependent ciliary responses were initially acquired in unicellular and small multicellular organisms, but the pathway is poorly understood in deuterostomes, whose behavior mostly depends on responses involving muscle. Therefore, it is unclear whether ciliary responses to light are present and/or functional in deuterostomes since these responses may be too subtle for observation, unlike muscle responses. This raises the questions of how light-response systems were established and how they diversified during deuterostome evolution. Here, we provide clear evidence that planktonic larvae of sea urchin species, which belong to the deuterostome group, display backward swimming when light inhibits cholinergic signal-dependent forward swimming.

Simultaneous Analysis of Ipratropium Bromide and its Related Substances Using HPLC

Background:

The main goal of process-related substances investigations is to understand how impurities should be controlled during the synthetic or purification process to produce a high-quality drug substance. The simultaneous determination of related substances is a very important factor in the quality control of API and pharmaceutical dosage forms.

Methods:

A new HPLC method was developed for the simultaneous analysis of Ipratropium bromide and its seven related substances. The separation was performed on a waters HPLC ZORBAX Eclipse XDB- C8 column (150 × 4.6 mm, 3.5 μm). The gradient method used mobile phases containing methanol, acetonitrile, trifluoroacetic acid (TFA), water: A: (methanol, acetonitrile, TFA, 500:500:0.3 v/v/v) and B (0.3% TFA in water v/v). The gradient elution conditions were as follows: 0-32.0 min, linear from 10% A to 35% A; 32.0-36.0 min isocratic 35% A; 36.0-42.0 min linear from 35% to 10%A. The wavelength by UV detector was 220 nm and the flow rate was 1.2 mL/min. The injection volume of sample was 20 μL, and the column temperature was 30 ºC. The proposed RP-HPLC method was applied for the determination of seven related substances.

Results:

All standard curves obtained exhibited good linear regression (r > 0.9939) within the tested range. The average recovery rates were in the range of 98.2-102.0% and RSD was less than 2.9% (n = 3). The process-related impurities were not observed in different batches (<0.025% purity).

Conclusion:

The method was applied to determine 7 process-related substances in ipratropium bromide and proved to be robust, linear, repeatable, sensitive, selective and easy to perform. The results are valuable for quality control in the manufacturing of ipratropium bromide.

Respiratory Cilia as a Therapeutic Target of Phosphodiesterase Inhibitors

Mucociliary clearance is an essential airway defense mechanism dependent predominantly on the proper ciliary function and mucus rheology. The crucial role of cilia is evident in `a variety of respiratory diseases, as the ciliary dysfunction is associated with a progressive decline in lung function over time. The activity of cilia is under supervision of multiple physiological regulators, including second messengers. Their role is to enable a movement in coordinated metachronal waves at certain beat frequency. Ciliary function can be modulated by various stimuli, including agents from the group of beta₂ agonists, cholinergic drugs, and adenosine triphosphate (ATP). They trigger cilia to move faster in response to elevated cytoplasmic Ca²⁺ originated from intracellular sources or replenished from extracellular space. Well-known cilia-stimulatory effect of Ca²⁺ ions can be abolished or even reversed by modulating the phosphodiesterase (PDE)-mediated breakdown of cyclic adenosine monophosphate (cAMP) since the overall change in ciliary beating has been dependent on the balance between Ca²⁺ ions and cAMP. Moreover, in chronic respiratory diseases, high ATP levels may contribute to cAMP hydrolysis and thus to a decrease in the ciliary beat frequency (CBF). The role of PDE inhibitors in airway cilia-driven transport may help in prevention of progressive loss of pulmonary function often observed despite current therapy. Furthermore, administration of selective PDE inhibitors by inhalation lowers the risk of their systemic effects. Based on this review we may conclude that selective (PDE1, PDE4) or dual PDE inhibitors (PDE3/4) increase the intracellular level of cyclic nucleotides in airway epithelial cells and thus may be an important target in the development of new inhaled mucokinetic agents. Further research is required to provide evidence of their effectiveness and feasibility regarding their cilia-modulating properties.

