Systemic corticosteriod rapidly reverses bronchodilator subsensitivity induced by formoterol in asthmatic patients

摘要

There is evidence that downregulation and desensitization of airway β_2-adrenoceptors (β_2-AR) devel- ops after continuous exposure to long-acting β_2-agonists such as formoterol and salmeterol. To inves- tigat the facilitatory effects of acute administration of systemic corticosteroid on bronchodilator subsensitivity, as might occur in the setting of acute asthma, 12 subjects with moderately severe asthma, with a mean FEV_1 of 66/100 predicted, of whom were all receiving inhaled corticosteriod, were randomized to receive either inhaled placebo (PL) or inhaled formoterol (FM) 24μg twice daily for 4 wk in a double-blind crossover study.