Inhaled formoterol during one year in asthma: a comparison with salbutamol.

Eighteen patients, who had previously taken part in a 2 wk cross-over comparison between formoterol and salbutamol, now took part in a one year double-blind study comparing salbutamol 200 micrograms b.i.d. with formoterol 12 micrograms b.i.d. Additional doses were taken when needed and were recorded. Ten patients were started on formoterol and eight on salbutamol. After one month, the patients were allowed to shift to the alternative drug. Two patients withdrew from the study. At the end of the study, 13 of 16 patients were on formoterol, thus showing a long-lasting preference for this drug. Forced expiratory volume in one second (FEV1) dose-response curves for inhaled salbutamol were repeatedly recorded during the study, and no tachyphylaxis was found. One patient stopped taking inhaled steroids but continued taking formoterol and theophylline. He deteriorated with a decreased response to salbutamol. After re-introduction of inhaled steroids his condition improved. This case indicates that effective bronchodilator therapy may mask the deterioration of asthma.     

A study with cumulative doses of formoterol and salbutamol in children with asthma.

In a double-blind, cross-over study, 9 children (7-13 yrs old) with stable, moderate asthma inhaled formoterol (6, 18 and 54 micrograms) and salbutamol (100, 300 and 900 micrograms) at hourly intervals, in order to compare the peak effect of cumulative doses of the two drugs. One hour after the last dose, 1 mg salbutamol was inhaled to ensure that maximum bronchodilatation was obtained. The forced expiratory volume in one second (FEV1), peak expiratory flow rate (PEFR), forced vital capacity (FVC), pulse rate, blood pressure and tremor were measured regularly after each dose and the PEFR 5, 7, 9 and 20 h after the last dose. The first dose of each drug improved the FEV1, PEFR and FVC substantially while the following doses only gave minor improvement. The final addition of 1 mg salbutamol produced no further improvement. No statistically significant difference in bronchodilating effect was seen between the two drugs at any point in time. Side-effects were minimal. Our data indicate that doses of 6-24 micrograms formoterol can be recommended for school children. For most patients with mild to moderate bronchial asthma higher doses will not add much to the bronchodilating effect.     

Comparison of domiciliary nebulized salbutamol and salbutamol from a metered-dose inhaler in stable chronic airflow limitation

Nineteen patients (12 men) mean age, 63.4 years (range, 32 to 78), with stable chronic airflow limitation, mean FEV, 0.55 L (range, 0.3 to 1.05 L), completed an eight-week, double-blind, double cross-over study comparing nebulized salbutamol and salbutamol from a metered-dose inhaler (MDI). Salbutamol from both delivery systems produced bronchodilation. The doses of salbutamol inhaled via the nebulizer and MDI producing maximal bronchodilation were established by cumulative dose-response curves. The contents of the nebulizer and MDI were inhaled four times a day, one system containing salbutamol and the other a placebo. Cross-over of salbutamol from one system to the other occurred every two weeks. There was no significant difference between the two delivery methods in daily peak expiratory flow rate (PEFR), severity of symptoms, or extra bronchodilator usage. Two weekly laboratory assessments of spirometry, PEFR, and exercise tolerance also showed no significant differences. Careful assessment is recommended before the provision of domiciliary nebulizers.     

A twelve month comparison of salmeterol with salbutamol in asthmatic patients. European Study Group.

The efficacy and tolerability of salmeterol, 50 micrograms b.i.d. was compared for three months with salbutamol, 200 micrograms q.i.d., administered from metered-dose inhaler. For the following nine months, safety and clinic lung function was monitored on salmeterol, 50 micrograms b.i.d., compared with salbutamol, 200 micrograms b.i.d. This comparison was made in a multicentre, double-blind, parallel-group study of 667 moderate asthmatics, who had a forced expiratory volume in one second (FEV1) or peak expiratory flow rate (PEFR) > 50% predicted, a 15% reversibility to inhaled salbutamol and who were experiencing symptoms. Throughout the first three month treatment period, both morning and evening PEFR were significantly higher on treatment with salmeterol than salbutamol (mean differences between the treatments 30 l.min-1 for morning, p < 0.001, and 11 l.min-1 for evening, p < 0.01). In addition, the diurnal variation in PEFR, nocturnal and daytime symptoms and use of additional salbutamol were significantly lower in the salmeterol treated group. This improvement was also apparent in the separate subpopulations of patients taking no concurrent glucocorticosteroid or concurrent inhaled and/or oral glucocorticosteroids. Both treatments were well-tolerated throughout the 12 months of treatment. There was a lower incidence of asthma and related events during salmeterol treatment compared to salbutamol treatment subgroups. The results of the study clearly demonstrate that salmeterol, 50 micrograms b.i.d., is well-tolerated and more effective than salbutamol, 200 micrograms q.i.d., in the treatment of moderate asthma.     

