Roflumilast is a product which has been approved for the treatment of severe chronic obstructive lung disease (COPD) and its approved dose is 500μg once daily. This study is primarily designed to see whether alternation in this dose can improve tolerability of Roflumilast in COPD patients. Therefore one in three patients will start roflumilast therapy at a lower dose of 250μg/375μg once daily, another one in three will only take the 500μg tablet every day (and one placebo every day). Furthermore, the study will evaluate the safety and pharmacokinetics of different dose roflumilast in China COPD patient.~Lastly, the study will investigate what the body does to roflumilast. Patients with a history of COPD for at least last 12 months and a former smoker or current smoker with history of at least 10 pack years will be invited to participate.~The Randomization visit is considered the Baseline visit and for participants that discontinue the Main Period and continue into the Down-Titration Period Day 1 of Down Titration is considered BaselineDT.
To evaluate the safety and pharmacokinetics of different dose roflumilast in China COPD patient.