Pulmonary function response to EDTA, an additive in nebulized bronchodilators.
BACKGROUND
Some nebulized bronchodilator solutions contain additives, such as EDTA, benzalkonium chloride (BAC), or both.


OBJECTIVE
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.


METHODS
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.


RESULTS
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.


CONCLUSIONS
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.
Asmus
M J
MJ
Asthma Research Laboratory, Department of Pharmacy Practice, College of Pharmacy, University of Florida, Gainesville, USA.
Barros
M D
MD
Liang
J
J
Chesrown
S E
SE
Hendeles
L
L
D000293:Adolescent; D000328:Adult; D001993:Bronchodilator Agents / Q000494:pharmacology*; D002614:Chelating Agents / Q000494:pharmacology; D004492:Edetic Acid / Q000494:pharmacology*; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008168:Lung / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D009330:Nebulizers and Vaporizers; D010592:Pharmaceutic Aids
D001993:Bronchodilator Agents; D002614:Chelating Agents; D010592:Pharmaceutic Aids; D004492:Edetic Acid