Combined inhaled beta-agonist and anticholinergic agents for emergency management in adults with asthma.

BACKGROUND: Inhaled short-acting anticholinergics (SAAC) and short-acting beta2-agonists (SABA) are effective therapies for adult patients with acute asthma who present to the emergency department (ED). It is unclear, however, whether the combination of SAAC and SABA treatment is more effective in reducing hospitalisations compared to treatment with SABA alone. OBJECTIVES: To conduct an up-to-date systematic search and meta-analysis on the effectiveness of combined inhaled therapy (SAAC + SABA agents) vs. SABA alone to reduce hospitalisations in adult patients presenting to the ED with an exacerbation of asthma. SEARCH METHODS: We searched MEDLINE, Embase, CINAHL, SCOPUS, LILACS, ProQuest Dissertations & Theses Global and evidence-based medicine (EBM) databases using controlled vocabulary, natural language terms, and a variety of specific and general terms for inhaled SAAC and SABA drugs. The search spanned from 1946 to July 2015. The Cochrane Airways Group provided search results from the Cochrane Airways Group Register of Trials which was most recently conducted in July 2016. An extensive search of the grey literature was completed to identify any other potentially relevant studies. SELECTION CRITERIA: Included studies were randomised or controlled clinical trials comparing the effectiveness of combined inhaled therapy (SAAC and SABA) to SABA treatment alone to prevent hospitalisations in adults with acute asthma in the emergency department. Two independent review authors assessed studies for inclusion using pre-determined criteria. DATA COLLECTION AND ANALYSIS: For dichotomous outcomes, we calculated individual and pooled statistics as risk ratios (RR) or odds ratios (OR) with 95% confidence intervals (CI) using a random-effects model and reporting heterogeneity (I²). For continuous outcomes, we reported individual trial results using mean differences (MD) and pooled results as weighted mean differences (WMD) or standardised mean differences (SMD) with 95% CIs using a random-effects model. MAIN RESULTS: We included 23 studies that involved a total of 2724 enrolled participants. Most studies were rated at unclear or high risk of bias.Overall, participants receiving combination inhaled therapy were less likely to be hospitalised (RR 0.72, 95% CI 0.59 to 0.87; participants = 2120; studies = 16; I² = 12%; moderate quality of evidence). An estimated 65 fewer patients per 1000 would require hospitalisation after receiving combination therapy (95% 30 to 95), compared to 231 per 1000 patients receiving SABA alone. Although combination inhaled therapy was more effective than SABA treatment alone in reducing hospitalisation in participants with severe asthma exacerbations, this was not found for participants with mild or moderate exacerbations (test for difference between subgroups P = 0.02).Participants receiving combination therapy were more likely to experience improved forced expiratory volume in one second (FEV1) (MD 0.25 L, 95% CI 0.02 to 0.48; participants = 687; studies = 6; I² = 70%; low quality of evidence), peak expiratory flow (PEF) (MD 36.58 L/min, 95% CI 23.07 to 50.09; participants = 1056; studies = 12; I² = 25%; very low quality of evidence), increased percent change in PEF from baseline (MD 24.88, 95% CI 14.83 to 34.93; participants = 551; studies = 7; I² = 23%; moderate quality of evidence), and were less likely to return to the ED for additional care (RR 0.80, 95% CI 0.66 to 0.98; participants = 1180; studies = 5; I² = 0%; moderate quality of evidence) than participants receiving SABA alone.Participants receiving combination inhaled therapy were more likely to experience adverse events than those treated with SABA agents alone (OR 2.03, 95% CI 1.28 to 3.20; participants = 1392; studies = 11; I² = 14%; moderate quality of evidence). Among patients receiving combination therapy, 103 per 1000 were likely to report adverse events (95% 31 to 195 more) compared to 131 per 1000 patients receiving SABA alone. AUTHORS' CONCLUSIONS: Overall, combination inhaled therapy with SAAC and SABA reduced hospitalisation and improved pulmonary function in adults presenting to the ED with acute asthma. In particular, combination inhaled therapy was more effective in preventing hospitalisation in adults with severe asthma exacerbations who are at increased risk of hospitalisation, compared to those with mild-moderate exacerbations, who were at a lower risk to be hospitalised. A single dose of combination therapy and multiple doses both showed reductions in the risk of hospitalisation among adults with acute asthma. However, adults receiving combination therapy were more likely to experience adverse events, such as tremor, agitation, and palpitations, compared to patients receiving SABA alone.

