Acute asthma in adults

Acute asthma can be defined as first appearance of asthma or as a rapid deterioration of the asthmatic's habitual condition which can develop into a life-threatening condition. The severity of an attack and the effect of treatment has to be evaluated with the aid of peak flow measurements. The patient's self-treatment consists of increasing the dose of inhaled beta-2-receptor agonist and eventually doubling the dose of inhaled steroids. First-line treatment in hospital is high-dose inhaled nebulized beta-2-receptor agonist and oral corticosteroids. Ipratropium bromide and theophylline infusions may be added if necessary.     

Protection by extracellular glutathione against sulfur mustard induced toxicity in vitro

BACKGROUND: Salmeterol xinafoate is a highly selective beta2-adrenoceptor for the maintenance treatment of asthma in adults and children. OBJECTIVE: To review the pharmacokinetics, clinical pharmacology, and therapeutic properties of a recently introduced, long acting antiasthmatic drug. METHODS: Recent English-language publications were selected using Medline as database. RESULTS: Salmeterol's pharmacokinetics, clinical pharmacology, and therapeutic properties are reviewed and aspects related to salmeterol's unusual duration of action, its high potency, beta2-selectivity, possible antiinflammatory actions, its interaction with other drugs, low systemic adverse effects, dosage, and administration are also discussed. CONCLUSION: Salmeterol is a safe long-acting beta2-agonist very useful for maintenance treatment of asthma.     

Efficacy of bronchodilators in the treatment of bronchiolitis

Bronchiolitis is a common respiratory infection affecting young children. Much controversy revolves around the efficacy of bronchodilators in the treatment of bronchiolitis. This study was conducted to address this issue. AIM: To determine the efficacy of bronchodilators in the treatment of bronchiolitis. METHOD: All children less than 2 years old with bronchiolitis were randomly assigned to receive nebulisations of Salbutamol, Ipratropium bromide or normal saline. A fourth group given only humidified oxygen without nebulisation were used as a control. RESULTS: Data were obtained for 120 patients. Fifty-one (42%) had respiratory syncytial virus (RSV) isolated from their nasopharyngeal aspirates. The demographic characteristics of the 4 groups were similar. There was no significant difference between the groups in terms of severity score, number of nebulisations required in the nebulised groups and the outcome as measured by the length of hospitalisation. CONCLUSION: The use of bronchodilators did not alter the course of the disease and is therefore not effective in the treatment of bronchiolitis.     

Salmeterol: a novel, long-acting beta 2-agonist

OBJECTIVE: The clinical pharmacology, pharmacokinetics, clinical efficacy, and adverse effects of the long-acting beta 2-agonist salmeterol are reviewed. DATA SOURCES: A MEDLINE search was performed to identify English-language publications pertaining to salmeterol. STUDY SELECTION: Open and controlled trials were reviewed in assessing clinical efficacy. Only the results of controlled, randomized trials were considered in the effectiveness evaluation. DATA EXTRACTION: The primary measures of effectiveness in the clinical trials were bronchodilator activity and reduction of hyperresponsiveness that may reflect antiinflammatory activity. Bronchodilator activity was measured as changes in pulmonary function; reduction of hyperresponsiveness was evaluated using respiratory challenge with methacholine, histamine, allergen, or cold air. Secondary measures included symptom scores, need for rescue doses, and patient preference. DATA SYNTHESIS: Salmeterol is a selective, beta 2-agonist that has been studied in the treatment of exercise-induced, nocturnal, and allergen-induced asthma. Salmeterol interacts with the traditional beta-receptor in a similar manner as other beta-agonists, and it exhibits potent in vitro antiinflammatory effects as an inhibitor of inflammatory mediator release. Less evidence exists for its in vivo antiinflammatory activity. Salmeterol demonstrates prolonged receptor occupancy, which is thought to contribute to its long duration of action. The recommended dose is 50 micrograms via metered-dose inhaler or dry-powdered inhalation. In the published clinical trials, salmeterol was more effective than albuterol in treating asthma, including exercise and allergen-induced asthma. Salmeterol's major advantage over other inhaled beta-agonists is its long duration of action (12 hours), making it an excellent choice for treatment of nocturnal asthma. A potential disadvantage is delayed onset of action. Tachyphylaxis to salmeterol's bronchodilator effects has not been shown, but tolerance to its protective effects against methacholine-induced bronchoconstriction has occurred. Adverse effects reported have been mild and have included headache, tremor, and palpitations. CONCLUSIONS: Salmeterol is an effective beta 2-agonist in the treatment of asthma. However, several issues require further investigation regarding its long-term effects on disease control, significance of antiinflammatory activity, and role as a rescue medication.     

