Effect of cetirizine dihydrochloride on the airway response to hypertonic saline aerosol in patients with chronic obstructive pulmonary disease (COPD)

Hypertonic saline aerosol can elicit airway obstruction in patients with moderate or severe COPD. In the present study we assessed whether cetirizine dihydrochloride is capable of modulating this response. After a screening visit, 20 patients with COPD (mean FEV(1) 49% pred) were treated with cetirizine 10mg daily or placebo over 1 week in a randomized, double-blind, cross-over fashion and measurements performed at the end of treatment periods. At each visit, patients were challenged by 3% saline aerosol (screening: 0.9%) over 5 min after prior inhalation of salbutamol, and 45 min later sputum was obtained after inhalation of 0.9% saline. Lung function was quantified in terms of forced expiratory (FEV(1)) and inspiratory (FIV(1)) volumes. Spirometric values did not differ between visits and salbutamol-induced bronchodilation was not altered by cetirizine. Compared to baseline or post-salbutamol values, the saline-induced fall in FEV(1) was smallest at screening (P<0.01), without a significant difference between treatments. Regarding FIV(1), however, the percent fall from baseline was higher after placebo (Delta=-10.1%; P<0.05) compared to screening (0.4%) or cetirizine (-4.3%). Sputum composition showed no significant differences except for a tendency towards reduced concentrations of alpha(2)-macroglobulin after cetirizine compared to placebo (P=0.045). The present data indicate some, though small, effects of the H1 receptor antagonist cetirizine on hypertonic saline-induced airway obstruction in patients with moderate-to-severe COPD. In view of the mechanisms involved, it is an open question whether stronger effects can be elicited with higher doses and whether such effects would translate into clinical benefits, e.g. during exacerbations.     

Effect of different inhaled bronchodilators on recovery from methacholine-induced bronchoconstriction in asthmatic children.

Two hundred fourteen children with mild to moderate asthma were studied to determine bronchodilator effects 5 min after administration of five different metered dose inhaler (MDI) aerosol formulations available in our country, and results were compared to placebo. Methacholine bronchial challenge was performed by the tidal breathing method, using increasing concentrations until a fall in forced expired volume in 1 s (FEV(1)) >/=20% was achieved (PC20). Immediately after FEV(1) had fallen 20% or more, children were randomly allocated into 1 of 6 groups to receive: salbutamol 200 microg (S), fenoterol 200 microg (F), salbutamol 200 microg + beclomethasone 100 microg (S + B), fenoterol 200 microg + ipratropium bromide 80 microg (F + IB), salmeterol 50 microg (SM), and placebo (P). The bronchodilator effect was determined by measuring FEV(1) 5 min after inhalation of medications. Nonparametric tests were used for statistical analysis. The six groups were similar in anthropometric and in respiratory characteristics. All five inhaled aerosols containing beta-agonists caused a significant bronchodilator effect as compared to placebo. However, the effect was significantly greater in the groups treated with F or F + IB (P < 0.05) compared to other formulations. We conclude that the five types of aerosols used in this study are able to reverse methacholine-induced bronchoconstriction 5 min after inhalation of a bronchodilator.     

Bronchodilating effect of combined therapy with ipratropium bromide and ondansetron in patients with COPD

The objectives of this study were to determine the effect of single and repeat dosing with oral ondansetron, a 5-HT3-specific receptor blocker, on the degree and duration of bronchodilation induced by inhaled ipratropium bromide in patients with COPD. Five clinics and university medical centers in four countries participated in the study; 47 patients with COPD were randomized to treatment; 44 completed all treatments. Patients had a baseline (pre-bronchodilator) FEV1>1L and post-bronchodilator (200 mcg salbutamol) FEV1<90% of predicted, with FEV1 reversibility (to 80 mcg inhaled ipratropium bromide and 400 mcg salbutamol) of at least 12% or 200 mL over baseline. The study was divided into two parts. In Part A, each patient received in a random order, four-way crossover manner, single doses of ondansetron placebo (oral) plus ipratropium bromide placebo (inhaled), ondansetron placebo plus ipratropium bromide 40 mcg inhaled via MDI, ondansetron 24 mg oral plus ipratropium bromide placebo and ondansetron 24 mg plus ipratropium bromide 40 mcg. In Part B, each patient received in a random order, two-way crossover manner, ipratropium bromide 40 mcg tid via MDI plus ondansetron 8 mg oral, qid, for 2 days; on day 3 patients received a single dose of ipratropium bromide 40 mcg plus 8 mg oral ondansetron. Alternatively, patients received ipratropium bromide via MDI and oral ondansetron placebo, as described above. Statistically significant differences in weighted mean FEV1 (0-6h), peak FEV1 and FEV1 determined 6h post-dose were noted comparing ipratropium bromide to placebo. Similar positive results were observed for sGaw and FVC. Addition of ondansetron to ipratropium bromide did not significantly modify values obtained with ipratropium alone. Ipratropium bromide induced a marked bronchodilation, compared to placebo. Addition of ondansetron (single or repeated doses) did not significantly increase the degree or duration of bronchodilation induced by ipratropium alone. sGaw was consistently more sensitive than FEV1 in measuring extent and duration of bronchodilation.     

