Salmeterol versus formoterol in patients with moderately severe asthma: onset and duration of action

Abstract

We evaluated the profile of the bronchodilatory effect of three inhaled β 2 -agonists, 24 µg formoterol, 50 µg salmeterol and 200 µg salbutamol, in patients with stable, moderately severe asthma.Thirty asthmatics (mean±SD age 54±8 yrs; forced expiratory volume in one second (FEV1) 58±12% predicted; reversibility of FEV1 21±8% from baseline) participated in a single-centre, double-blind, randomized, single-dose, cross-over study. FEV1 was obtained in baseline condition and 10, 20, 30, 60 min, and every hour up to 12 h after inhalation of the trial drug. Specific airway conductance (sGaw) was measured at baseline condition and 1, 3, 5, 7, 10, 20, 30, 60 min, and every hour up to 12 h after inhalation.Formoterol produced a mean increase in sGaw (as % of baseline) of 44% after 1 min, maximal (135%) after 2 h, and 56% after 12 h. The mean increase in FEV1 was maximal (27%) after 2h, and 10% after 12 h. After salmeterol, mean increase in sGaw amounted to 16% after 3 min, maximal (111%) after 2-4 h, and 58% after 12 h. The mean increase in FEV1 was maximally 25% after 3h, being 11% after 12 h. After salbutamol, mean increase in sGaw was 44% after 1 min and maximal (100%) after 30 min. The peak increase in FEV1 was 25%.We conclude that formoterol (24 µg) and salmeterol (50 µg) had an equal bronchodilatory capacity, which was similar to that of 200 µg salbutamol and lasted for at least 12 h in patients with asthma. However, formoterol had a more rapid onset of action than salmeterol, equal to that of salbutamol. Eur Respir J., 1996Respir J., , 9, 1684Respir J., -1688 Formoterol and salmeterol are the first two drugs of a new generation of β 2 -agonists with prolonged effect. Both compounds, when administered as an aerosol by a metered-dose inhaler (MDI) or when inhaled as a powder, have the property of retaining a bronchodilatory effect for up to 12 h, which accounts for their use in patients with nocturnal asthma. Moreover, the long duration of action allows for a twice daily treatment frequency, for example, on arising in the morning and on going to bed at night, which could be helpful in promoting patient compliance [1][2][3][4][5][6].In vitro work and noncomparative studies on formoterol and salmeterol have shown evidence that there are small differences between the two inhaled drugs with regard to the speed of onset of a bronchodilatory effect, duration of action and dose-dependency of the duration of effect [6][7][8][9][10][11][12][13]. At the present time, a few comparative studies in patients with chronic obstructive pulmonary disease (COPD) have been published [14,15], however, a direct comparison of the profile of the bronchodilatory effect in asthma is still lacking.The purpose of the present study was to compare the onset and duration of action of 24 µg formoterol, 50 µg salmeterol and 200 µg salbutamol in patients with moderately severe asthma. Patients and methodsThirty adults with asthma, 8 females and 22 males, who met the American Thoracic Society (ATS) diagnostic criteria for asthma [16], vo...

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

“…The dose of 50 mg salbutamol (when inhaled via Turbuhaler), has not been compared previously to the other two test drugs, but has been shown to be equipotent with two-to four-fold higher doses of salbutamol when given via other inhalation devices [12,13]. A dose of 200 mg salbutamol via a pressurized metered-dose inhaler has been shown to induce the same maximal bronchodilating effect as both 24 mg formoterol and 50 mg salmeterol, also inhaled via a metered-dose inhaler [10].…”

A comparison of lung function methods for assessing dose–response effects of salbutamol

“…Pulmonary function was performed 15 min after each dose. Short-and long-acting bronchodilatators were withheld for 6 and 12 h, respectively, prior to study days in accordance with their duration of action [10] . …”

Poor adherence with inhaled corticosteroids for asthma: can using a single inhaler containing budesonide and formoterol help?

“…[4][5][6] Reasons for poor adherence are numerous, but include a dislike of inhaled corticosteroids, lack of rapid symptom relief, and complicated treatment regimens. [7][8][9] Because the β 2 -agonist formoterol has a rapid onset and long duration of action, 10 it can be used for symptom relief and maintenance treatment. [11][12][13] When combined with budesonide in a single inhaler and used in this way it simplifies asthma treatment and provides a dose of inhaled corticosteroid with every dose of relief medication.…”