Investigation into the therapeutic efficacy of continuous isoproterenol inhalation in relation to respiratory infections in asthmatic children

In our Department, continuous isoproterenol inhalation therapy has been conducted on status asthmatics over the last 10 years. In the present study, we investigated whether there are any differences in the therapeutic efficacy of continuous inhalation of isoproterenol in the presence or absence of respiratory infections which may induce or aggravate asthma attacks. The treatment period was significantly longer in patients with pneumonia. Further prolongation of the treatment period was noted in patients with atelectasis. However, there were no apparent differences in therapeutic efficacy according to age or the severity of attacks. These findings suggest that continuous inhalation of isoproterenol is very effective for status asthmatics if respiratory infections are thoroughly controlled.     

Asthma treatment during pregnancy. What can be safely taken?

'Safe' pharmacological therapy for gestational asthma is defined as therapy during which the apparent risks of the drug appear to be lower than the maternal and potential fetal risks of uncontrolled asthma that could result if the drug were not used. Major malformations occur in 2 to 4% of all newborns, 1% of which can be attributed to medication in general. Information regarding the effects of drugs administered during pregnancy may come from animal studies, human case reports, and prospective cohort studies. Based on a review of the available information, it is recommended that mild asthma during pregnancy be managed with inhaled beta 2-agonists, as required; step therapy for moderate asthma would include inhaled sodium cromoglycate (cromolyn sodium), inhaled beclomethasone dipropionate and oral theophylline. Severe gestational asthma should be treated with oral corticosteroids at the lowest effective dosage. The pharmacological management of acute asthma during pregnancy should include nebulised beta 2-agonists and ipratropium bromide, and intravenous methylprednisolone. Intravenous aminophylline would not generally be recommended, unless the patient requires hospitalisation. Optimal medical practice medico-legal considerations demand that the patient's informed consent be obtained for that recommended gestational management programme.     

Oesophageal dysfunction in male patients with angina-like pain

The value of betamethasone valerate by inhalation in the prophylactic therapy of severe childhood asthma has been established. To determine whether the efficacy of this drug is due to a local or a systemic action a double-blind crossover study of 28 days' treatment with oral betamethasone valerate and 28 days' treatment with inhaled steroid was carried out in 10 asthmatic children. Daily doses used were 1 mg orally and 800 mug by inhalation. Nine patients had fewer symptoms, higher peak expiratory flow rates, and a lower bronchodilator requirement on inhaled than on oral therapy. Exercise-induced bronchoconstriction was diminished on inhaled therapy. Five children requested early termination of the oral therapy period because of unacceptable symptoms. Nine parents stated a preference for the period of inhaled therapy. It is concluded that betamethasone valerate is highly effective by inhalation but that a comparable oral dose has no appreciable clinical effect.     

Inhaled atropine sulfate: dose response characteristics

Inhaled atropine sulfate is a bronchodilator in man, but its efficacy and optimal dosage are still unknown. In the current study, the dose-response characteristics of this agent were examined in 20 children with chronic perennial asthma, using maximal expiratory flow-volume curves. Inhaled drug was delivered in incremental doses of 0.005 to 0.1 mg per kg. A peak action of atropine on the maximal flow after exhalation of 50 per cent of the forced vital capacity was seen 1 hour after inhalation; significant bronchodilatation was observed for as long as 300 min, depending on the dose. A plateau was observed in the dose-response curve in the dose range, 0.05 to 0.1 mg per kg. Changes in the maximal expiratory flow after exhalation of 75 per cent of the forced vital capacity paralleled those in the maximal expiratory flow after exhalation of 50 per cent of the forced vital capacity. Specific conductance significantly increased, and the ratio of residual volume to total lung capacity significantly decreased in 10 patients examined. In no case could the observed increases in flows be explained by the patient's breathing at a higher lung volume. Considerable intersubject variation was found in the effects of a given dose of atropine. This may be explained by variations in baseline flows. It was concluded that atropine sulfate by inhalation is an effective bronchodilator in children with severe asthma and that reported variations in its efficacy may be related to inadequate dosage.     

