Objective
To evaluate the duration of the inhibitory action of intranasal atropine on the secretory response to nasal challenge with methacholine.
Design
Double-blind, placebo-controlled, four-way crossover trial.
Subjects
Twelve volunteers with perennial allergic rhinitis.
Interventions
Subjects were treated intranasally with placebo or 100, 200, and 400 µg of atropine in each nostril. They were then challenged 30 minutes after administration of the nasal spray and hourly for 6 hours with 0.19 mg of methacholine. The weight of nasal secretions generated by methacholine challenge served as an indicator of the secretory response. The nasal challenges and the collection of nasal secretions were performed using filter paper disks.
Results
After placebo treatment, the response to methacholine was similar at each time point. In contrast, all doses of atropine significantly reduced the response to methacholine stimulation at the 30-minute, 1-hour, and 2-hour time points.
Conclusions
Our data show that the anticholinergic activity of intranasal atropine lasts at least 2 hours with no significant difference in the duration of inhibitory action between the doses used. The results suggest that intranasal atropine could become a therapeutic modality for patients in whom glandular hypersecretion is a major symptom.
(Arch Otolaryngol Head Neck Surg. 1996;122:321-323)
