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Effect of inhaled preservatives on asthmatic subjects. I. Sodium metabisulfite
W Wright1, Y G Zhang, C M Salome
1Department of Medicine, University of Sydney, New South Wales, Australia.
Abstract:
Sodium metabisulfite (MBS) is used as a preservative in food and wine and frequently triggers attacks of asthma. To determine the characteristics of responses to inhaled MBS, 30 asthmatic subjects and 16 nonasthmatic subjects inhaled MBS, in concentrations of 6.2, 12.5, 50, and 100 mg/ml, from a DeVilbiss No. 40 nebulizer (DeVilbiss Co., Somerset, PA) in doses ranging from 0.1 to 12.8 mumol. Response was measured as the dose that caused a 20% fall in FEV1 (PD20FEV1). All the asthmatic subjects responded; one of the atopic, nonasthmatic subjects responded and none of the nonatopic, nonasthmatic subjects responded. The response occurred within 1 min, and most subjects recovered to within 10% of baseline after 30 to 40 min. Dose-response curves to MBS were steep and were reproducible, within a 7-day period, to within one doubling dose, with mean PD20FEV1 values of 2.17 and 2.11 mumol in 11 subjects. There was no correlation between PD20FEV1 values to MBS and histamine, and inhalation of MBS did not enhance responses to subsequent challenge with histamine (mean PD20FEV1 to histamine was 0.65 mumol and to histamine 1 h after MBS was 0.74 mumol). Challenge with MBS (mean PD20FEV1 4.07 mumol) did not cause refractoriness to a second challenge 1 h later (mean PD20FEV1 5.39 mumol). Of 20 subjects tested, prior inhalation of 8 mg nedocromil sodium blocked the response to MBS in 15 subjects and reduced it in two others. Cromolyn sodium (4 mg) blocked the response to MBS in three subjects but did not alter the mean PD20FEV1 in the remaining 17 subjects.(ABSTRACT TRUNCATED AT 250 WORDS)
Insights
Inhaled sodium metabisulfite (MBS) triggers asthma attacks in most asthmatic individuals. Nedocromil sodium effectively blocked MBS-induced asthma responses, unlike cromolyn sodium.
Area of Science:
- Pulmonary Medicine
- Allergy and Immunology
- Pharmacology
Background:
- Sodium metabisulfite (MBS) is a common food and wine preservative.
- MBS is known to frequently trigger asthma attacks in susceptible individuals.
Purpose of the Study:
- To characterize the respiratory responses to inhaled sodium metabisulfite (MBS) in asthmatic and nonasthmatic subjects.
- To evaluate the efficacy of nedocromil sodium and cromolyn sodium in preventing MBS-induced bronchoconstriction.
Main Methods:
- 30 asthmatic and 16 nonasthmatic subjects inhaled varying concentrations of MBS.
- Response was measured by the dose causing a 20% fall in FEV1 (PD20FEV1).
- Subjects were also challenged with histamine before and after MBS, and with MBS before and after a second MBS challenge; some received nedocromil sodium or cromolyn sodium prior to MBS.
Main Results:
- All asthmatic subjects responded to MBS, while only one atopic nonasthmatic subject responded.
- MBS-induced responses were rapid, transient, and reproducible, with steep dose-response curves.
- No correlation was found between MBS and histamine responsiveness, and MBS did not enhance histamine response or cause refractoriness.
- Nedocromil sodium blocked MBS response in 15 of 20 subjects, while cromolyn sodium had a limited effect.
Conclusions:
- Inhaled sodium metabisulfite is a potent bronchoconstrictor in asthmatic individuals.
- Nedocromil sodium demonstrates significant efficacy in preventing MBS-induced bronchoconstriction.
- Cromolyn sodium showed limited effectiveness in preventing MBS-induced asthma attacks in this study.