Rapid onset of bronchodilation in COPD: a placebo-controlled study comparing formoterol (Foradil Aerolizer) with salbutamol (Ventodisk)

Formoterol fumarate is a beta2-agonist bronchodilator that combines a fast onset of action with a long duration of action. Its fast onset of action is well documented in asthma but has not been directly compared with that of salbutamol in patients with chronic obstructive pulmonary disease (COPD). This randomized, double-blind, placebo-controlled study was conducted to assess the bronchodilatory effects over the first 3 h after inhalation of single doses of formoterol 24 microg delivered via the Aerolizer dry powder inhaler device (double-blind), or salbutamol 400 microg delivered by a Diskhaler dry powder inhaler (single-blind) in patients with COPD. A total of 24 patients with COPD were randomized [mean age 61.6 +/- 7.8 years, mean forced expiratory volume in 1 sec (FEV1) 1.38 +/- 0.32 l and 45.8 +/- 9.6% of predicted]. Inhalation of formoterol or salbutamol resulted in similar increases in FEV from 0 to 3 h post-dose. Both drugs produced similar bronchodilation by 5 min, which became almost maximal by 30 min. The primary efficacy variable, the area under the curve (AUC) of the FEV increase above predose baseline from 0 to 30 min (AUC(0-30 min)), demonstrated significant effects for formoterol (mean 5.89 +/- 4.67 l min(-1)), and salbutamol (mean 6.06 +/- 4.34 l min(-1)), which were not statistically different from each other but statistically significantly higher (P<0.0001) than that observed with placebo (-0.32 +/- 2.59 l min(-1)). In addition, both formoterol and salbutamol produced similar and rapid increases in forced vital capacity (FVC). In summary, this study confirms the rapid onset of action of formoterol and indicates that the onset of action of formoterol and salbutamol are similar in patients with COPD.     

The pulmonary and extra-pulmonary effects of high-dose formoterol in COPD: a comparison with salbutamol

OBJECTIVES: Formoterol, a beta(2) agonist with a rapid onset of effect and long duration of action, can be used as maintenance and reliever medication for asthma and COPD. We compared the pulmonary and extra-pulmonary effects of cumulative doses of formoterol and salbutamol in patients with COPD to assess efficacy and safety. METHODOLOGY: In a randomized, double-blind, cross-over study, 12 patients with moderate to severe COPD inhaled, via Turbuhaler, 10 doses of formoterol (total metered dose, 120 microg, equivalent to a 90- microg delivered dose), salbutamol (total metered dose 2000 microg) or placebo at 2-min intervals on separate days. The effects on lung function (FEV(1) and PEF), heart rate, blood pressure, oxygen saturation, corrected QT interval (QTc), T-wave height and plasma potassium were assessed before each dose, 15 min after each dose, and at half-hourly intervals for 3 h following the final dose. RESULTS: Inhalation of formoterol or salbutamol resulted in significant improvement in lung function (measured 30 min after the last dose) when compared with placebo. There were no clinically important or statistically significant changes in heart rate, QTc, T-wave height, plasma potassium, oxygen saturation, or systolic and diastolic blood pressures with formoterol or salbutamol. One patient developed ventricular trigeminy after both formoterol and salbutamol. She had had ventricular ectopics on her screening electrocardiogram. CONCLUSION: Formoterol and salbutamol both produced significant improvement in lung function and were similarly well tolerated in high doses, as might be taken by a patient for relief of COPD symptoms.     

Formoterol (OXIS) Turbuhaler as a rescue therapy compared with salbutamol pMDI plus spacer in patients with acute severe asthma