Beta2-adrenoceptor agonists for dysmenorrhoea.

BACKGROUND: Dysmenorrhoea is a common gynaecological complaint that can affect as many as 50% of premenopausal women, 10% of whom suffer severely enough to be rendered incapacitated for one to three days during each menstrual cycle. Primary dysmenorrhoea is where women suffer from menstrual pain but lack any pathology in their pelvic anatomy. Beta2-adrenoceptor agonists have been used in the treatment of women with primary dysmenorrhoea but their effects are unclear. OBJECTIVES: To determine the effectiveness and safety of beta2-adrenoceptor agonists in the treatment of primary dysmenorrhoea. SEARCH METHODS: We searched the Cochrane Menstrual Disorders and Subfertility Group Specialised Register; CENTRAL (The Cochrane Library 2011, Issue 8); MEDLINE; EMBASE; PsycINFO and the EBM Reviews databases. The last search was on 22 August 2011. SELECTION CRITERIA: Randomised controlled trials comparing beta2-adrenoceptor agonists with placebo or no treatment, each other or any other conventional treatment in women of reproductive age with primary dysmenorrhoea. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed trial quality and extracted the data. MAIN RESULTS: Five trials involving 187 women with an age range of 15 to 40 years were included. Oral isoxsuprine was compared with placebo in two trials; terbutaline oral spray, ritodrine chloride and oral hydroxyphenyl-orciprenalin were compared with placebo in a further three trials. Clinical diversity in the studies in terms of the interventions being evaluated, assessments at different time points and the use of different assessment tools mitigated against pooling of outcome data across studies in order to provide a summary estimate of effect for any of the comparisons. Only one study, with unclear risk of bias, reported pain relief with a combination of isoxsuprine, acetaminophen and caffeine. None of the other studies reported any significant clinical difference in effectiveness between the intervention and placebo. Adverse effects were reported with all of these medications in up to a quarter of the total number of participants. They included nausea, vomiting, dizziness, quivering, tremor and palpitations. AUTHORS' CONCLUSIONS: The evidence presented in this review was based on a few relatively small-sized studies that were categorised to have unclear to high risk of bias, which does not allow confident decision-making at present about the use of beta2-adrenoceptor agonists for dysmenorrhoea. The benefits as reported in one study should be balanced against the wide array of unacceptable side effects documented with this class of medication. We have emphasised the lack of precision and limitations in the reported data where appropriate.

Cromoglycate, reproterol, or both--what's best for exercise-induced asthma?

OBJECTIVE: International guidelines recommend short- (SABA) or long-acting b-agonists for the prevention of bronchoconstriction after exercise (EIB) in patients with exercise-induced asthma (EIA). However, other drugs are still in discussion for the prevention of EIB. We investigated the efficacy of a combination of inhaled sodium cromoglycate and the ß-mimetic drug reproterol versus inhaled reproterol alone and both versus inhaled placebo in subjects with exercise-induced asthma (EIA). METHODS: The study aimed to prove the preventive effect of a combination of 1-mg reproterol and 2-mg disodium cromoglycate (DSCG) and its single components vs. placebo, measuring the decrease of FEV1 after a standardized treadmill test in 11 patients with recorded EIA. The study medication was twice as high as those of drugs which are commercially available (e.g., Allergospasmin®, Aarane®). RESULTS: The results revealed that the combination of reproterol and DSCG was significantly effective against a decrease of FEV1 after a standardized exercise challenge test (ECT) compared to placebo. The short-acting b-agonist reproterol alone had almost the same effectiveness as the combination of reproterol and DNCG. The difference between the combination with DNCG and reproterol alone was less than 10% and insignificant (p 0.48). DNCG alone did not show a difference in the effectiveness compared to placebo. CONCLUSION: Prevention of EIA with the combination of reproterol and DSCG or with reproterol only is effective. An exclusive recommendation in favor of the combination cannot be given due to the low difference in the effectiveness versus reproterol alone. Due to the limited number of subjects and some probands showing protection under DSCG, it cannot be completely excluded that there is some preventive power of DSCG in individual cases.

