Effects of Salmeterol and Fluticasone Propionate Combination versus Fluticasone Propionate on Airway Function and Eosinophilic Inflammation in Mild Asthma

Abstract

Salmeterol and fluticasone propionate combination (SFC) provides better asthma control than fluticasone propionate (FP) alone, however, little is known on the effects of differential treatments on airway function and inflammation in patients with mild asthma. We randomized 27 mild persistent asthma patients treated with the equivalent of 400 microg beclomethasone dipropionate to receive SFC (50/100 microg , 13 patients) or FP (100 microg , 14 patients) twice daily for 8 weeks. We compared the effects of SFC and FP on pulmonary function assessed by spirometry and impulse oscillometry (IOS), eosinophil percentage of induced sputum and serum, and with asthma symptoms and control after each treatment. We observed that SFC significantly improved forced expiratory volume in one second (p < 0.05), IOS measurements of total resistance R5 (p < 0.01), central resistance R20 (p < 0.05), and distal reactance X5 (p < 0.01) compared with FP. The percentage of eosinophils in sputum, but not in serum, decreased significantly more in the SFC group than in the FP group (p < 0.05). There was also a significant improvement in symptom control in the SFC group (p < 0.05). These findings suggest that SFC is more useful than FP in mild asthma cases. The clinical benefit of SFC provides evidence that IOS and induced sputum allows for the detection of changes in airway function and inflammation.