Formoterol has a similar onset of effect to salbutamol but a prolonged duration of action. However, the relative efficacy of the two drugs in acute severe asthma is not known. This double-blind, double-dummy study compared the safety and efficacy of the maximum recommended daily dose of formoterol and a predicted equivalent dose of salbutamol in 88 patients presenting to the emergency department with acute severe asthma. Patients were randomized to formoterol 54 microg via Turbuhaler or salbutamol 2400 microg via pressurized metered dose inhaler (pMDI) plus spacer in three equal doses over 1 h. Following the full dose, mean FEV1 at 75 min increased by 37% for formoterol and 28% for salbutamol (P = 0.18). The maximum increase in FEV1 over 4 h was significantly greater with formoterol compared with salbutamol (51% vs. 36%, respectively P < 0.05) and formoterol was as effective as salbutamol at improving symptoms and wellbeing. Both treatments were well tolerated. Formoterol caused a greater decrease in serum potassium (difference -0.2 mmol/l). In severe acute asthma, bronchodilator therapy with high-dose (54 microg) formoterol Turbuhaler provided equally rapid improvements in lung function of greater magnitude over 4 h than high-dose (2400 microg) salbutamol pMDI plus spacer.     

Efficacy and safety of budesonide/formoterol compared with salbutamol in the treatment of acute asthma

This study compared the efficacy and safety of budesonide/formoterol (Symbicort) Turbuhaler)) with salbutamol pressurized metered-dose inhaler (pMDI) with spacer for relief of acute bronchoconstriction in patients with asthma. In this randomized, double-blind, parallel-group study, patients (n = 104 allocated to treatment; n = 103 received treatment; mean age 45 years) seeking medical attention for acute asthma (mean FEV(1) 43% of predicted) received two doses repeated at t = -5 and 0 min of either budesonide/formoterol (320/9 microg, two inhalations) or salbutamol (100 microg x eight inhalations); total doses 1280/36 microg and 1600 microg, respectively. All patients received prednisolone 60 mg at 90 min and FEV(1) was assessed over 3h. FEV(1) 90 min after dosing (primary variable) increased compared with pre-dose FEV(1) by an average of 30% and 32% for budesonide/formoterol and salbutamol, respectively (P = 0.66), with similar increases at all timepoints from 3 to 180 min for both groups. Mean pulse rate over 3h was significantly higher in the salbutamol group versus the budesonide/formoterol group (92 vs. 88 bpm; P < 0.01). No treatment differences were seen for other vital signs, including ECG. High-dose budesonide/formoterol was effective and well tolerated for the treatment of acute asthma, with rapid onset of efficacy and a safety profile over 3h similar to high-dose salbutamol.     

Formoterol Turbuhaler 4.5 microg (delivered dose) has a rapid onset and 12-h duration of bronchodilation

Clinical trials show that formoterol (Oxis) Turbuhaler 4.5 microg delivered dose (6 microg metered dose) has a rapid onset of bronchodilation similar to that of salbutamol and a 12-h duration of action. Maximum increase in FEV(1) and duration of bronchodilation are dose-dependent, the 4.5 microg dose being the lowest dose tested giving both effects.Clinical studies investigating onset of bronchodilation show a significant increase in specific airway conductance occurring within 1 min after inhalation of formoterol Turbuhaler 4.5 microg. When measured from 3-20 min after inhalation, formoterol Turbuhaler 4.5 microg showed similar increases in FEV(1) to salbutamol administered via pMDI. No difference in onset of bronchodilation was observed between the formoterol Turbuhaler 4.5 and 9 microg doses.Single-dose studies and studies of 1-12 weeks' duration show that formoterol Turbuhaler 4.5 microg produces a significant and clinically important mean bronchodilating effect for > or =12 h after inhalation. In the cited studies no significant differences in duration of bronchodilation were observed between the formoterol Turbuhaler 4.5 and 9 microg doses.Conclusion: clinical data show that formoterol Turbuhaler 4.5 microg is an effective dose in patients with asthma, with a rapid onset of bronchodilation and a duration of at least 12 h.     

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.     

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.     

Acute protection against exercise-induced bronchoconstriction by formoterol, salmeterol and terbutaline.