Use of ozone-depleting substances; removal of essential-use designation (flunisolide, etc.). Final rule.

The Food and Drug Administration (FDA), after consultation with the Environmental Protection Agency (EPA), is amending FDA's regulation on the use of ozone-depleting substances (ODSs) in self-pressurized containers to remove the essential-use designations for flunisolide, triamcinolone, metaproterenol, pirbuterol, albuterol and ipratropium in combination, cromolyn, and nedocromil used in oral pressurized metered-dose inhalers (MDIs). The Clean Air Act requires FDA, in consultation with the EPA, to determine whether an FDA-regulated product that releases an ODS is an essential use of the ODS. FDA has concluded that there are no substantial technical barriers to formulating flunisolide, triamcinolone, metaproterenol, pirbuterol, albuterol and ipratropium in combination, cromolyn, and nedocromil as products that do not release ODSs, and therefore they will no longer be essential uses of ODSs as of the effective dates of this rule. MDIs for these active moieties containing an ODS may not be marketed after the relevant effective date.

Why the lower reported prevalence of asthma in patients diagnosed with COVID-19 validates repurposing EDTA solutions to prevent and manage treat COVID-19 disease.

There currently is no specific antiviral drug or a vaccine for SARS-CoV-2/COVID-19 infections; now exceeding 10,300,000 infections worldwide. In the absence of animal models to test drugs, we need to find molecular explanations for any unforeseen peculiarities in clinical data, especially the recent reports describing an unexpected asthma paradox. Asthma is considered a high medical risk factor for susceptibility to SARS-CoV-2/COVID-19 infection, yet asthma is not on the list of top 10 chronic health problems suffered by people who died from SARS-CoV-2/COVID-19. Resolving this paradox requires looking beyond the binary model of a viral receptor-binding domain (RBD) attaching to the ACE-2 receptor. A NCBI pBlast analysis revealed that the SARS-CoV-2 surface spike protein contains key two calcium-dependent fusion domains that are almost identical to those that were recently discovered SARS-CoV-1. These viral calcium-dependent binding domains can facilitate membrane fusion only after cleavage by the host surface protease TMPRSS2. Importantly, TMPRSS2 also requires calcium for its SRCR (scavenger receptor cysteine-rich) domain and itsLDLRA(LDL receptor class A) domain. Thus, the presence of EDTA excipients in nebulized ß2-agonist medicines can disrupt SARS-CoV-2/COVID-19 infection and can explain the asthma paradox. This model validates repurposing EDTA in nebulizer solutions from a passive excipient to an active drug for treating COVID-19 infections. Repurposed EDTA delivery to respiratory tissues at an initial target dose of 2.4 mg per aerosol treatment is readily achievable with standard nebulizer and mechanical ventilator equipment. EDTA warrants further investigation as a potential treatment for SARS-CoV-2/COVID-19 in consideration of the new calcium requirements for virus infection and the regular presence of EDTA excipients in common asthma medications such as Metaproterenol. Finally, the natural history of Coronavirus diseases and further analysis of the fusion loop homologies between the Betacorona SARS-CoV-2 virus and the less pathogenic Alphacorona HC0V-229E virus suggest how to engineer a hybrid virus suitable for an attenuated alpha-beta SARS-CoV-2/COVID-19 vaccine. Thus, replacing SARS-CoV-2 fusion loops (amino acids 816-855) with the less pathogenic HCoV-229E fusion loop (amino acids 923-982) may provide antigenicity of COVID-19, but limit the pathogenicity to the level of HCoV-229E.

