Abstract
The aim of this study was to compare the clinical efficacy of salmeterol versus theophylline in the treatment of moderate-to-severe asthma. One hundred and eighty nine asthmatic patients (forced expiratory volume in one second (FEV1) or peak expiratory flow (PEF) >50% of predicted) were randomized to receive either salmeterol dry powder, 50 microg b.i.d. via a Diskhaler (n=92) or dose-titrated slow-release theophylline capsules ("Theo-Dur") b.i.d. (n=97), in a double-blind, double-dummy, parallel group study for 4 weeks. Patients had previously been titrated with theophylline to a serum theophylline level of 10-20 microg x mL-1. The median percentage of nights with no asthma symptoms rose from 14% in both groups at baseline to 71% with salmeterol and to 46% with theophylline (p=0.044). There was also a significant increase for salmeterol in the median percentage of nights with no rescue salbutamol use (from 36 to 86%) compared with theophylline (from 71 to 78%; p=0.002). The mean morning PEF increased from 337 L x min-1 in the salmeterol group and 332 L x min-1 in the theophylline group to 372 and 357 L x min-1, respectively. No significant difference between the two treatments was observed for PEF, symptoms or additional salbutamol medication during the day. The incidence of gastrointestinal symptoms (gastric irritation, nausea and vomiting) was greater among patients receiving theophylline (11%) than with salmeterol (3%). These findings suggest that inhaled salmeterol is more effective in relieving symptoms of asthma, and better tolerated than theophylline in patients with moderate-to-severe asthma.