The onset of bronchoprotection as obtained by various beta2-agonists has not been examined in a comparitive study. In this study, the onset of bronchodilation and protection against exercise-induced bronchoconstriction in asthmatics after inhalation of the long-acting beta2-agonists formoterol and salmeterol and the short-acting beta2-agonist terbutaline were measured. Twenty-five subjects with asthma and a history of exercise-induced bronchoconstriction (mean baseline forced expiratory volume in one second (FEV1): 90% predicted; mean fall in FEV1 after exercise: 31% from baseline) were enrolled in this double-blind, double-dummy, placebo-controlled, randomized, four-period crossover study. Exercise challenges were performed on 12 days at either 5, 30, or 60 min after inhalation of a single dose of formoterol (12 microg Turbuhaler), salmeterol (50 microg Diskus), terbutaline (500 microg Turbuhaler) or placebo. Exercise-induced bronchoconstriction (maximum fall in FEV1 or area under the curve) did not differ significantly between terbutaline, formorerol and salmeterol either 5, 30, or 60 min after inhalation of the study medication. In contrast, the onset of bronchodilation was slower after salmeterol compared to terbutaline and formoterol (p<0.05, each), which both showed a similar time course. At all time points between 5 and 60 min, formoterol provided significantly greater bronchodilation than salmeterol (p<0.05). These data indicate that equipotent doses of the bronchodilators salmeterol, formoterol and terbutaline were similarly effective with respect to their short-term protective potency against exercise-induced bronchoconstriction, despite the fact that the time course of bronchodilation was significantly different between the three beta2-agonists.     

Formoterol Turbuhaler as reliever medication in patients with acute asthma.

The aim of this study was to compare the efficacy and safety of formoterol versus salbutamol as reliever medication in patients presenting at an emergency dept with acute asthma. A randomised, double-blind, double-dummy, parallel group study was performed in four Australian emergency treatment centres. The study included a total of 78 adult patients (mean baseline forced expiratory volume in one second (FEV1) 1.83 L; 59% predicted) with acute asthma. Based on the expected dose equivalence of formoterol Turbuhaler 4.5 microg (delivered dose) and salbutamol pressurised metered-dose inhaler 200 microg (metered dose), patients received a total of formoterol Turbuhaler 36 microg (delivered) or salbutamol pressurised metered-dose inhaler with spacer 1,600 microg (metered), divided into two equal doses at 0 and 30 min. FEV1, peak expiratory flow and systemic beta2-agonist effects were monitored for 4 h. The primary variable was FEV1% pred at 45 min. At 45 min, mean increases in FEV1 expressed in % pred were 6.6% and 9.3%, respectively, with a small adjusted mean difference in favour of salbutamol (3.0%, 95% confidence interval -2.0-8.0). Transient increases in systemic beta2-agonist effects occurred predominantly with salbutamol, although no significant treatment differences were observed. Eight patients discontinued due to adverse events. In this study of patients presenting at emergency depts with acute asthma, formoterol Turbuhaler 36 microg was well tolerated and, as rescue therapy, had an efficacy that was not different from that of salbutamol pressurised metered-dose inhaler with spacer 1,600 microg in the number of patients studied.     

A single high dose of formoterol is as effective as the same dose administered in a cumulative manner in patients with acute exacerbation of COPD

Several clinical trials have shown that the inhaled beta2-agonists with long-acting properties, formoterol and salmeterol, may be effective in acute exacerbations of chronic obstructive pulmonary disease (COPD). However, there is a great deal of controversy regarding the timing and optimal dose of inhaled beta2-agonists in this pathologic condition. In this double-blind, randomised, crossover study, we have compared the bronchodilating effect and the safety of inhaled formoterol administered via Turbuhaler using either a cumulative dose regimen or the equivalent single dose in 16 patients with acute exacerbations of COPD. On the two consecutive days, the patients received, in a randomised order, each of the following active dose regimens: (A): 9 + 9 + 18 microg of formoterol via Turbuhaler (36 microg cumulative delivered dose) or (B): 36 + 0 + 0 microg of formoterol via Turbuhaler. The three doses on each treatment day were administered at 30-mm intervals, with measurements being made 5 and 30 min after each dose. Contemporaneously, we also measured oxygen saturation by pulse oximetry (SpO2) and pulse rate. Both the high dose and the cumulative one induced a significant bronchodilation expressed as change in FEV1. The difference between the two regimens was significant (P=0.0332) only 60 min after the first inhalation. The trend of FVC and IC was similar to that of FEV1. All treatment regimens were well tolerated and no adverse events were reported. Neither the administration ofthe high dose nor that of the cumulative one modified heart rate in a significant manner. Also they did not influence SpO2. This study indicates that a single high dose offormoterol is as effective as the same dose administered in a cumulative manner in patients with acute exacerbation of COPD.     