Electrical storm in Brugada syndrome successfully treated with orciprenaline; effect of low-dose quinidine on the electrocardiogram.

We report a case of an electrical storm occurring in a patient implanted with a cardioverter defibrillator for symptomatic Brugada syndrome. Recurrent ventricular fibrillation was initiated by short-coupled premature ventricular beats of right ventricular origin, associated with a fixed Brugada type 2 electrocardiographic pattern. Low-dose orciprenaline application as an intravenous bolus followed by an infusion inhibited the recurrence of ventricular fibrillation and normalized the electrocardiographic pattern. Low-dose oral quinidine had only a moderate effect on the ST-elevation.

An adrenergic drug in depression.

It has been suggested that depression is a disease of cholinergic dominance and since the beta-adrenergic blocking drug propranolol hydrochloride can cause depression, there arises the possibility that a beta-adrenergic stimulant could benefit the condition. For ethical reasons, the adrenergic drug metaproterenol sulfate was combined with chlordiazepoxide hydrochloride and compared to placebo and chlordiazepoxide in a formal double-blind trial. However, the results did not show any advantage for the addition of metaproterenol either in respect of enhanced antidepressant effect or a reduced incidence, nature, or severity of side-effects.

Aerosol bronchodilator delivery methods. Relative impact on pulmonary function and cost of respiratory care.

Thirty-six acutely III, hospitalized patients with acute exacerbations of obstructive airway disease and a greater than 10% increase in forced expiratory volume in 1 s after administration of aerosolized bronchodilator were randomized to receive either metaproterenol sulfate delivered by updraft-compressor nebulization (UDN) or terbutaline sulfate delivered by metered-dose inhaler (MDI) with a spacer. Serial analyses of pulmonary function measurements were performed with the use of 95% confidence intervals for the percentage response ratios of MDI to UDN. The response to MDI was at least equivalent to that of UDN, and MDI use was associated with no prolongation of hospital stay. Equivalent bronchodilation was achieved with MDI therapy with a lower daily charge for therapy for each patient and less respiratory therapist time. In hospitalized bronchodilator-responsive patients with acute exacerbations of obstructive airway disease, the MDI/spacer combination is the preferred approach when the status of the patient allows its use.

Aminophylline in the treatment of acute asthma when beta 2-adrenergics and steroids are provided.

BACKGROUND: The purpose of this study was to test the contribution of aminophylline in improving peak expiratory flow rate (PEFR) during emergency department treatment of acute asthma when metaproterenol sulfate and steroid therapy are also provided. METHODS: In a prospective, randomized, double-blind, and placebo-controlled trial at a municipal hospital emergency department, 44 patients with acute asthma, aged 18 to 45 years, with theophylline levels below 28 mumol/L, who had failed to achieve a PEFR of 40% predicted after one nebulized metaproterenol treatment, were recruited. An aminophylline or placebo loading dose and maintenance infusion were administered. All patients received hourly nebulized metaproterenol and initial methylprednisolone sodium succinate. The PEFR was measured hourly for 5 hours. Two-factor repeated-measures analysis of variance of improvement in PEFR ([final-initial PEFR]/predicted PEFR) was assessed. RESULTS: There was no difference in improvement of PEFR at any hour between the treatment and placebo groups. After 5 hours, the difference in improvement ratio was 0.40 (aminophylline) vs 0.36 (placebo) (P = .30; n = 22 in each group). The treatment group suffered more tremor, nausea or vomiting, and palpitations (P < .05). CONCLUSION: In the emergency department setting, aminophylline contributes no significant improvement in PEFR when beta 2-agonists and corticosteroids are being provided, while causing more side effects.

Metaproterenol in children with chronic asthma.

