Safety issues are addressed in the AE section. There is no standardised and unanimously accepted definition of exacerbation in COPD; 4 definitions are widely used: (1) using a combination of 3 cardinal symptoms: increased dyspnea, sputum volume, and sputum purulence; (2) looking at the presence of the following patterns of symptoms during \>=2 consecutive days: either 2 or more of 3 major symptoms (increase in dyspnoea, sputum volume and sputum purulence); or any 1 major symptom together with any 1 minor symptom (increase in nasal discharge, wheeze, sore throat, cough or fever); (3) a sustained worsening of the patient's condition, from the stable state and beyond normal day-to-day variations, that is acute in onset and necessitates a change in regular medication in a patient with underlying COPD; (4) a complex of respiratory events (i.e. cough, wheezing, dyspnoea or sputum production) lasting \>=3 days.
