- Medications prior to screening: use of the following medications according to the following defined time intervals prior to Visit 1: depot corticosteroids 12 weeks, systemic, oral or parenteral corticosteroids 6 weeks, antibiotics (for lower respiratory tract infection) 6 weeks, inhaled long acting beta2 agonists/ inhaled corticosteroid (LABA/ICS) combination products if LABA/ICS therapy is discontinued completely 30 days; LABA/ICS combination products only If discontinuing ICS/ LABA therapy and switching to ICS monotherapy 48 hours for the salmeterol or formoterol component 14 days for the vilanterol component (note: the dose of ICS must be a dose of fluticasone propionate (FP) or equivalent but not to exceed 1000 mcg/day), use of ICS at a dose >1000 microgram (mcg)/day of FP or equivalent 30 days (note: use of ICS is permitted provided the dose does not exceed 1000 mcg of FP or equivalent; ICS use not to be initiated or discontinued within 30 days prior to Visit 1, except for subjects on LABA/ICS therapy who may discontinue the ICS/LABA product as indicated in the table above and switch to ICS monotherapy); initiation or discontinuation of ICS use 30 days (note: use of ICS is permitted provided the dose does not exceed 1000 mcg of FP or equivalent; ICS use not to be initiated or discontinued within 30 days prior to Visit 1, except for subjects on LABA/ICS therapy who may discontinue the ICS/LABA product as indicated in the table above and switch to ICS monotherapy); phosphodiesterase 4 (PDE4) Inhibitor (roflumilast) 14 days; LABA: salmeterol and formoterol 48 hours; olodaterol, indacaterol, and vilanterol 14 days; LAMA: tiotropium, aclidinium, glycopyrronium, umeclidinium 7 days; LAMA/LABA combination products if LAMA/LABA therapy is discontinued completely then apply whichever mono component has the longest washout; theophyllines 48 hours; Oral beta2-agonists: long-acting 48 hours, short-acting 12 hours; inhaled short acting beta2-agonists 4 hours (note: use of study provided albuterol/salbutamol is permitted during the study, except in the 4-hour period prior to spirometry testing); inhaled short-acting anticholinergics 4 hours; inhaled short-acting anticholinergic/short-acting beta2-agonist combination products 4 hours; any other investigational medication 30 days or within 5 drug half-lives (whichever is longer).