NCIt definition : The bromide salt form of ipratropium, a synthetic derivative of the alkaloid atropine
with anticholinergic properties. Ipratropium antagonizes the actions of acetylcholine
at parasympathetic, postganglionic, effector-cell junctions. When inhaled, ipratropium
binds competitively to cholinergic receptors in the bronchial smooth muscle thereby
blocking the bronchoconstrictor actions of the acetylcholine mediated vagal impulses.
Inhibition of the vagal tone leads to dilation of the large central airways resulting
in bronchodilation.;