Limitation in exercise capacity is a key feature of COPD
and is one of the main factors to negatively impact patients’
quality of life.8 Improving exercise tolerance, lung hyperinflation,
and dyspnea are therefore important goals in the
therapeutic management of COPD as it will help patients be
more active during the day. Inhaled muscarinic antagonists,
which include ipratropium and tiotropium bromide, are one
of the principal classes of bronchodilators used for the treatment
of COPD. Short-acting ipratropium9,10 and long-acting
tiotropium11,12 are known to improve lung function and reduce
COPD symptoms. Both agents are generally well-tolerated
in patients with COPD. Furthermore, long-acting muscarinic
antagonists (LAMAs) have been shown to increase IC both
at rest (prior to exercise) and during exercise in patients
with COPD by reducing lung hyperinflation, with a resulting
improvement in exercise capacity.13–15 Short-acting bronchodilators
have not consistently been shown to improve exercise
tolerance or dynamic hyperinflation