Therapeutic equivalence of three metered-dose inhalers containing salbutamol (Albuterol) in protecting against methacholine-induced bronchoconstriction in children with asthma.

Many pharmaceutical companies sell salbutamol in metered-dose inhalers (MDI) for the treatment of asthma. However, the therapeutic equivalence of the more recently released generic products has not been compared with the original patented product in children. Twenty children with mild to moderate asthma, presently asymptomatic and with normal lung function, were randomly allocated to receive 200 microg of inhaled salbutamol (Albuterol) from three MDIs prepared by different manufacturers: the original Glaxo product and two generic products. The three drug formulations and placebo were given 10 min before a methacholine challenge test to determine the degree of protection provided against methacholine-induced bronchoconstriction (MIB) by each salbutamol aerosol. Tests were performed on 4 consecutive days. Doubling concentrations of methacholine were inhaled until the forced expired volume in 1 sec (FEV(1)) decreased by 20% from its baseline value. Compared to placebo, all patients increased significantly the provocation concentration that decreased FEV(1) by 20% (PC(20)) by more than one doubling concentration after inhaling each of the three salbutamol aerosols. The effectiveness was not significantly different between medications (P = 0.8). There was a small but significant difference among MDIs in aerosol particle size and total and fine-particle dose released per actuation. However, no relation was found between aerosol particle size or released dose and the protective effect. This study shows that the three tested brands of salbutamol MDI protected asthmatic children equally from MIB. When prescribing these salbutamol MDIs to prevent symptoms triggered by nonspecific stimuli in asthmatic children, the selection may be based on cost-benefit criteria.     

Efficacy of inhaled steroids (beclomethasone dipropionate) for treatment of mild to moderately severe asthma in the emergency department: a randomized clinical trial

STUDY OBJECTIVE: To examine the efficacy of an inhaled steroid, when added to a standard regimen of beta-agonist therapy, in the treatment of patients with mild to moderately severe asthma in the emergency department. METHODS: A convenience sample of adult patients with asthma (FEV1 % predicted 40% to 69%) presenting to the ED was randomly assigned in a double-blind fashion into 2 treatment groups. The first group received 2.5 mg nebulized salbutamol plus 1 mg (4 puffs) of beclomethasone dipropionate (BDP) at baseline, 30 minutes, and at 1, 2, and 4 hours, delivered by a metered-dose inhaler (MDI) attached to a spacer device (Vent-AH-aler, Glaxo). The second group was given the same salbutamol regimen plus MDI placebo through the Vent-AH-aler. The primary endpoint was improvement in FEV1 %predicted at 6 hours. RESULTS: Of 54 patients enrolled, 28 were assigned to the BDP group and 26 to the placebo group. Spirometry improved significantly in both groups over the 6 hours compared with baseline (ANOVA, P <.001). At 6 hours, the mean absolute improvement in FEV1 % predicted for BDP was 18% versus 17% for placebo (95% confidence interval for the absolute difference of 1% [-8% to 10%]). The proportion of patients in the BDP group who were hospitalized was 7% compared with 19% for patients in the placebo group (95% confidence interval for the difference of 12% [-6%, 30%]). CONCLUSION: In this group of patients with mild to moderately severe asthma, 5 mg BDP delivered by MDI during the initial 4 hours of an emergency visit was of no added benefit over standard therapy, as measured by improvement in FEV1 % predicted at 6 hours. However, a trend toward a difference in admission favoring BDP was observed. [Afilalo M, Guttman A, Colacone A, Dankoff J, Tselios C, Stern E, Wolkove N, Kreisman H: Efficacy of inhaled steroids (beclomethasone dipropionate) for treatment of mild to moderately severe asthma in the emergency department: A randomized clinical trial.     

