Ipratropium Bromide

Ipratropium bromide is a muscarinic antagonist, bronchodilator, N-Isopropyl salt of atropine. 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 ug/kg); the maximum effect was obtained with 1.0 ug/kg which doubled the bronchoconstriction. When the dose was increased above 1.0 ug/kg potentiation no longer occurred; instead the vagally induced bronchoconstriction was antagonised.