Addition of inhaled salmeterol to inhaled corticosteroids in patients with poorly controlled nocturnal asthma

The effect of adding inhaled salmeterol to inhaled corticosteroids was studied in patients with poorly controlled nocturnal asthma. In a double-blind, cross-over study, 20 patients were randomized to receive either salmeterol 50 micrograms twice daily or placebo via a Diskhaler after a 1-week run-in period. After 4 weeks of treatment, patients were subsequently crossed over to receive the other treatment for a further 4 weeks with a 2-week wash-out period in between. The response to treatment was assessed by peak expiratory flow rates (PEF) measured in the morning and evening, symptom scores of asthma, number of bronchodilators used, forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) at regular intervals. Patients' preference for the Diskhaler or metered-dose inhaler was assessed at the last visit. The results showed that morning PEF was significantly higher while on salmeterol than on placebo (296.9 +/- 70.2 vs 274.6 +/- 77.4 L/min). Evening PEF showed a trend towards a higher value while on salmeterol than on placebo (321.1 +/- 73.4 vs 288.7 +/- 79.4 L/min), but the difference was not significant. There was no statistically significant improvement in symptom scores, number of rescue bronchodilators used and FEV1 or FVC between the two treatment groups. The occurrence of side effects in terms of tremors and palpitations between treatment and placebo were similar. There were more patients who preferred Diskhaler to metered-dose inhaler (70% vs 30%). We conclude that salmeterol 50 micrograms twice daily produces significant improvement in morning PEF and is well tolerated in patients with nocturnal asthma. Diskhaler is a device which is easy to use and preferred to a metered-dose inhaler.
Study site: Respiratory Clinic, Pusat Perubatan Universiti Kebangsaan Malaysia (PPUKM), Kuala Lumpur, Malaysia