The role of domiciliary nebulizers in managing patients with severe COPD

The difficulty of assessing nebulizer responses in chronic obstructive pulmonary disease (COPD) has been demonstrated before. This study aims to re-examine both the role of domiciliary nebulizers in COPD and also bronchodilator (BD) assessment in individuals. In a double-blind, randomized, cross-over trial, 19 stable patients with severe COPD were given the following medication 6-hourly for 2-week periods: (1) nebulized salbutamol 2.5 mg with ipratropium 0.5 mg and placebo inhalers (MDI) with spacer; (2) placebo nebules and inhaled salbutamol 400 microg with ipratropium 80 microg via MDI with spacer; (3) inhaled salbutamol 400 microg with ipratropium 80 microg via MDI with spacer (but no placebo nebulized drugs). Both nebulized and MDI drugs produced highly significant improvements in forced expiratory volume in 1 sec (FEV1), forced vital capacity (FVC), specific airways conductance, 6-min walking distance (6MWD) and residual volume. There were no significant differences between BD responses obtained after active nebulized and active MDI BDs. From the diary cards, 2 weeks of active nebulized BDs produced a slightly higher median peak expiratory flow (PEF) than active MDI BDs (236 and 219 l m(-1), respectively, P=0.01) and slightly less extra inhaler use (0.8 and 1.1 puffs, respectively, P<0.05) but no significant difference in dyspnoea or quality of life (QOL) scores. There were significant correlations between domiciliary PEF and acute BD-induced changes in FVC and 6MWD, and also between domiciliary dyspnoea scores and acute changes in both total lung capacity and 6MWD. In conclusion, nebulized medication conferred little clinical advantage over the regular use of inhalers with spacers in this group of patients with severe COPD. However, acute changes in total lung capacity, FVC and 6MWD may be useful predictors of the longer-term effects of nebulized BDs in individual patients.     

Relief of dyspnoea by beta2-agonists after methacholine-induced bronchoconstriction

Virtually all asthma patients use brorichodilators. Formoterol and salbutamol have a rapid onset of bronchodilating effect, whereas salmeterol acts slower. We studied the onset of improvement of dyspnoea sensation after inhalation with these bronchodilators and placebo to reverse a methacholine-induced bronchoconstriction as a model for an acute asthma attack. Seventeen patients with asthma completed this randomised, double-blind, crossover, double-dummy study. On 4 test days, forced expiratory volume in 1 s (FEV1) and Borg score were recorded and patients were challenged with methacholine until FEV1 fell with > or = 30% of baseline value. Thereafter, formoterol 12 microg via Turbuhaler, salbutamol 50 microg via Turbuhaler, salmeterol 50 microg via Diskhaler, or placebo was inhaled. FEV1 and Borg scores were assessed during the following 60 min. The first sensed improvement of Borg score was significantly (P<0.05) faster achieved with formoterol (geometric mean (Gmean) (range) 1.5 (1-40) min) and salbutamol 1.8 (1-10) min than with salmeterol 4.5 (1-30) min and placebo 3.4 (1-40) min. The Borg score returned significantly faster to the baseline value with formoterol, salbutamol, and salmeterol (Gmean time 13.8 (1-75), 13.4 (1-60), and 18.0 (1-75) min, respectively) than with placebo (33.6 (1-75 min). Formoterol and salbutamol act significantly faster than salmeterol in relieving dyspnoea induced by methacholine-induced bronchoconstriction, in patients with asthma.     

