Background:

Ipratropium Bromide is a muscarinic antagonist, bronchodilator, N-Isopropyl salt of atropine.Target: mAChRIpratropium bromide, a nonselective muscarinic antagonist, is widely prescribed for the treatment of chronic obstructive pulmonary disease (COPD). In anaesthetised guinea-pigs, bronchoconstriction induced by vagal nerve stimulation was potentiated by low doses of the antimuscarinic bronchodilator drug, ipratropium (0.01-1.0 g/kg); the maximum effect was obtained with 1.0 g/kg which doubled the bronchoconstriction. When the dose was increased above 1.0 g/kg potentiation no longer occurred; instead the vagally induced bronchoconstriction was antagonized [1, 2].

参考文献:
[1]. Fryer, A.D. and J. Maclagan, Ipratropium bromide potentiates bronchoconstriction induced by vagal nerve stimulation in the guinea-pig. Eur J Pharmacol, 1987. 139(2): p. 187-91.
[2]. Harvey, K.L., A. Hussain, and H.L. Maddock, Ipratropium Bromide-Mediated Myocardial Injury in In Vitro Models of Myocardial Ischaemia/Reperfusion. Toxicol Sci, 2014.