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.     

Bronchodilator Responses to Salbutamol Using Diskhaler Versus Metered-Dose Inhaler

In adults inhaling salbutamol via metered-dose inhalers (MDIs) 200 μ.g doses are recommended, but with diskhalers the manufacturer advocates 400 rather than 200 µg doses. To assess this advice, a partially double-blind, placebo-controlled salbutamol dose response, crossover study (also incorporating MDI doses) was conducted in 12 mild/moderate asthmatics. After active treatment, mean peak expiratory flow rate (PEFR) increments yielded no clinically or statistically significant differences; compared to placebo, respective median differences in PEFR increments (95% CIs) were 10 (-10, 50), 20 (0, 50), and 15 (0, 30) following 400 and 200 µg via diskhalers and 200 u.g via MDIs. Diskhalers are a suitable alternative for patients with poor MDI technique, but the use of 400 rather than 200 µg salbutamol doses is not supported by evidence.     

Bronchodilator Responses to Salbutamol Using Diskhaler Versus Metered-Dose Inhaler

In adults inhaling salbutamol via metered-dose inhalers (MDIs) 200 μ.g doses are recommended, but with diskhalers the manufacturer advocates 400 rather than 200 µg doses. To assess this advice, a partially double-blind, placebo-controlled salbutamol dose response, crossover study (also incorporating MDI doses) was conducted in 12 mild/moderate asthmatics. After active treatment, mean peak expiratory flow rate (PEFR) increments yielded no clinically or statistically significant differences; compared to placebo, respective median differences in PEFR increments (95% CIs) were 10 (-10, 50), 20 (0, 50), and 15 (0, 30) following 400 and 200 µg via diskhalers and 200 u.g via MDIs. Diskhalers are a suitable alternative for patients with poor MDI technique, but the use of 400 rather than 200 µg salbutamol doses is not supported by evidence.     

Formoterol and salbutamol metered aerosols: comparison of a new and an established beta-2-agonist for their bronchodilating efficacy in the treatment of childhood bronchial asthma

In this placebo-controlled, double-blind, single-dose study the new beta-2-agonist formoterol (one puff, 12 micrograms) was intraindividually compared with salbutamol (one puff, 100 micrograms) for onset, magnitude, and duration of bronchodilating efficacy in 15 young asthmatics aged 5 to 14 years with mild to severe asthma. All but one had regular antiasthmatic medication before beginning the study, but none was oral steroid dependent. Both medications produced rapid bronchodilatation within 10 minutes, reflected by a decrease in specific airway resistance (sRaw) with maximum effects at 10 minutes (salbutamol, 51%) and 30 minutes (formoterol, 60%). Significant bronchodilation was present at 10 minutes to 2 hours after inhalation of salbutamol and at 30 minutes to 8 hours after formoterol. Mean percent improvement over baseline was higher for formoterol at all measured times from 30 minutes to 12 hours, when 55% mean decrease in sRaw was still present. The effect of salbutamol was a less than 10% mean decrease in sRaw after 6 hours. The differences in sRaw decrease between the two medications were statistically significant at 4 to 10 hours after inhalation. Neither medication administered as an aerosol caused cardiac side effects. Both had a rapid onset of action and a comparable maximal effect. However, at the doses studied, formoterol produced a larger decrease in sRaw from baseline for longer periods after inhalation than did salbutamol.     

