Therapeutic effects of an anticholinergic-sympathomimetic combination in induced rhinovirus colds

This study's objective was to determine if the combination of pseudoephedrine hydrochloride and atropine sulfate attenuates the symptomatic and pathophysiologic response of individuals to experimental rhinovirus infection when given after illness begins. Forty-three susceptible adult volunteers were challenged with rhinovirus type 39 and randomly assigned to 1 of 2 treatment groups. Twenty-one subjects were treated with the active medication (0.3 mg atropine sulfate and 60 mg pseudoephedrine) and 22 subjects were treated with inert capsules identical in appearance. Treatments were administered 4 times daily beginning approximately 24 hours after rhinovirus challenge and extending for 5 days. Before challenge and on each of 5 treatment days, all volunteers were asked to rate symptom severity and were evaluated for secretion production (weighted tissues), nasal patency (active posterior rhinomanometry), nasal clearance (dyed saccharin technique), eustachian tube function (9-step test), and middle ear status (tympanometry). Twenty subjects in each group were infected with rhinovirus type 39 and were included in the efficacy analysis. Between-group comparisons showed no significant differences in total symptom scores, combined nasal symptom score, secretion production, or the frequencies of persons with eustachian tube obstruction or abnormal middle ear pressures. However, an objective measure of nasal congestion was significantly lower in the active treatment group. The nasal mucociliary clearance rate was significantly more impaired in that group. Side effects consistent with anticholinergic activity were reported more frequently in the active treatment group.