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.     

Onset of bronchodilation of budesonide/formoterol vs. salmeterol/fluticasone in single inhalers

Combinations of inhaled glucocorticoids and long-acting beta2-agonists in the same inhaler device have become available in recent years. In this double-blind, randomized, placebo-controlled and crossover study we have evaluated the onset of action of budesonide and formoterol in a single inhaler (Symbicort Turbuhaler) and that of the fixed combination of salmeterol and fluticasone (Seretide Diskus). Thirty patients with a mean FEV1 of 2.54 l (range: 1.48-4.28) and a mean inclusion reversibility in FEV1 of 19.1% were included. Single doses of budesonide/formoterol 160/4.5 microg and 2x (160/4.5) microg, salmeterol/fluticasone 50/250 microg, or placebo were given. Serial measurements of FEV1 were performed over 3 h. The combination of one or two inhalations of budesonide/formoterol showed a faster onset of action than salmeterol/fluticasone, both evaluated as mean FEV1 at 3 min (2.74, 2.75 and 2.56 l respectively P<0.001 for both doses of budesonide/formoterol), or as average FEV1 from 0 to 15 min (2.80, 2.83 and 2.67 l respectively P<0.001 for both doses of budesonide/formoterol). For placebo, mean FEV1 at 3 min was 2.46 l, and the average FEV1 at 0-15 min was 2.50 l. Furthermore, budesonide/formoterol at both doses resulted in higher FEV1 than salmeterol/fluticasone at 3 h. We conclude that the combination of budesonide/formoterol has a faster onset of action than salmeterol/fluticasone.     

Safety and tolerability of high-dose formoterol (via Aerolizer) and salbutamol in patients with chronic obstructive pulmonary disease

To evaluate the safety and tolerability of high-dose formoterol and salbutamol in patients with chronic obstructive pulmonary disease (COPD). In this two-way crossover, double-blind, double-dummy study, 17 adults with mild-to-moderate COPD were randomized to receive either formoterol 24 microg (2 x 12 microg via Aerolizer), or salbutamol 600 microg (6 x 100 microg via metered-dose inhaler), and the appropriate double-dummy q.i.d. at 4-h intervals for 3 consecutive days (total daily dose: 96 and 2400 microg, respectively). After a 4-7-day washout period, patients were switched to the other treatment. Treatment with high-dose formoterol and salbutamol was equally well tolerated, with no reports of serious adverse events. Both agents were associated with decreased plasma potassium (mean minimum values: 3.4 and 3.3 mmol/l for formoterol and salbutamol, respectively; P=0.914), increased serum glucose (mean maximum values: 9.0 and 8.7 mmol/l, respectively; P=0.373), and small increases in mean QTc interval (mean maximum 439 ms with both treatments; P=0.813). No clinically relevant between-treatment differences in adverse events or laboratory values occurred. Both drugs improved lung function (mean maximum forced expiratory volume in 1s [FEV(1)] 2.6 l with both treatments; P=0.624), with the improvement being significantly greater with formoterol than with salbutamol on all 3 days of treatment (mean area under the curve [AUC](0-24 h) of FEV(1) formoterol vs. salbutamol on days 1-3, all P<0.05). High-dose formoterol via Aerolizer (up to 96 microg/day) has a comparable tolerability profile to that of salbutamol in patients with mild-to-moderate COPD.     