Intranasal salmeterol inhibits allergen-induced vascular permeability but not mast cell activation or cellular infiltration

BACKGROUND: Salmeterol is a long-acting beta2-adrenergic agonist that is widely used in the treatment of asthma. It has been suggested that non-bronchodilator actions of salmeterol may contribute to its efficacy. OBJECTIVE: To further evaluate the potential non-bronchodilator actions of salmeterol in vivo, using a model of nasal challenge with allergen. METHODS: Twelve asymptomatic subjects with seasonal allergic rhinitis participated in a randomized, double-blind, placebo-controlled crossover trial of the effects of a single dose of 100 microg of salmeterol on the response to allergen challenge. Sneezing and symptom scores, and levels of histamine and albumin in nasal lavages, were measured throughout the protocol. Concentrations of tryptase, prostaglandin D2 and lysozyme were measured during the acute allergic response, while levels of IL-3, IL-5 and IL-8 were measured at later time points. Numbers of eosinophils and of total white blood cells were also recorded. RESULTS: Salmeterol did not affect sneezing or symptom scores at any point. During the immediate response to allergen challenge, mast cell activation, reflected by concentrations of histamine, tryptase and prostaglandin D2, and serous glandular secretion, assessed by measurements of lysozyme, were unaffected by salmeterol treatment but vascular permeability, reflected by concentrations of albumin in nasal lavages, was significantly reduced. At later time points, salmeterol had no effect on levels of histamine or albumin and did not affect cellular infiltration. Concentrations of IL-3, IL-5 and IL-8 were not increased by allergen challenge in these subjects, so the effects of salmeterol could not be evaluated. CONCLUSIONS: Treatment with a single dose of salmeterol had no effect on activation of mast cells or cellular infiltration but inhibited vascular permeability. The ability of salmeterol to inhibit antigen-induced vascular permeability may contribute to its therapeutic efficacy in asthma.     

Acute treatment-related diarrhea during postoperative adjuvant therapy for high-risk rectal carcinoma

STUDY OBJECTIVES: To examine the main therapeutic response patterns to high doses of salbutamol and to determine the factors that contribute to outcome in acute severe asthma. SETTING: The emergency department (ED) of a large, urban hospital with primary and referral care responsibilities. PATIENTS AND DESIGN: One hundred sixteen consecutive patients with acute exacerbations of asthma were enrolled in the trial, using a prospective sequential design. INTERVENTIONS: All patients were treated with salbutamol delivered with a metered-dose inhaler into a spacer device in four puffs (400 microg) at 10-min intervals. The protocol involved 3 h of this treatment (1,200 microg each 30 min). MEASURES AND RESULTS: A dose-response increase in pulmonary function was found, but only 70% improved sufficiently to be discharged. Of these, almost 70% required < or =2.4 mg of the drug within 1 h to reach the discharge threshold, whereas the remainder 30% need > or =3.6 mg. In 30% of subjects, salbutamol was ineffective. These patients were characterized by a more severe disease as judged by previous beta2-agonist use, larger duration of attack before ED visit, and a more severe obstruction at presentation. However, the most important predictors of outcome were peak expiratory flow rate (PEFR) as percent of predicted, PEFR as liters per minute, and PEFR variation over baseline value, all at 30 min. CONCLUSIONS: This study described two different therapeutic response patterns to salbutamol. Almost 70% of patients were sensitive to salbutamol (good response pattern), and in this group, 2.4 to 3.6 mg represents optimal treatment. In the remainder 30% of patients (poor response pattern), salbutamol in high doses had little effect. However, the outcome was not determined by the intensity of the initial symptoms or by the value of the presenting PEFR, but rather by the early (30 min) short-term response to treatment.     

The separation of ipratropium bromide and its related compounds

Ipratropium bromide, the active component in ipratropium bromide metered dose inhalers (MDI), is used as a bronchodilator for the maintenance and treatment of bronchospasms associated with chronic obstructive pulmonary disease (COPD). The separation of ipratropium bromide, tropic acid, N-isopropyl-nor-atropine (NINA), 8-s ipratropium bromide, apo-ipratropium bromide and the excipients found in the formulation is important for analyzing raw materials and stability samples. We now report a reversed-phase HPLC method that can be used for separating ipratropium bromide and its related compounds, using an acetonitrile/potassium phosphate buffer (100 mM, pH 4.0) gradient mobile phase. Previous methods used for separating ipratropium bromide from its related compounds involved reversed-phase ion-pairing HPLC with UV detection. These methods exhibited less reproducibility, less ruggedness and required a high flow rate. The reported method is linear from 10 to 1000 micrograms ml-1 with a limit of detection of 60 ng ml-1. In addition, analysis of samples subjected to accelerated stability conditions showed that all degradants are resolved from the active component, resulting in stability-indicating assay. This assay also saved mobile phase and eliminated problems associated with ion-pairing reagents.     

