Since the introduction of inhaled quaternary anticholinergic bronchodi
lators, their clinical usefulness has been explored in a variety of se
ttings. They have emerged as the inhaled bronchodilators of first choi
ce in the management of chronic obstructive pulmonary disease (COPD).
In other countries, they have also found an adjunctive role in the man
agement of asthma. This may be best seen in the treatment of acute ast
hma where the combination of anticholinergic and adrenergic bronchodil
ators appear more effective than single-agent inhalation therapy. This
finding appears consistently in large studies, whether in adult or pe
diatric populations. Such combination nebulizer therapy would appear t
o be cost effective, but further study is required.