GSK573719 monotherapy and GSK573719/vilanterol combination are currently under development for the treatment of COPD. This study will assess the pharmacokinetics and safety of inhaled GSK573719 and GSK573719/vilanterol (VI) in healthy subjects and in subjects with severe renal impairment. Nine subjects with severe renal impairment (as defined by a Clcr<30mL/min) will be recruited along with healthy control subjects (as defined by a Clcr>80mL/min matched to the severe renal impairment subjects based on gender, ethnicity, body mass index (±15%) and age (±5 years)). The results from this study will provide guidance on the use of GSK573719 and GSK573719/VI in severe renally impaired patients.