Sympathomimetic enantiomers and asthma

Airways of asthma patients can become hyperresponsive to airway spasmogens following regular use of isoprenaline or beta 2-selective sympathomimetics. Hyper-reactivity that results from acute exposure of animals to these drugs is pre-empted by vagal section (a procedure which does not influence spasmolytic efficacy of sympathomimetics), is not diminished by antagonism of beta 2-adrenoceptors and is not associated with loss of responsivity of beta 2-adrenoceptors in the airways. Since activation, modulation, or blockade of beta 2-adrenoceptors does not determine this form of hyperreactivity, the possibility that distomers may induce hyperreactivity must be considered. Ocular and vascular responses to distomers of sympathomimetics have long been recognised and, more recently, comparable observations have been made for the airways. Thus, reactivity of guinea-pig airways to spasmogens was increased following exposure to S-isoprenaline, S-salbutamol, or S-terbutaline and exposure to S-isoprenaline or S-salbutamol can intensify symptoms in asthmatics. Regular exposure to the racemate, especially during or following an allergic reaction, predisposes to expression of hyper-reactivity, which is nullified, acutely, by the eutomer. These observations imply that biological effects of sympathomimetic distomers may contribute to morbidity and mortality in asthma patients.     

Inhaled furosemide prevents ultrasonically nebulized water bronchoconstriction in children with both atopic and nonatopic asthma

To determine whether inhaled furosemide can modify the bronchoconstriction induced by ultrasonically nebulized distilled water (UNDW) in children with both atopic and nonatopic asthma, a single-blind, randomized, placebo-controlled study was undertaken. The UNDW inhalation challenge was performed in 21 asthmatic children (atopic, 14; nonatopic, 7; mean +/- SEM age, 11.5 +/- 0.5 years), who had a fall in FEV1 of at least 20 percent after distilled water inhalation. On separate days, these subjects underwent UNDW challenge test after inhalation of furosemide (10 mg/body square meters) or placebo (saline solution). Inhaled furosemide exerted a protective effect against bronchoconstriction induced by UNDW in children with both atopic and nonatopic asthma (p < 0.01, p < 0.05, respectively). These results indicate that the protective action of furosemide against UNDW-induced bronchoconstriction may be independent of its direct inhibitory effect on airway mast cell activation.     

Use of helium-oxygen gas mixtures in acute obstructive respiratory insufficiencies

Therapeutic use of helium has been described since 1930. Its main action is to reduce bronchial resistances and consequently overall respiratory work. Helium is substituted for nitrogen. The effects of inhaling a helium-oxygen mixture result exclusively from the physicochemical properties of helium: very low density, high kinetic viscosity. With the advent of selective bronchodilators, use of helium was rapidly abandoned until recently with new interest for the treatment of severe acute asthma. We review the literature on the physical properties of helium-oxygen mixtures and propose an analysis of their therapeutic use in severe acute asthma as well as other indications such as acute episodes of obstructive bronchopneumonia and obstruction of the upper airways. Due to the non-invasive nature of this technique, its easy use with spontaneous ventilation and the large body of theoretical data emphasizing its adaptation for therapeutic use, helium-oxygen gas mixtures offer an important therapeutic option for treating severe diseases with poor prognosis. A multicentric national study is under way to validate its use early by emergency ambulatory units for the treatment of severe acute asthma.     

Coagulatory response after femoral instrumentation after severe trauma in sheep

Budesonide inhalation powder, available as Pulmicort Turbuhaler, is a corticosteroid with a high ratio of local to systemic effects that is administered to treat persistent asthma. The Turbuhaler achieves lung deposition approximately twice that of a metered-dose inhaler (MDI) with or without a spacer device. Budesonide inhalation powder has clinical efficacy equivalent to that of fluticasone and beclomethasone, but it has lower systemic bioavailability and fewer systemic side effects. As with other inhaled corticosteroids, dysphonia and oral candidiasis are the most frequent adverse effects, and systemic effects are infrequent. The initial starting dosage is 200 microg (1 puff) twice/day and may be increased to 800 microg twice/day in adults or 400 microg twice/day in children. Patients prefer the Turbuhaler to the MDI, Diskhaler, and Rotahaler because it is easier to use and more convenient to carry.     

