PT  - JOURNAL ARTICLE
AU  - M Palmqvist
AU  - G Persson
AU  - L Lazer
AU  - J Rosenborg
AU  - P Larsson
AU  - J Lotvall
TI  - Inhaled dry-powder formoterol and salmeterol in asthmatic patients: onset of action, duration of effect and potency
AID  - 10.1183/09031936.97.10112489
DP  - 1997 Nov 01
TA  - European Respiratory Journal
PG  - 2484--2489
VI  - 10
IP  - 11
4099  - http://erj.ersjournals.com/content/10/11/2484.short
4100  - http://erj.ersjournals.com/content/10/11/2484.full
SO  - Eur Respir J1997 Nov 01; 10
AB  - Salmeterol and formoterol are two long-acting beta2-agonists for inhalation, currently being used in clinical practice. The aim of the present study was to investigate the onset of action, duration of effect and potency of these two beta2-agonists in asthmatic patients. Patients (n=28) were included on the basis of salbutamol stepwise reversibility (100, 100 and 200 microg, given cumulatively; total reversibility > or =15%). In a double-blind placebo-controlled crossover study, the bronchodilating properties of formoterol 6, 12 and 24 microg were compared with the effects of salmeterol 50 microg. Formoterol was given via Turbuhaler and salmeterol via Diskhaler, and forced expiratory volume in one second (FEV1) was monitored during 12 h. Formoterol at all doses had a more rapid onset than salmeterol as judged from bronchodilation at 3 min after the dose. Formoterol at all doses had a similar duration of effect to salmeterol 50 microg, as judged from bronchodilation at 12 h after dose administration. When the relative potency of the two drugs was compared, salmeterol 50 microg was estimated to correspond to formoterol 9 microg (95% confidence interval: 3-19 microg). We confirm that formoterol and salmeterol are both long-acting beta2-agonists, but with some differences in effect profile. We confirm the more rapid onset of action of formoterol compared with salmeterol, and furthermore, no difference in duration of effect is evident.