Muscarinic Receptor Antagonists

Parasympathetic activity is increased in patients with chronic obstructive pulmonary disease (COPD) and asthma and appears to be the major reversible component of airway obstruction. Therefore, treatment with muscarinic receptor antagonists is an effective bronchodilator therapy in COPD and also in asthmatic patients. In recent years, the accumulating evidence that the cholinergic system controls not only contraction by airway smooth muscle but also the functions of inflammatory cells and airway epithelial cells has suggested that muscarinic receptor antagonists could exert other effects that may be of clinical relevance when we must treat a patient suffering from COPD or asthma. There are currently six muscarinic receptor antagonists licenced for use in the treatment of COPD, the short-acting muscarinic receptor antagonists (SAMAs) ipratropium bromide and oxitropium bromide and the long-acting muscarinic receptor antagonists (LAMAs) aclidinium bromide, tiotropium bromide, glycopyrronium bromide and umeclidinium bromide. Concerns have been raised about possible associations of muscarinic receptor antagonists with cardiovascular safety, but the most advanced compounds seem to have an improved safety profile. Further beneficial effects of SAMAs and LAMAs are seen when added to existing treatments, including LABAs, inhaled corticosteroids and phosphodiesterase 4 inhibitors. The importance of tiotropium bromide in the maintenance treatment of COPD, and likely in asthma, has spurred further research to identify new LAMAs. There are a number of molecules that are being identified, but only few have reached the clinical development.

Subcellular distribution of choline acetyltransferase by immunogold electron microscopy in non-neuronal cells: placenta, airways and murine embryonic stem cells

AIMS

Acetylcholine is synthesized in more or less all mammalian cells. However, little is known about the subcellular location of acetylcholine synthesis. Therefore, in the present experiments the subcellular location of the synthesizing enzyme choline acetyltransferase (ChAT) was investigated by anti-ChAT immunogold electron microscopy in human placenta and airways as well as in a murine embryonic stem cell line (CGR8 cell line).

MAIN METHODS

Human tissue was obtained as so-called surplus tissue (after delivery/surgical removal because of lung tumor); the CGR8 stem cell line was cultured under standard conditions. For human tissue a monoclonal mouse anti-ChAT antibody (ab) was used and for the CGR8 cell line a polyclonal goat anti-ChAT ab. Immunogold electron microscopy was applied to identify the subcellular location of ChAT.

KEY FINDINGS

In trophoblast cells (placenta) specific anti-ChAT immunogold deposition was found within the cell membrane, microvilli, and caveolae but also within the cytosol, for example associated with intermediate filaments. In addition, immunogold deposition was identified within mitochondria and the nuclear membrane. In airway epithelial cells anti-ChAT immunogold was found particularly within the apical cell membrane, cilia, submucosa, cytosol and nuclear membrane. Likewise alveolar macrophages showed positive anti-ChAT immunogold within the nucleus, nuclear membrane and granula. Also in the CGR8 cell line positive anti-ChAT immunogold was identified within the cell nucleus and cytosol.

SIGNIFICANCE

The present experiments demonstrate a wide subcellular distribution of ChAT with particular preference of the cell membrane in human epithelial cells.

Activation of muscarinic receptors by non-neuronal acetylcholine

The biological role of acetylcholine and the cholinergic system is revisited based particularly on scientific research early and late in the last century. On the one hand, acetylcholine represents the classical neurotransmitter, whereas on the other hand, acetylcholine and the pivotal components of the cholinergic system (high-affinity choline uptake, choline acetyltransferase and its end product acetylcholine, muscarinic and nicotinic receptors and esterase) are expressed by more or less all mammalian cells, i.e. by the majority of cells not innervated by neurons at all. Moreover, it has been demonstrated that acetylcholine and "cholinergic receptors" are expressed in non-neuronal organisms such as plants and protists. Acetylcholine is even synthesized by bacteria and algae representing an extremely old signalling molecule on the evolutionary timescale. The following article summarizes examples, in which non-neuronal acetylcholine is released from primitive organisms as well as from mammalian non-neuronal cells and binds to muscarinic receptors to modulate/regulate phenotypic cell functions via auto-/paracrine pathways. The examples demonstrate that non-neuronal acetylcholine and the non-neuronal cholinergic system are vital for various types of cells such as epithelial, endothelial and immune cells.

Ear, nose, and throat effects of high altitude

High altitude changes human physiology and can result in illnesses such as acute mountain sickness, high-altitude cerebral edema, and high-altitude pulmonary edema. The physiological impacts of high-altitude illnesses occur secondary to extravasation of fluid from the intravascular space into the extravascular space during a rapid ascent. Headache, hearing disturbances, vestibular disturbances, epistaxis, sleep apnea, coughing, respiratory tract infections, and nasal obstruction are main ear, nose, and throat complaints of individuals travelling to high altitude. These complaints can cause delays or cancelations in a person's climbing plans. In this article, we review the ear, nose, and throat effects of high altitude based on the relevant literature.

