Cockcroft D W, O'Byrne P M, Swystun V A, Bhagat R
Department of Medicine, Royal University Hospital, Saskatoon, Canada.
J Allergy Clin Immunol. 1995 Jul;96(1):44-9. doi: 10.1016/s0091-6749(95)70031-5.
We have recently demonstrated that a 2-week course of inhaled albuterol 200 micrograms four times daily caused a near doubling of the allergen-induced early asthmatic response. We hypothesized that this might extend to the more clinically relevant late asthmatic response.
We studied 11 patients with atopic asthma who were free from all medications including inhaled beta 2-agonists for more than 4 weeks. We performed a double-blind, random-order, crossover study, comparing the effect of 1-week treatment periods of albuterol 200 micrograms four times daily and placebo 2 puffs four times daily on the early and late asthmatic responses to the same dose of allergen.
Regular use of albuterol did not influence the baseline forced expiratory volume in 1 second (FEV1) (3.40 vs 3.42 L, p = 0.84) or the baseline methacholine provocative concentration causing a 20% fall in FEV1 (PC20) (geometric mean, 2.4 mg/ml vs 1.9 mg/ml, p = 0.38). However, all aspects of the allergen-induced asthmatic response were increased. After the 1-week albuterol treatment, the early asthmatic response was slightly greater (21.1% vs 17.9% FEV1 fall, p = 0.26), the late response was greater (23.1% vs 13.2% FEV1 fall, p = 0.0027), and the allergen-induced increase in airway responsiveness (change in log methacholine PC20) was greater (0.37 vs 0.20, p = 0.045).
One week of albuterol treatment (200 micrograms four times daily) increased the late asthmatic response and allergen-induced increase in airway responsiveness. This suggests that the combination of regular use of inhaled beta 2-agonist and allergen exposure may cause more airway inflammation than allergen exposure alone.
我们最近证实，为期2周、每日4次吸入200微克沙丁胺醇可使变应原诱导的早期哮喘反应增加近一倍。我们推测这可能会扩展到更具临床相关性的晚期哮喘反应。
我们研究了11例特应性哮喘患者，他们停用包括吸入β2激动剂在内的所有药物超过4周。我们进行了一项双盲、随机顺序、交叉研究，比较每日4次吸入200微克沙丁胺醇1周治疗期和每日4次吸入2喷安慰剂对同一剂量变应原诱发的早期和晚期哮喘反应的影响。
规律使用沙丁胺醇对基线第1秒用力呼气量（FEV1）（3.40对3.42升，p = 0.84）或导致FEV1下降20%的基线乙酰甲胆碱激发浓度（PC20）（几何均值，2.4毫克/毫升对1.9毫克/毫升，p = 0.38）无影响。然而，变应原诱发的哮喘反应的各个方面均增加。在1周沙丁胺醇治疗后，早期哮喘反应略大（FEV1下降21.1%对17.9%，p = 0.26），晚期反应更大（FEV1下降23.1%对13.2%，p = 0.0027），变应原诱发的气道反应性增加（乙酰甲胆碱PC20对数变化）更大（0.37对0.20，p = 0.045）。
1周的沙丁胺醇治疗（每日4次，每次200微克）增加了晚期哮喘反应以及变应原诱发的气道反应性增加。这表明规律使用吸入β2激动剂与变应原暴露相结合可能比单独变应原暴露引起更多的气道炎症。