Metaproterenol sulfate was given to 25 children with asthma in the form of a syrup in a continuous treatment course of 180 days. Dosage amounted to 10 to 20 mg metaproterenol four times daily, depending on the patient's age and weight. Double-blind crossover tests of pulmonary function were run against placebo at the beginning and after 3 and 6 mo of treatment. The peak expiratory flow rate responses to metaproterenol consistently exceeded the responses to placebo, the differences proving statistically significant at several intervals after administration. Adverse reactions were limited to instances of hyperactivity in one child and of mild tremors in another; laboratory values remained normal throughout the 6-mo period except for low normal fasting blood sugar values recorded in 2 patients at the end of the study. Pulse rate increases occurring after metaproterenol were not considered clinically important.

beta-Adrenergic treatment of hyperkalemic periodic paralysis.

In a patient with hyperkalemic periodic paralysis, metaproterenol prevented muscular weakness and hyperkalemia in periods of rest after exercise. During a severe attack, the drug rapidly corrected hyperkalemia and seemed to enhance the return of strength. The action of metaproterenol may involve a beta-adrenergic-mediated increase of potassium transport via the sodium-potassium pump.

Effect of odors in asthma.

Many patients complain that some odors worsen their asthma. Perfume and cologne are two of the most frequently mentioned offenders. Four patients with a history of worsening of asthma on exposure to cologne underwent challenge with a cologne, and their pulmonary function was tested before, during, and after the exposure. Forced expiratory volume in one second declined 18 to 58 percent below the baseline period during the 10-minute exposure and gradually increased in the next 20 minutes. Saline placebo pretreatment did not affect the response to subsequent challenge. Single-blind pretreatment with metaproterenol and atropine prevented decline in one-second forced expiratory volume in three of four patients and blunted the response in the other. Cromolyn sodium prevented decline in one of four, and occlusion of nostrils prevented decline in one of three. A survey of 60 asthmatic patients revealed a history of respiratory symptoms in 57 on exposure to one or more common odors. Odors are an important cause of worsening of asthma.

Comparison of the anticholinergic bronchodilator ipratropium bromide with metaproterenol in chronic obstructive pulmonary disease. A 90-day multi-center study.

The short- and long-term efficacy and safety of an inhaled quaternary ammonium anticholinergic agent, ipratropium bromide, and a beta agonist aerosol, metaproterenol, were compared in 261 nonatopic patients with chronic obstructive pulmonary disease (COPD). The study was a randomized, double-blind, 90-day, parallel-group trial. On three test days-one, 45, and 90-mean peak responses for forced expiratory volume in one second and forced vital capacity and mean area under the time-response curve were higher for ipratropium than for metaproterenol. Clinical improvement was noted in both treatment groups, especially during the first treatment month, with persistence of improvement throughout the remainder of the study. Side effects were relatively infrequent and generally mild; tremor, a complication of beta agonists, was not reported by any subject receiving ipratropium. These results support the effectiveness and safety of long-term treatment with inhaled ipratropium in COPD.

"Noninvasive" oral treatment of asthma in the emergency room.

One hundred forty consecutive patients with acute asthmatic episodes presenting to the emergency room were studied prospectively to assess the efficacy of oral therapy. After the emergency room staff was oriented to the pharmacologic action of hydroalcoholic elixir of theophylline, oral terbutaline, and a metered-dose hand-held nebulizer (metaproterenol), use of oral therapy as initial therapy rose from 12 percent to 76 percent (p = 0.005). More than half of these patients were discharged without receiving any of the traditional more invasive therapies of subcutaneous epinephrine, intravenous hydrating fluids with aminophylline, and machine-delivered sympathomimetic aerosols. Oral therapy did not substantially alter the total time spent in the emergency room. Only 4 percent treated with oral therapy required further treatment in the emergency room within 48 hours; 2 percent vomited after treatment. Oral therapy is safe and effective for most asthmatic patients presenting to the emergency room, as they generally are undermedicated with regard to theophyllines and sympathomimetic drugs. Use of oral therapy in the emergency room is a potent tool for educating asthmatic patients in the use of medication available for home use. The patients who require emergency room treatment despite being well-medicated at home (a small minority) need a higher level of care including intermittent positive-pressure breathing, corticosteroids, and often hospitalization.

Effects of an inhaled bronchodilator on gas distribution and over-all ventilatory efficiency in patients with chronic obstructive pulmonary disease.