Onset of action of single doses of formoterol administered via Turbuhaler in patients with stable COPD

We studied 16 patients with stable COPD in a double blind, double dummy, placebo-controlled, within patient study to see if formoterol could be used as a rescue drug. We compared the of onset of bronchodilation obtained with formoterol 12 microg (metered dose corresponding to 9 microg delivered dose) and formoterol 24 microg (metered dose corresponding to 18 microg delivered dose), both delivered via Turbuhaler, with that of salbutamol 400 microg and salbutamol 800 microg delivered via pressurized metered-dose inhaler (pMDI). Patients inhaled single doses of placebo, formoterol and salbutamol on five separate days. FEV1 was measured in baseline condition and 3, 6, 9, 12, 15, 18, 21, 24, 30, 40, 50, and 60 min after inhalation of each treatment. We examined two separate criteria for deciding if a response was greater than that expected by a random variation of the measurement: (1) a rise in FEV1 of at least 15% from the baseline value; (2) an absolute increase in FEV1 of at least 200 ml. Formoterol 12 microg (15.2 min; 95% CI 9.5-21.0) and formoterol 24 microg (15.1 min; 95% CI 8.9-21.2) caused a rise in FEV1 of at least 15% from the baseline value almost rapidly as salbutamol 400 microg (13.6 min; 95% CI 7.1-20.1) and salbutamol 800 microg (14.5 min; 95% CI 7.1-21.9). No significant difference (P=0.982) in onset of action was seen between the four active treatments. According to Criterion 2, the mean time to 200 ml increase in FEV1 was 11.1 min (95% CI: 7.0-15.2) after salbutamol 400 microg, 13.0 min (95% CI: 7.9-18.1) after salbutamol 800 microg, 14.7 min (95% CI: 7.1-22.4) after formoterol 12 microg, and 12.7 min (95% CI: 7.4-18.0) after formoterol 24 microg. Again, there was no significant difference (P= 0.817) between the four active treatments. Formoterol Turbuhaler 12 microg and 24 microg caused bronchodilation as rapidly as salbutamol 400 microg and 800 microg given via pMDI.     

A comparison of the effects of oral montelukast and inhaled salmeterol on response to rescue bronchodilation after challenge

OBJECTIVES: To compare the effects of addition of montelukast or salmeterol to inhaled corticosteroids (ICS) on the response to rescue beta2-agonist use after exercise-induced bronchoconstriction. METHODS: A double-blind, placebo-controlled study was performed at 16 centers in the United States. Patients with asthma (n = 122, ages 15-58) whose symptoms were uncontrolled on Low-dose inhaled fluticasone and who had a history of exercise-induced worsening of asthma were randomized to receive either montelukast (10 mg once daily), salmeterol (50microg twice daily), or placebo for 4 weeks. Standardized spirometry after exercise challenge and beta2-agonist rescue was performed at baseline, week 1 and 4. RESULTS: Maximum achievable forced expiratory volume in 1 s (FEV1) percent predicted after rescue beta2-agonist improved in the montelukast (+1.5%) and placebo (+1.2%) groups at 4 weeks, but diminished in the salmeterol (-3.9%) group (P < 0.001). Although pre-exercise FEV1 was greatest with salmeterol (P = 0.10), patients taking montelukast had significantly greater protection from an exercise-induced decrease in FEV1 than those taking salmeterol (P < 0.001). Both the magnitude and rate of rescue bronchodilation were greater with montelukast compared with salmeterol (P < 0.001). Five minutes after rescue beta2-agonist, 92% of patients taking montelukast and 68% of those taking placebo had recovered to pre-exercise levels, whereas only 50% of those taking salmeterol had recovered to pre-exercise levels. CONCLUSION: In patients whose asthma symptoms remain uncontrolled using ICS, addition of montelukast permits a greater and more rapid rescue bronchodilation with a short-acting beta2-agonist than addition of salmeterol and provides consistent and clinically meaningful protection against exercise-induced bronchoconstriction.     

Reversing acute bronchoconstriction in asthma: the effect of bronchodilator tolerance after treatment with formoterol.