A study of the duration of the bronchodilator effect of 12 micrograms and 24 micrograms of inhaled formoterol and 200 micrograms inhaled salbutamol in asthma

Formoterol is a new catecholamine analogue for which a longer duration of action is claimed. We studied the bronchodilator action of 12 micrograms and 24 micrograms of inhaled formoterol compared to 200 micrograms of inhaled salbutamol and placebo, in seven patients (mean age 59.3 yr) with moderate asthma. The adjusted mean peak rise in FEV1 was +0.331 each for salbutamol, 12 micrograms formoterol and 24 micrograms formoterol, all being significantly greater than that of placebo (+0.161; P less than 0.01). The duration of action was calculated in two ways. When calculating the time for the group mean FEV1 to return to baseline, the values were: for placebo, 3.1 h; salbutamol, 4.2 h; 12 micrograms formoterol, 6.8 h; and 24 micrograms formoterol, 11.2 h. When taking the times for each treatment at which individual FEV1 values returned to baseline and then calculating the adjusted mean time for each treatment group, the durations of action were: placebo, 3.5 h; salbutamol, 3.9 h; 12 micrograms formoterol, 5.9 h; and 24 micrograms formoterol, 8.1 h (24 micrograms formoterol compared to placebo, P = 0.02 and to 200 micrograms salbutamol, P = 0.03). The second method of calculation is nearer to a patient's approach in treating their asthma (i.e. taking an extra dose when needed), and may be a more realistic method of assessing duration of action. Formoterol is an effective bronchodilator, and the 24 micrograms dose should be assessed in the treatment of nocturnal asthma. In this group of older asthmatics with a degree of fixed airflow obstruction, we suggest that doses should be taken 8 hourly.     

Long-acting beta(2)-agonists in management of childhood asthma: A critical review of the literature

This review assesses the evidence regarding the use of long-acting beta(2)-agonists in the management of pediatric asthma. Thirty double-blind, randomized, controlled trials on the effects of formoterol and salmeterol on lung function in asthmatic children were identified. Single doses of inhaled salmeterol or formoterol cause prolonged bronchodilatation (>12 h) and extended bronchoprotection against exercise-induced bronchoconstriction in children, some children achieving full protection for more than 12 h. Heterogeneity in bronchoprotection has been observed, and individual dose-titration may be attempted. The onset of action of formoterol is comparable to salbutamol, while salmeterol has a slower onset of action. Partial tolerance develops when long-acting beta(2)-agonists are used as regular treatment, including cross-tolerance to short-acting beta(2)-agonists. Regular treatment with salmeterol in children with or without corticosteroids provides statistically significant bronchodilatation, but the degree of improvement in lung function or bronchoprotection against exercise and nonspecific irritants is small with regular use. There is no evidence of anti-inflammatory effects from inhaled long-acting beta(2)-agonists, which is reflected by unchanged or increased bronchial hyperreactivity and no reduction of exacerbation rates. The evidence does not support a recommendation for long-acting beta(2)-agonists as monotherapy, nor does it support their general use as regular add-on therapy. In conclusion, long-acting beta(2)-agonists provide effective bronchodilatation and bronchoprotection when used as intermittent, single-dose treatment of asthma in children, but not when used as regular treatment. Future studies should examine the positioning of long-acting beta(2)-agonists as an "as needed" rescue medication instead of short-acting beta(2)-agonists for pediatric asthma management.     

Incremental benefit of adding oxitropium bromide to formoterol in patients with stable COPD.

The effects of the long-acting beta(2)-agonist formoterol, the anticholinergic drug oxitropium bromide, and their combination were compared in 16 patients with partially reversible stable COPD. On each of 4 study days patients inhaled both drugs separated by 180 min in alternate sequence, with formoterol being administered in two doses (formoterol 12 microg + oxitropium bromide 200 microg; oxitropium bromide 200 microg + formoterol 12 microg; formoterol 24 microg + oxitropium bromide 200 microg; oxitropium bromide 200 microg + formoterol 24 microg). FEV(1)and FVC were measured baseline and after 30, 60, 120, 180, 210, 240, 300 and 360 min. In terms of onset of action, formoterol performed better than oxitropium bromide. Within the first 180 min after inhalation formoterol 24 microg was the most effective drug (maximal change in FEV(1): formoterol 24 microg = 25.6%, formoterol 12 microg = 21.1%, oxitropium bromide = 18.2%). Increased bronchodilation was obtained when the second drug was added, the sequence formoterol 24 microg + oxitropium bromide being the most effective (maximal change in FEV(1)over baseline: formoterol 24 microg + oxitropium bromide 28.8%, oxitropium bromide + formoterol 24 microg 20.9%, formoterol 12 microg + oxitropium bromide 26.6%, oxitropium bromide + formoterol 12 microg 22.5%). Significant improvement in pulmonary function may be achieved by giving two different bronchodilators in stable COPD patients. The sequence formoterol 24 microg + oxitropium bromide 200 microg seems to be the most effective.     

