Cigarette smoking impairs the therapeutic response to oral corticosteroids in chronic asthma

Abstract

Those with chronic asthma are strongly advised to avoid cigarette smoking. This report provides further evidence of the deleterious effects of smoking in chronic asthma. A group of adults with relatively mild chronic asthma (FEV1 > 80% predicted) and good bronchodilator responses to inhaled albuterol were divided into 3 subgroups: active smokers, ex-smokers, and those who had never smoked. Each group was then treated with 2-week courses of oral corticosteroids (40 mg prednisolone/day) and placebo given in a randomized, crossover, blinded protocol. In comparison with the placebo treatment period, the corticosteroid therapy in the nonsmokers was followed by significant improvement in FEV1 (P = .02), peak flow rate (P = .006), and asthma control score (P = .004). In contrast, there was no significant improvement in any of these parameters after corticosteroid therapy in the active smokers. After corticosteroid treatment in the ex-smokers, the peak flow rates at night improved significantly (P = .003); however, there was no significant improvement in FEV1 or asthma control scores in these ex-smokers. The authors concluded that active smoking impairs the efficacy of short-term oral corticosteroid treatment in chronic asthma. However, the mechanisms underlying this deleterious effect of smoking are not defined. The limited therapeutic response to corticosteroid treatment in ex-smokers suggests that more than a pharmacologic inhibition of corticosteroid binding to receptors or other biologic effects by components of cigarette smoke is involved. (Chaudhuri et al. Am J Respir Crit Care Med 2003;168:1308-11.)