Absence of tachyphylaxis to inhaled atropine in patients with chronic obstructive pulmonary disease.

A multicenter, 14-wk, double-blind, randomized, parallel group study of 60 patients with obstructive lung disease was performed to assess tachyphylaxis with inhaled atropine sulfate versus placebo. Forty patients completed the study; twenty-one were treated with placebo and nineteen were treated with atropine sulfate. Atropine and placebo groups were compared before and after inhaled atropine by spirometry at Weeks zero, 6, and 14. Medication side effects, other medication usage, and symptoms were recorded daily. Comparison of FEV1 response to atropine sulfate from baseline at Weeks zero, 6, and 14 did not show a statistically significant decrease. Inhaled atropine sulfate continued to be an effective bronchodilator in both placebo groups and atropine sulfate groups. There was no evidence of significant tachyphylaxis with atropine. Significant side effects in the atropine group when compared with placebo included dry mouth, dry skin, rapid heart rate, and nausea.