Continuous treatment with a short-acting beta2-agonist can lead to reduced bronchodilator responsiveness during acute bronchoconstriction. This study evaluated bronchodilator tolerance to salbutamol following regular treatment with a long-acting beta2-agonist, formoterol. The modifying effect of intravenous corticosteroid was also studied. Ten asthmatic subjects (using inhaled steroids) participated in a randomised, double-blind, placebo-controlled, cross-over study. Formoterol 12 microg b.i.d. or matching placebo was given for 10-14 days with >2 weeks washout. Following each treatment, patients underwent a methacholine challenge to induce a fall in forced expired volume in one second (FEV1) of at least 20%, then salbutamol 100 microg, 100 microg, and 200 microg was inhaled via a spacer at 5 min intervals, with a further 400 microg at 45 min. After a third single-blind formoterol treatment period, hydrocortisone 200 mg was given intravenously prior to salbutamol. Dose-response curves for change in FEV1 with salbutamol were compared using analysis of covariance to take account of methacholine-induced changes in spirometry. Regular formoterol resulted in a significantly lower FEV1 after salbutamol at each time point compared to placebo (p<0.01). The area under the curves (AUCs) for 15 (AUC0-15) and 45 (AUC0-45) min were 28.8% and 29.5% lower following formoterol treatment (p<0.001). Pretreatment with hydrocortisone had no significant modifying effect within 2 h of administration. It is concluded that significant tolerance to the bronchodilator effects of inhaled salbutamol occurs 36 h after stopping the regular administration of formoterol. This bronchodilator tolerance is evident in circumstances of acute bronchconstriction.     

Distribution of therapeutic response in asthma control between oral montelukast and inhaled beclomethasone.

The distribution of responses in study populations provides a novel method of comparing the benefit of two treatments. This 6-week, randomised, placebo-controlled, double-blind study compared the effectiveness of oral montelukast with inhaled beclomethasone in chronic asthma by assessing the distribution and overlap of patient responses to therapy, as measured by a clinical outcome (asthma control days). A total of 730 adult patients with asthma, age 15-65 yrs, with a forced expiratory volume in one second (FEV1) at baseline of 50-85% of predicted and > or = 15% improvement in FEV1 after inhaled beta-agonist were enrolled. After a 2-week placebo run-in period, patients were randomly allocated to receive montelukast (10 mg once daily), inhaled beclomethasone (200 microg twice daily) or placebo. The primary end-point (per cent of asthma control days) was compared between treatments as the overlap in the response distributions. The overlap of the distribution of responses between the montelukast and beclomethasone groups was 89% for per cent asthma control days and 96% for change from baseline in FEV1. The mean (+/-SD) per cent asthma control days in the montelukast and beclomethasone groups was significantly higher than that in the placebo group (placebo 40.0+/-35.8, montelukast 50.7+/-37.1, beclomethasone 57.9+/-36.1). The mean differences between montelukast and placebo, beclomethasone and placebo, and montelukast and beclomethasone were significant. The mean per cent change (+/-SD) from baseline in FEV1 was 12.1+/-18.7 and 13.9+/-20.8 in the montelukast and beclomethasone groups, respectively, and significantly greater than that in the placebo group (6.4+/-20.1); there was no significant difference between the montelukast and beclomethasone groups in mean values or response distribution. There was also no difference among treatment groups in the frequency of adverse experiences. A comparison of the response distribution is an important approach to comparing therapies; montelukast and beclomethasone provided similar response distributions for the end-point of per cent asthma control days over a 6-week treatment period.     

Dose reduction of inhaled corticosteroids under concomitant medication with montelukast in patients with asthma.

The present study aimed at comparing the effects of a dose reduction of inhaled corticosteroids on lung function, indirect measures of airway inflammation and clinical scores during treatment with a leucotriene receptor antagonist. In 50 patients (mean forced expiratory volume in one second (FEV1) 94% predicted), steroid doses (800 microg beclomethasone dipropionate) were first reduced to 50% and then to 25%, for 6 weeks each. One group received a placebo and the other group received montelukast (10 mg). The first reduction did not cause significant effects. During the second, FEV1 and peak expiratory flow decreased in both groups (p<0.001). Daytime symptoms were not altered with placebo but were reduced by montelukast (p<0.05). Night-time symptoms were slightly elevated with placebo (p<0.05) but not montelukast, as well as the use of supplemental salbutamol. Changes in provocative concentration of methacholine causing a 20% fall in FEV1 (PC20), sputum eosinophils and exhaled nitric oxide were mostly nonsignificant for both placebo and montelukast. These data demonstrate that a 75% reduction in the dose of steroid given to patients with asthma led to a deterioration in lung function not prevented by montelukast, whereas changes in clinical state seemed to favour montelukast treatment. It therefore appears that potential effects of montelukast, in the presence of low-dose steroids, could not be attributed to single indices of lung function or airway inflammation.     

