Methods: Parallel-group, prospective, randomized, double blind, placebo-controlled trial of roflumilast 500 ug daily vs. placebo in approximately 100 hospitalized AECOPD patients. Inclusion Criteria. Primary diagnosis of AECOPD; admission to the hospital <12 hours; patient age >40, < 80 years old; cigarette smoking > 10 pack-years. Exclusion Criteria. Prior diagnosis or high suspicion for asthma; pulmonary edema, pneumonia, interstitial lung disease or significant bronchiectasis; intubated and mechanically ventilated at the time of evaluation; active liver disease, or transaminase elevations (> 3xULN); history of heavy ethanol use; history of suicidal behavior ≤ 2 years or suicidal ideation ≤ 6 months prior to enrollment; pregnant or lactating females. Those on the following excluded medications: P450 inducers and CYP3A4 inhibitors or dual inhibitors that inhibit both CYP3A4 and CYP1A2 simultaneously