Inhaled salmeterol and salbutamol in asthmatic patients. An evaluation of asthma symptoms and the possible development of tachyphylaxis

Salmeterol (SM) is a new beta 2-adrenoceptor agonist for inhaled use that has been shown to produce long-lasting bronchodilation in asthmatic patients. In the present study, evaluating efficacy and possible development of tachyphylaxis after SM, 12 patients with stable asthma were included after the demonstration of reversibility in FEV1 of at least 15% to 200 micrograms salbutamol (SB) or 20% to 500 micrograms SB. At inclusion all patients were receiving treatment with inhaled beta 2-agonists, and 11 of the 12 patients were also receiving inhaled corticosteroids. The patients were treated for two 2-wk periods with either inhaled SM 50 micrograms twice a day or SB 200 micrograms four times a day, following a double-blind, double-dummy, randomized design. The treatment periods were separated by a washout period of 1 wk. Dose-response curves to inhaled SB were obtained the day before and the day after each treatment period. On each of these days, basal FEV1, tremor, heart rate, and blood pressure were recorded and were then followed after the inhalation of 100 + 300 + 900 micrograms SB to obtain a cumulative dose-response curve. During the treatment periods, as well as during the washout week after each treatment, the patients recorded their morning and evening peak expiratory flow (PEF) each day before the inhalation of the study drug. Subjective asthma symptoms were monitored by a visual analog scale after each treatment period. The dose-response curves to SB revealed no signs of a reduced response to SB after any of the treatments, but significant increases in basal FEV1 and FVC were seen after the SM period (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)     

Formoterol, a new long-acting beta 2 agonist, inhaled twice daily, in stable asthmatic subjects.

STUDY OBJECTIVE: To determine whether formoterol, a new beta 2 agonist with experimentally documented long duration, is clinically more effective than salbutamol in the maintenance treatment of chronic asthma. DESIGN: Randomized double-blind between-patient comparison between treatment with formoterol and with salbutamol during four weeks. SETTING: Asthma/allergy department in a university hospital. PATIENTS: Thirty-seven patients with chronic stable asthma, who during a two-week run-in period with inhaled salbutamol, 4 x 100 micrograms twice a day, used at least four additional doses (100 micrograms each) daily, were randomly assigned to use either formoterol or salbutamol. Thirty-five patients were evaluated for efficacy. One early withdrawal and one dropout were found in the salbutamol group. The groups were similar with respect to demographic data and baseline lung function. INTERVENTIONS: During the four-week study period, the patients used either formoterol (4 x 6 micrograms twice a day and as necessary, n = 19) or salbutamol (4 x 100 micrograms twice a day and as necessary, n = 16). Inhaled steroids and orally administered theophylline were allowed if doses were kept constant. MEASUREMENTS AND MAIN RESULTS: The median number of additional doses per 24 h (median of two weeks) of the test aerosols was 0 (range, 0 to 6) for formoterol and 4 (range, 0 to 14) for salbutamol (p less than 0.01). Morning and evening PEFRs were 422 (SEM = 31) and 443 (SEM = 30), respectively, for formoterol, and 335 (SEM = 30) and 360 (SEM = 26), respectively, for salbutamol (p = 0.05 for both). Formoterol was superior (p less than 0.05) to salbutamol with respect to control of asthma symptoms, estimated duration of action and patient preference. Side effects did not differ. CONCLUSIONS: Inhaled formoterol administered twice a day and as necessary was clinically more effective than the same regimen of salbutamol.     

Improved lung function and symptom control with formoterol on demand in asthma.

Many asthma patients remain symptomatic despite maintenance therapy with inhaled corticosteroids (ICS) and salbutamol as rescue medication. In the present study the relative efficacy and preference for as-needed formoterol compared with salbutamol was examined. In total, 211 patients with a mean age of 45 yrs (mean forced expiratory volume in one second (FEV1) 77% predicted normal), using ICS, were randomised to 3 weeks' double-blind treatment with as-needed formoterol 4.5 microg Turbuhaler and with as-needed salbutamol 100 mug Turbuhaler in a cross-over fashion. Overall, lung function and symptom control were better with as-needed formoterol than with as-needed salbutamol. During as-needed formoterol treatment daytime and night-time symptom scores were lower, peak expiratory flow and FEV1 were higher and patients experienced fewer disturbed nights (34%) compared with as-needed salbutamol. Patients preferred the formoterol treatment to salbutamol. Of the 162 patients expressing a preference, formoterol was preferred by 68% (95% confidence interval: 60-75). Subjective assessment of effectiveness also favoured formoterol, which was perceived as slightly faster acting than salbutamol. In conclusion, as-needed formoterol improved symptoms and lung function compared with salbutamol and was perceived as more effective and at least as fast acting for symptom relief.     

