Altered therapeutic response towards inhaled corticosteroids in asthmatics –smokers with mild asthma

Abstract

The exposure to tobacco smoke could cause bronchoconstriction and acute asthma attack. Smoking asthmatics have an insufficient therapeutic response to the standard therapy and unsatisfactory improvement of the respiratory function. In a randomized parallel study, a therapeutic response to inhaled fluticasone propionate in a dose of 250 µg twice per day was determined in 38 asthmatics with mild asthma, smokers and nonsmokers. Short-acting ß2 agonist (salbutamol) in a dosage of 0.1 mg/per inhaled dose was used as a rescue medication when needed. In patients, asthma was detected with a positive metacholine test and/or positive bronchodilatator response of > 12% with ≥ 200 ml increase of FEV1. They were randomized in two groups according to sex, age and starting values of FEV1. Before and after 6 weeks of treatment with fluticasone propionate of the previously corticosteroid-naive patients, lung function test (spirometry) was performed. A statistically significant effect (p<0.05) was achieved during the fluticasone propionate therapy in a group of non-smoking asthmatic patients. The same effect was not seen in the group of smoking asthmatics. Although the percentage of elevated FEV1 values was small, it was satisfactory because of the starting FEV1 values in patients with mild asthma. More studies are needed in asthmatics determining the asthma symptom score, the number of night awakenings due to asthma, the asthma exacerbations and the frequency of rescue therapy usage which will define the altered therapeutic response to inhaled corticosteroids in smoking asthmatics.