Lung function improvement in smokers suffering from COPD with zafirlukast, a CysLT(1)-receptor antagonist

The present study was designed to evaluate the bronchodilating role of zafirlukast, a CysLT(1)receptor antagonist, at the standard dosage currently recommended in the marketing of this agent in smokers with COPD. The study was performed using a double-blind, cross-over, randomized design and was conducted on 2 non-consecutive days. Sixteen outpatients suffering from stable COPD received 40 mg oral zafirlukast, or placebo. Lung function was controlled before drug administration and 30, 60, 120, 180, 240 min thereafter. At the end of the 4-h period, each patient received 400 microg inhaled salbutamol and spirometric testing was performed 30 min later. Zafirlukast, but not placebo, produced a significant (P<0.05) bronchodilation between 30 min and 4 h following administration, with a maximum mean increase in FEV(1)of 0.134 l (11.2%) above baseline after 2 h. Nine of 16 patients showed an increase in FEV(1)of at least 15% above baseline after zafirlukast. The maximum mean increase in FEV(1)after zafirlukast in these subjects, who were considered responders, observed after 2 h, was 0.221 (19.4%). The mean difference of post-salbutamol FEV(1)values after zafirlukast and placebo (-0.036 l) was not significant (P<0.05). In responders, the mean of differences in pre- and post-salbutamol FEV(1)values after zafirlukast was 0.077 l, whereas the mean of differences between post-salbutamol values after zafirlukast and those after placebo was -0.064 l. The mean AUC(0-4 h)for all patients was 0.121 l for placebo and 0.385 l for zafirlukast. The difference between the placebo and zafirlukast AUC(0-4 h)was significant (P<0.05). The individual FEV(1)AUC(0-4 h)after zafirlukast were higher than those after placebo in 12 out of 16 patients. These findings suggest that cysteinyl leukotrienes might be one of the causes of persistent bronchoconstriction in COPD, at least in several smokers, but do not confirm the hypothesis that the effects of zafirlukast and salbutamol are independent and additive.     

Comparison of the bronchodilator effects of salbutamol delivered via a metered-dose inhaler with spacer, a dry-powder inhaler, and a jet nebulizer in patients with chronic obstructive pulmonary disease

The aim of this study was to compare the bronchodilator effects of salbutamol delivered via three different devices: a dry-powder inhaler (DPI), a metered-dose inhaler (MDI) with a large-volume spacer and a jet nebulizer (NEB) in patients with stable chronic obstructive pulmonary disease (COPD). Ten male patients with stable COPD [age: 67.2 +/- 3.8 years, forced expiratory volume in 1 s (FEV1): 1.56 +/- 0.32 liters] were studied in a randomized, double-blind and crossover manner. Each patient received 200 or 1, 000 microg salbutamol via an MDI with an InspirEaseTM spacer, a RotahalerTM, or a DeVilbiss 646(TM) nebulizer (NEB), or matching placebo on 7 separate days. Spirometry was performed before and 15, 30, 60, 90, 120, and 240 min after inhalation. With the 200- microg dose, only DPI produced a small but greater response in maximum FEV1 and in area under the time-response curve (AUC-FEV1) compared with placebo. With the 1,000- microg dose, DPI and MDI produced equally greater improvements in both maximum FEV1 and AUC-FEV1 than NEB. An equal bronchodilating effect can be obtained using either DPI or MDI with a spacer device, whereas the NEB was less effective when the same dose was administered.     

Comparison of formoterol, salbutamol and salmeterol in methacholine-induced severe bronchoconstriction.

