Ipratropium (ipratropium bromide, ATROVENT® HFA) is a muscarinic antagonist structurally related to atropine but often considered safer and more effective for inhalation use. It is indicated for the maintenance treatment of bronchospasm associated with chronic obstructive pulmonary disease (COPD), including chronic bronchitis and emphysema. Ipratropium (ipratropium bromide, ATROVENT® HFA) is an anticholinergic (parasympatholytic) agent which, based on animal studies, appears to inhibit vagally-mediated reflexes by antagonizing the action of acetylcholine, the transmitter agent released at the neuromuscular junctions in the lung. Anticholinergics prevent the increases in intracellular concentration of Ca2+ which is caused by interaction of acetylcholine with the muscarinic receptors on bronchial smooth muscle.

Ipratropium (ipratropium bromide, ATROVENT® HFA) is a muscarinic antagonist structurally related to atropine but often considered safer and more effective for inhalation use. It is indicated for the maintenance treatment of bronchospasm associated with chronic obstructive pulmonary disease (COPD), including chronic bronchitis and emphysema. Ipratropium (ipratropium bromide, ATROVENT® HFA) is an anticholinergic (parasympatholytic) agent which, based on animal studies, appears to inhibit vagally-mediated reflexes by antagonizing the action of acetylcholine, the transmitter agent released at the neuromuscular junctions in the lung. Anticholinergics prevent the increases in intracellular concentration of Ca2+ which is caused by interaction of acetylcholine with the muscarinic receptors on bronchial smooth muscle.

Fenoterol is a beta2-adrenoreceptor agonist, used as a bronchodilator for the treatment and prevention of bronchospasms, associated with asthma and chronic obstructive airway disease, including bronchitis and pulmonary emphysema. Fenoterol is also used for tocolysis during premature labor. Marketing of fenoterol for treatment of asthma was suspended in Australia and New Zealand because of an increased risk of deaths, most likely due to excessive self-administration of the drug.