Eficácia antitussígena de duas formulações fitoterápicas

Avaliaram-se os efeitos antitussígenos-expectorantes de duas formulações fitoterápicas utilizando-se três modelos biológicos diferentes. Foram utilizados ratos Wistar no modelo da secreção das vias aéreas, cobaias no modelo de tosse induzido por ácido cítrico e codornas japonesas na determinação da velocidade de transporte mucociliar. Os animais foram distribuídos em grupos e tratados por via oral com as formulações, com doses equivalentes a 10 vezes a terapêutica recomendada, 9ml.kg-1. O grupo-controle negativo de cada espécie foi tratado com solução fisiológica, 10ml.kg-1. O grupo-controle positivo no modelo de tosse induzida pelo ácido cítrico foi tratado com morfina, 1mg.kg-1, por via subcutânea. No modelo em que foram utilizados ratos e codornas, o grupo-controle positivo recebeu erdosteína por via oral, 600mg.kg-1. Os resultados mostraram que as duas formulações fitoterápicas foram eficazes no reflexo da tosse em cobaias, causando 36,4% e 27,3%, respectivamente, de redução. Nos modelos de secreção das vias aéreas e determinação da velocidade de transporte mucociliar, ambas as formulações não apresentaram eficácia significativa.

Mucociliary transport determined by in vivo microdialysis in the airways of normal and CF mice

We report a novel method to measure mucociliary transport (MCT) in both the upper and lower airways of normal and CF mice. The in vivo microdialysis technique involves placing a small quantity of dye on the airway surface and a microdialysis probe a defined distance from the site of dye deposition. The dye is transported toward the probe by ciliary transport and, upon reaching the microdialysis probe, diffuses across the dialysis membrane and is collected in the dialysate leaving the probe. The rate of MCT is calculated from the length of time from dye deposition to recovery. The rate of tracheal MCT in normal mice was 2.2 +/- 0.45 (SE) mm/min (n = 6), a value similar to that in reports using other techniques. MCT in CF mice was not different (2.3 +/- 0.29, n = 6), consistent with previous observations suggesting that tracheal ion transport properties are not different between CF and normal mice. The rate of MCT in the nasal cavity of normal mice was slower than in the trachea (1.3 +/- 0.26, n = 4). MCT in the CF mouse nasal cavity (1.4 +/- 0.31, n = 8), a region in which the CF mouse exhibits bioelectric properties similar to the human CF patient, was, again, not different from the normal mouse, perhaps reflecting copious gland secretion offsetting Na(+) and liquid hyperabsorption. In conclusion, we have developed a versatile, simple in vivo method to measure MCT in both upper and lower airways of mice and larger animals.

Using anti-muscarinic drugs in the management of death rattle: evidence-based guidelines for palliative care

The management of 'death rattle' was reviewed by a task group on behalf of the Association for Palliative Medicine's Science Committee. Evidence was searched for the effectiveness of various anti-muscarinic drugs in drying oropharyngeal and bronchial secretions in dying patients. Clinical guidelines were constructed based on evidence from volunteer and clinical studies. Death rattle occurs in half of all dying patients and some response occurs in around 80% of treated patients. Clinical studies demonstrate that subcutaneous hyoscine hydrobromide 400 microg is more effective at improving symptoms at 30 min than glycopyrronium 200 microg by the same route. Volunteer studies demonstrate that intramuscular glycopyrronium 400 microg is as effective in drying secretions at 30 min as a dose of 200 microg given intravenously. Duration of response is shortest for hyoscine butylbromide (1 h) and longest for glycopyrronium (more than 6 h). There is insufficient evidence to support the use of one drug over another in a continuous infusion and prescribers should base decisions on different characteristics of each anti-muscarinic drug.

Death rattle: prevalence, prevention and treatment

A retrospective analysis was performed to study the occurrence and treatment of death rattle (DR) in 107 consecutive dying patients on the palliative care unit of the University Hospital Leuven. The incidence of DR (23%) is lower than reported in literature, possibly due to low hydration. We found 2 types of rattle: "Real DR" responds generally very well to anticholinergic therapy, and is probably caused by non-expectorated secretions. "Pseudo DR" is poorly responsive to therapy and is probably caused by bronchial secretions due to pulmonary pathology, such as infection, tumor, fluid retention, or aspiration. Rattle disappeared in >90% for the patients with real DR. Real DR is a strong predictor for death, and 76% (19/25) died within 48h after onset. Administration of subcutaneous hyoscine hydrobromide, as a bolus or continuous infusion, is effective therapy for real DR and is comfortable for the patient and caregivers.