Acute effects of higher than customary doses of salmeterol and salbutamol in patients with acute exacerbation of COPD

Worsening of underlying bronchospasm may be associated with acute exacerbations of chronic obstructive pulmonary disease (COPD). As airway obstruction becomes more severe, the therapeutic option is to add salbutamol, but not salmeterol, as needed to cause rapid relief of bronchospasm. Unfortunately the most effective dosage of beta2-agonists may increase above that recommended during acute exacerbations. In this study, we compared the acute effects of higher than customary doses of salmeterol and salbutamol in 20 patients with acute exacerbation of COPD. A dose-response curve to salmeterol pMDI, 25 microg/puff or salbutamol pMDI, 100 microg/puff, was constructed using 1, 1, and 2 puff' i.e., a total cumulative dose of 100 microg salmeterol or 400 microg salbutamol on 2 consecutive days. After baseline measurements, dose increments were given at 30-min intervals with measurements being made 25 min after each dose. Hear rate (HR) and pulse-oximetry (SpO2) measurements were then taken. Both salmeterol and salbutamol induced a larg and significant (P < 0.05) dose-dependent increase in FEV1 [mean differences from baseline (L) = after 100 microg salmeterol 0.174 (95% CI: 0.112 to 0.237); after 400 microg salbutamol: 0.165 (95% CI: 0.080 to 0.249)], in IC [mean differences from baseline (L) = after 100 microg salmeterol: 0.332 (95% CI: 0.165 to 0.499); after 400 microg salbutamol: 0.281 (95% CI: 0.107 to 0.456)] (Fig. 2), and in FVC mean differences from baseline (L) = after 100 microg salmeterol: 0.224 (95% CI: 0.117 to 0.331); after 400 microg salbutamol: 0.242 (95% CI: 0.090 to 0.395)]. There was no significant difference between the FEV1 values (P=0.418), the ICvalues (P=0.585), and the FVCvalue (P=0.610) after 100 microg salmeterol and 400 microg salbutamol. HR [mean differences from baseline (beats/min) = after 100 microg salmeterol: 3.15 (95% CI: -0.65 to 6.96); after 400 microg salbutamol: 2.30 (95% CI: -0.91 to 5.51)] and SpO2 [mean differences from baseline (%) = after 100 microg salmeterol: -0.20 (95% CI: -1.00 to 0.60); after 400 microg salbutamol: -0.11 (95% CI: -1.00 to 0.79)] did not change significantly from baseline (P > 0.05). These data indicate that salmeterol is effective and safe in the treatment of acute exacerbation of COPD and support its use in this clinical condition.     

Budesonide/formoterol in a single inhaler rapidly relieves methacholine-induced moderate-to-severe bronchoconstriction

Inhalers containing corticosteroids and long-acting beta2-agonists are becoming increasingly important in asthma management. A rapid effect is important to patients, particularly during exacerbations. We compared the onset of bronchodilation and patient-perceived relief from dyspnoea following single-inhaler budesonide/formoterol or salmeterol/fluticasone in a model of acute bronchoconstriction. A randomised, double-blind, double-dummy, single-dose, crossover study included 27 outpatients with asthma (mean age 35 years; mean FEV1 90% predicted normal). Immediately following methacholine-induced bronchoconstriction (fall in FEV1 > or = 30%), patients inhaled budesonide/formoterol (160/4.5 microg, 1 or 2 inhalations; Symbicort Turbuhaler), salmeterol/fluticasone (50/250 microg; Seretide Diskus) or placebo on 4 study days. Lung function and Borg score were assessed for 30 min. During methacholine-induced provocation (final mean FEV1 62.5% of baseline), mean Borg score increased 10-fold (from 0.3 to 3.0 units). Hereafter, mean FEV1 at 3 min improved significantly more after budesonide/formoterol 1 and 2 inhalations (37 and 38%, respectively) than after salmeterol/fluticasone (23%; P < 0.001) or placebo (10%; P < 0.001). Median recovery times to 85% of baseline FEV1 were shorter for budesonide/formoterol (1 or 2 inhalations: 3.3 and 2.8 min, respectively) than salmeterol/fluticasone (8.9 min; P < 0.001) and placebo (> 30 min). One min after budesonide/formoterol, dyspnoea was significantly reduced (Borg score -0.86 units, both doses) compared with salmeterol/fluticasone (-0.55 units; P < 0.05) and placebo (-0.23 units; P < 0.001). Budesonide/formoterol provides immediate bronchodilation, faster than salmeterol/fluticasone, which patients can feel during acute methacholine-induced bronchoconstriction.     