The onset of the bronchodilating effect of formoterol (12 microg by Turbuhaler) was compared with that of salbutamol (50 microg by Turbuhaler), salmeterol (50 microg by Diskhaler) and placebo in methacholine-induced severe bronchoconstriction. Seventeen subjects with mild-to-moderate asthma completed this randomized, double blind, cross-over, double-dummy study. On four study days, baseline forced expiratory volume in one second (FEV1) was recorded and the subjects were challenged with methacholine until FEV1 fell by at least 30%. Immediately thereafter, the study drugs were inhaled and lung function was assessed for 60 min. The geometric mean time for FEV1 to return to 85% of baseline was 7.2 min with formoterol, 6.5 min with salbutamol, 14.1 min with salmeterol and 34.7 min with placebo (p=0.0001, overall ANOVA). The difference between formoterol and salmeterol was statistically significant (p=0.01); there was no difference between formoterol and salbutamol (p=0.69). In conclusion, formoterol reversed methacholine-induced severe bronchoconstriction as rapidly as salbutamol and more rapidly than salmeterol. Classifying beta2-agonists as "fast"- and "slow"- acting may be supplemental to "short"- and "long"-acting.     

Bronchodilator tolerance: the impact of increasing bronchoconstriction.

Chronic exposure to beta-agonists causes tolerance to their bronchodilator effects, which is best demonstrated during acute bronchoconstriction. The aim of the present study was to assess whether tolerance becomes more evident with increasing bronchoconstriction, as might occur in acute asthma. In a randomised, double-blind, placebo-controlled, crossover study comprising 15 patients, the treatments were salbutamol 400 microg q.i.d. or placebo given via Diskhaler for 28 days with a 2-week washout between treatments. Patients attended on days 14, 21 and 28. Bronchoconstriction was induced on two of these three occasions to achieve a reduction in the forced expiratory volume in one second (FEV1) of 0 (no methacholine), 15 and 30% (using methacholine) in a randomised order. Immediately after this, salbutamol 100 microg, 100 microg and 200 microg was inhaled at 0, 5, and 10 min. FEV1 was measured over 40 min. Dose/response curves were plotted and values for the area under the curve (AUC)0-40 FEV1 were compared between treatments and by degree of bronchoconstriction. Regular salbutamol resulted in attenuation of the acute response to beta-agonist, which was increasingly evident with greater bronchoconstriction. With a reduction in FEV1 of 0, 15 and 30%, the AUC0-40 FEV1 with salbutamol were 11.2, -14.6 and -35.7% respectively, compared to placebo. There was a linear relationship between the magnitude of bronchoconstriction and the between-treatment differences in AUC0-40 FEV1. Increasing bronchoconstriction conferred greater susceptibility to the effects of bronchodilator tolerance.     

Bronchodilator effect of salbutamol from two different spacer devices

Our aim was to compare the bronchodilator effect of salbutamol delivered via a new holding chamber (Volumatic Soft, VS) with that of an established device (Volumatic, V) in asthmatic children. Children with stable asthma were recruited. They inhaled 100 microg, and 10 min later, 300 microg of salbutamol aerosol delivered via VS or V on day 1, and vice versa on day 2. Spirometry was measured at baseline, 10 min after 100 microg, and 15 min after 300 microg of salbutamol were given. The preference for either device was assessed by visual analogue score. Forty-four children with a median age of 9.2 years (interquartile range, 8.0-10.7) completed the study. There were significant improvements in forced expired volume in 1 sec (FEV1) with time throughout the study period for both V and VS (linear and quadratic trend P < 0.001). There was a statistically significant difference in postbronchodilator FEV1 between V and VS (P = 0.013). VS gave an overall greater change in FEV1 than V, by 1.8%. The preference scores for V and VS were 7.0 (IQR 5.0-8.0) and 9.0 (IQR 8.0-10.0) (p < 0.0005), respectively. In conclusion, comparable clinical efficacy was found for V and VS with respect to changes in FEV1 after salbutamol. Patients also showed a strong preference for the new device.     

The safety and success rate of sputum induction using a low output ultrasonic nebuliser.

