Asmus M J, Barros M D, Liang J, Chesrown S E, Hendeles L
Asthma Research Laboratory, Department of Pharmacy Practice, College of Pharmacy, University of Florida, Gainesville, USA.
J Allergy Clin Immunol. 2001 Jan;107(1):68-72. doi: 10.1067/mai.2001.111591.
Some nebulized bronchodilator solutions contain additives, such as EDTA, benzalkonium chloride (BAC), or both.
Although BAC-induced bronchoconstriction has been well documented in patients with asthma, there is no information on the effects of EDTA on FEV(1) when inhaled in the amounts that would be administered during emergency department treatment of asthma.
Eighteen subjects with stable asthma and airway responsiveness to methacholine were randomly assigned to inhale up to four 600-microg nebulized doses of EDTA, BAC (positive control), and normal saline (placebo) in a double-blind crossover manner on separate days. FEV(1) was measured 15 minutes after each dose. Treatments were repeated every 20 minutes until FEV(1) decreased by 20% or greater or a maximum of 4 doses were administered.
Mean +/- SD maximum percent decrease in FEV(1) was 1.8% +/- 5.8% after EDTA, 16.6% +/- 13.9% after BAC, and 3.6% +/- 8.2% after placebo (P <.001); there was no significant difference between EDTA and placebo.
The amount of EDTA contained in maximum recommended doses of nebulized bronchodilators does not induce bronchospasm. In contrast, BAC induces clinically important bronchospasm, which could decrease the efficacy of a bronchodilator during an emergency.
一些雾化支气管扩张剂溶液含有添加剂，如乙二胺四乙酸（EDTA）、苯扎氯铵（BAC）或两者都有。
虽然BAC诱发的支气管收缩在哮喘患者中已有充分记录，但对于在急诊科治疗哮喘时吸入的EDTA剂量对第一秒用力呼气量（FEV₁）的影响尚无相关信息。
18名患有稳定型哮喘且对乙酰甲胆碱有气道反应性的受试者被随机分配，以双盲交叉方式在不同日期吸入多达四剂600微克雾化的EDTA、BAC（阳性对照）和生理盐水（安慰剂）。每次给药后15分钟测量FEV₁。每20分钟重复一次治疗，直到FEV₁下降20%或更多，或最多给予4剂。
EDTA给药后FEV₁的平均最大百分比下降为1.8%±5.8%，BAC给药后为16.6%±13.9%，安慰剂给药后为3.6%±8.2%（P<.001）；EDTA与安慰剂之间无显著差异。
雾化支气管扩张剂最大推荐剂量中所含的EDTA量不会诱发支气管痉挛。相比之下，BAC会诱发具有临床意义的支气管痉挛，这可能会降低紧急情况下支气管扩张剂的疗效。