Drug therapy approaches in the treatment of acute severe asthma in hospitalised children

Acute severe paediatric asthma remains a serious and debilitating disease throughout the world. The incidence and mortality from asthma continue to increase. Early, effective and aggressive outpatient therapy is essential in reducing symptoms and preventing life-threatening progression. When complications occur or when the disease progresses to incipient respiratory failure, these children need to be managed in a continuous care facility where aggressive and potentially dangerous interventions can be safely instituted to reverse persistent bronchospasm. The primary drugs for acute severe asthma include oxygen, corticosteroids, salbutamol (albuterol) and anticholinergics. Second-line drugs include heliox, magnesium sulfate, ketamine and inhalational anaesthetics. Future therapies may include furosemide, leukotriene modifiers, antihistamines and phosphodiesterase inhibitors. This review attempts to explore the multitude of medications available with emphasis on pharmacology and pathophysiology.

Mucolytic and antitussive effects of erdosteine

To investigate the influence of erdosteine, a new homocysteine-derived expectorant, on airway clearance we studied the effects of the drug on the viscosity of mucin, on the mucociliary transport rate in quails, on airway secretion in rats and on the cough reflex in guinea-pigs. The active metabolite of erdosteine, M1 (10 microM to 1 mM), significantly reduced the viscosity of porcine stomach mucin. Erdosteine by itself did not reduce viscosity. Erdosteine significantly promoted mucociliary transport in quails and increased airway secretion in rats. The effect was still apparent 24h after administration. Erdosteine significantly suppressed citric acid-induced cough reflexes in guinea-pigs but did not suppress mechanical stimuli-induced cough reflexes. Erdosteine suppressed the reduction of the recovery volume of bronchoalveolar lavage fluid and albumin leakage into the fluid in citric acid-exposed guinea-pigs. These results indicate that erdosteine removes sputum by reducing its viscosity, and by promoting mucociliary transport and sustained enhancement of airway secretion. It also suppressed the chemical stimulation-induced cough reflex and plasma leakage into the airway. These results suggest that erdosteine is an excellent expectorant with several modes of action.

Therapeutic aerosols and airway secretions

Despite common misconceptions, airway mucus is not an impermeable barrier that entraps and clears all inhaled material. To be therapeutically effective, an aerosol medication must efficiently deposit in the airway and then diffuse or translocate across the mucous barrier while retaining bioactivity. Characteristics of aerosols that affect their ability to penetrate the mucous barrier include particle charge, solubility, and size. Aerosol medications can also change the biophysical properties of secretions and influence how rapidly mucus is cleared. Surfactant is probably responsible for the displacement of inhaled particles through the mucous layer (Schürch et al., 1990). As well, exogenous surfactant has been shown to increase tracheal mucociliary clearance in anesthetized dogs (de Sanctis et al., 1994) and to improve the mucociliary clearability of secretions from babies with neonatal respiratory distress syndrome (Rubin et al., 1992). Using measurements of sputum-substrate contact angle and interfacial tension, cystic fibrosis (CF) sputum had been shown to have an abnormally high adhesion tension, (Girod et al., 1992). We assessed the in vitro effects of synthetic surfactant (Exosurf, Burroughs-Wellcome, Research Triangle Park, NC) on the physical and transport properties of sputum from 15 patients with CF and 30 patients with stable chronic bronchitis (CB). The concentration of ExosurfTM used was 13.5 mg of DPPC/ml corresponding to the reconstituted concentration for aerosol administration. The sputum was divided so that aliquots each were treated with Exosurf and amphibian Ringer's solution layered on the sputum at a concentration of 1:5 v/v for 15 min at 24 degrees C. There was a reduction in spinnability (p < 0.0001) in CF sputum from baseline and a fall in adhesion tension (0.05 < p < 0.1) with Exosurf treatment. Potentially important increases in both mucociliary and cough clearability were noted without associated changes in sputum rheology. In bronchitis sputum, surfactant reduced adhesiveness (p < 0.01), but this was not associated with improved clearability. Adhesive forces are involved in ciliary coupling and cough transport. This raises the possibility of using surfactant as a mucokinetic agent in the therapy of chronic suppurative lung disease.

