Abstract

The purpose of this study was to investigate whether inhaled frusemide was able to inhibit the increase in nonspecific bronchial reactivity that occurs after the early response to allergen exposure in subjects with allergic rhinitis or asthma (or both). Ten symptom free patients initially underwent a challenge with methacholine, to determine the dose of methacholine that caused a 15% fall in FEV1 (PD15 FEV1 meth) and a challenge with a specific allergen, to determine the concentration of allergen that caused a fall in FEV1 of at least 15%. On two further occasions they inhaled allergen concentration that had caused the greater than or equal to 15% fall in FEV1 preceded by inhaled frusemide (40 mg frusemide in 4 ml buffered saline) or placebo (4 ml of diluent solution), according to a randomised, double blind, crossover design. All allergen studies were separated by at least seven days. A methacholine challenge was performed two hours after the allergen challenge, a time when the early response to allergen had completely resolved. Frusemide inhibited the early response to antigen, causing mean (95% confidence interval) protection of 87.6% (96-80%) for the maximum fall in FEV1. The increase in non-specific airway reactivity that occurred after antigen when this was preceded by placebo was reduced by frusemide. The mean (95% CI) difference in PD15 values between the placebo and the frusemide days was 1.73 (2.30-1.16) doubling doses of methacholine. These results confirm that frusemide is highly effective in preventing the early response to allergen, and show that it inhibits the increase in reactivity to methacholine that follows the early response.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.