The effects of an inhaled bronchodilator on the distribution of inspired gas and over-all efficiency of ventilation were studied by the nitrogen washout technic in 16 patients with chronic obstructive pulmonary disease; three normal subjects and two patients with asymptomatic asthma (and normal spirometric values) were also studied. In normal and asthmatic subjects and in patients with chronic obstructive pulmonary disease and mild to moderate functional impairment, the nitrogen clearance did not vary significantly or showed changes suggesting less uniform gas distribution and reduced ventilatory efficiency. In most patients with advanced chronic obstructive pulmonary disease, the bronchodilator caused changes suggesting more uniform distribution of inspired gas and increased efficiency of ventilation. Multiple regression analysis showed that the behavior of the nitrogen clearance after treatment was also related to the response of the anatomic dead space. The effects of the bronchodilator varied with time. The results are consistent with the assumption that the changes in nitrogen clearance after bronchodilator therapy reflect the concourse of multiple factors, which may be expected to have favorable or unfavorable effects on the distribution of inspired gas and the efficiency of ventilation.

Results of a multicenter study of nebulized inhalant bronchodilator solutions.

The efficacy, persistence of bronchodilator action, and safety of the quaternary ammonium anticholinergic agent, ipratropium bromide (500 microgram), and placebo were compared when each was added in solution form to the beta-adrenergic agonist solution, metaproterenol sulfate (15 mg), and administered three times daily for 12 weeks to a total of 213 patients with chronic obstructive pulmonary disease (COPD). Subjects had a mean forced expiratory volume in 1 second (FEV1) of approximately 1 liter (37% of predicted) and were permitted to use nonanticholinergic therapy for COPD throughout the trial. The study was a randomized, double-blind, 85-day, parallel-group, eight-center study. On a 3 test days, 1, 43, and 85, mean peak responses for FEV1 and forced vital capacity and mean area under the curve were significantly higher for the iprathropium bromide-metaproterenol combination than for metaproterenol only. Duration of action was also significantly longer for the combination therapy than for the beta-agonist alone on test days 1 and 43. Neither treatment regimen produced an demonstrable effect on daily morning peak expiratory flow rates, reported respiratory symptoms, or quality of life. Both treatment regimens were similarly well tolerated with a comparable frequency of adverse events. These results suggest that the combination of iprathropium bromide and metaproterenol inhalation solutions offers a potential therapeutic advantage to patients with symptomatic COPD over nebulized metaproterenol alone without the risk of increased side effects.

A multicenter study of nebulized bronchodilator solutions in chronic obstructive pulmonary disease.

A multicenter, 85-day, double-blind, randomized study was conducted to compare the effects of a single-dose and chronic inhalation of ipratropium bromide solution (500 micrograms) to the beta-adrenergic agonist metaproterenol (5% solution, 15 mg) in patients with chronic obstructive pulmonary disease (COPD). Patients were required to have a relatively stable, moderately severe COPD, forced expiratory volume in 1 second (FEV1) < 65% of predicted normal, FEV1 <70% of forced vital capacity (FVC), and a smoking history of > 10 pack-years. Following a 2-week baseline period, patients were randomized into either the ipratropium bromide (106 patients) or metaproterenol (107 patients) study groups. Pulmonary function testing was performed on days 1, 43, and 85. Secondary efficacy variables examined included peak expiratory flow rates, physician's global evaluation, quality of life, COPD symptom score, and use of concomitant medications. FEV1 was comparable between the two groups on day 1 (1.00 and 1.02 liters, ipratropium bromide vs metaproterenol, respectively; p = nonsignificant). The baseline FEV1 increased significantly in the ipratropium bromide group between day 1 and 43 by 10% (from 1.00 to 1.10 liters, p < 0.002) and remained 7% elevated on day 85 (1.07 liters) compared to day 1 (p < 0.02); it did not change in the metaproterenol group across all three test days. A clinically significant (> 15%) mean FEV1 response was observed on each of the 3 test days following drug inhalation in both treatment groups. The median duration of action was similar between groups (5 hours) on test day 1, but on day 85 the median duration for ipratropium bromide was r.5 hours compared to 3.0 hours for metaproterenol (p < 0.04). The secondary efficacy variables were uniformly better in the ipratropium bromide than the metaproterenol group. Side effects were infrequent and generally mild in both groups. These data suggest that the availability of a high-dose ipratropium bromide solution offers a safe and effective means of producing prolonged bronchodilation in patients with COPD.