Death rattle: an audit of hyoscine (scopolamine) use and review of management

This study investigated the pattern and determinants of hyoscine (scopolamine) use for death rattle by a retrospective analysis of 100 consecutive deaths in a 22-bed hospice. Patient diagnoses, duration of stay, and doses and route of administration of hyoscine used in the final 48 hr before death were recorded. One-half of the patients received hyoscine in some form during the final 24 hr before death. Patients who were in the hospice for longer than 9 days and those with cerebral malignancy were given the highest doses of hyoscine in the final 24 hr (z = -2.558, P = 0.011, and z = -1.968, P = 0.048, respectively). Response to hyoscine appears to be variable, and a distinction is proposed between death while due to salivary secretions (type 1) and that due to bronchial secretions (type 2) to explain the observed patterns of use. It is likely that hyoscine is more efficacious in treating type 1 death rattle than it is in treating type 2 death rattle.

Therapeutic approaches to chronic obstructive pulmonary disease: an emerging consensus

In response to reports of rising asthma morbidity and mortality, several consensus statements have been drafted to guide the treatment of asthma. More recently, attempts have been made to develop similar guidelines for the management of chronic obstructive pulmonary disease (COPD). Just as the two diseases differ in their pathophysiology, their treatment algorithms have differed. For both disease groups, avoidance of further airway injury is the initial step in treatment. For asthmatics, this is often allergen avoidance, but for patients with COPD the usual inciting factor is cigarette smoking, thereby making smoking cessation the necessary first step. Whereas beta 2-agonist bronchodilators are used as needed in asthma management, regular bronchodilator therapy with anticholinergic drugs is the first-line approach in COPD. The role of anti-inflammatory drugs differs markedly between the two disease groups. Asthmatic patients benefit dramatically from inhaled anti-inflammatory drugs; little or no benefit can be demonstrated for the majority of patients with COPD. In COPD, the role of exercise rehabilitation programs can improve exercise tolerance. For selected patients with COPD with persistent hypoxemia, the use of supplemental oxygen can reduce mortality. For both patient groups, educational interventions can play a valuable role in making patients patients effective partners in their own care.

Use of anticholinergic bronchodilation in children

Ipratropium bromide is a quaternary ammonium anticholinergic bronchodilator with minimal systemic absorption across the blood-airway barrier. Ipratropium bromide has become primary therapy for the treatment of adults with chronic bronchitis, but its use in children has been limited. Ipratropium bromide can be safely used in the management of acute bronchiolitis, recognizing that most infants do not appear to respond to any bronchodilator medication. When used with a beta-agonist bronchodilator for the therapy of acute childhood asthma, ipratropium bromide appears to provide bronchodilation beyond that achieved by either agent used alone. There are insufficient published data to determine the appropriate use if ipratropium bromide in infants with bronchopulmonary dysplasia, although many of those symptomatic after the age of 6 months seem to benefit from either ipratropium bromide or beta-agonists. As ipratropium bromide has no intrinsic anti-inflammatory properties, its role in the chronic therapy of asthma and related disorders is still unclear.

The acute effect of ipratropium bromide bronchodilator therapy on cough clearance in COPD

Using radiolabeled, monodispersed aerosols (99mTc-iron oxide) and gamma camera analysis, we measured the efficacy of cough for clearing mucus from the airways of the lung following inhalation of the bronchodilator ipratropium bromide (IB) (Atrovent, Boehringer Ingelheim, Inc), a drug that has been shown to have no effect on mucociliary clearance in COPD. Clearance of radiolabeled aerosol was studied over a 2.5-h period on three separate days, a control day with no coughing, and two study days during which the patient performed controlled cough maneuvers over the course of clearance measurements following IB or placebo therapy (double blind, crossover). Fifteen patients, age > 45 years, with stable moderate-to-severe airway obstruction (mean FEV1/FVC = 0.45) were studied. IB diminished the effectiveness of cough for clearing the radiolabeled particles from the airways. This effect of IB on cough clearance may be due to (1) changes in the airflow dynamics induced by bronchodilation or (2) altered rheology or depth of airway secretions.