Evidence for a role of phospholipase C-gamma1 in the pathogenesis of bipolar disorder

OBJECTIVES: To determine whether readmission to hospital for children aged 1-7 years with asthma can be predicted; and to discover whether factors related to the severity of the attack and past pattern of asthma, assessment of the parents' intention to treat the child with inhaled therapy, perceived consequences of treatment, habits of treatment and self-efficacy show a difference between those children subsequently readmitted and those who were not. METHODS: A specifically developed questionnaire was administered to parents of 121 children admitted with asthma. Clinical assessment was made of severity of the acute attack and past pattern of the asthma. One year after admission subjects were reviewed to determine those who had been readmitted. RESULTS: On univariate analysis, the negative perceived consequences of treatment with inhaled therapy were associated with an increased risk of readmission over a one-year period (P = 0.04). After adjusting for confounders (place of birth of mother, two- or one-parent family) and the effect-modifier of past pattern of the asthma (infrequent episodic, frequent episodic, persistent), the greater the negative perceived consequences of treatment, the more likely there would be readmission in children with infrequent episodic asthma. After adjusting for potential confounders, using logistic regression a decrease of one standard deviation in the negative perceived consequences score resulted in a one-third decrease in the odds of readmission (odds ratio (OR) = 0.31, 95% CI 0.12-0.83). CONCLUSIONS: Parents whose children are readmitted see greater negative perceived consequences of treatment. If asthma is infrequent episodic, the negative perceived consequences may be an inhibitor of treatment, whereas for more severe past patterns of asthma the severity is the controller of treatment. If parental negative consequences could be decreased, admissions for asthma may decrease.     

Accuracy of asthma treatment in schoolchildren in NSW, Australia

Insufficient use of anti-inflammatory drugs, such as inhaled corticosteroids and cromoglycate, may contribute to the disease burden associated with asthma. Conversely, aggressive treatment of mild disease may result in avoidable costs and/or adverse drug effects. The aim of this study was to determine the relationship between asthma severity and inhaled corticosteroid/cromoglycate use in a large (n=4,909) random sample of children, aged 8-11 yrs, in NSW, Australia. Asthma and its treatment were assessed by questionnaire responses. Asthma, defined as diagnosis plus current wheeze, was present in 901 children (18% of the sample), of whom 225 (5%) had moderate asthma, defined as asthma plus additional symptoms (sleep disturbance), utilization (hospital, casualty), or disability (reduced activity, school absence). Use of inhaled corticosteroid/cromoglycate was reported by 636 children (13% of the sample). Determinants of use included: asthma diagnosis, current wheeze, and troublesome dry nocturnal cough. There was also a strong relationship between anti-inflammatory treatment and a multicomponent asthma severity score constructed for each child. Inhaled corticosteroids and/or cromoglycate were used by 56% of the children with asthma (24% daily) and by 76% of children with moderate asthma (42% daily). Undertreatment, defined as less than daily inhaled corticosteroids/cromoglycate in moderate asthma, was identified in 130 children (14% of those with asthma or 3% of the sample). Conversely, apparently aggressive treatment, defined as inhaled corticosteroid/cromoglycate use in children with persistent minimal symptoms (asthma severity score of less than 3) was identified in 101 children (2% of the sample). Although there were significant differences between regions in the choice of anti-inflammatory drugs and in the prevalence both of undertreatment and apparently aggressive treatment, there was no clear relationship to regional utilization of emergency and hospital services for asthma. Nevertheless, the frequency of undertreatment suggests an opportunity to reduce asthma morbidity by more consistent application of current therapeutic guidelines.     

Caring for AIDS patients at home--requirements for development of the concept

Exercise tolerance in chronic obstructive pulmonary disease (COPD) patients treated with oral aminophylline may be different from those treated with high-dose inhaled ipratropium bromide. The purpose of this study was to compare the effects of therapeutic doses of oral aminophylline with high-dose ipratropium bromide on spirometry and exercise tolerance. The study was conducted on three consecutive days in a double-blind, randomized, crossover fashion. Baseline studies obtained on each study day included vital signs, simple spirometry and a symptom-limited maximal cardiopulmonary stress test, after which patients received one of the following treatments on each day: Treatment 1, inhaled ipratropium (total dose of 144 micrograms) with placebo tablets; Treatment 2, inhaled placebo with oral aminophylline (400 mg); Treatment 3, inhaled placebo and placebo tablets. Simple spirometry was repeated at 60 and 120 min after baseline. Vital signs and cardiopulmonary stress testing was repeated at 120 min. Eighteen patients were enrolled in the study, and 17 of these completed the study. There was a significant (P < 0.05) increase in both forced expiratory volume in 1 s (FEV1), from 0.75 (0.21) to 0.92 (0.3), and forced vital capacity (FVC), from 1.8 (0.79) to 2.11 (0.84), with high-dose ipratropium despite prior beta-agonist therapy. Lack of improvement in exercise capacity was noted with ipratropium despite improvement in spirometry. These results suggest that elderly patients with severe COPD may have exercise limitation that is not directly dependent on severity of airflow obstruction. Ipratropium bromide and aminophylline demonstrated no acute effects on exercise capacity.