Induced sputum differential cell counts have been advocated as a method of non-invasively assessing airway inflammation in asthma and other airway diseases. Since sputum induction usually involves delivering hypertonic saline via a high output ultrasonic nebulizer there have been concerns about its safety in asthma. There are relatively little data on the effects of sputum induction in large numbers of patients. We have examined the success rate and effect of sputum induction on forced expiratory volume in 1 sec (FEV1) in 100 inductions performed on 79 patients using a low output nebulizer. Thirty-seven patients had asthma, 29 had miscellaneous conditions (mainly chronic cough) and 13 were subjects without respiratory symptoms. Sputum was induced 10 min after 200 micrograms of inhaled salbutamol by sequential 5-min inhalations of 3, 4 and 5% saline delivered via a Fisoneb ultrasonic nebulizer and FEV1 was measured after each inhalation. Sputum induction resulted in a sample suitable for analysis in 92% of asthmatics, 90% of those with miscellaneous conditions and 100% of normal subjects. The mean (SEM) maximum per cent fall in FEV1 was 5.4% (0.1), 4.3%, (1.0) and 2.6% (1.1) in subjects with asthma, miscellaneous conditions and in asymptomatic subjects respectively. Only 13 inductions resulted in a > 10% fall in FEV1, and only three of these resulted in a > 20% fall. The maximum per cent fall in FEV1 did not correlate with baseline FEV1 % predicted (r = -0.17), the log sputum eosinophil count (r = -0.12), or the methacholine PC20 (r = -0.14). We conclude that sputum induction using a relatively low output ultrasonic nebulizer with premedication with salbutamol is successful and safe in the majority of patients with asthma and other airway conditions.     

Fexofenadine decreases sensitivity to and montelukast improves recovery from inhaled mannitol

We studied, separately, the effects of the histamine antagonist, fexofenadine hydrochloride, and the leukotriene antagonist, montelukast sodium, and their placebos on airway sensitivity to and recovery from inhaled mannitol in subjects with asthma. Two 180-mg doses of fexofenadine were taken over 14 h, and three 10-mg doses of montelukast over 36 h, with the last dose 5 h before challenge. Fexofenadine reduced sensitivity to mannitol and the PD(15) was (mean [95% confidence interval] 138 [95, 201]) mg versus placebo (51 [25, 106] mg) (p < 0.001). The final percent reduction in FEV(1) with fexofenadine was 20.8 +/- 5.4% and not different from placebo (20.1 +/- 5.3%) (p = 0.7); however, recovery was slower with fexofenadine compared with placebo (p < 0.001). By contrast, montelukast had no effect on sensitivity to mannitol and the PD(15) was 71 [36, 144] mg versus placebo (87 [51, 148] mg (p = 0.35). The total dose of mannitol delivered and the final percent reduction in FEV(1) with montelukast were 171 +/- 142 mg and 21 +/- 4% and for placebo were 182 +/- 144 mg and 20 +/- 5% (p = 0.35, p = 0.59, respectively). However, recovery of FEV(1) to baseline was faster with montelukast, with the area under the percent reduction FEV(1)-versus-time curve reduced (220 +/- 121% change.min) compared with placebo (513 +/- 182% change.min) (p < 0.001). We conclude that whereas histamine is important for the initial airway response, leukotrienes are important in sustaining the airway response to inhaled mannitol.     

Oxis (formoterol given by Turbuhaler) showed as rapid an onset of action as salbutamol given by a pMDI

Thirty-six adult patients (16 women) with mild to moderate asthma with a mean baseline forced expiratory volume in 1 sec (FEV1) of 73.8% (46-106%) of predicted normal value and mean reversibility of 24.2% (14.6-47.1%) were included in this double-blind, double-dummy, randomized, placebo-controlled and cross-over study. The patients inhaled single doses 4.5 or 9 microg of formoterol (Oxis) via Turbuhaler salbutamol (Ventolin) 100 or 200 microg from a pressurized metered dose inhaler (pMDI) or placebo at five randomized visits. Efficacy was measured by FEV1 pre-dose and then 1, 3, 5, 7, 10, 15, 20, 25 and 30 min after inhalation of the study drug. The primary variable of efficacy was the FEV1-value 3 min after dose intake. No statistically significant differences were found between active treatments. All active treatments gave a higher bronchodilating effect at 3 min than placebo: 10.0, 11.4% for salbutamol 100 and 200 microg and 11.7, 11.8% for formoterol 4.5 and 9 microg (P<0.001 in all cases). There was a correlation between the measured response at 3 min and the subjective experience of the patients. The relative difference vs. placebo remained throughout the study period for all active treatments except for low dose salbutamol. All treatments were well tolerated. In conclusion, formoterol Turbuhaler has as rapid an onset of action as salbutamol pMDI when given at recommended doses.