Tiotropium is a once daily, inhaled, long acting anticholinergic drug that provides at least 24 hour improvement in airflow and hyperinflation in patients with chronic obstructive pulmonary disease (COPD). Clinical trials have consistently shown that these physiological effects translate into improvements in lung function, exercise tolerance, and health related quality of life, in addition to fewer exacerbations.1

Many national and international guidelines suggest using either a long acting β2 agonist or long acting anticholinergic to treat COPD, but because both are effective and convenient no guidance has been given on which one to choose if short acting agents fail to improve dyspnoea.2

Over the past two decades, the short acting anticholinergic, ipratropium, has been widely prescribed for maintenance treatment, at two inhalations of 20 mg four times a day via a metered dose inhaler. This dosage has also been used as the standard comparison in registration clinical trials. However, this dosage is not ideal, and most doctors commonly prescribe much higher doses in an attempt to improve efficacy. Yet boosting the dosage cannot overcome the short lived activity of ipratropium. Alternatively, a once daily long acting anticholinergic improves outcomes more than the standard dose of a short acting anticholinergic …