Toxicologic testing of inhaled pharmaceutical aerosols

This paper reviews technical issues related to the toxicologic testing of inhaled pharmaceuticals. Although there are commonalities between approaches to general and inhalation toxicity testing, there also are specific challenges in the toxicity testing of inhaled pharmaceuticals. A major issue is that of dose; inhaled dose is more difficult to determine than intravenous or oral doses. Also, it is harder to relate dose in laboratory animals to that in man for inhalation exposure than for other routes of administration. Additionally, in the case of inhaled pharmaceuticals, people generally inhale through the mouth, whereas most laboratory animals inhale primarily through the nose. This presents significant challenges in exposure methodology and technology that often need innovative approaches involving alteration to particle size of the agent or dosing procedure. Because the respiratory tract is the site of deposition, local respiratory toxicity and possible damage to lung cells need to be assessed. Systemic toxicity also needs to be evaluated and may be an issue in some cases. Special studies on pulmonary function, mucociliary clearance, or immune response may be needed, depending on the nature of the inhaled pharmaceutical. This review explores the main issues involved in toxicity testing of inhaled pharmaceuticals, the approaches that have been used, and the current and future challenges.

Comparison of ipratropium bromide and albuterol in chronic obstructive pulmonary disease: a three-center study

Seventy-two subjects who had severe chronic obstructive pulmonary disease and a history of heavy smoking completed a study to compare the effect of single doses of ipratropium bromide (0.036 mg), albuterol (0.18 mg), and placebo on the forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), heart rate, and blood pressure during a period of 6 hours. During initial testing for reversibility, 40 subjects did not demonstrate a 15% increase in FEV1 from baseline after metaproterenol. Ipratropium produced a significantly greater response than albuterol in FEV1 at 3, 4, and 5 hours and in FVC at 1, 2, 3, 4, and 5 hours. For the entire 6-hour period, ipratropium produced a 25% greater response than albuterol in FEV1 and a 50% greater response in FVC. The difference between the two drugs was even greater between 3 and 6 hours. There were no significant differences between the three treatments as regards adverse reactions, heart rate, and blood pressure measurements. In patients who have chronic obstructive pulmonary disease, ipratropium bromide has apparent benefits over beta 2 agonist therapy, including a longer duration of action. Ipratropium may also be effective when beta 2 agonists are not effective.

Therapeutic algorithm for chronic obstructive pulmonary disease

It would be foolhardy to offer an inflexible step-care protocol for the management of chronic obstructive pulmonary disease, given its heterogeneity and our uncertainty about its pathogenesis. Instead, the following outline might be regarded as a statement of principles to guide individual treatment plans. Smoking cessation is an essential, if difficult, first step, which is necessary to slow the accelerated rate of decline in pulmonary function that is characteristic of this disease. There is a compelling rationale for the use of influenza and pneumococcal vaccination, although proof of efficacy is lacking. If airways obstruction is present, inhaled quaternary anticholinergic bronchodilators seem to offer the greatest benefit with fewest side effects, making them the obvious first choice in bronchodilator therapy. In some patients, the addition of beta-agonists, theophylline, or both may augment bronchodilation. If significant airways obstruction persists despite the foregoing, an oral steroid trial is required. Some carefully selected patients whose exercise capacity has been limited despite optimal medical therapy may respond to a supervised exercise rehabilitation program. If hypoxemia is present, supplemental oxygen improves survival. Additional therapeutic modalities, ranging from preventive antioxidant administration to lung transplantation, remain investigational.

Chemical properties of bronchorrhea sputum in bronchial asthma

Bronchorrhea, defined as watery sputum of 100 ml or more per day, was seen in 18 of 207 patients (8.7 percent) with bronchial asthma during attack. Fifteen bronchorrhea sputum samples were chemically examined using ten parameters: dry weight, albumin, IgA, pH, Na+, Cl-, K+, prostaglandins E and F and histamine, and compared with eight saliva samples and 17 mucoid sputum samples. Bronchorrhea sputum differed from saliva in its chemical parameters. Bronchorrhea sputum exhibited parameter values intermediate between those of saliva and mucoid sputum, except for the two following parameters. The pH of bronchorrhea sputum was significantly lower than that of mucoid sputum and histamine concentration, expressed as weight per dry weight of sample, was significantly higher in bronchorrhea than in mucoid sputum. Administration of corticosteroid or an histamine H1-blocker to five to nine asthmatic patients with associated bronchorrhea sputum during asthmatic attacks, significantly reduced the volume of bronchorrhea sputum, whereas anticholinergics and H2-blocker did not alter the sputum volume.