Salmeterol: a four week study of a long-acting beta-adrenoceptor agonist for the treatment of reversible airways disease.

A total of 1,068 patients, aged 18-70 yrs, with mild to moderate reversible airways disease, were recruited into a multicentre, double-blind, parallel group study in 76 European centres. Following a 2 week run-in period, the 692 patients fulfilling the entry criteria were randomized to 4 weeks treatment with either salmeterol 12.5, 50 or 100 micrograms or placebo b.d. all given by pressurized inhaler, with assessments of symptoms and ventilatory lung function prior to dosing. All three doses of salmeterol had significant efficacy, manifested by increased morning and evening peak expiratory flow rate (PEFR) (by 35-59 l.min-1 and 11-38 l.min-1, respectively), by reduced diurnal variation in PEFR, and by reduced requirement for additional bronchodilator for symptomatic relief. These effects were dose-related. Daytime asthma symptoms and nocturnal awakenings were significantly reduced by salmeterol treatment, although these reductions were not dose-related. The incidence of adverse events was low. Pharmacologically predictable events (e.g. tremor) were more frequent after treatment with 100 micrograms b.d. than with placebo. On the basis of the efficacy and side-effect information, 50 micrograms b.d. is considered to be the optimum dose for the treatment of this group of asthmatics.     

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.     

Protective effect and duration of action of formoterol aerosol on exercise-induced asthma.

The short-term protective effect on exercise-induced asthma (EIA) and the duration of action of formoterol, given by metered dose aerosol at a dose of 24 micrograms, were compared with salbutamol (200 micrograms) and placebo in twelve asthmatic EIA-positive patients in a double-blind, placebo-controlled, three period cross-over study. On each treatment day the patients were given one of the drugs or placebo and two exercise tests were performed at the second and at the eighth hour after dosing. Using a standard procedure, exercise was performed by treadmill in well-controlled environmental conditions. In the first test at 2 h a significant difference relative to placebo (p less than 0.001) at each incremental time after exercise (i.e. 5, 10, 15, 20, 30 min) was obtained with both formoterol and salbutamol, without any significant difference between formoterol and salbutamol. After the eighth hour test formoterol still protected against EIA in comparison to both salbutamol and placebo. The effect of salbutamol at this time was not different from placebo. No adverse effects were reported in any treatment group. Formoterol has a long duration of action in protecting against EIA that persisted for eight hours, removing the need to dose with beta 2-agonist before every exercise.     

Comparison of Berodual and salbutamol in asthma: a multicenter evaluation

A 2-month study was carried out to compare the efficacy and safety of Berodual (B) (Boehringer Ingelheim) and salbutamol (S) in asthma. B is a combined agent with 20 micrograms of ipratropium bromide and 50 micrograms of fenoterol in each metered aerosol puff. Each puff of S contained 100 micrograms of drug. 196 patients were included in the study and received 4 x 2 puffs a day of either B or S. FEV1 and FVC were measured every month, and peak expiratory flow rate (PEFR) 4 times a day, i.e. morning and evening before and after administration of drug. Improvement of PEFR was the same in the two groups. No tachyphylaxis occurred. No difference was observed between the two drugs with regard to heart and respiratory rate, dyspnea and blood pressure. Tremor seemed less frequent with B but this difference was not statistically significant. B achieved the same effects as S though containing less beta-2-agonist agent.     

Preventive effects of inhaled formoterol and salbutamol on histamine-induced bronchoconstriction--a placebo-controlled study.

The preventive effects of inhaled formoterol (a new beta 2-agonist) and salbutamol aerosols on histamine-induced bronchoconstriction were studied in 12 patients with mild or moderate asthma in a placebo-controlled, double-blind study. Three hours after the administration of 12 micrograms formoterol, 200 micrograms salbutamol (doses with equal bronchodilator effects) or placebo via aerosol, histamine challenge was undertaken, using a dosimetric jet nebulizer with controlled tidal breathing. The noncumulative dose of histamine diphosphate aerosol provoking a 15% fall in FEV1 (PD15) was calculated. The PD15 after inhalation of 12 micrograms formoterol was significantly higher than that after 200 micrograms salbutamol (median values 640 and 310 micrograms, respectively; p < 0.01). For both treatments, the PD15 was significantly higher than that after placebo (median 185 micrograms). The results indicate that the preventive effect against histamine-induced bronchoconstriction at 3 h after drug is significantly better with formoterol than with salbutamol when using inhaled doses with an equal acute bronchodilator effect.     