Onset of action of formoterol/budesonide in single inhaler vs. formoterol in patients with COPD

Formoterol is a beta(2)-agonist bronchodilator that combines a fast onset of action with a long duration of broncholytic effect. An increasing documentation is showing that the combination of a long acting beta(2)-adrenoceptor agonist bronchodilator and an inhaled corticosteroid targets the airways obstruction in patients with COPD. In this study, we have explored whether the acute addition of an inhaled corticosteroid influences the fast bronchodilator response to formoterol. A total of 20 patients with stable COPD were randomized. Single doses of formoterol/budesonide 2 x (4.5/160)microg or formoterol 2 x 4.5 microg were given via Turbuhaler. Serial measurements of FEV(1) were performed over 60 min. Formoterol/budesonide elicited a significantly larger mean FEV(1)-AUC(0-15 min) than formoterol alone. Also the change in FEV(1) 15 min after inhalation of formoterol/budesonide combination (0.197 l; 95% CI: to 0.142-0.252) was greater than that induced by formoterol alone (0.147 l; 95% CI: to 0.092-0.201). The mean increases in FEV(1) were always higher after budesonide/formoterol than formoterol alone, although both treatments induced a significant improvement over baseline at each explored time point. Even the FEV(1)-AUC(0-60 min) after formoterol/budesonide was significantly larger than that after formoterol. Both treatments induced a significant reduction in VAS score but did not modify heart rate in a statistically significant manner. This study indicates that the addition of budesonide influences the fast onset of action of formoterol, but does not induce systemic effects, in patients with stable COPD.     

Formoterol Turbuhaler for as-needed therapy in patients with mild acute exacerbations of COPD.

Worsening of underlying bronchospasm may be associated with acute exacerbations of chronic obstructive pulmonary disease (COPD). As airway obstruction becomes more severe, the therapeutic option is to add a short-acting inhaled beta2-agonist as needed to cause rapid relief of bronchospasm. Unfortunately however, the most effective dosage may increase above that recommended during acute exacerbations. Formoterol (Oxis) Turbuhaler has a rapid onset of action (within minutes) and demonstrates a maintained effect on a rway function. In this study, we examined the effects of formoterol used as needed in 20 patients with acute exacerbations of COPD. A dose response curve to inhaled formoterol (9 microg per inhalation) or placebo was constructed using three separate inhalations, i.e. a total cumulative dose of 27 microg. Dose increments were given at 20-min intervals, with measurements being made 15 min after each dose. Formoterol, but not placebo, induced a large and significant (P<0.001) dose-dependent increase in forced expiratory volume in 1 sec (FEV1) [mean differences from baseline = 0.1311 after 9 microg formoterol (95% CI: 0.096-0.167)] 0.1811 after 18 microg formoterol (95% CI: 0.140-0.2221) and 0.2081 after 27 microg formoterol (95% CI: 0.153-0.2631). However, 27 microg formoterol did not induce further benefit [0.0271 (95% CI: -0.008-0.0621); P=0.121] when compared wth 18 microg formoterol. Results of this study suggest the use of higher than customary dose of formoterol for as-needed therapy to provide rapid relief of bronchospasm in patients suffering from acute exacerbations of partially reversible COPD.