Childhood asthma: prevention of attacks with short-term corticosteroid treatment of upper respiratory tract infection.

In this study, the potential for short courses of glucocorticoids to prevent or reduce the severity of asthma induced by viral respiratory infections in preschool children was investigated. Two groups of children with a mean age of 36.4 +/- 3.9 months and 40.4 +/- 4.9 months were monitored during a 2-year period. Group 1, considered as the control group, received theophylline preparations and orciprenaline either on a continuous basis or during attacks. During severe attacks, albuterol was administered by nebulization, with corticosteroids occasionally added for seven to 14 days in cases of poor response to albuterol. Group 2 received the same treatment during the first year. During the second year, however, a short-term course of prednisone (1 mg/kg) was given as soon as the first symptoms of an upper respiratory tract infection appeared, prior to any signs of wheezing. Results indicate that, whereas morbidity remained constant in the control group during the 2-year observation period, a significant decrease in the number of wheezing days (65%), attacks (56%), visits to the emergency room (61%), and hospitalizations (90%) occurred in group 2. It was concluded that preschool children who suffer from repeated asthma attacks related to upper respiratory tract infections may benefit greatly from the preventive administration of corticosteroids.

Albuterol protects against exercise-induced asthma longer than metaproterenol sulfate.

Both metaproterenol sulfate and albuterol are inhaled medications commonly used to prevent exercise-induced bronchospasm. Their efficacy and duration of action in controlling exercise-induced bronchospasm were compared with placebo in 18 asthmatic children (age range: 12 to 17 years) in a single-blind randomized crossover study. Standardized treadmill exercise challenges were repeated every two hours for up to six hours following the initial exercise test. With the initial exercise challenge, both active medications blocked exercise-induced bronchospasm with equal efficacy. On the other hand, when the duration of action of the medications was compared: albuterol blocked exercise-induced bronchospasm longer than metaproterenol sulfate in eight subjects, the reverse was true in only one patient, and the medications blocked for equal duration in nine subjects. Thus, although both active agents were equally efficacious in blocking exercise-induced bronchospasm initially, the duration of action of albuterol was significantly (P less than .05) longer on serial testing than that of metaproterenol sulfate. Both medications were significantly better than placebo in efficacy and duration of action.

Comparison of albuterol and metaproterenol syrup in the treatment of childhood asthma.

This study compared the acute and chronic effects of albuterol syrup (2 mg) and metaproterenol syrup (10 mg) three times a day over 28 days in 65 children, aged 6 to 9 years, with mild to moderate asthma. Wright peak flow, symptom scores, and rescue medication use were recorded twice daily during the 28 days; the acute cardiopulmonary effects of these syrups were compared over 8 hours on treatment days 1 and 28. Albuterol syrup produced a significantly greater peak magnitude of bronchodilation than metaproterenol, 29% vs 20% above baseline, respectively, on treatment day 1. Albuterol syrup had a duration of action of at least 8 hours and produced greater bronchodilation than metaproterenol syrup from 2 to 8 hours on both treatment days 1 and 28. The chronotropic effect of metaproterenol was greater than that of albuterol at 1 to 1 1/2 hours postdose on treatment days 1 and 28. There was a trend toward higher morning and evening Wright peak flow measurements during 28 days of treatment in the albuterol group. Side effects of both drugs were comparable. These findings imply therapeutic advantages of albuterol syrup over metaproterenol syrup in currently recommended doses with respect to improvement in pulmonary function, chronotropic effects, and frequency of dosing required to maintain optimum bronchodilation over a 24-hour period.