Prolongation of gastric emptying by aerosolized atropine

Aerosolized atropine causes anticholinergic side effects. We evaluated gastroparesis, a previously unreported side effect of inhaled atropine, in a double-blind, placebo-controlled, crossover study. Six young asthmatics received atropine (0.05 mg/kg) or placebo at 4-h intervals for 3 dosages, on 2 separate days at least 1 wk apart. Subjective complaints, pulse, visual accommodation, and citric-acid-stimulated salivary flow were recorded 30 min after each dose on each study day. A radionuclide (99mTc) study of gastric emptying time was done 30 min after the final dose on each study day. Atropine prolonged mean gastric half emptying time (112 +/- 59 min) compared with placebo (65 +/- 34 min) (p less than 0.05). However, gastric emptying after atropine was in the abnormal range in only 2 patients. Stimulated salivary flow decreased after atropine (1.97 +/- 1.7 g saliva) compared with flow after placebo (4.1 +/- 1.2 g) (p less than 0.05). No changes in visual accommodation or pulse rate were seen. Dry mouth and decreased salivation correlated with delayed gastric emptying (r = 0.76, p less than 0.05). Anticholinergic side effects of aerosolized atropine include prolonged gastric emptying in some patients. Gastroparesis after inhaled atropine is suggested by the symptom of dry mouth.