Inhaled salmeterol in the treatment of patients with moderate to severe reversible obstructive airways disease--a 3-month comparison of the efficacy and safety of twice-daily salmeterol (100 micrograms) with salmeterol (50 micrograms).

Three-hundred and fifty patients with moderate to severe reversible obstructive airways disease (forced expiratory volume in 1 s or peak expiratory flow rate < or = 50% predicted, a 15% reversibility to inhaled salbutamol and symptomatic) were recruited into a multi-centre, multinational, double-blind, parallel-group randomized study. Two-hundred and eighty-three patients were randomized to receive 50 micrograms salmeterol twice daily or 100 micrograms salmeterol twice daily administered from a metered-dose inhaler for 3 months. Salbutamol (100 micrograms per metered actuation) was provided for symptomatic relief. Morning and evening peak expiratory flow rate (PEFR), day-time and night-time asthma symptoms and additional bronchodilator usage were recorded by the patient on a daily basis. Lung function and patient/physician assessment of treatment efficacy were recorded at scheduled clinic visits. Safety was determined by monitoring adverse events and standard biochemical, haematological and cardiovascular parameters. Salmeterol 100 micrograms twice daily was consistently superior to salmeterol 50 micrograms twice daily in morning and evening PEFR measurements (mean differences between the treatments: 10-14 l min-1 for morning, 95% CI-0, 22 l min-1, P = 0.047; and 10-15 l min-1 for evening, 95% CI 2, 22 l min-1, P = 0.023). The improvement in PEFR was independent of concurrent steroid usage, with the most marked improvement being seen in the more severe asthmatics requiring concurrent oral corticosteroids (mean differences between the treatments: 27-31 l min-1, 95% CI: 3,55 l m-1, P = 0.027).(ABSTRACT TRUNCATED AT 250 WORDS)     

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.     

Rapid onset of tolerance to beta-agonist bronchodilation

INTRODUCTION: Regular use of beta-agonists leads to tolerance to their bronchodilator effects. This is easily demonstrated if dilation is tested following methacholine challenge. It is not known how quickly tolerance develops or how long it lasts after stopping beta-agonist therapy. METHODS: Ten subjects with stable asthma were studied. Following 2 weeks without beta-agonists, methacholine was inhaled to induce a 20% reduction in FEV1. The response to inhaled salbutamol (100, 100, 200 microg at 5-min intervals) was then measured. This procedure was repeated 24 h after one dose and 24 h after 3, 7 and 14 days of inhaled formoterol 12 microg twice daily, and 3 and 5 days after formoterol was discontinued. Unscheduled use of beta-agonists was not permitted. RESULTS: Bronchodilator tolerance, assessed by a reduction of the area under the salbutamol dose-response curve, occurred after 1 dose of formoterol (28% reduction, 95% CI 12, 45%), increased up to 1 week and plateaued between 1 and 2 weeks (58% reduction, 95% CI 38, 78%). Three days after stopping formoterol, the response to salbutamol was similar to baseline (12% reduction, 95% CI -9, 33%). The first dose of formoterol provided significant bronchoprotection to methacholine (1.6 doubling doses, P=0.007). This diminished with regular treatment and by 2 weeks the PD20 methacholine was not significantly different to baseline. CONCLUSIONS: Bronchodilator tolerance occurs after a single dose and reaches a maximum after 1 week of regular formoterol. Sensitivity recovers 3 days after stopping treatment.     

COMPARISON OF WET and DRY AEROSOL SALBUTAMOL

Wet aerosol and metered dose inhaler (MDI) modes of inhalation of salbutamol were compared in ten asthmatic patients with severe, reversible airways obstruction and in ten chronic bronchitic patients with severe, poorly reversible airways obstruction. The responses to cumulative doses to 800 μgm (8 times 100 μgm) by MDI and 10 mg (4 times 0.5 ml of 0.5% standard solution) by wet aerosol were studied. From maximum expiratory flow-volume curves, measurements were made of FEV₁, FVC, PEFR, Vmax 50% and Vmax 75%, and pulse and blood pressure responses to cumulative doses of salbutamol were measured. In both groups of patients there was no significant difference between the two modes of inhalation either for each treatment interval or for the maximal response in any of these indices.